Claims:

1. A method for navigation of a vehicle (104), the method comprising:
detecting an availability of a vacant slot (208C) in a designated area (106) based on a designated light beam (212) that is emitted by a light-based sensing system (108), wherein the light-based sensing system (108) comprises a light source (112) that is capable of generating a plurality of light beams to illuminate at least a selected portion of the designated area (106) and each of the light beams forms a corresponding angle with respect to the light-based sensing system (108);
calculating an actual path distance from the light-based sensing system (108) to an end (410) of the vacant slot (208C) based on a path distance between the light-based sensing system (108) and an object(210D) disposed in an adjacent slot (208D) to the vacant slot (208C), a gap between the end (410) of the vacant slot (208C) and the object (210D), and an angle that is formed between an imaginary line (412) perpendicular to the light-based sensing system (108) and a path of the designated light beam (212) to the object (210D);
estimating a first distance by which the vehicle (104) has to be moved from a first position (230) to an intermediate position (404) in the designated area (106) based on the actual path distance and the angle;
estimating a second distance by which the vehicle (104) has to be moved from the intermediate position (404) to a final position (406, 604) in the designated area (106); and
navigating the vehicle (104) autonomously into the vacant slot (208C) based on a third distance and a fourth distance, wherein the third distance corresponds to a distance by which the vehicle (104) has to move from the final position (406, 604) to a reference point (408) in the vacant slot (208C), and wherein the fourth distance corresponds to a distance by which the vehicle (104) has to move further from the reference point (408) into the vacant slot (208C).

2. The method as claimed in claim 1, further comprising:
determining the path distance from the light-based sensing system (108) to the object (210D) when the vehicle (104) is in the first position (230) based on a time taken by the designated light beam (212) to reflect back to the light-based sensing system (108) after being reflected by the object (210D), wherein the object is a vehicle (210D) located at the adjacent slot (208D) to the vacant slot (208C); and
determining the gap between the end (410) of the vacant slot (208C) and the object (210D) based on a duration between identification of the end (410) of the vacant slot (208C) and identification of the object (210D).

3. The method as claimed in claim 2, wherein the light-based sensing system (108) is attached to the vehicle (104), wherein the first position (230) is a location in the designated area (106) at which the light-based sensing system (108) receives back the designated light beam (212) reflected by the object (210D) after the vehicle (104) passes beyond the end (410) of the vacant slot (208C), and wherein the intermediate position (404) is another location in the designated area (106) that lies perpendicular to the end (410) of the vacant slot (208C).

4. The method as claimed in claim 3, further comprising determining half of a width of the vacant slot (208C).

5. The method as claimed in claim 4, wherein the second distance is the half of the width of the vacant slot (208C).

6. The method as claimed in claim 5, further comprising:
moving the vehicle (104) by the first distance in a forward direction from the first position (230) to the intermediate position (404);
moving the vehicle (104) by the second distance in a reverse direction from the intermediate position (404) to the final position (604);
steering the vehicle (104) by a desired angle in a selected direction when the vehicle (104) is in the final position (604);
moving the vehicle (104) by the third distance from the final position (604) to the reference point (408) in the vacant slot (208C) in the designated area (106), wherein the third distance is determined based on the actual path distance and the angle, and wherein the reference point (408) is a midpoint of the vacant slot (208C); and
moving the vehicle (104) by the fourth distance from the reference point (408) for autonomously navigating the vehicle (104) into the vacant slot (208C), wherein the fourth distance corresponds to a length of the vacant slot (208C).

7. The method as claimed in claim 4, wherein the vehicle (104) is an automobile having a steering wheel, a front axle, a rear axle, and a plurality of wheels.

8. The method as claimed in claim 7, further comprising:
moving the vehicle (104) by the first distance in a forward direction from the first position (230) to the intermediate position (404);
determining a wheel turn angle required to park the vehicle (104) in the detected vacant slot (208C) before the vehicle (104) is moved from the intermediate position (404) to the final position (406);
determining a perpendicular distance between another reference point (414) in the designated area (106) to a vehicle reference point (416) based on a longitudinal wheelbase and the determined wheel turn angle, wherein the vehicle reference point (416) is a midpoint of a rear axle of the vehicle (104); and
moving the vehicle (104) by the second distance in the forward direction from the intermediate position (404) to the final position (406), wherein the second distance is a difference between the determined perpendicular distance and the half of the width of the vacant slot (208C).

9. The method as claimed in claim 8, further comprising:
steering the vehicle (104) to achieve the determined wheel turn angle when the vehicle (104) is in the final position (406); and
moving the vehicle (104) by the third distance in an arc-path (402) from the final position (406) to a reference point (408) in the vacant slot (208C) in the designated area (106), wherein the third distance is determined based on the determined perpendicular distance, and wherein the reference point (408) is a midpoint of the vacant slot (208C); and
moving the vehicle (104) by the fourth distance from the reference point (408) for autonomously navigating the vehicle (104) into the vacant slot (208C), wherein the fourth distance corresponds to a length of the vacant slot (208C).

10. The method as claimed in claim 4, further comprising determining a distance threshold associated with at least one of the plurality of light beams based on a width of the vehicle (104), a field of view of the light-based sensing system (108), a corresponding light beam sequence number, and a total number of the light beams, wherein the determined distance threshold is used to detect potential obstacles in a potential navigation path of the vehicle (104).

11. A system (102) for navigation of a vehicle (104), the system (102) comprising:
a light-based sensing system (108) that comprises a light source (112) that is capable of generating a plurality of light beams to illuminate at least a selected portion of a designated area (106), wherein each of the light beams forms a corresponding angle with respect to the light-based sensing system (108); and
a parking assistance system (110) that is communicatively coupled to the light-based sensing system (108), wherein the parking assistance system (110) is configured to:
calculate an actual path distance from the light-based sensing system (108) to an end (410) of a vacant slot (208C) based on a path distance from the light-based sensing system (108) to an object (210D) disposed in an adjacent slot (208D) to the vacant slot (208C), a gap between the end (410) of the vacant slot (208C) and the object (210D), and an angle that is formed between an imaginary line (412) perpendicular to the light-based sensing system (108) and a path of a designated light beam (212) to the object (210D);
estimate a first distance by which the vehicle (104) has to be moved from a first position (230) to an intermediate position (404) in the designated area (106) based on the actual path distance and the angle; and
estimate a second distance by which the vehicle (104) has to be moved from the intermediate position (404) to a final position (406, 604) in the designated area (106), wherein the vehicle (104) navigates autonomously into the vacant slot (208C) based on a third distance and a fourth distance, wherein the third distance corresponds to a distance by which the vehicle (104) has to move from the final position (406, 604) to a reference point (408) in the vacant slot (208C), and wherein the fourth distance corresponds to a distance by which the vehicle (104) has to move further from the reference point (408) into the vacant slot (208C).

