DESC:FIELD OF THE INVENTION
[001] The present invention relates to a system for monitoring road surface condition and a method thereof.

BACKGROUND OF THE INVENTION
[002] Bumps and potholes on a road are often a concern for vehicle drivers, especially when the vehicle is moving at moderate to high speeds or in low visibility conditions as it is difficult to visually detect all potholes and bumps. While bumps are provided to slow down a vehicle, potholes are formed primarily due to poor road quality/conditions. It is important for the driver to spot bumps and potholes, as passing through bumps / speed breakers or potholes without slowing down can adversely damage a vehicle’s parts and cause great discomfort to the riders. Going over bumps or potholes without slowing down at the correct time/instant can also lead to accidents, which is undesirable.
[003] In the art, it is known that vehicles are often equipped with cameras that detect potholes and bumps / speed breakers and alert the driver. However, such systems require high speed image processing power. Further, in low visibility conditions, such cameras may be unable to detect all potholes and bumps. Vehicles are also equipped with navigation systems with map databases to provide various navigation functions including map display, route guidance, traffic information, etc. Navigation functions are thus limited to route and traffic information only.
[004] Thus, there is a need in the art for a system and method for monitoring road surface condition which addresses the aforementioned problems.

SUMMARY OF THE INVENTION
[005] In one aspect of the present invention, a system for monitoring road surface condition is disclosed. The system includes at-least one accelerometer to monitor acceleration of a vehicle along X, Y and Z axis; a location module to monitor location of the vehicle; and a control unit in communication with the accelerometer and the location module. The control unit is configured to: receive information of vehicle acceleration along X, Y and Z-axis; determine deviation of the vehicle acceleration along Z-axis by comparing the vehicle acceleration along Z- axis with a pre-determined value; classify any deviation from the pre-determined value as an unevenness in the road surface condition; determine location co-ordinates of the unevenness in road surface condition; and tag the unevenness in road surface condition to the location co-ordinates on a map database.
[006] In an embodiment, the control unit is configured to determine whether the deviation in acceleration is a positive deviation or a negative deviation and classify the road surface condition as a speed breaker in case of positive deviation in acceleration, and the control unit is configured to classify the road surface condition as a pothole in case of negative deviation in acceleration.
[007] In an embodiment, the positive deviation is determined when an initial positive Z-axis acceleration is followed by a negative Z-axis acceleration detected by the accelerometer and the negative deviation is determined when an initial negative Z-axis acceleration is followed by a positive Z-axis acceleration detected by the accelerometer.
[008] In an embodiment, the system further includes a roll and pitch sensor to monitor the roll and pitch of the vehicle; a vehicle speed sensor to monitor vehicle speed, and a tire pressure sensor to monitor tire pressure.
[009] In an embodiment, the control unit is configured to receive information from the roll and pitch sensor, the vehicle speed sensor and the tire pressure sensor and correlate the acceleration on X or Y axis of the vehicle, speed of the vehicle and tire pressure of the tire with the acceleration determined by the accelerometer to correct any offset in the acceleration thereby providing accurate detection of pothole or speed breaker.
[010] In an embodiment, the system further comprises a yaw rate sensor to monitor lateral movement of the vehicle.
[011] In an embodiment, the control unit receives information of lateral movement from the yaw rate sensor and classifies such lateral movement as an unevenness in the road surface condition.
[012] In an embodiment, the system further comprises of a wheel speed sensor for each vehicle to monitor change in wheel speed.
[013] In an embodiment, the control unit receives wheel speed of each wheel and determines any variation in wheel speed and classifies such variation as an unevenness in the road surface condition.
[014] In an embodiment, the system is installed on a primary vehicle enabling the primary vehicle to identify road surface condition such as potholes and bumps and communicate the road surface condition to a server and/or secondary vehicles in communication with the server.
[015] In another aspect of the present invention, a method for monitoring road surface condition is disclosed. The method includes the steps of: monitoring, by at least one accelerometer, acceleration of a vehicle along X, Y and Z axis; monitoring, by a location module, location of the vehicle; receiving, by a control unit, information of vehicle acceleration along X, Y and Z-axis; determining, deviation of the vehicle acceleration along Z-axis by comparing the vehicle acceleration along Z-axis with a pre-determined value; classifying, any deviation from the pre-determined value as an unevenness in the road surface condition; determining, location co-ordinates of the unevenness in road surface condition; and tagging, the unevenness in road surface condition to the location co-ordinates on a map database.
[016] In an embodiment, the method includes the steps of: determining, by the control unit, whether the deviation is a positive deviation or a negative deviation; classifying the road surface condition as a speed breaker in case of positive deviation in acceleration and classifying the road surface condition as a pothole in case of negative deviation in acceleration.
[017] In an embodiment, the method includes the steps of: determining, by the control unit, the positive deviation when an initial positive Z-axis acceleration is followed by a negative Z-axis acceleration detected by the sensor; and determining negative deviation when an initial negative Z-axis acceleration is followed by a positive Z-axis acceleration detected by the sensor.
[018] In an embodiment, the method includes the steps of: monitoring, by a roll and pitch sensor, roll and pitch of the vehicle; monitoring, by a vehicle speed sensor, vehicle speed of the vehicle; monitoring, by a tire pressure sensor, tire pressure of the vehicle; receiving, by the control unit, information from the roll and pitch sensor to determine acceleration on X or Y axis; receiving, by the control unit, information from the vehicle speed sensor to determine vehicle speed; receiving, by the control unit, information from the tire pressure sensor to determine tire pressure; and correlating, the acceleration on X or Y axis of the vehicle, speed of the vehicle and tire pressure of the tire with the acceleration determined by the accelerometer to correct any offset in the acceleration, thereby providing accurate detection of pothole or speed breaker.
[019] In an embodiment, the method includes the steps of: monitoring, by a yaw rate sensor, lateral movement of the vehicle.
[020] In an embodiment, the method includes the steps of: receiving, by the control unit, information of lateral movement from the yaw rate sensor and classifying such lateral movement as an unevenness in the road surface condition.
[021] In an embodiment, the method includes the steps of: monitoring, by a wheel speed sensor, change in wheel speed.
[022] In an embodiment, the method includes the steps of: receiving, by a control unit, wheel speed of each wheel; determining, any variation in wheel speed; and classifying, such variation as an unevenness in the road surface condition.
[023] In an embodiment, the method includes the steps of: identifying, by a primary vehicle, road surface condition such as potholes and bumps; communicating, the road surface condition to a server and/or secondary vehicles in communication with the server.

