VEHICLE TRAVEL TRACK CONTROL DEVICE

• US 20140257640A1
• Filed: 11/08/2011
• Published: 09/11/2014
• Est. Priority Date: 11/08/2011
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kojo, Takahiro, Kunihiro, Yoji, Takashima, Toru, Mitsumoto, Hisanori
• Granted Patent: US 9,168,953 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2420/42 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: B60W 2710/207 Steering angle of wheels
• CPC Class Codes: B60W 30/10 Path keeping cruise control for automatically following a preceding vehicle B60W30/165
• CPC Class Codes: B60W 30/12 Lane keeping
• CPC Class Codes: B60W 40/101 Side slip angle of tyre
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence

Abstract

A vehicle travel track control device which includes a forward image capture device which captures an image ahead of a vehicle, and side image capture devices which capture an image on the left side and/or the right side of the vehicle. When it is possible to properly execute a travel track control on the basis of captured forward image information ahead of the vehicle, the travel track control is executed on the basis of the captured forward image information sent from the forward image capture device, and when it is not possible to properly execute a travel track control on the basis of the captured forward image information, the travel track control is executed on the basis of at least captured side image information sent from the side image capture devices.

Claims

1-18. -18. (canceled)

19. :

A vehicle travel track control device comprising an image capture means which captures image around a vehicle and can vary at least one of capturing direction and capturing range, and a calculation/control unit which calculates a target steered angle of steered wheels on the basis of the captured image information sent from said image capture means and controls steered angle of steered wheels on the basis of said target steered angle to control the vehicle to travel along a lane, wherein

in a situation where a target steered angle of steered wheels cannot properly be calculated on the basis of the captured forward image information ahead of the vehicle, said calculation/control unit makes said image capture means capture side image on a side of the vehicle, estimates lateral differences of the vehicle relative to the lane at front and rear reference positions spaced apart from each other longitudinally of the vehicle on the basis of the captured side image information, estimates yaw angle of the vehicle relative to the lane on the basis of the lateral differences of the vehicle relative to the lane at the front and rear reference positions, calculates a target lateral difference of the vehicle relative to the lane on the basis of the lateral differences of the vehicle and the yaw angle of the vehicle, and calculates a target steered angle of the steered wheels on the basis of at least the lateral differences of the vehicle and the target lateral difference of the vehicle.

20. :

A vehicle travel track control device according to claim 19, wherein said calculation/control unit estimates curvature radius of the lane on the basis of the captured side image information, calculates a target yaw angle of the vehicle relative to the lane on the basis of the curvature radius of the lane, and calculates a target steered angle of the steered wheels on the basis of a difference between the lateral difference of the vehicle and the target lateral difference of the vehicle, a difference between yaw angle of the vehicle and the target yaw angle of the vehicle, and the curvature radius of the lane.

21. :

A vehicle travel track control device according to claim 19, wherein said calculation/control unit estimates yaw angles of the vehicle with respect to three time points on the basis of vehicle travel motion, estimates positions of the vehicle in rectangular coordinates with respect to the three time points on the basis of the yaw angles of the vehicle and vehicle travel motion, estimates lateral differences of the vehicle relative to the lane at a reference position of the vehicle with respect to the three time points on the basis of the captured side image information, estimates curvature radius of the lane on the basis of the lateral difference of the vehicle relative to the lane, the yaw angle of the vehicle and the position of the vehicle at the third time point, calculates a target yaw angle of the vehicle on the basis of the curvature radius of the lane, and calculates a target steered angle of the steered wheels on the basis of a difference between the lateral difference of the vehicle and the target lateral difference of the vehicle at the third time, a difference between the yaw angle of the vehicle and the target yaw angle of the vehicle at the third time point, and the curvature radius of the lane.

22. :

A vehicle travel track control device according to claim 19, wherein said calculation/control unit estimates lateral difference of the vehicle relative to the lane at a reference position of the vehicle on the basis of the captured side image information, calculates a target lateral difference of the vehicle relative to the lane on the basis of at least one of the lateral difference of the vehicle and width information of the lane, and calculates a target steered angle of the steered wheels on the basis of the lateral difference of the vehicle and the target lateral difference of the vehicle.