12. The system (102) as claimed in claim 11, wherein the system (102) is deployed in a land vehicle, an automobile, a boat, an airplane, a drone, or a robotic device. , Description:BACKGROUND

[0001] Embodiments of the present specification relate generally to vehicle navigation. More particularly, the present specification relates to a system and method for autonomous navigation of a vehicle within a designated area using a light based sensing system.
[0002] With advancement in automotive technology, semi-autonomous and autonomous vehicles have come into existence. The semi-autonomous vehicles are driven with driver assistance and are equipped to perform some functions, such as parking, autonomously. In contrast, the autonomous vehicles are driven and parked automatically.
[0003] Both the semi-autonomous and the autonomous vehicles utilize various types of sensors for parking the vehicles automatically. One such type of sensor used for autonomous vehicle parking is an ultrasonic sensor. Ultrasound based autonomous parking systems use multiple ultrasonic sensors to detect availability of a vacant parking slot within a parking space, to plan a vehicular path from a current vehicle location within the parking space to the detected vacant parking slot, and to detect obstacles in the vehicular path. However, such ultrasound based autonomous parking systems require the vehicle to be aligned in a predefined manner to detect the vacant parking slot leading to additional processing and time delay. Furthermore, a driver of the vehicle is required to indicate a side of the vehicle to scan for a vacant parking slot resulting in complexity in parking the vehicle.
[0004] The driver is further required to manually provide a type of parking of the vehicle, such as parallel or perpendicular parking, based on an orientation of the vacant parking slot, thus adding to manual efforts. In addition, the ultrasonic sensors have limitations in identifying obstacles at certain distances that are greater than a threshold distance from the sensor.
[0005] Another type of sensor that is conventionally used for autonomous vehicle parking includes one or more optical sensors such as cameras. Though camera-based autonomous parking systems are considered to be cost-effective solutions for vehicle parking, such camera-based autonomous parking systems have limitations in identifying vacant parking slots especially during bad weather conditions, for example during dense fog or during heavy rain. Typically, the camera-based autonomous parking systems perform a large number of image-processing operations on one or more captured images during bad weather conditions to detect and select a vacant parking slot, to detect obstacles in the surroundings, and to plan the vehicular path. Hence, such systems require high computational powers in order to execute desired functionalities quickly, which make the systems more complex and expensive.
[0006] Hence, there is a need for an improved system and method to address the aforementioned issues.

BRIEF DESCRIPTION

[0007] According to an exemplary aspect of the present specification, a method for navigation of a vehicle is provided. The method includes detecting an availability of a vacant slot in a designated area based on a designated light beam that is emitted by a light-based sensing system. The light-based sensing system includes a light source that is capable of generating a plurality of light beams to illuminate at least a selected portion of the designated area and each of the light beams forms a corresponding angle with respect to the light-based sensing system. An actual path distance from the light-based sensing system to an end of the vacant slot is calculated based on a path distance from the light-based sensing system to an object disposed in an adjacent slot to the vacant slot. Further, the actual path distance is calculated also based on a gap between the end of the vacant slot and the object, and an angle that is formed between an imaginary line perpendicular to the light-based sensing system and a path of the designated light beam to the object.
[0008] A first distance by which the vehicle has to be moved from a first position to an intermediate position in the designated area is estimated based on the actual path distance and the angle. A second distance by which the vehicle has to be moved from the intermediate position to a final position in the designated area is estimated. The vehicle is navigated autonomously into the vacant slot based on a third distance and a fourth distance. The third distance corresponds to a distance by which the vehicle has to move from the final position to a reference point in the vacant slot. The fourth distance corresponds to a distance by which the vehicle has to move further from the reference point into the vacant slot.
[0009] The path distance from the light-based sensing system to the object may be determined when the vehicle is in the first position based on a time taken by the designated light beam to reflect back to the light-based sensing system after being reflected by the object. The object may be a vehicle located at the at the adjacent slot to the vacant slot. The gap between the end of the vacant slot and the object may be determined based on a duration between identification of the end of the vacant slot and identification of the object. The light-based sensing system may be attached to the vehicle. The first position may be a location in the designated area at which the light-based sensing system receives back the designated light beam reflected by the parked vehicle after the vehicle passes beyond the end of the vacant slot. The intermediate position may be another location in the designated area that lies perpendicular to the end of the vacant slot.
[0010] Half of a width of the vacant slot may be determined. The vehicle may be an automobile having a steering wheel, a front axle, a rear axle, and a plurality of wheels. The second distance may be the half of the width of the vacant slot. The vehicle may be moved by the first distance in a forward direction from the first position to the intermediate position. The vehicle may be moved by the second distance in a reverse direction from the intermediate position to the final position. The vehicle may be steered by a desired angle in a selected direction when the vehicle is in the final position. The vehicle may be moved by the third distance from the final position to the reference point in the vacant slot in the designated area. The third distance may be determined based on the actual path distance and the angle. The reference point may be a midpoint of the vacant slot. The vehicle may be moved by the fourth distance from the reference point for autonomously navigating the vehicle into the vacant slot. The fourth distance may correspond to a length of the vacant slot.
[0011] The vehicle may be moved by the first distance in a forward direction from the first position to the intermediate position. A wheel turn angle required to park the vehicle in the detected vacant slot may be determined before the vehicle is moved from the intermediate position to the final position. A perpendicular distance between another reference point in the designated area to a vehicle reference point may be determined based on a longitudinal wheelbase and the determined wheel turn angle. The vehicle reference point may be a midpoint of a rear axle of the vehicle. The vehicle may be moved by the second distance in the forward direction from the intermediate position to the final position. The second distance may be a difference between the determined perpendicular distance and the half of the width of the vacant slot.
[0012] The vehicle may be steered to achieve the determined wheel turn angle when the vehicle is in the final position. The vehicle may be moved by the third distance in an arc-path from the final position to a reference point in the vacant slot in the designated area. The third distance may be determined based on the determined perpendicular distance. The vehicle may be moved by the fourth distance from the reference point for autonomously navigating the vehicle into the vacant slot. The fourth distance may correspond to a length of the vacant slot. A distance threshold associated with at least one of the plurality of light beams may be determined based on a width of the vehicle, a field of view of the light-based sensing system, a corresponding light beam sequence number, and a total number of the light beams. The determined distance threshold may be used to detect potential obstacles in a potential navigation path of the vehicle.
[0013] According to another exemplary aspect of the present specification, a system for navigation of a vehicle is provided. The system includes a light-based sensing system and a parking assistance system that is communicatively coupled to the light-based sensing system. The light-based sensing system includes a light source that is capable of generating a plurality of light beams to illuminate at least a selected portion of a designated area and each of the light beams forms a corresponding angle with respect to the light-based sensing system. The parking assistance system is configured to calculate an actual path distance from the light-based sensing system to an end of a vacant slot based on a path distance from the light-based sensing system to an object disposed in an adjacent slot to the vacant slot. The parking assistance system calculates the actual path distance also based on a gap between the end of the vacant slot and the object, and an angle that is formed between an imaginary line perpendicular to the light-based sensing system and a path of a designated light beam to the object.
[0014] The parking assistance system estimates a first distance by which the vehicle has to be moved from a first position to an intermediate position in the designated area based on the actual path distance and the angle. Further, the parking assistance system estimates a second distance by which the vehicle has to be moved from the intermediate position to a final position in the designated area. The vehicle is navigated autonomously into the vacant slot based on a third distance and a fourth distance. The third distance corresponds to a distance by which the vehicle has to move from the final position to a reference point in the vacant slot. The fourth distance corresponds to a distance by which the vehicle has to move further from the reference point into the vacant slot. The system may be implemented in automobiles, cars, trucks, cruises, airplanes drones, or robotic devices.