BRIEF DESCRIPTION OF THE DRAWINGS
[024] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a system for monitoring road surface condition in accordance with an embodiment of the invention.
Figure 2 illustrates a method for monitoring road surface condition in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION
[025] The present invention is directed towards monitoring surface conditions of a road travelled by a vehicle and communicating information of the monitored road condition to a server and/or other vehicles. The present invention is configured to identify road surface condition such as potholes and bumps / speed breakers.
[026] Figure 1 illustrates a system 100 for monitoring road surface condition. The system 100 is installed on a primary vehicle enabling the primary vehicle to identify uneven road surface condition such as potholes and bumps / speed breakers, associate the road surface condition with its geographic location and communicate the road surface condition to a server 150 and/or secondary vehicles in communication with the server 150. In an embodiment, the primary vehicle and the secondary vehicles are part of a fleet of vehicles. Accordingly, road surface condition monitored by one vehicle will be available to other vehicles of the fleet. The primary vehicle and the secondary vehicle can be passenger vehicles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, etc.
[027] In an embodiment, a plurality of sensors, and a telematics unit 110 are installed on the primary vehicle. As shown, the telematics unit 110 is connected with various sensors such as an accelerometer 40, a roll and pitch sensor 20, a yaw rate sensor 30, a tire pressure sensor, a vehicle speed sensor 60, a wheel speed sensor 50, and a location module 140. The telematics unit 110 includes a control unit 130 in communication with the plurality of sensors and the location module 140, and a communication module 120 enables the telematics unit 110 to establish a communication link with the server 150. The server 150 as shown further establishes a communication link with the secondary vehicle. The communication link in the system 100 can be established over a radio frequency network, a cellular network, an internet network or the like.
[028] The accelerometer 40 is configured to monitor acceleration of the vehicle along X, Y and Z axis and is further configured to send a determined value to the control unit 130. In an embodiment, the accelerometer 40 is configured to provide vehicle acceleration in Z-axis of vehicle movement. The vehicle acceleration recorded by the accelerometer 40 is checked for deviations in acceleration due to gravity. In normal running state at constant speed and no steering movement, the acceleration of the vehicle along X and Y axis is zero, while on Z- axis the acceleration is a constant - For example: 1 g (9.81 m/s2). The detection is based on change in the value of g rather than a fixed value of acceleration. If there is positive Z-axis acceleration, value will be above 1 g, while if there is negative Z-axis acceleration, the value will be less than 1 g. Change or deviation in value of Z axis needs to be considered for the monitoring of the acceleration. The deviation is classified as a positive deviation in acceleration and a negative deviation in acceleration, wherein the positive deviation in acceleration corresponds to a speed breaker, while negative deviation in acceleration corresponds to a pothole. In an embodiment, the positive deviation in acceleration is determined when an initial positive Z-axis acceleration is followed by a negative Z-axis acceleration detected by the accelerometer 40, and the negative deviation in acceleration is determined when an initial negative Z-axis acceleration is followed by a positive Z-axis acceleration detected by the accelerometer 40.
[029] The roll and pitch sensor 20 is configured to monitor roll and pitch of the vehicle - distribution of acceleration values of the vehicle on X, Y and Z axis and is further configured to send information to the control unit 130. The control unit 130 is configured to determine distribution of acceleration values of the vehicle on X, Y and Z axis. As a vehicle passes through a speed breaker / pothole, and if less than four wheels have interference from the speed breaker / pothole, the acceleration values will get distributed on three axes, and the roll and pitch sensor 20 is configured to monitor the distribution of the acceleration values. As an example, when the vehicle crosses a pothole having sufficient width to receive two adjacent wheels either in front or rear, there would be no change of acceleration at least on the X axis. However, when a pothole has width that can receive only one wheel, the adjacent wheel stays on the road causing a change in acceleration along Z-axis as well as the X axis or Y axis. In this scenario where only one out of two wheels are in the pothole, there may not be a substantial deviation along the Z axis thereby not leading to identification of the pothole. The roll and pitch sensor 20 is configured to monitor X and Y axis acceleration which in combination with Z axis acceleration aids in detection of the pothole. Similarly, bumps can be detected. In case of a speed breaker, both adjacent wheels are disposed in the same manner due to which there is only deviation in the Z axis acceleration.
