Description:FIELD OF THE INVENTION
[0001] The present disclosure is generally related to a crawl control system and method and, more particularly, to automatically operate a vehicle on a gradient by maintaining and adjusting a crawl reference speed of the vehicle without using brakes.
BACKGROUND OF THE INVENTION
[0002] A road gradient is a rise or falls along the road length in relation to the horizontal alignment of the road. Road gradient recognition is very helpful for drivers as well as for vehicle manufacturers in terms of the emission, energy consumption of electric vehicles, fuel economy, and safety.
[0003] Riding a two-wheeler on the gradient is inconvenient due to the constant need to actuate brakes and apply throttle to maintain their speed throughout the gradient. Due to this, the rider faces inconvenience in focusing on steering and it impacts the fuel efficiency of the vehicle. However, there may be instances, when the vehicle driver is trying to ride the vehicle on the gradients at the time of rain, snow, slush, sleet, and other whether conditions then it is required to maintain a constant speed in order to avoid slipping of the vehicle.
[0004] Torque is a required force that is available at the wheels to propel the bike further. There are two types of torque such as positive torque and negative torque. Positive and negative torque is required at the time of riding the vehicle on an up-gradient and down-gradient respectively. For a seamless riding experience, it is necessary for the rider to change the torque rapidly and it is done by using throttles and brakes. But this may create high chances of human error.
[0005] For example, US20200398844A1 discloses a method and system for creep torque control. The methods and systems are provided for providing off-road capabilities in electric vehicles with a single gear reduction. In one example, when a 4×4 mode is selected in an electric vehicle, a relationship between motor torque and accelerator pedal position is changed so as to increase the vehicle creep wheel torque. A degree of increase of the creep wheel torque is adjusted as a function of the terrain on which the vehicle is off-roading.
[0006] The above solution discloses multiple sensor and navigation data for determining the nature of the track on which the vehicle has to move. This system helps in improving the driver experience where they have to apply minimal effort to drive the vehicle on the rough terrain without having to manually change terrain modes. But the above system neither discloses the use of throttle to adjust a crawl reference speed as per the rider indication nor the speed controller for maintaining the speed of the vehicle on the gradients by applying motoring and regenerative braking.
[0007] In order to overcome the aforementioned drawbacks, there is a need to provide a novel crawl control system that is automatically activated when the vehicle is on a gradient and also uses motoring and regenerative braking to maintain a crawl reference speed of the vehicle and uses throttle for adjustment of the crawl reference speed.
OBJECTS OF THE INVENTION
[0008] The principal object of the present invention is to overcome the disadvantages of the prior art.
[0009] Another object of the present invention is to provide a crawl control system that automatically gets activated after detecting a gradient.
[0010] Another object of the present invention is to provide the crawl control system that uses motoring and regenerative braking to maintain a crawl reference speed of a vehicle when a rider drives the vehicle on the gradient.
[0011] Another object of the present invention is to provide the crawl control system that uses a throttle for adjusting the crawl reference speed in order to avoid the use of additional input like a button.
[0012] Another object of the present invention is to provide the crawl control system that is easy in design, economical and reduces manual efforts while riding the vehicle on the gradient.
[0013] Another object of the present invention is to provide the crawl control system that provides a seamless driving experience for the rider by making the system conveniently operable and automatic since the speed is always in control of the rider without the use of brakes.
[0014] Another object of the present invention is to provide the crawl control system that reduces the chances of road accidents.
[0015] Another object of the present invention is to provide the crawl control system that is used for riding on hilly roads, rough terrain, and multi-level parking lots, among others.
SUMMARY OF THE INVENTION
[0016] The present invention relates to a crawl control system for maintaining a crawl reference speed of the vehicle while riding on a gradient and also adjusting the crawl reference speed in response to a throttle torque that is monitored by a crawl control module. This system is automatic that's why it makes the ride more convenient, and effortless and does not involve any human intervention.