DRAWINGS

[0015] These and other features, aspects, and advantages of the claimed subject matter will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0016] FIG. 1 is a block diagram illustrating an exemplary system for parking a vehicle in a vacant parking slot in a parking space;
[0017] FIG. 2 is a schematic diagram illustrating an exemplary target zone within the parking space, where the vehicle moves at a designated speed for detecting and selecting the vacant parking slot using the system of FIG. 1;
[0018] FIG. 3 is a flow diagram illustrating an exemplary method for detecting and selecting the vacant parking slot in the target zone of the parking space using the system of FIG. 1;
[0019] FIG. 4 is a schematic diagram illustrating the target zone in which the system of FIG. 1 configures the vehicle to navigate in an arc-path to automatically park the vehicle in the selected vacant parking slot;
[0020] FIG. 5A and FIG. 5B depict a flow diagram illustrating an exemplary method for parking the vehicle in the selected vacant parking slot, the vehicle configured to navigate the arc-path using the system of FIG. 1;
[0021] FIG. 6 is a schematic diagram illustrating the target zone in which the system of FIG. 1 configures the vehicle to navigate in a non-arc path to automatically park the vehicle in the selected vacant parking slot;
[0022] FIG. 7 is a flow diagram illustrating an exemplary method for parking the vehicle in the selected vacant parking slot, the vehicle configured to navigate the non-arc path using the system of FIG. 1; and
[0023] FIG. 8 is a schematic diagram illustrating the vehicle having a light-based sensing system used for environment perception while the vehicle is navigating within the parking space of FIG. 1.