[030] The yaw rate sensor 30 is configured to monitor lateral movement of the vehicle/angular velocity of the vehicle and is further configured to send the information to the control unit 130. The control unit 130 is configured to determine the yaw rate of the vehicle. The yaw rate sensor 30 will thus detect any significant lateral movement of the vehicle and detects the possible avoidance of uneven road condition speed breaker / pothole by the driver. Thus, in cases where a speed breaker or pothole is avoided, the lateral movement captured by the yaw rate sensor 30 enables identification of speed breaker or pothole.
[031] The tire pressure sensor 10 is configured to monitor changes in tire pressure of the vehicle and is further configured to send the information to the control unit 130. The control unit 130 is configured to determine the tire pressure of the vehicle. In case high tire pressure is detected, a positive detection in acceleration is considered, and in case low tire low tire pressure is detected, a negative detection in acceleration is considered.
[032] The vehicle speed sensor 60 is configured to monitor a speed at which the vehicle is travelling at and is further configured to send the information to the control unit 130. The control unit 130 is configured to determine the vehicle speed.
[033] Alternately, acceleration of the vehicle along X, Y and Z axis, roll and pitch of the vehicle and yaw rate of the vehicle can be monitored by an Antilock Braking System ECU, or an Electronic Stability Control ECU connected with telematics unit 110 of the vehicle.
[034] The wheel speed sensor 50 monitors wheel speed values of at least one or more wheels of the vehicle. The said wheel speed values change momentarily during dynamic movement of the vehicle which occurs especially when the vehicle manoeuvres over or around potholes or speed breakers. The wheel speed sensor 50 is further configured to the information to the control unit 130. The control unit 130 is configured to determine the wheel speed based on the information received from the wheel speed sensor 50.
[035] Based on information provided by the aforementioned sensors/sensor data, pothole or bump / speed breaker in the road is detected by the control unit 130. The control unit 130 includes a microcontroller. The information from the sensors i.e., raw sensor data, is filtered to remove noise generated by the vehicle mechanical components. In an embodiment, vehicle acceleration in Z-axis monitored by the accelerometer 40 is recorded at frequent time intervals / instant. The vehicle acceleration recorded by the accelerometer 40 at each time interval / instant is checked for deviations in acceleration due to gravity and compare the vehicle acceleration along Z- axis with a pre-determined value. In case of any deviation beyond the pre-determined limit (For example: change or deviation of more than 1.2 g), a speed breaker or pothole is detected. In this regard, the deviation is classified as a positive deviation in acceleration and a negative deviation in acceleration, wherein the positive deviation in acceleration corresponds to a speed breaker, while negative deviation in acceleration is corresponds to a pothole. In an embodiment, the positive deviation in acceleration is determined when an initial positive Z-axis acceleration is followed by a negative Z-axis acceleration detected by the accelerometer 40, and the negative deviation in acceleration is determined when an initial negative Z-axis acceleration is followed by a positive Z-axis acceleration detected by the accelerometer 40.
[036] In an embodiment, the control unit 130 is configured to receive information from the roll and pitch sensor 20, the wheel speed sensor 50 and the tire pressure sensor 10 and by correlating the acceleration on X or Y axis of the vehicle, speed of the vehicle and tire pressure of the tire with the acceleration determined by the accelerometer 40, corrects any offset in the acceleration, thereby providing more accurate detection of uneven road condition such as pothole or speed breaker. As the potholes generally don’t cover the entire vehicle width, this leads to a single tire going down and other remains on the road surface. This is detected by roll and pitch change of the vehicle in that instance, on detection of roll and pitch, the X and Y-axis acceleration are also added on to the Z-axis acceleration calibrated as per the roll and pitch to determine the actual Z-axis acceleration. Tire pressure of the front and rear wheels leads to a variation in acceleration - high tire pressure leads to increased acceleration spike and low tire pressure leads to a