[0017] According to an embodiment of the present invention, disclosed is a crawl control system. The crawl control system comprises an IMU (Inertial Measurement Unit), a host vehicle, a crawl control module, a speed controller, and a throttle. The IMU (Inertial Measurement Unit) is configured in the host vehicle for generating an input signal indicative of a gradient detection via a gyroscope and an accelerometer. The IMU and a motor encoder is configured for estimating the gradient by estimating an orientation of the host vehicle. The crawl control module is configured with the IMU to automatically activate when the detected gradient is greater than a threshold pitch value. The gradient includes an up-gradient and a down-gradient. The speed controller is configured with the crawl control module to determine a crawl reference speed indicative of the host vehicle speed before activation of the crawl control module. The speed controller applies motoring and regenerative braking to a traction motor in order to maintain the crawl reference speed. The crawl reference speed is constant when the crawl control module is in an enable state and the crawl reference speed is modified to the current vehicle speed when the crawl control module is in a reset state. The throttle is communicably coupled with the crawl control module for adjusting the crawl reference speed, wherein the traction motor changes the crawl reference speed in response to a throttle torque that is monitored by the crawl control module. The throttle torque is anyone of a positive torque or a negative torque.
[0018] According to another embodiment of the present invention, the crawl control module either activated automatically by the gradient detection or manually by using an input module that includes a user interface that is anyone of a smartphone, a laptop, a dashboard or a button placed on the vehicle, among others. Further, the system may use different logic for activating and deactivating the crawl control module that is anyone of a time logic and a distance logic. The distance logic compares the estimated pitch with the threshold pitch, wherein if the estimated pitch is greater than the threshold pitch for a specific distance then the distance logic activates the crawl control module and if the estimated pitch is lower than the threshold pitch for the specific distance then the distance logic deactivates the crawl control module while the time logic compares an estimated pitch with a threshold pitch, wherein if the estimated pitch is greater than the threshold pitch for a specific time slot then the time logic activates the crawl control module and if the estimated pitch is lower than the threshold pitch for the specific time slot then the time logic deactivates the crawl control module. Further, the system may use different brakes such as an ABS (Antilock Braking System) for decreasing the crawl reference speed while the host vehicle is moving on the down-gradient.
[0019] According to another embodiment of the present invention, the crawl control method comprises multiple steps. In the first step, an IMU (Inertial Measurement Unit) is configured in a host vehicle for generating an input signal indicative of a gradient detection, and the IMU and a motor encoder is configured for estimating the gradient by estimating an orientation of the host vehicle. The gradient includes an up-gradient and a down-gradient. In the next step, the IMU activates a crawl control module automatically when the detected gradient is greater than a threshold pitch value. In the next steps, a speed controller is configured with the crawl control module for determining a crawl reference speed indicative of the host vehicle speed before activation of the crawl control module, wherein the speed controller applies motoring and regenerative braking to a traction motor in order to maintain the crawl reference speed. In the last step, a throttle is communicably coupled with the crawl control module for adjusting the crawl reference speed and the traction motor changes the crawl reference speed in response to a throttle torque that is monitored by the crawl control module. The throttle torque is anyone of a positive torque or a negative torque.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings illustrate various embodiments of systems, methods, and embodiments of various other aspects of the disclosure. Any person with ordinary skills in the art will appreciate that the illustrated element boundaries (e.g. boxes, groups of boxes, or other shapes) in the figures represent one example of the boundaries. It may be that in some examples one element may be designed as multiple elements or that multiple elements may be designed as one element. In some examples, an element shown as an internal component of one element may be implemented as an external component in another, and vice versa. Furthermore, elements may not be drawn to scale. Non-limiting and non-exhaustive descriptions are described with reference to the following drawings. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating principles.
[0021] FIG. 1 illustrates a perspective view of a crawl control system 100, according to an embodiment of a present invention;
[0022] FIG. 2 illustrates a perspective view of an IMU (Inertial Measurement Unit), according to an embodiment of a present invention;
[0023] FIG. 3 shows a flow chart illustrating a method 300 for a gradient detection, according to an exemplary embodiment of the present invention;
[0024] FIG. 4 shows a flow chart illustrating a method 400 for determining a crawl reference speed at different states of a crawl control module, according to another exemplary embodiment of the present invention;
[0025] FIG. 5 shows a flow chart illustrating a method 500 for determining an output torque depending on a crawl torque and a throttle torque, according to another exemplary embodiment of the present invention;
[0026] FIG. 6 illustrates a block diagram depicting a method 600 for crawl controlling, according to an embodiment of the invention;
[0027] Fig. 7 depicts a graph 700 illustrating the gradient detection, according to another exemplary embodiment of the present invention; and
[0028] Fig. 8 depicts a graph 800 illustrating a crawl control status by taking a host vehicle on the up-gradient and down-gradient, according to another exemplary embodiment of the present invention.