DETAILED DESCRIPTION

[0024] The following description presents exemplary systems and methods for vehicle navigation. Particularly, embodiments described herein disclose systems and methods for autonomous navigation of a vehicle within a designated area using one or more light based sensing systems. Examples of the vehicle include, but are not limited to, automobiles, cars, trucks, drones, robotic devices, cruises, and airplanes. The light-based sensing system configures the vehicle to navigate from its current location to a desired location within the designated area. In addition, the light-based sensing system identifies obstacles in the vehicle surroundings when the vehicle navigates from one location to another location within the designated area and configures the vehicle to move safely without colliding with any nearby objects.
[0025] It may be noted that different embodiments of the present navigation system may be used in many application areas. For example, in a drone-based package organizing application, a navigation system assists the drone to navigate within a warehouse and to identify vacant slots available within the warehouse for dropping packages, such that, the packages are organized efficiently in a timely fashion without requiring any manual intervention. In another example, the navigation system assists a car or a truck to navigate within a designated area (e.g., a parking space) and to detect and select a vacant parking slot in the parking space. Upon selecting the vacant parking slot, the navigation system plans a vehicle path from a current location of the vehicle in the parking space to the selected parking slot, and identifies obstacles in the surroundings of the vehicle. Therefore, it is to be understood that different embodiments of the present navigation system can be used in many application areas, where autonomous navigation of the vehicle is required. However, for clarity, the navigation system will be described herein with reference to autonomous parking of an automobile in a vacant parking slot with reference to FIG. 1.
[0026] FIG. 1 is a block diagram illustrating an exemplary navigation system (102) for parking a vehicle (104) in a vacant parking slot in a parking space (106). The navigation system (102) includes at least one light-based sensing system (108) that is mounted on a vehicle (104) (shown in FIG. 8), a parking assistance system (110), and a vehicle control system (111). In one embodiment, the vehicle (104) is a semi-autonomous vehicle or an autonomous vehicle. In case of the semi-autonomous vehicle, a user drives the vehicle (104) to a target zone within the parking space (106) where a plurality of parking aisles (shown in FIG. 2) is available. Subsequently, the user may activate the navigation system (102) in order to configure the vehicle (104) to park on its own. In one embodiment, the user may activate the navigation system (102) by pressing an activation button that may be part of a human-machine interface of the vehicle (104).
[0027] In case the vehicle (104) is an autonomous vehicle, the vehicle (104) identifies and drives itself to the target zone where the plurality of parking aisles are available using one or more on-board sensors, for example optical sensors, ultrasonic sensors, radar sensors, lidar sensors, and/or the light-based sensing system (108). Further, one or more on-board cameras mounted onto the vehicle (104) may be configured to capture one or more images of the target zone. The parking assistance system (110) processes the one or more captured images using suitable image-processing algorithms such as optical character recognition and/or pattern recognition algorithms, and detects if there are any parking signboards kept at the target zone. Upon detecting the parking signboards, the parking assistance system (110) identifies specific information mentioned in the parking signboards. For example, the parking assistance system (110) identifies symbols that indicate no parking zones, parking zones, directions to parking zones, and any texts mentioned in the parking signboards, for example, using the aforementioned algorithms. Upon determining that the vehicle (104) is entering a target parking zone, the parking assistance system (110) may trigger the navigation system (102) to automatically park the vehicle (104) without requiring any user action.
[0028] In one embodiment, the navigation system (102) is configured to detect and select a vacant parking slot for parking the vehicle (104) using the light based sensing system (108). Specifically, the navigation system (102) is configured to detect and select a vacant parking slot while the vehicle (104) moves at a constant designated speed. In certain embodiments, the navigation system (102) is configured to store information such as the constant designated speed at which the vehicle (104) should move in the parking space (106), a width information of the vacant parking slot, and a time that takes to cross a single vacant parking slot for identifying a vacant parking slot. For example, the navigation system (102) may store the constant designated speed of 0.833 meters/second, the width of the vacant parking slot as 3 meters, and the time that takes to cross the vacant parking slot as 3.6 seconds. In a real-world scenario, when the vehicle (104) moves at a speed that is different from the set constant designated speed, for example at 0.42 meters/second, the vehicle (104) may cross the vacant parking slot in a time that is approximately equal to 7.2 seconds that is equivalent to a time that takes to cross two vacant parking slots. In this example, the navigation system (102) may inaccurately identify a presence of the single vacant parking slot as two different vacant parking slots because a total time taken to cross the vacant parking slot is 7.2 seconds and not 3.6 seconds. Therefore, the vehicle (104) is configured to move at the set constant designated speed while detecting and selecting the vacant parking slot.
[0029] In one embodiment, the light-based sensing system (108) may be mounted on a front side of the vehicle (104) to aid in identifying the vacant parking slot. In certain embodiments, the light-based sensing system (108) operates on the principle of time-of-flight, and includes at least one light source (112) that emits light signals to illuminate at least a selected portion of the parking space (106). The light-based sensing system (108) further includes one or more photodetector arrays (114) for receiving backscattered light signals from objects in the surroundings of the vehicle (104). Moreover, the light-based sensing system (108) includes a processor (116) configured to process the backscattered light signals using various signal-processing algorithms to detect and locate the surrounding objects and to measure corresponding range information. The light-based sensing system (108) measures the range information of the surrounding objects based on time taken by the light signals emitted from the light-based sensing system (108) to reflect back from the objects to the light-based sensing system (108). To that end, the light-based sensing system (108), for example, includes one or more LeddarTM sensors that emit light signals to detect ranging information for use in identifying the vacant parking slot.
[0030] Further, the light source (112) configured to emit the light signals includes one or more light-emitting diodes. The light source (112), having the one or more light-emitting diodes, generates and emits a plurality of light beams. Throughout description of various embodiments herein, the term “light beam” refers to a projection of light energy radiating from the light source (112) in a specific direction. For example, the light source (112) may generate sixteen light beams and each of the light beams is projected from the light source (112) in a different direction, as depicted in FIG. 2.The generated beams allow for detection of the vacant parking slot, as described in detail with reference to FIG. 2 and FIG. 3.
[0031] FIG. 2 is a schematic diagram illustrating an exemplary target zone (202) within the parking space (106), where the vehicle (104) moves at a designated speed for detecting and selecting a vacant parking slot. Further, FIG. 2 depicts six such light beams being projected from the light source (112). The light beams (labelled as (212) and (214)) represent extreme light beams that are outermost beams in a horizontal field of view of the light-based sensing system (108). All the other light beams emitted from the light source (112) are projected between the extreme light beams (212) and (214) in different angular orientations. In particular, FIG. 2 depicts four intermediate light beams (labelled as (216), (218), (220), and (222)) projected between the extreme light beams (212) and (214) in different directions. Though FIG. 2 depicts only four intermediate beams, it is to be understood that fewer or greater number of intermediate beams may be projected between the extreme light beams (212) and (214).
[0032] In certain embodiments, an angle between each selected light beam from the plurality of light beams and a subsequent light beam is constant and depends upon a selected horizontal field of view (HFOV) of the light-based sensing system (108). The horizontal field of view represents an overall angle formed between the extreme light beams (212) and (214). Accordingly, the overall angle will be divided equally such that an angle between two adjacent light beams remains the same.
[0033] For example, if the selected horizontal field of view is 95 degrees, then the overall angle formed between the extreme light beams (212) and (214) is 95 degrees. Further, when using sixteen light beams, the angle between any two adjacent light beams will be approximately 5.94 degrees. For example, an angle formed between the extreme light beam (212) and an intermediate light beam (216) will be approximately 5.94 degrees. Further, an angle formed between the intermediate light beam (216) and a subsequent light beam (220) will similarly be approximately 5.94 degrees. Consequently, the angle between the extreme light beam (212) and the intermediate light beam (220) will be approximately 11.88 degrees. In one embodiment, the number of light beams and the horizontal field of view of the light-based sensing system (108) are selected such that the extreme light beams (212) and (214) from the light source (112) can travel in a wider angle and suitably reach the surrounding objects located at right and left sides of the vehicle (104).
[0034] In one embodiment, the navigation system (102) considers light signals associated only with the extreme light beams (212) and (214) for detecting and selecting a vacant parking slot in the parking space (106) and for planning a vehicular path to the selected vacant parking slot. This is because the extreme light beams (212) and (214) diffuse in a wider angle and reach vehicles that are already parked in parking aisles, whereas the intermediate light beams may not diffuse in the wider angle as the extreme light beams (212) and (214), thus failing to reach the already parked vehicles.