decreased acceleration spike. Tire pressure of the front and rear wheels leads to a variation in acceleration - high tire pressure leads to increased acceleration spike and low tire pressure leads to a decreased acceleration spike. Accordingly, in case of high tire pressure there will be an increased deviation in acceleration detected by the accelerometer 40, and in case of low tire pressure there will be a decreased deviation in acceleration detected by the accelerometer 40. Based on the tire pressure, the acceleration detected by the accelerometer 40 is normalized, thereby providing more accurate detection. Further, vehicle speed-based calibration is based on at-least vehicle suspension behaviour and co-related with speed of the vehicle. In this regard, vehicle suspension changes its stiffness based on the change in vehicle speed, whereby increase in speed leads to reduced stiffness, thus a negative deviation in acceleration. Similarly, decrease in speed leads to an increase in stiffness, thus a positive deviation in acceleration. Accordingly, in case of high speed, there will be a decreased deviation in acceleration detected by the accelerometer 40, and in case of low speed there will be an increased deviation in acceleration detected by the accelerometer 40. Based on the vehicle, the acceleration detected by the accelerometer 40 is normalized, thereby providing more accurate detection.
[037] Further, the control unit 130 receives information of lateral movement from the yaw rate sensor 30 and classifies such lateral movement as an unevenness in the road surface condition. Furthermore, the control unit 130 receives wheel speed of each wheel and determines any variation in wheel speed and classifies such variation as an unevenness in the road surface condition.
[038] In an embodiment, the location module 140 determines location co-ordinates of the pothole or bump / speed breaker detected by the system 100 and such potholes or bumps / speed breaker are tagged to the location on a map database.
[039] Further, the communication module 120 enables the telematics unit 110 to communicate with the server 150, wherein the sensor data along with location co-ordinates are sent to the server 150. The server 150 includes a processing unit 170, a storage unit 180, and at-least one server communication module 160. Further, the server communication module 160 enables the secondary vehicles to establish a communication link with the server 150 to obtain information obtained by the primary vehicle i.e., information of the road surface condition.
[040] The storage unit 180 of the server 150 includes the map database. The processing unit 170 is configured to update road surface condition such as potholes and bumps / speed breaker on the map database.
[041] As shown, a location module 230, a telematics unit 200, a communication module 210 and an infotainment unit 250 are installed on the secondary vehicle. The secondary vehicle through the communication module 210 establishes a communication link with the server 150. The infotainment unit 250 is configured to receive a request for data on speed breakers and potholes. For example, the secondary vehicle can trigger a request to the server 150 via telematics unit 200 / infotainment unit 250 for map data on speed breakers and potholes. The request is processed and a data set comprising a map updated with the speed breaker / potholes is generated and sent to the secondary vehicle and displayed on the infotainment system. In an alternate embodiment, an electronic device like a mobile phone, a tablet etc., can be configured to receive a request for data on speed breakers and potholes. For example, the electronic device which is equipped with a communication module can trigger a request to the server 150 for data on speed breakers and potholes. The secondary vehicle or the electronic device is configured to show an alert to the driver on the infotainment unit 250.
[042] Figure 2 illustrates a method 300 for monitoring road surface condition. The method 300 at step 3A, includes monitoring by at least one accelerometer 40, acceleration of a vehicle along X, Y and Z axis. Thereafter, the method 300 at step 3B, includes monitoring, by a location module 140, location of the vehicle. Further, at step 3C, a control unit 130 receives information of vehicle acceleration along X, Y and Z-axis. Thereafter, the method 300 includes the step 3D of determining, deviation of the vehicle acceleration along Z-axis by comparing the vehicle acceleration along Z-axis with a pre-determined value. Further, the method 300 determines whether the deviation is a positive deviation or a negative deviation. In an embodiment, the positive deviation in acceleration is determined when an initial positive Z-axis acceleration is followed by a negative Z-axis acceleration detected by the accelerometer 40, and the negative deviation in acceleration is determined when an initial negative Z-axis acceleration is followed by a positive Z-axis acceleration detected by the accelerometer 40. Then, the step 3E includes classifying, any deviation from the pre-determined value as an unevenness in the road surface condition. In an embodiment, the road surface condition is classified as a speed breaker / bump in case of positive deviation in acceleration and the road surface condition is classified as a pothole in case of negative deviation in acceleration.