23. :

A vehicle travel track control device according to claim 22, wherein said side image capture device includes a left side image capture device which captures left side image on the left side of the vehicle and a right side image capture device which captures right side image on the right side of the vehicle; and

said calculation/control unit estimates lateral differences of the vehicle relative to edges of the lane on the left and right sides of the vehicle on the basis of the captured left and right side image information, and calculates a target lateral difference of the vehicle relative to the lane on the basis of lateral differences of the vehicle relative to edges of the lane on the left and right sides of the vehicle.

24. :

A vehicle travel track control device according to claim 19, wherein said calculation/control unit estimates lateral differences of the vehicle relative to the lane at front and rear reference positions spaced apart from each other longitudinally of the vehicle on the basis of the captured side image information, estimates yaw angle of the vehicle relative to the lane on the basis of the lateral differences of the vehicle relative to the lane at the front and rear reference positions, calculates curvature radius of the lane on the basis of the lateral differences of the vehicle, calculates a target yaw angle of the vehicle on the basis of the curvature radius of the lane, and, with a target lateral difference of the vehicle being one of a value variably set based on width of the lane and a predetermined value, calculates a target steered angle of the steered wheels on the basis of a difference between the lateral difference of the vehicle and the target lateral difference of the vehicle and a difference between the yaw angle of the vehicle and the target yaw angle of the vehicle.

25. :

A vehicle travel track control device according to claim 19, wherein said image capture means includes a forward image capture device which captures forward image ahead of the vehicle and a side image capture device which captures side image on at least one of the left and right sides of the vehicle; and

said calculation/control unit calculates a target steered angle of the steered wheels on the basis of the captured forward image information from said forward image capture device in a situation where a target steered angle of the steered wheels can properly be calculated on the basis of the captured forward image information ahead of the vehicle and calculates a target steered angle of the steered wheels on the basis of at least the captured side image information from said side image capture device in a situation where a target steered angle of the steered wheels cannot properly be calculated on the basis of the captured forward image information ahead of the vehicle.

26. :

A vehicle travel track control device according to claim 19, wherein said calculation/control unit calculates a target steered angle of the steered wheels on the basis of the captured forward image information sent from said forward image capture device in a situation where curvature radius of vehicle travel track is larger than a reference value, and calculates a target steered angle of the steered wheels on the basis of the captured side image information sent from said side image capture device in a situation where curvature radius of vehicle travel track is not larger than said reference value.

27. :

A vehicle travel track control device according to claim 19, wherein said calculation/control unit gradually changes a target steered angle of steered wheels when vehicle travel track control is interchanged between the mode where a target steered angle of the steered wheels is calculated on the basis of the captured forward image information and the mode where a target steered angle of the steered wheels is calculated on the basis of at least the captured side image information.

28. :

A vehicle travel track control device according to claim 26, wherein in a situation where curvature radius of vehicle travel track is not larger than said reference value, said calculation/control unit calculates a first target steered angle of the steered wheels on the basis of the captured forward image information sent from said forward image capture device and calculates a second target steered angle of the steered wheels on the basis of the captured side image information sent from said side image capture device, estimates forward observing distance of a driver on the basis of vehicle speed and the curvature radius of vehicle travel track, variably sets contribution degree of the second target steered angle so that the degree becomes high when image-capturable distance of said forward image capture device is shorter relative to the forward observing distance as compared to a case where image-capturable distance of said forward image capture device is long relative to the forward observing distance, and calculates a target steered angle of the steered wheels on the basis of the first target steered angle, the second target steered angle and the contribution degree.

29. :

A vehicle travel track control device according to claim 19, wherein said calculation/control unit decreases vehicle speed to continue the control of vehicle travel track in either case where there is a risk for the vehicle to escape from the lane or the performance of said image capture means deteriorates in image capture accuracy.