[0035] Referring back to description of FIG. 1, the light-based sensing system (108) processes the light signals obtained due to backscattering of the extreme light beams (212) and (214) from the surrounding objects. Subsequently, the light-based sensing system (108) identifies range information of the surrounding objects and provides inputs including the range information to the parking assistance system (110). In one embodiment, the parking assistance system (110) resides in an electronic control unit (ECU) of the vehicle (104). More specifically, if the vehicle (104) is the semi-autonomous type or the autonomous type, the parking assistance system (110) resides in an advanced driver assistance system ECU. In another embodiment, the parking assistance system (110) resides in the processor (116) associated with the light-based sensing system (108) instead in the advanced driver assistance system ECU.
[0036] In certain embodiments, the parking assistance system (110) and the light-based sensing system (108) are communicatively coupled via a communication network, for example, a controller area network, a universal serial bus, a serial port, a short-range communications network such as a Bluetooth network, a Wi-Fi network, an Ethernet, a cellular data network, and electrical wires based communication medium. Based on the range information received from the light-based sensing system (108), the parking assistance system (110) detects an availability of a vacant parking slot. Additionally, the parking assistance system (110) performs path planning in order to configure the vehicle (104) to park automatically in the detected vacant parking slot, as described in detail with reference to description of FIG. 2 through FIG. 7. An exemplary method employed for detecting and selecting a vacant parking slot using the navigation system (102) is described in detail with reference to description FIG. 3.
[0037] As previously noted, FIG. 2 depicts the exemplary target zone (202) within the parking space (106), where the vehicle (104) moves at a designated speed for detecting and selecting a vacant parking slot. In one embodiment, the target zone (202) includes a plurality of parking aisles. FIG. 2 depicts two such exemplary parking aisles (204) and (206). However, it is to be understood that the target zone (202) can have any number of parking aisles depending on a size of the parking space (106). Each of the parking aisles (204) and (206) includes a plurality of parking slots. For example, the parking aisle (204) includes five parking slots that are labelled as (208A), (208B), (208C), (208D), and (208E). It may be noted that, other than the parking slot (208C), all the other parking slots are occupied with corresponding vehicles that are labelled as (210A), (210B), (210D), and (210E). In one embodiment, a width associated with each of the parking slots (208A-E) is same. The exemplary parking aisle (206) also includes five parking slots and all the parking slots are occupied with vehicles. The parking slots and the vehicles associated with the parking aisle (206) are not labelled in FIG. 2 for the sake of simplicity.
[0038] In one embodiment, the vehicle (104) enters the target zone (202) and navigates through the target zone (202). As the vehicle (104) navigates through the target zone (202), the light-based sensing system (108) emits light signals, and in response, receives backscattered light signals associated with the extreme light beams (212) and (214). The light-based sensing system (108) detects an availability of a vacant parking slot based on the backscattered light signals using the parking assistance system (110), as described in detail with reference to description of FIG. 3.
[0039] FIG. 3 is a flow diagram (300) illustrating an exemplary method for detecting and selecting a vacant parking slot in the target zone (202) of the parking space (106) using the navigation system (102) of FIG. 1. It may also be noted that throughout description of various embodiments of the method presented herein, a position or a location of the vehicle (104) in the parking space (106) is defined based on a midpoint of a rear axle of the vehicle (104). The order in which the exemplary method is described is not intended to be construed as a limitation, and any number of the described blocks may be combined in any order to implement the exemplary method disclosed herein, or an equivalent alternative method. Additionally, certain blocks may be deleted from the exemplary method or augmented by additional blocks with added functionality without departing from the spirit and scope of the subject matter described herein.
[0040] At step (302), the parking assistance system (110) identifies a requirement to initiate the automatic parking of the vehicle (104) based on one or more designated actions. For example, in case of the semi-autonomous vehicle, the designated action may include a user manually pressing a parking activation button that may be part of a human-machine interface of the vehicle (104). In another example, where the vehicle (104) is an autonomous vehicle, the action may include identification of parking signboards kept near the target zone (202), such as, from one or more images captured using one or more on-board cameras.
[0041] In certain embodiments, the navigation system (102) may store or receive certain predetermined information in order to accurately detect and select a vacant parking slot and to automatically park the vehicle (104) in the selected vacant parking slot. The predetermined information may include a width and length associated with the parking aisles (204) and (206), a width and length associated with each of the parking slots (208A-E), a distance between the parking aisle (204) and the parking aisle (206). In an exemplary implementation, predetermined information may correspond to pre-specified standard values, and/or may be specific to a particular geographic location. The parking assistance system (110) may pre-store these standard values and the light-based sensing system (108) may not need to determine these standard values in real-world scenario. However, in reality, not all the parking spaces may be constructed in adherence with these standards. Hence, the predetermined information may be obtained by the vehicle (104) for certain parking spaces that were not constructed in adherence with these standards. Therefore, at step (304), the vehicle (104) obtains a width and length information associated with the parking slots (208A-E). In one example, the vehicle (104) includes a barcode reader that scans a barcode, which is affixed near the target zone (202), to obtain the width and length information associated with the parking slots (208A-E).
[0042] In another example, the vehicle (104) includes a communication unit having a receiver that receives the width and length information associated with the parking slots (208A-E) from a communication device deployed near or within the target zone (202). Examples of the communication device include, but are not limited to, Bluetooth-enabled devices, infrared-enabled devices, internet-enabled devices, and one or more image acquisition devices such as cameras.
[0043] In yet another example, the light-based sensing system (108) itself determines the width information associated with the parking slots (208A-E) instead of obtaining the width information from an external source such as the barcode and the communication device. In this example, a slot end indicator (not shown in FIG. 2) may be placed at an end of each parking slot for accurately determining the width information using the light-based sensing system (108). Examples of the slot end indicators include any physical structure such as metal blocks, concrete walls, guardrails, reflective strips, and active and/or passive markers that can backscatter light signals. In one embodiment, the slot end indicators backscatter the emitted light signals to the light-based sensing system (108) at a designated frequency that may be different from frequencies associated with light signals backscattered by other objects. Hence, the light-based sensing system (108) may differentiate the slot end indicators from other objects such as vehicles, wall structures, etc. located in the parking space (106). Further, the light-based sensing system (108) may detect the presence of the slot end indicators based on a frequency associated with the backscattered lights signals.
[0044] When the vehicle (104) navigates through a region between the parking aisles (204) and (206), the slot end indicators backscatter the light beams (212) and (214) and the light-based sensing system (108) receives such backscattered light beams at one or more frequencies. The light-based sensing system (108) then determines duration between receiving of a light beam from a designated slot end indicator and receiving of the light beam from another slot end indicator that is subsequent to the designated slot end indicator. Subsequently, the light-based sensing system (108) determines the width information associated with the parking slots (208A-E) based on the determined duration. For example, the light-based sensing system (108) determines duration between receiving of a light beam from a first slot end indicator at the parking slot (208A) and receiving of a light beam from a second slot end indicator at the parking slot (208B) to determine the width information of the second slot (208B).
[0045] At step (306), when the vehicle (104) navigates forward from a current exemplary position (226), the light-based sensing system (108) determines a duration between detection of a first object and detection of a second object to determine a distance between the first and second objects. The first and second objects are located inside a distance threshold and are adjacent to each other. In one embodiment, the distance threshold represents a boundary (232) associated with a parking aisle (e.g., the parking aisle 204). In one example, the light-based sensing system (108) may illuminate a boundary end indicator that is kept at the boundary (232) of the parking aisle (204). Examples of the boundary end indicator include any physical structure such as metal blocks, concrete walls, guardrails, reflective strips, and active and/or passive markers that can backscatter light signals. Further, the light-based sensing system (108) may identify a time taken by the light beam (212) to reach the boundary end indicator and reflect back to the light-based sensing system (108) to determine the distance threshold.
[0046] For example, when the vehicle (104) navigates forward from the exemplary position (226) to an exemplary position (228), the light-based sensing system (108) first identifies the vehicle (210A), and subsequently, identifies the vehicle (210B). Then the light-based sensing system (108) determines the distance between the vehicle (210A) and the vehicle (210B) based on a duration between identification of the vehicle (210A) and identification of the vehicle (210B). In this example, both the first and second vehicles (210A) and (210B) are inside the boundary (232) of the parking aisle (204) and are subsequent to each other.