[043] Thereafter, at step 3F, the method 300 includes determining, location co-ordinates of the unevenness in road surface condition. Finally, at step 3G, the method 300 includes tagging, the unevenness in road surface condition to the location co-ordinates on a map database.
[044] In an embodiment, the method 300 includes the steps of monitoring, by a roll and pitch sensor 20, roll and pitch of the vehicle; monitoring, by a vehicle speed sensor 60, distribution of acceleration values of the vehicle on X, Y and Z axis; monitoring, by a tire pressure sensor 10, tire pressure of the vehicle; receiving, by the control unit 130, information from the roll and pitch sensor 20 to determine acceleration on X or Y axis; receiving, by the control unit 130, information from the vehicle speed sensor 60 to determine vehicle speed; receiving, by the control unit 130, information from the tire pressure sensor 10 to determine tire pressure; and correlating, the acceleration on X or Y axis of the vehicle, speed of the vehicle and tire pressure of the tire with the acceleration determined by the accelerometer 40 to correct any offset in the acceleration, thereby providing accurate detection of pothole or speed breaker.
[045] In an embodiment, the method 300 includes the steps of monitoring, by a yaw rate sensor 30, lateral movement of the vehicle.
[046] In an embodiment, the method 300 includes the steps of receiving, by the control unit 130, information of lateral movement from the yaw rate sensor 30 and classifying such lateral movement as an unevenness in the road surface condition.
[047] In an embodiment, the method 300 includes the steps of monitoring, by a wheel speed sensor 60, change in wheel speed.
[048] In an embodiment, the method 300 includes the steps of: receiving, by a control unit 130, wheel speed of each wheel. Thereafter, the method 300 includes the step of determining, any variation in wheel speed; and classifying, such variation as an unevenness in the road surface condition.
[049] In an embodiment, the method 300 includes the steps of identifying, by a primary vehicle, road surface condition such as potholes and bumps; and thereafter, communicating, the road surface condition to a server 150 and/or secondary vehicles in communication with the server 150.
[050] By way of an example, detection of a speed breaker / bump by the system 100 of the present invention is now discussed. When a vehicle approaches a speed breaker, the first point of contact are front wheels of the vehicle. As the vehicle moves forward, the front wheels climb on the speed breaker generating a positive Z-axis acceleration. The wheels move forward reach the top-most point of the speed breaker and then starts descending, which generates a negative Z-axis acceleration. Similar movement is observed in the rear wheels. The method 300 determines if there is deviation in Z-axis acceleration of the vehicle by comparing the vehicle acceleration along Z- axis with a pre-determined value. For example, for a specific vehicle a standard deviation of more than 1.2g is detected for a speed breaker, with the initial Z-axis acceleration being positive. The deviation is thus determined as a positive deviation and road surface is classified as a speed breaker. The data from the accelerometer 40 is collected from this instance/time frame and modified based on tire pressure of front and rear wheels and vehicle speed-based calibration. Tire pressure of the front and rear wheels leads to a variation in acceleration - high tire pressure leads to increased acceleration spike and low tire pressure leads to a decreased acceleration spike. Accordingly, in case of high tire pressure there will be a positive deviation in acceleration detected by the accelerometer 40, and in case of low tire pressure there will be a negative deviation in acceleration detected by the accelerometer 40. Based on the tire pressure, the acceleration detected by the accelerometer 40 is normalized, thereby providing more accurate detection. Vehicle speed-based calibration is based on at-least vehicle suspension behaviour and co-related with speed of the vehicle. In this regard, vehicle suspension changes its stiffness based on the change in vehicle speed, whereby increase in speed leads to reduced stiffness, thus a negative deviation in acceleration. Similarly, decrease in speed leads to an increase in stiffness, thus a positive deviation in acceleration. Accordingly, in case of high speed there will be a negative deviation in acceleration detected by the accelerometer 40, and in case of low speed there will be a positive deviation in acceleration detected by the accelerometer 40. Based on the vehicle, the acceleration detected by the accelerometer 40 is normalized, thereby providing more accurate detection. It will be appreciated that deviation in acceleration due to speed and tire pressure will vary upon type of vehicle, and hence ranges in this regard will be dependent on the type of vehicle.
