Apparatus for estimating the coefficient of friction and method for estimating the coefficient of friction

Abstract

This makes it possible to estimate the coefficient of friction of the road surface with greater accuracy, even when there are differences in the tires of individual vehicles. [Solution] The system includes an environmental information acquisition unit 101 that acquires environmental information about the surrounding environment of the vehicle, a tire characteristic identification unit 104 that identifies tire characteristics based on the detection results of at least one of the motion sensors 12 and the tire sensor 13, a road surface characteristic identification unit 102 that identifies road surface characteristics around the vehicle based on the environmental information acquisition unit 101, a model storage unit 106 that holds a tire model for outputting the coefficient of friction between the road surface and the tire according to the combination of road surface characteristics and tire characteristics, and a friction coefficient estimation unit 108 that estimates the coefficient of friction around the vehicle using the road surface characteristics identified by the road surface characteristic identification unit 102, the tire model held in the model storage unit 106, and the tire characteristics identified by the tire characteristic identification unit 104.

Claims

1. A friction coefficient estimation device that can be used in vehicles, An environmental information acquisition unit (101) acquires surrounding environment information, which is information about the surrounding environment of the vehicle, A tire characteristic identification unit (104) identifies the tire characteristics, which are the characteristics of the tire, based on the detection results of at least one of the vehicle motion sensor (12) for detecting various states related to the behavior or operation correlated with the tire force of the vehicle and the tire sensor (13) for monitoring the tires of the vehicle. Based on the surrounding environmental information acquired by the aforementioned environmental information acquisition unit, a road surface characteristic identification unit (102) identifies the road surface characteristics, which are the characteristics of the road surface around the vehicle, A model holding unit (106) for holding a tire model for outputting the coefficient of friction between the road surface and the tire according to the combination of the road surface characteristics and the tire characteristics, A friction coefficient estimation device comprising a friction coefficient estimation unit (108) that estimates the friction coefficient around the vehicle using the road surface characteristics identified by the road surface characteristics identification unit, the tire model held in the model holding unit, and the tire characteristics identified by the tire characteristics identification unit.

2. A friction coefficient estimation device according to claim 1, A friction coefficient estimation device comprising a correction processing unit (107) that corrects the tire model held in the model holding unit using the tire characteristics identified in the tire characteristics identification unit.

3. A friction coefficient estimation device according to claim 2, The friction coefficient estimation unit is a friction coefficient estimation device that estimates the friction coefficient around the vehicle using the road surface characteristics identified by the road surface characteristics identification unit and the tire model corrected by the correction processing unit.

4. A friction coefficient estimation device according to claim 2, The correction processing unit is a friction coefficient estimation device that corrects the tire model held in the model holding unit according to the road surface characteristics identified in the road surface characteristics identification unit, based on the tire characteristics identified in the tire characteristics identification unit.

5. A friction coefficient estimation device according to claim 1, The tire characteristic identification unit identifies the tire characteristics based at least on the detection results of the vehicle motion sensor, The vehicle is equipped with a braking identification unit (109) that identifies the degree of braking effectiveness of the vehicle based on the detection results of the vehicle motion sensor. The braking specification unit is a friction coefficient estimation device that also utilizes the detection results of the vehicle motion sensor used to specify the tire characteristics in the tire characteristic specification unit to specify the degree of braking effectiveness.

6. A friction coefficient estimation device according to claim 5, The vehicle is equipped with a control modification unit (112) that changes the state of the vehicle's driving control, The control modification unit is a friction coefficient estimation device that modifies the state of the vehicle's driving control according to the friction coefficient estimated by the friction coefficient estimation unit and the degree of braking specified by the braking specification unit.

7. A friction coefficient estimation device according to claim 1, The tire characteristic identification unit identifies the tire characteristics based at least on the detection results of the vehicle motion sensor, The vehicle is equipped with a cornering identification unit (110) that identifies the degree of steering effectiveness of the vehicle based on the detection results of the vehicle motion sensor. The cornering specification unit is a friction coefficient estimation device that also utilizes the detection results of the vehicle motion sensor used to specify the tire characteristics in the tire characteristics specification unit to specify the degree of steering effectiveness.

8. A friction coefficient estimation device according to claim 7, The vehicle is equipped with a control modification unit (112) that changes the state of the vehicle's driving control, The control modification unit is a friction coefficient estimation device that modifies the state of the vehicle's driving control according to the friction coefficient estimated by the friction coefficient estimation unit and the degree of steering effectiveness specified by the cornering specification unit.

9. A friction coefficient estimation device according to claim 1, The tire characteristic identification unit identifies the tire characteristics based at least on the detection results of the vehicle motion sensor, The vehicle includes a tire abnormality determination unit (111) that determines abnormalities in the vehicle's tires based on the detection results of the vehicle motion sensor. The tire abnormality determination unit is a friction coefficient estimation device that also utilizes the detection results of the vehicle motion sensor used to determine the tire characteristics in the tire characteristic determination unit for determining abnormalities in the tire.

10. A friction coefficient estimation device according to claim 9, The vehicle is equipped with a display instruction unit (1131) that displays information to the user of the vehicle, The presentation instruction unit is a friction coefficient estimation device that presents information according to the friction coefficient estimated by the friction coefficient estimation unit and the result of the abnormality determination by the tire abnormality determination unit.

11. A friction coefficient estimation device according to claim 9, The vehicle is equipped with a control modification unit (112) that changes the state of the vehicle's driving control, The control modification unit is a friction coefficient estimation device that modifies the state of the vehicle's driving control according to the friction coefficient estimated by the friction coefficient estimation unit and the result of the abnormality determination by the tire abnormality determination unit.

12. A method for estimating the coefficient of friction that can be used in vehicles, Executed by at least one of a processor and a circuit, An environmental information acquisition step is to acquire surrounding environment information, which is information about the surrounding environment of the vehicle. A tire characteristic identification step, which identifies the tire characteristics, based on the detection results of at least one of a vehicle motion sensor (12) for detecting various states related to the behavior or operation correlated with the tire force of the vehicle and a tire sensor (13) for monitoring the tires of the vehicle, Based on the surrounding environmental information acquired in the aforementioned environmental information acquisition step, a road surface characteristics identification step is performed to identify the road surface characteristics, which are the characteristics of the road surface around the vehicle. A friction coefficient estimation method comprising: a friction coefficient estimation step, which estimates the friction coefficient around the vehicle using the road surface characteristics identified in the road surface characteristics identification step, the tire model held in a model holding unit (106) that holds a tire model for outputting a friction coefficient between the road surface and the tire according to a combination of the road surface characteristics and the tire characteristics, and the tire characteristics identified in the tire characteristics identification step.

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