[0047] In another example, an object (e.g., a construction wall) may exist between the vehicle (210A) and the vehicle (210B), such that the object is inside the boundary (232). In this scenario, when the vehicle (104) navigates forward from the exemplary position (226), the light-based sensing system (108) first identifies the vehicle (210A) and subsequently identifies the object. The light-based sensing system (108) then determines a distance between the vehicle (210A) and the object based on a duration between identification of the vehicle (210A) and identification of the object.
[0048] In yet another example, an object may exist between the vehicle (210A) and the vehicle (210B), but the object may be located outside the boundary (232). In this scenario, when the vehicle (104) navigates forward from the exemplary position (226), the light-based sensing system (108) first identifies the vehicle (210A) and subsequently identifies the object, but the light-based sensing system (108) does not consider the object as a potential obstacle for parking the vehicle (104) as the object is located outside the boundary (232). The vehicle (104) continues to navigate forward and the vehicle (210B) is identified subsequently. As noted previously, the light-based sensing system (108) then determines the distance between the vehicle (210A) and the vehicle (210B) based on a duration between identification of the vehicle (210A) and identification of the vehicle (210B).
[0049] At step (308), the light-based sensing system (108) determines a distance between the subsequent objects that are inside the distance threshold based on the identified duration. In certain embodiments, the light-based sensing system (108) may also consider a speed at which the vehicle (104) moves within the target zone (202), a refresh rate associated with the light-based sensing system (108), and/or the width associated with the parking slots (208A-D) for determining the distance between the subsequent objects. As noted previously, examples of the subsequent objects include vehicles parked adjacent to each other, an object such as a construction wall exists adjacent to a parked vehicle, an object such as a slot end indicator exists adjacent to a parked vehicle, etc. In certain embodiments, the light-based sensing system (108) provides the determined distance between the subsequent objects to the parking assistance system (110) in real-time, as the vehicle (104) navigates forward from the exemplary position (226) to the exemplary position (228), as depicted in FIG. 2. At step (310), the parking assistance system (110) receives the determined distance between the subsequent objects and checks whether the determined distance is equal to or greater than the width associated with the parking slots (208A-E) and a dimension of the vehicle (104). At step (312), the parking assistance system (110) detects an availability of a vacant parking slot when the determined distance is equal to or greater than the width associated with the parking slots (208A-E) and the dimension of the vehicle (104).
[0050] For example, if the determined distance between the first vehicle (210A) and the second vehicle (210B) is 1.5 meters, a width of the vehicle is 2.5 meters, and the width of the parking slots (208A-E) is 3 meters. In this example, the parking assistance system (110) compares the determined distance and the width of the parking slots (208A-E), and determines that a gap exists between the first vehicle (210A) and the second vehicle (210B) is actually not a vacant parking slot. Therefore, the vehicle (104) continues to navigate further within the target zone (202), and the steps (306), (308), (310), and (312) are repeated until an availability of a vacant parking slot is detected.
[0051] In certain embodiments, the vehicle (104) continues to move from the exemplary position (228) to another exemplary position (230), and, the light-based sensing system (108) identifies a duration between identification of the second vehicle (210B) and identification of the third vehicle (210D). Then, the light-based sensing system (108) determines a distance between the second vehicle (210B) and the third vehicle (210D) based on the identified duration. For example, the distance determined between the vehicles (210B) and (210D) may be 4 meters. In such a scenario, the parking assistance system (110) determines an availability of a vacant parking slot (i.e., the third parking slot 208C) between the vehicles (210B) and (210D), as the distance determined is greater than the width of the parking slots (208A-E) and the width of the vehicle (104). Therefore, the parking assistance system (110) selects the parking slot (208C as the vacant parking slot for parking the vehicle (104).
[0052] Irrespective of parking slots type (i.e., a perpendicular parking type, a parallel parking type, or an angular parking type), the light-based sensing system (108) and the parking assistance system (110) can be used for slot detection and selection, and for environment perception for all types of parking slots. In case two or more subsequent parking slots are empty, the parking assistance system (110) selects the last detected vacant slot for automatically parking the vehicle (104). In certain embodiments, upon detecting and selecting the vacant parking slot (208C), the vehicle (104) plans a navigation path for automatically parking in the selected vacant parking slot (208C) using the light-based sensing system (108) and the parking assistance system (110). The vehicle (104) may be automatically parked in the selected vacant parking slot (208C) based on a first method in which the vehicle (104) moves in an arc-path or a second method in which the vehicle moves in a non-arc path. An exemplary method in which the vehicle (104) moves in the arc-path for automatically parking the vehicle (104) in the selected vacant parking slot (208C) is explained in detail with reference to FIG. 4, FIG. 5A, and FIG. 5B.
[0053] FIG. 4 is a schematic diagram (400) illustrating the target zone (202) in which the vehicle (104) navigates in an arc-path (402) in order to configure the vehicle (104) to automatically park in a selected vacant parking slot according to one embodiment of the present disclosure. For example, when the vehicle (104) reaches the exemplary position (230) from the exemplary position (228), the parking assistance system (110) identifies an availability of the vacant paring slot (208C) using the light-based sensing system (108). Further, when the vehicle (104) is located at the exemplary position (230), the vehicle (210D) backscatters the light beam (212) and the light-based sensing system (108) receives such backscattered light beam from the vehicle (210D). In order to automatically park the vehicle (104) in the selected vacant parking slot (208C), the vehicle (104) moves by a first distance from the exemplary position (230) to an intermediate position (404), and further moves in a straight path from the intermediate position (404) to a final position (406) by a second distance. An exemplary method to determine the first distance, the intermediate position and the final position will be described in greater detail with reference to FIG. 5A and FIG. 5B.
[0054] Upon reaching the final position (406), the vehicle (104) is steered by a designated angle and moves in a reverse direction in the arc-path (402) using the vehicle control system (111) until the vehicle (104) reaches a midpoint (408) of the vacant parking slot (208C). The vehicle (104) then moves from the midpoint (408) of the vacant parking slot (208C) in an approximately straight path in a reverse-direction by a distance that is approximately equal to a length of the vacant parking slot (208C), for automatically parking the vehicle (104) in the selected vacant parking slot (208C). In one embodiment, the vehicle control system (111) is an electronic control unit of the vehicle (104). Further, the parking assistance system (110) obtains the length of the vacant parking slot (208C) from an image acquisition device such as a camera that is deployed near or within the target zone (202). An exemplary methodology associated with navigation of the vehicle (104) in the arc-path (402) for parking the vehicle (104) in the selected vacant parking slot (208C) is further described in detail with reference to FIG. 5A and FIG. 5B.
[0055] FIG. 5A and FIG. 5B depict a flow diagram illustrating an exemplary method (500) for parking the vehicle (104) in the selected vacant parking slot (208C), in which the vehicle (104) navigates in the arc-path (402). For clarity, the method will be described with reference to the depictions of FIG. 4. At step (502), when the vehicle (104) navigates within the target zone (202) and reaches the exemplary position (230), the light-based sensing system (108) determines a path distance ‘SB’. The path distance ‘SB’ represents a distance between the light-based sensing system (108) that is mounted onto the vehicle (104) and an object along the path of the light beam (212). An example of the object along the path of the light beam (212) is the vehicle (210D) parked at the parking slot (208D). In one embodiment, the light-based sensing system (108) determines the path distance based on a time taken by the light beam (212) to reflect back from the parked vehicle (210D) to the light-based sensing system (108).
[0056] At step (504), a gap between one end (410) of the vacant parking slot (208C) and the object at the adjacent slot (208D) to the vacant slot (208C) is determined. In one example, the object is the vehicle (210D) at the adjacent slot (208D) to the vacant slot (208C). To that end, the light-based sensing system (108) first identifies the end (410) of the vacant parking slot (208C), and subsequently identifies the parked vehicle (210D). In one example, the light-based sensing system (108) identifies the end (410) based on receipt of light signals reflected by the slot end indicator kept at the end (410) of the vacant parking slot (208C). In another example, the light-based sensing system (108) identifies the parked vehicle (210D) based on receipt of light signals reflected by a designated portion of the parked vehicle (210D). Then, the light-based sensing system (108) determines the gap based on a time duration between receipt of the light signals reflected by the slot end indicator at the end (410) and receipt of the light signals by the designated portion of the parked vehicle (210D).
[0057] At step (506), an actual path distance, represented using ‘SE’ in FIG. 4, of the light beam (212) from the light-based sensing system (108) to the end (410) of the vacant parking slot (208C) along the path of the light beam (212) is calculated. In one embodiment, the parking assistance system (110) calculates the actual path distance in accordance with an exemplary equation (1).