DETAILED DESCRIPTION
[0029] Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings in which, like numerals represent like elements throughout the several figures, and in which example embodiments are shown. Embodiments of the claims may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples among other possible examples.
[0030] Some embodiments of this invention, illustrating all its features, will now be discussed in detail. The words “comprising,” “having,” “containing,” and “including,” and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items.
[0031] It must also be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred systems and methods are now described.
[0032] FIG. 1 illustrates a perspective view of a crawl control system 100, according to an embodiment of a present invention. The crawl control system 100 comprises an IMU (Inertial Measurement Unit) 102, a motor encoder 106, a crawl control module 108, a speed controller 110, a throttle 114, and a traction motor 112.
[0033] In an embodiment, the IMU 102 is configured in a host vehicle 104 to generate an input signal that indicates a gradient detection. The gradient includes an up-gradient and a down-gradient. In an embodiment, the crawl control module 108 is connected with the IMU 102 to automatically activate when the detected gradient is greater than a threshold pitch value.
[0034] In an embodiment, the speed controller 110 is configured with the crawl control module 108 to determine a crawl reference speed indicative of the host vehicle 104 speed before activation of the crawl control module 108. Further, the speed controller 110 applies motoring and regenerative braking to the traction motor 112 in order to maintain the crawl reference speed. In an embodiment, the crawl control module 108 uses the speed controller 110 to maintain the crawl reference speed of the vehicle 104 and determines a crawl torque required to maintain it. Further, the crawl control module 108 compares the crawl reference speed with the host vehicle's 104 current speed in order to determine the difference between them, and based on that, the crawl control module 108 requests the crawl torque so that the motor increases the speed up or down to maintain the crawl reference speed.
[0035] In an embodiment, the throttle 114 is communicably coupled with the crawl control module 108 for adjusting the crawl reference speed. Further, the traction motor 112 changes the crawl reference speed in response to a throttle torque that is monitored by the crawl control module 108. In one embodiment, the throttle torque is anyone of a positive torque or a negative torque.
[0036] FIG. 2 illustrates a perspective view of the IMU 102, according to an embodiment of a present invention. Since the crawl control module 108 activates automatically, it is important to be able to detect the gradient that the vehicle 104 is operating on. This is done by using the input signal that is generated from the IMU 102 and the motor encoder 106 to estimate the orientation of the vehicle 104. The IMU 102 may measure angular or linear acceleration and may be used to determine a lateral acceleration, a longitudinal acceleration, a pitch angle, a roll angle, and a yaw rate. In one embodiment, the IMU 102 includes a gyroscope 204 and an accelerometer 202 to include data about the movement of the host vehicle 104 (refer fi.1). From the orientation, the IMU 102 estimates the pitch that is greater than the gradient. By pitch estimation, the crawl control module 108 is activated automatically without any manual activation by a user and therefore increases convenience in driving on the gradient.
[0037] In an alternative embodiment, the crawl control module 108 is activated manually by using an input module that includes a user interface that is anyone of a smartphone, a laptop, a dashboard, or a button placed on the vehicle 104, among others.
[0038] In another alternative embodiment, the system may use time logic for activating and deactivating the crawl control module 108. The time logic compares an estimated pitch with a threshold pitch, wherein if the estimated pitch is greater than the threshold pitch for a specific time slot then the time logic activates the crawl control module 108 and if the estimated pitch is lower than the threshold pitch for the specific time slot then the time logic deactivates the crawl control module 108.