[051] Further, the accuracy of the detection is improved based on data obtained by yaw rate sensor 30 and wheel speed sensor 50. As mentioned hereinabove, yaw rate sensor 30 monitors the sideways movement of the vehicle, which determines if the vehicle has been moved to avoid a speed breaker. Further, as the vehicle moves over a speed breaker, the wheel speed of the different wheels changes with respect to each other for the momentary time frame, this change in speed is determined to ascertain if the speed breaker detection was accurate or not.
[052] By way of example, detection of a pothole by the system 100 of the present invention is now discussed. When the vehicle approaches a pothole, the first point of contact are front wheels of the vehicle. As the vehicle moves forward, the front wheels move downwards on the pothole generating a negative Z-axis acceleration. The wheels move forward reaching the bottom-most point of the pothole and then starts ascending, which generates a positive Z-axis acceleration. Similar movement is observed in the rear wheels. The method 300 determines if there is deviation in Z-axis acceleration of the vehicle by comparing the vehicle acceleration along Z- axis with a pre-determined value. For example, for a specific vehicle a standard deviation of more than 1.2g is detected only for a pothole, with the initial Z-axis acceleration being negative. The deviation is thus determined as a negative deviation and road surface is classified as a pothole.
[053] The data from the accelerometer 40 is collected from this instance/time frame. The data is then modified based on roll and pitch of the vehicle; tire pressure of the wheels and vehicle speed-based calibration. As the potholes generally don’t cover the entire vehicle width, this leads to single tire going down and other remains on the road surface. This is detected by roll and pitch change of the vehicle in that instance, on detection of roll and pitch, the X and Y-axis acceleration are also added on to the Z-axis acceleration calibrated as per the roll and pitch to determine the actual Z-axis acceleration. Tire pressure of the front and rear wheels leads to a variation in acceleration - high tire pressure leads to increased acceleration spike and low tire pressure leads to a decreased acceleration spike. Accordingly, in case of high tire pressure there will be a positive deviation in acceleration detected by the accelerometer 40, and in case of low tire pressure there will be a negative deviation in acceleration detected by the accelerometer 40. Based on the tire pressure, the acceleration detected by the accelerometer 40 is normalized, thereby providing more accurate detection. Vehicle speed-based calibration is based on at-least vehicle suspension behaviour and co-related with speed of the vehicle. In this regard, vehicle suspension changes its stiffness based on the change in vehicle speed, whereby increase in speed leads to reduced stiffness, thus a negative deviation in acceleration. Similarly, decrease in speed leads to an increase in stiffness, thus a positive deviation in acceleration. Accordingly, in case of high speed there will be a negative deviation in acceleration detected by accelerometer 40, and in case of low speed there will be a positive deviation in acceleration detected by the accelerometer 40. Based on the vehicle, the acceleration detected by the accelerometer 40 is normalized, thereby providing more accurate detection.
[054] Further, the accuracy of the detection is improved based on data obtained by the yaw rate sensor 30 and the wheel speed sensor 50. As mentioned hereinabove, the yaw rate sensor 30 monitors sideways movement of the vehicle, which determines if the vehicle has been moved to avoid a pothole. Further, as the vehicle moves over a pothole, the wheel speed of the different wheels changes with respect to each other for the momentary time frame, this change in speed is determined to ascertain if the pothole detection was accurate or not. It may be noted that the change in wheel speed for pothole is far more significant than speed breaker, as amount of time a wheel is in air due to lateral movement is far higher than a speed breaker, which makes the accuracy detection of the pothole more accurate w.r.t wheel speed.
[055] Advantageously, the present invention provides a system for monitoring road surface condition wherein, all potholes and bumps are detected by a vehicle travelling on a road. Further, location co-ordinates are saved on a server which would alert other vehicles regarding presence of potholes and bumps on the road.
[056] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