Lad = Ld2 + g2 - (2 * Ld * g * cos (90-a)) (1)

where, ‘Lad’ corresponds to the actual path distance from the light-based sensing system (108) to the end (410) of the vacant parking slot (208C). ’Ld’ corresponds to the path distance from the light-based sensing system (108) to the object (e.g., parked vehicle (210D)), and ‘g’ corresponds to the gap between the end (410) of the vacant parking slot (208C) and the parked vehicle (210D). Furthermore, ‘a’ corresponds to an angle between an imaginary line (412) perpendicular to the light-based sensing system (108) and the path of the light beam (212) to the parked vehicle (210D).

[0058] In one embodiment, the angle ‘a’ is a constant value for a selected horizontal field of view. However, the angle ‘a’ may vary based on the selected horizontal field of view associated with the light-based sensing system (108). For example, if the selected horizontal field of view associated with the light-based sensing system (108) is 95 degrees, then the angle ‘a’ formed between an imaginary perpendicular line (412) and the path of the light beam (212) to the parked vehicle (210D) is 42.5 degrees. At step (508), a first distance by which the vehicle (104) has to be moved from the exemplary position (230) to the intermediate position (404) is estimated, for example, in accordance with an equation (2).

First distance = (Lad^½ - d^½) ^½ (2)

where ‘Lad’ is the actual path distance, and where ‘d’ is calculated using the angle ‘a’ that is formed between the imaginary perpendicular line (412) and the path of the light beam (212) to the parked vehicle (210D), and a value of the ‘Lad’, for example, in accordance with an equation (3).

d = (cosa)*Lad (3)

[0059] At step (510), the vehicle control system (111) moves the vehicle (104) by the first distance in a forward direction from the exemplary position (230) to the intermediate position (404). At step (512), before the vehicle (104) reaches the final position (406) from the intermediate position (404), the parking assistance system (110) selects a designated steering angle and/or a corresponding wheel turn angle required to steer the vehicle (104) in the arc-path (402) for parking the vehicle (104) in the selected vacant parking slot (208C). In one embodiment, the parking assistance system (110) also requires a pre-selection of the designated steering angle and/or the wheel turn angle in order to calculate a second distance by which the vehicle (104) has to be moved from the intermediate position (404) to the final position (406).
[0060] In certain embodiments, the parking assistance system (110) selects the designated steering angle and/or the wheel turn angle based on an availability of a vacant space along the path of the vehicle (104). For example, if a pedestrian is standing at a distance of 5 meters from the intermediate position (404) along the path of the vehicle (104), the parking assistance system (110) may select the wheel turn angle as 20 degrees, such that, the second distance by which the vehicle (104) requires to be moved is less than 5 meters. In another example, if a construction wall exists at a distance of 4 meters from the intermediate position (404) along the path of the vehicle (104), the parking assistance system (110) may select the wheel turn angle as 30 degrees, such that, the second distance by which the vehicle (104) requires to be moved is less than 4 meters.
[0061] At step (514), a perpendicular distance between a reference point (414) in the parking space (106) to a reference point (416) associated with the vehicle (104) is determined based on a longitudinal wheelbase distance and the selected wheel turn angle. In one embodiment, the reference point (414) in the parking space (106) corresponds to a center of the arc-path (404). The reference point (416) associated with the vehicle (104) corresponds to a midpoint of a rear axle of the vehicle (104). In certain embodiments, the parking assistance system (110) determines the perpendicular distance between the reference points (414) and (416), for example, in accordance with an equation (4)

Perpendicular distance = L / tan (u) (4)

where, ‘L’ corresponds to the longitudinal wheelbase distance that is a distance between a front axle and a rear axle of the vehicle (104), and ‘u’ corresponds to the selected wheel turn angle.

[0001] Further, at step (516) depicted in FIG. 5B, the parking assistance system (110) determines a second distance by which the vehicle (104) has to be moved from the intermediate position (404) to the final position (406). The second distance is a difference between the determined perpendicular distance and a half of the width of the selected vacant parking slot (208C). At step (518), the vehicle control system (111) moves the vehicle (104) by the second distance in a forward direction from the intermediate position (404) to the final position (406). At step (520), the vehicle control system (111) steers the vehicle (104) by the selected wheel turn angle, while moving the vehicle (104) by a third distance in a reverse direction in the arc-path (402) until the vehicle (104) reaches a reference point (e.g., the midpoint 408) in the vacant parking slot (208C). In one embodiment, the parking assistance system (110) determines the third distance by which the vehicle (104) is to be moved in the arc-path (402), for example, in accordance with an equation (A):

(2 * 3.14 * perpendicular distance / 4) radians (A)

[0063] At step (522), the vehicle control system (111) moves the vehicle (104) by a fourth distance from the midpoint (408) of the vacant parking slot (208C) in an approximately straight path in the reverse-direction. In one embodiment, the fourth distance is approximately equal to the length of the vacant parking slot (208C), such that the vehicle (104) is autonomously navigated into the selected vacant parking slot (208C).
[0064] In certain embodiments, when the vehicle (104) moves in the arc-path (402) for parking the vehicle (104) in the selected vacant parking slot (208C), the vehicle (104) may require and may occupy more space within the target zone (202). If any obstacles exist, for example a pedestrian or another vehicle in the arc-path (402) or adjacent to the arc-path (402), the vehicle (104) may collide with the obstacles while navigating in the arc-path (402). In such scenarios, the vehicle (104) may select the second method in which the vehicle moves in a non-arc path for parking the vehicle (104) in the selected vacant parking slot (208C). When the vehicle (104) navigates in the non-arc path, the vehicle (104) occupies lesser space comparatively as compared to when navigating in the arc path. An exemplary method for configuring the vehicle (104) to navigate in the non-arc path for automatically parking the vehicle (104) in the selected vacant parking slot (208C) is described in detail with reference to FIGS. 6 and 7.
[0065] FIG. 6 is a schematic diagram (600) illustrating the target zone (202) in which the vehicle (104) navigates in a non-arc-path (602) (a L-shaped path shown with dotted lines) after the vacant parking slot (208C) is selected in order to configure the vehicle (104) to automatically park in the vacant parking slot (208C). In order to automatically park the vehicle (104) in the selected vacant parking slot (208C), the vehicle (104) moves by a first distance from the exemplary position (230) to the intermediate position (404), and further moves in an approximately straight path in a reverse direction from the intermediate position (404) to a final position (604) by a second distance.
[0066] Upon reaching the final position (604), the vehicle (104) is steered by a designated angle (e.g., 90 degrees in an anti-clockwise direction) and moves in a reverse direction in the non arc-path (602) until the vehicle (104) reaches the midpoint (408) of the vacant parking slot (208C). Then, the vehicle (104) moves from the midpoint (408) of the vacant parking slot (208C) in an approximately straight path in the reverse-direction by a distance that is approximately equal to the length of the vacant parking slot (208C) for automatically parking the vehicle (104) in the selected vacant parking slot (208C). An exemplary methodology associated with navigation of the vehicle (104) in the non arc-path (602) for parking the vehicle (104) in the selected vacant parking slot (208C) is further described in detail with reference to FIG. 7.
[0067] FIG. 7 is a flow diagram illustrating an exemplary method (700) for parking the vehicle (104) in the selected vacant parking slot (208C) by configuring the vehicle (104) to navigate in the non-arc-path (602). At step (701), the vehicle control system (111) moves the vehicle (104) by the first distance in a forward direction from the exemplary position (230) to the intermediate position (404) in a similar manner as described in detail with reference to steps (502), (504), (506), (508), and (510) of FIG. 5A.
[0068] At step (702), the parking assistance system (110) estimates a second distance by which the vehicle (104) needs to be moved from the intermediate position (404) to the final position (604), where the second distance is a half of the width of the selected vacant parking slot (208C). At step (704), the vehicle control system (111) moves the vehicle (104) by the second distance in a reverse direction from the intermediate position (404) to the final position (604). At step (706), when the vehicle (104) is located at the final position (604), the parking assistance system (110) determines a third distance by which the vehicle (104) needs to be moved from the final position (604) to a reference point (e.g., the midpoint 408) in the selected vacant parking slot (208C). In one embodiment, the third distance may be determined, for example, using equation (5):

d = (cosa)*Lad (5)

where, ‘Lad’ corresponds to the actual path distance, and the angle ‘a’ that is formed between the imaginary perpendicular line (412) and the path of the light beam (212) to the parked vehicle (210D).