[0039] In another alternative embodiment, the system may use distance logic for activating and deactivating the crawl control module 108. The distance logic compares the estimated pitch with the threshold pitch, wherein if the estimated pitch is greater than the threshold pitch for a specific distance then the distance logic activates the crawl control module 108 and if the estimated pitch is lower than the threshold pitch for the specific distance then the distance logic deactivates the crawl control module 108.
[0040] FIG. 3 shows a flow chart illustrating a method 300 for the gradient detection, according to an exemplary embodiment of the present invention. Flowchart 300 starts at step 305 and proceeds to steps 310, 315, 320, 325. The method 300 is first operative at step 305. At step 310, the IMU 102 (refer fig.1) generates the input signal indicative of the gradient detection. At step 315, a determination is made if the gradient is detected or not. In one embodiment, when the determination is “YES”, and the gradient is detected then the flowchart proceeds to step 320 otherwise the flowchart moves back to step 310. At step 320, another determination is made whether the system applied time/distance logic or not. In one embodiment, when the determination is “YES” then the flowchart proceeds to step 325 otherwise the flowchart moves back to step 315. At step 325, the crawl control module 108 is activated.
[0041] FIG. 4 shows a flow chart illustrating a method 400 for determining a crawl reference speed at different states of a crawl control module (refer fig.1), according to another exemplary embodiment of the present invention. Flowchart 400 starts at step 405 and proceeds to steps 410, 415, 420, 425, and 430. The method 400 is first operative at step 405. At step 410, a determination is made whether the crawl control module 108 is in an enable state. In one embodiment, when the determination is “YES”, and the crawl control module 108 is in the enable state then the flowchart proceeds to step 415 otherwise the flowchart proceeds to step 420. At step 415, when the crawl control module 108 is activated then the crawl reference speed becomes constant. At step 420, another determination is made whether the crawl control module 108 is in a reset state. In one embodiment, when the determination is “YES”, and the crawl control module 108 is in the reset state then the flowchart proceeds to step 425 otherwise the flowchart proceeds to step 430. At step 425, when the crawl control module 108 is activated then the crawl reference speed is modified to the current vehicle 104 (refer fig.1) speed. At step 430, when the crawl control module 108 is deactivated then in that case also the crawl reference speed is same as the current vehicle 104 speed.
[0042] In an exemplary embodiment, the crawl control module 108 (refer fig.1) is activated after the gradient detection. Further, when the vehicle 104 (refer fig.1) is moving on the up-gradient it tends to roll backwards then it requires the positive torque using motoring to increase the host vehicle 104 speed, similarly when the vehicle 104 is moving on the down-gradient it tends to roll forward then it requires the negative torque using regenerative braking to decrease the host vehicle 104 speed. For this, the speed controller 110 (refer fig.1) automatically determines how to blend the crawl torque such that the crawl reference speed of the vehicle 104 is maintained.
[0043] FIG. 5 shows a flow chart illustrating a method 500 for determining an output torque depending on the crawl torque and the throttle torque, according to another exemplary embodiment of the present invention. Flowchart 500 starts at step 505 and proceeds to steps 510, 515, 520, 525, 530, 535, 540, 545, 555, and 560. The method 500 is first operative at step 505. At step 510, a determination is made whether the crawl control module 108 (refer fig.1) is active. In one embodiment, when the determination is “YES”, and the crawl control module 108 is active then the flowchart proceeds to step 520 otherwise the flowchart proceeds to step 515. At step 515, an output torque for the vehicle 104 (refer fig.1) is the throttle torque. At step 520, another determination is made whether the throttle torque is positive. In one embodiment, when the determination is “YES”, and the throttle torque is positive then the flowchart proceeds to step 525 otherwise the flowchart proceeds to step 540. At step, 525, another determination is made whether the throttle torque is greater than the crawl torque. In one embodiment, when the determination is “YES”, then the flowchart proceeds to step 535 otherwise the flowchart proceeds to step 530. At step 530, the output torque for the vehicle 104 is equal to the crawl torque. At step 535, the output torque for the vehicle 104 is the same as the throttle torque.