,CLAIMS:WE CLAIM:
1. A system (100) for monitoring road surface condition, the system (100) comprising:
at-least one accelerometer (40) to monitor acceleration of a vehicle along X, Y and Z axis;
a location module (140) to monitor location of the vehicle;
a control unit (130) in communication with the accelerometer (40) and the location module (140), the control unit (130) configured to:
receive information of vehicle acceleration along X, Y and Z-axis;
determine deviation of the vehicle acceleration along Z-axis by comparing the vehicle acceleration along Z- axis with a pre-determined value;
classify any deviation from the pre-determined value as an unevenness in the road surface condition;
determine location co-ordinates of the unevenness in road surface condition; and
tag the unevenness in road surface condition to the location co-ordinates on a map database.

2. The system (100) as claimed in claim 1, wherein the control unit (130) is configured to determine whether the deviation in acceleration is a positive deviation or a negative deviation, the positive deviation is determined when an initial positive Z-axis acceleration is followed by a negative Z-axis acceleration detected by the accelerometer (40) and the negative deviation is determined when an initial negative Z-axis acceleration is followed by a positive Z-axis acceleration detected by the accelerometer (40); and
classify the road surface condition as a speed breaker in case of positive deviation in acceleration, and the control unit (130) is configured to classify the road surface condition as a pothole in case of negative deviation in acceleration.