[0069] At step (708), the vehicle control system (111) steers the vehicle (104) by a desired angle (e.g., 90 degrees) in a specific direction (e.g., an anti-clockwise direction), while also moving the vehicle (104) by the third distance in a reverse direction from the final position (604) to the midpoint (408) of the vacant parking slot (208C). At step (710), once the vehicle (104) navigates to the midpoint (408), the vehicle control system (111) moves the vehicle (104) by a fourth distance from the midpoint (408) in a straight path in the reverse-direction that is approximately equal to the length of the vacant parking slot (208C). Specifically, the vehicle control system (111) moves the vehicle (104) by the fourth distance from the midpoint (408) in a straight path in the reverse-direction such that the vehicle (104) is autonomously navigated into the vacant parking slot (208C). It may be noted that the first and second methods that are described with reference to description of FIGS. 4, 5A, 5B, 6 and 7 correspond to a reverse perpendicular vehicular parking.
[0070] In certain embodiments, when the vehicle (104) navigates within the parking space (106), the light-based sensing system (108) is used for environment perception. Specifically, the light-based sensing system (108) may be used for detecting obstacles in a potential navigation path of the vehicle (104) and for estimating the detected obstacles range information. FIG. 8 is a schematic diagram (800) illustrating the vehicle (104) having the light-based sensing system (108) used for the environment perception while the vehicle (104) is navigating within the parking space (106). To that end, the light source (112) of the light-based sensing system (108) of FIG. 1 may be configured to generate and emit light beams having wider angles such that the light beams may reach objects that are far away from the vehicle (104) and may reflect back to the light-based sensing system (108). In one embodiment, the light-based sensing system (108) is configured to disregard such distant objects as being threats when determining a potential navigation path of the vehicle (104) by defining a distance threshold for at least one of the light beams, as described in detail with reference to FIG. 8. If any objects are determined to be located outside the defined distance threshold, the light-based sensing system (108) does not consider the objects as potential obstacles in the potential navigation path of the vehicle (104).
[0071] For example, as shown in FIG. 8, a light beam (802) that is represented as 0th beam travels beyond a boundary (804) associated with a potential navigation path (805) of the vehicle (104). The boundary (804) associated with the potential navigation path (805) is depicted in FIG. 8 using two dotted lines. The light beam (802) emitted from the light-based sensing system (108) reaches the object (806) that is located outside the boundary (804), and in response, the light-based sensing system (108) receives back the light beam (802) from the object (806). In this example, the light-based sensing system (108) is configured to determine that the object (806) is not really a threat along the potential navigation path (805) of the vehicle (104). To that end, the parking assistance system (110) first determines a distance threshold that corresponds to a distance between the light-based sensing system (108) and a reference point (810) where the light beam (802) intersects with the boundary (804) associated with the potential navigation path (805). Consequently, the parking assistance system (110) compares the determined distance threshold with a distance at which the object (806) is located from the light-based sensing system (108) to determine if the object (806) is really a threat along the potential navigation path (805) of the vehicle (104). For example, if the determined distance threshold is 1 meters and the object (806) is located at a distance of 2 meters, then the parking assistance system (110) determines that the object (806) is not really a threat along the potential navigation path (805) of the vehicle (104). In one embodiment, the parking assistance system (110) determines the threshold distance associated with the light beam (802), in accordance with an equation (6).

r = ((V/2) / cos (a)) (6)

where, ‘r’ is the threshold distance associated with the light beam (802), ‘V’ is a width (812) associated with the vehicle (104), and ‘a’ is an angle that is specific to the light beam (802) and is calculated, for example, in accordance with an equation (7).

a = (((180 – selected HFOV))/2 + [beam sequence number * ((selected HFOV)/(total number of light beams))])/2 (7)

[0072] For example, if the selected horizontal field of view is 95 degrees and the total number of light beams emitted from the light-based sensing system (108) is 16, then the ‘a’ associated with the 0th beam (802) is determined using equation (7) to be 42.5 degrees. Subsequently, the parking assistance system (110) uses the calculated ‘a’ value to determine the distance threshold associated the light beam (802), using equation (6).
[0073] Similarly, it is to be understood that the threshold distance associated with other light beams can be calculated in accordance with the previously mentioned equations (6) and (7). In certain embodiments, the threshold distance defined for the 15th beam may be same as the threshold distance defined for the 0th beam (802). Similarly, the threshold distance associated with a 14th beam, a 13th beam, a 12th beam, a 11th beam, and a 10th beam would be same as the threshold distance associated with a 1st beam, a 2nd beam, a 3rd beam, a 4th beam, and a 5th beam, respectively. Hence, the parking assistance system (110) may require determining the threshold distance associated with only a set of light beams that are applicable for other set of light beams as well.
[0074] The light beams generated by the light-based sensing system (108), such as, the 6th beam, 7th beam, 8th beam, and 9th beam travel more or less in a straight path. Therefore, the parking assistance system (110) may not be required to determine the distance threshold associated with the 6th beam, 7th beam, 8th beam, and 9th beam. Further, the 6th beam, 7th beam, 8th beam, and 9th beam are used to detect objects along the straight path of the vehicle (104) and whereas the other beams (e.g., 0th beam to 5th and 10th beam to 15th beam) may be used to detect objects along left and right sides of the vehicle (104). Though the FIG. 8 depicts only a single light-based sensing system (108) deployed at a front side of the vehicle (104), it is to be understood that the vehicle (104) can have any number of light-based sensing systems (108). For example, another light-based sensing system (108) may be deployed at a rear side of the vehicle (104), such that, the rear side light-based sensing system (108) detects obstacles at the rear side of the vehicle (104) and estimates the range information associated with the detected obstacles.
[0075] Unlike conventional approaches that use ultrasonic sensors and/or cameras-based autonomous parking systems, the navigation system (102) uses the light-based sensing system (108) that accurately detects vacant parking slots even if the vacant parking slots are located far away from the vehicle (104). This is because the extreme light beams emitted by the light-based sensing system (108) are capable of scattering in a wider angle and reach distantly located vacant parking slots easily. Unlike, the camera-based autonomous parking systems that require high computational power to quickly execute autonomic parking during bad weather conditions, the light-based sensing system (108) reliably operates in varied environment conditions without requiring high computational power and associated costs.
[0076] Further, the parking assistance system (110) is configured to select a first method or a second method for parking the vehicle (104) in a selected vacant parking slot based on an availability of a vacant space along the path of the vehicle (104). For example, if more than a defined amount of space is available along the path of the vehicle (104), the vehicle (104) navigates in the arc-path (402), as described with reference to FIGS. 5A and 5B for automatically parking the vehicle (104) in the selected vacant parking slot. Alternatively, the vehicle (104) navigates in the non-arc-path (602), as described with reference to FIG. 7 for automatically parking the vehicle (104) in the selected vacant parking slot. Apart from using the light-based sensing system (108) for automatically parking the vehicle (104) in the selected vacant parking slot, the range information from the light-based sensing system (108) can also be used for various other autonomous driving functionalities. For example, including distance information regarding a nearby object may be received by an advanced emergency braking system (AEBS) of the vehicle (104) from the light-based sensing system (108) to allow the AEBS to configure a necessary control of an associated brake system. In another example, the same distance input from the light-based sensing system (108) may be used by a lane change assistance system to take a decision on changing a lane of the vehicle (104).
[0077] It may be noted that the foregoing examples, demonstrations, and process steps that may be performed by certain components of the present systems, for example, by the parking assistance system (110) may be implemented by suitable code on a processor-based system, such as a general-purpose or a special-purpose computer. Accordingly, the parking assistance system (110), for example, includes one or more general-purpose processors, specialized processors, graphical processing units, microprocessors, programming logic arrays, field programming gate arrays, and/or other suitable computing devices. It may also be noted that different implementations of the present specification may perform some or all of the steps described herein in different orders or substantially concurrently.
[0078] Although specific features of various embodiments of the present systems and methods may be shown in and/or described with respect to some drawings and not in others, this is for convenience only. It is to be understood that the described features, structures, and/or characteristics may be combined and/or used interchangeably in any suitable manner in the various embodiments shown in the different figures.
[0079] While only certain features of the present systems and methods have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the claimed invention.