[0044] At step 540, another determination is made whether the throttle torque is negative. In one embodiment, when the determination is “YES”, and the throttle torque is negative then the flowchart proceeds to step 550 otherwise the flowchart proceeds to step 545. At step 545, the output torque for the vehicle 104 is equal to the crawl torque. At step, 550, another determination is made whether the throttle torque is lesser than the crawl torque. In one embodiment, when the determination is “YES”, then the flowchart proceeds to step 560 otherwise the flowchart proceeds to step 555. At step 555, the output torque for the vehicle 104 is equal to the crawl torque. At step 560, the output torque for the vehicle 104 is the same as the throttle torque.
[0045] In an embodiment, when the crawl control module 108 (refer fig.1) is active, and the throttle torque is positive and greater than the crawl torque then the throttle torque overrides the crawl torque to increase the crawl reference speed and similarly, if the throttle torque is negative and lower than the crawl torque then the throttle torque overrides the crawl torque to decrease the crawl reference speed. Without the throttle torque, the vehicle 104 may remain at a set speed and require deactivation of the crawl control module 108 (refer fig.1) before allowing the change in the crawl reference speed.
[0046] In another alternative embodiment, the system 100 may use different brakes such as an ABS (Antilock Braking System) for decreasing the crawl reference speed while the host vehicle 104 (refer fig.1) is moving on the down-gradient.
[0047] FIG. 6 illustrates a block diagram depicting a method 600 for crawl controlling, according to an embodiment of the invention. The method 600 includes an IMU 102 (refer fig.1) (Inertial Measurement Unit) that is configured in a host vehicle 104 (refer fig.1) for generating an input signal indicative of a gradient detection by estimating an orientation of the host vehicle 104, as shown in step 605. Further, the IMU 102 and a motor encoder 106 (refer fig.1) are configured for estimating the orientation of the host vehicle 104. At step 610, the IMU 102 is used for activating a crawl control module 108 (refer fig.1) automatically when the detected gradient is greater than a threshold pitch value. At step 615, a speed controller 110 (refer fig.1) is configured with the crawl control module 108 for determining a crawl reference speed and applies motoring and regenerative braking to a traction motor 112 (refer fig.1) in order to maintain the crawl reference speed. Further, the crawl reference speed indicates the host vehicle 104 speed before activation of the crawl control module. At step 620, a throttle 114 (refer fig.1) is communicably coupled with the crawl control module 108 for adjusting the crawl reference speed of the host vehicle 104 by changing the crawl reference speed in response to a throttle torque that is monitored by the crawl control module 108. Further, the traction motor 112 changes the crawl reference speed in response to the throttle torque.
[0048] Fig. 7 depicts a graph 700 illustrating the gradient detection, according to another exemplary embodiment of the present invention. The gradient detection is tested by taking the vehicle 104 (refer fig.1) on a slope and stopping. Plot 702 shows the logged speed with respect to the time. Plot 706 shows the pitch or the gradient over time. Plot 710 shows the crawl control module 108 (refer fig.1) status over time. When the vehicle 104 is moving on flat ground (as shown by 714), the speed varies according to the vehicle's 104 current speed, and the crawl control module 108 is in the deactivated state because the gradient is not detected due to the low pitch value (almost close to zero). When the pitch estimated by the vehicle 104 was found to be greater than the actual measured gradient of the slope, as shown in plot 708, then the crawl control module 108 is activated as shown in plot 712 and the speed of the vehicle 104 is maintained. When the vehicle 104 is on the slope and stopped (as shown by 716), then it is found that the crawl control module 108 is still in the activated state as shown in plot 712 because the vehicle 104 is on the gradient for a long duration (as shown in plot 708) while the speed is zero (as shown in plot 704). When the vehicle 104 is stopped on flat ground (as shown by 718), then it is found that the pitch is zero and the speed is zero hence the crawl control module 108 is also in the deactivated state.