3. The system (100) as claimed in claim 1 further comprising a roll and pitch sensor (20) to monitor distribution of acceleration values of the vehicle on X, Y and Z axis; a vehicle speed sensor (60) to monitor vehicle speed, and a tire pressure sensor (10) to monitor tire pressure, wherein the control unit (130) is configured to receive information from the roll and pitch sensor (20) to determine acceleration on X or Y axis, receive information from the vehicle speed sensor (60) to determine vehicle speed and receive information from the tire pressure sensor (10) to determine tire pressure; and correlate the acceleration on X or Y axis of the vehicle, speed of the vehicle and tire pressure of the tire with the acceleration determined by the accelerometer to correct any offset in the acceleration, thereby providing accurate detection of pothole or speed breaker.

4. The system (100) as claimed in claim 1 further comprising a yaw rate sensor (30) to monitor lateral movement of the vehicle, wherein the control unit (130) receives information of lateral movement from the yaw rate sensor (30) and classify such lateral movement as an unevenness in the road surface condition.

5. The system (100) as claimed in claim 1 further comprising of a wheel speed sensor (50) for each wheel to monitor change in wheel speed, wherein the control unit (130) receives wheel speed of each wheel and determines any variation in wheel speed and classify such variation as an unevenness in the road surface condition.

6. The system (100) as claimed in claim 1, wherein the system (100) is installed on a primary vehicle enabling the primary vehicle to identify road surface condition such as potholes and bumps and communicate the road surface condition to a server (150) and/or secondary vehicles in communication with the server (150).

7. A method (300) for monitoring road surface condition, the method (300) comprising the steps of:
monitoring (3A), by at least one accelerometer (40), acceleration of a vehicle along X, Y and Z axis;
monitoring (3B), by a location module (140), location of the vehicle;
receiving (3C), by a control unit (130), information of vehicle acceleration along X, Y and Z-axis;
determining (3D), deviation of the vehicle acceleration along Z-axis by comparing the vehicle acceleration along Z-axis with a pre-determined value;
classifying (3E), any deviation from the pre-determined value as an unevenness in the road surface condition;
determining (3F), location co-ordinates of the unevenness in road surface condition; and
tagging (3G), the unevenness in road surface condition to the location co-ordinates on a map database.

8. The method (300) as claimed in claim 7 comprising the steps of: determining, by the control unit (130), whether the deviation is a positive deviation or a negative deviation, the positive deviation is determined when an initial positive Z-axis acceleration is followed by a negative Z-axis acceleration detected by the accelerometer (40) and the negative deviation is determined when an initial negative Z-axis acceleration is followed by a positive Z-axis acceleration detected by the accelerometer (40) ;
classifying the road surface condition as a speed breaker in case of positive deviation in acceleration and
classifying the road surface condition as a pothole in case of negative deviation in acceleration.

9. The method (300) as claimed in claim 7 comprising the steps of:
monitoring, by a roll and pitch sensor (20), distribution of acceleration values of the vehicle on X, Y and Z axis;
monitoring, by a vehicle speed sensor (60), vehicle speed of the vehicle;
monitoring, by a tire pressure sensor (10), tire pressure of the vehicle;
receiving, by the control unit (130), information from the roll and pitch sensor (20) to determine acceleration on X or Y axis;
receiving, by the control unit (130), information from the vehicle speed sensor (60) to determine vehicle speed;
receiving, by the control unit (130), information from the tire pressure sensor (10) to determine tire pressure; and
correlating, the acceleration on X or Y axis of the vehicle, speed of the vehicle and tire pressure of the tire with the acceleration determined by the accelerometer (40) to correct any offset in the acceleration, thereby providing accurate detection of pothole or speed breaker.

10. The method (300) as claimed in claim 7 comprising the steps of:
monitoring, by a yaw rate sensor (30), lateral movement of the vehicle; receiving, by the control unit (130), information of lateral movement from the yaw rate sensor (30); and
classifying such lateral movement as an unevenness in the road surface condition.

11. The method (300) as claimed in claim 7 comprising the steps of:
monitoring, by a wheel speed sensor (60), change in wheel speed; receiving, by a control unit (130), wheel speed of each wheel;
determining, any variation in wheel speed; and
classifying, such variation as an unevenness in the road surface condition.

12. The method (300) as claimed in claim 7 comprising the steps of:
identifying, by a primary vehicle, road surface condition such as potholes and bumps;
communicating, the road surface condition to a server (150) and/or secondary vehicles in communication with the server (150).