[0049] Fig. 8 depicts a graph 800 illustrating a crawl control status by taking the host vehicle 104 (refer fig.1) on the up-gradient and down-gradient, according to another exemplary embodiment of the present invention. Plot 802 shows the throttle 114 (refer fig.1) with respect to the time. Plot 804 shows the pitch or the gradient over time. Plot 806 shows the crawl control module 108 (refer fig.1) status over time. Plot 810 shows the throttle torque over time. 812 shows the plot generated in the plot 802, 804, 806, 808, and 810 when the vehicle 104 is moving on the up gradient. 814 shows the plot generated in the plot 802, 804, 806, 808, and 810 when the vehicle 104 is moving on the down gradient. It is found that the speed controller 110 (refer fig.1) maintains the crawl reference speed on the upgradient 812 (pitch positive) by applying motoring torque even when the throttle 114 is zero while the crawl control module 108 is activated. The same is observed on the downgradient 814 (pitch negative). The speed controller 110 maintains the crawl reference speed by applying regenerative braking (negative torque).
[0050] Moreover, although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
, Claims:I/We Claim:
1. A crawl control system, comprising:
an IMU (Inertial Measurement Unit) (102) configured in a host vehicle (104) for generating an input signal indicative of a gradient detection, wherein the IMU (102) and a motor encoder (106) configured for estimating the gradient by estimating an orientation of the host vehicle (104);
a crawl control module (108) configured with the IMU (102) to automatically activate when the detected gradient is greater than a threshold pitch value;
a speed controller (110) configured with the crawl control module to determine a crawl reference speed indicative of the host vehicle (104) speed before activation of the crawl control module (108), wherein the speed controller (110) applies motoring and regenerative braking to a traction motor (112) in order to maintain the crawl reference speed; and
a throttle (114) communicably coupled with the crawl control module (108) for adjusting the crawl reference speed, wherein the traction motor (110) changes the crawl reference speed in response to a throttle torque that is monitored by the crawl control module (108).
2. The crawl control system (100) as claimed in claim 1, wherein the IMU (102) includes a gyroscope (204) and an accelerometer (202) to include data about the movement of the host vehicle.
3. The crawl control system (100) as claimed in claim 1, wherein the system (100) may use different logic for activating and deactivating the crawl control module (108) that is anyone of a time logic and a distance logic.
4. The crawl control system (100) as claimed in claim 3, wherein the time logic compares an estimated pitch with a threshold pitch, wherein if the estimated pitch is greater than the threshold pitch for a specific time slot then the time logic activates the crawl control module (108) and if the estimated pitch is lower than the threshold pitch for the specific time slot then the time logic deactivates the crawl control module (108).
5. The crawl control system (100) as claimed in claim 3, wherein the distance logic compares the estimated pitch with the threshold pitch, wherein if the estimated pitch is greater than the threshold pitch for a specific distance then the distance logic activates the crawl control module (108) and if the estimated pitch is lower than the threshold pitch for the specific distance then the distance logic deactivates the crawl control module (108).
6. The crawl control system (100) as claimed in claim 1, wherein the crawl control module (108) is either activated automatically by the gradient detection or manually by using an input module for activating the crawl control module (108) that includes a user interface that is anyone of a smartphone, a laptop, a dashboard or a button placed on the vehicle, among others.
7. The crawl control system (100) as claimed in claim 1, wherein the gradient includes an up-gradient and a down-gradient.
8. The crawl control system (100) as claimed in claim 1, wherein the crawl control module (108) compares the crawl reference speed with the host vehicle's (104) current speed in order to determine the difference between them and based on that, the crawl control module (108) requests a crawl torque so that the motor (112) increases the speed up or down to maintain the crawl reference speed.
9. The crawl control system (100) as claimed in claims 1,7, wherein the throttle torque is anyone of a positive torque or a negative torque, wherein when the vehicle (104) is moving on the up-gradient it requires the positive torque using motoring to increase the host vehicle (104) speed, and when the vehicle (104) is moving on the down-gradient it requires the negative torque using regenerative braking to decrease the host vehicle (104) speed.
10. The crawl control system (100) as claimed in claim 1, wherein the crawl reference speed is constant when the crawl control module (108) is in an enable state and the crawl reference speed is modified to the current vehicle (104) speed when the crawl control module (108) is in a reset state.
11. The crawl control system (100) as claimed in claim 1, wherein when the crawl control module (108) is active, and the throttle torque is positive and greater than the crawl torque then the throttle torque overrides the crawl torque to increase the crawl reference speed and similarly if the throttle torque is negative and lower than the crawl torque then the throttle torque overrides the crawl torque to decrease the crawl reference speed.
12. The crawl control system (100) as claimed in claims 1,7, wherein the system (100) may use different brakes such as an ABS (Antilock Braking System) for decreasing the crawl reference speed while the host vehicle (104) is moving on the down-gradient.
13. A method for crawl control, comprising:
generating, by an IMU (Inertial Measurement Unit) (102) configured in a host vehicle (104), an input signal indicative of a gradient detection, wherein the IMU (102) and a motor encoder (106) configured for estimating the gradient by estimating an orientation of the host vehicle (104);
activating, by the IMU (102), a crawl control module (108) automatically when the detected gradient is greater than a threshold pitch value;
determining, by a speed controller (110) configured with the crawl control module (108), a crawl reference speed indicative of the host vehicle (104) speed before activation of the crawl control module (108), wherein the speed controller (110) applies motoring and regenerative braking to a traction motor (112) in order to maintain the crawl reference speed; and
adjusting, by a throttle (114) communicably coupled with the crawl control module (108), the crawl reference speed, wherein the traction motor (112) changes the crawl reference speed in response to a throttle torque that is monitored by the crawl control module (108).
14. The crawl control method (600) as claimed in claim 13, wherein the IMU (102) includes a gyroscope (204) and an accelerometer (202) to include data about the movement of the host vehicle (104).
15. The crawl control method (600) as claimed in claim 13, wherein the method (600) may use different logic for activating and deactivating the crawl control module (108) that is anyone of a time logic and a distance logic.
16. The crawl control method (600) as claimed in claim 15, wherein the time logic compares an estimated pitch with a threshold pitch, wherein if the estimated pitch is greater than the threshold pitch for a specific time slot then the time logic activates the crawl control module (108) and if the estimated pitch is lower than the threshold pitch for the specific time slot then the time logic deactivates the crawl control module (108).
17. The crawl control method (600) as claimed in claim 15, wherein the distance logic compares the estimated pitch with the threshold pitch, wherein if the estimated pitch is greater than the threshold pitch for a specific distance then the distance logic activates the crawl control module (108) and if the estimated pitch is lower than the threshold pitch for the specific distance then the distance logic deactivates the crawl control module (108).
18. The crawl control method (600) as claimed in claim 13, wherein the crawl control module (108) is either activated automatically by the gradient detection or manually by using an input module for activating the crawl control module (108) that includes a user interface that is anyone of a smartphone, a laptop, a dashboard or a button placed on the vehicle, among others.
19. The crawl control method (600) as claimed in claim 13, wherein the gradient includes an up-gradient and a down-gradient.
20. The crawl control method (600) as claimed in claim 13, wherein the crawl control module (108) compares the crawl reference speed with the host vehicle's (104) current speed in order to determine the difference between them and based on that, the crawl control module (108) requests a crawl torque so that the motor (112) increases the speed up or down to maintain the crawl reference speed.
21. The crawl control method (600) as claimed in claims 13,19, wherein the throttle torque is anyone of a positive torque or a negative torque, wherein when the vehicle (104) is moving on the up-gradient it requires the positive torque using motoring to increase the host vehicle (104) speed, and when the vehicle (104) is moving on the down-gradient it requires the negative torque using regenerative braking to decrease the host vehicle (104) speed.
22. The crawl control method (600) as claimed in claim 13, wherein the crawl reference speed is constant when the crawl control module (108) is in an enable state and the crawl reference speed is modified to the current speed of the vehicle (104) when the crawl control module (108) is in a reset state.
23. The crawl control method (600) as claimed in claim 13, wherein when the crawl control module (108) is active, and the throttle torque is positive and greater than the crawl torque then the throttle torque overrides the crawl torque to increase the crawl reference speed and similarly if the throttle torque is negative and lower than the crawl torque then the throttle torque overrides the crawl torque to decrease the crawl reference speed.
24. The crawl control method (600) as claimed in claims 13,19, wherein the method (600) may use different brakes such as an ABS (Antilock Braking System) for decreasing the crawl reference speed while the host vehicle (104) is moving on the down-gradient.