Vehicle control device

Abstract

To suppress damage of a turning wheel and power consumption, when turning the turning wheel in order to identify a neutral position of the turning wheel.SOLUTION: An estimating part 20 estimates a grounding load on a turning wheel 12B. For instance, the estimating part 20 estimates the grounding load on the turning wheel 12B on the basis of a stroke amount of a suspension provided in the turning wheel 12B. A changing part 22 controls an electric-type shock absorber of the turning wheel 12B so that the turning wheel 12B is moved to an upper side of a vehicle 26. This can prevent the turning wheel 12B from contacting a road surface 28, so that the grounding load on the turning wheel 12B can be reduced. This can suppress damage of the turning wheel 12B and power consumption by a turning mechanism, even when turning the turning wheel 12B.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a technique for learning the neutral position of steered wheels mounted on a vehicle. [Background technology]

[0002] Patent Document 1 describes an electric power steering device that detects the neutral position (straight-ahead position) of the steering wheels. Specifically, to detect the neutral position, a rack shaft used in the steering system is driven in the left and right directions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-230275 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, to learn the neutral position of the steered wheels, the steered wheels are turned by rotating the steering wheel from one end to the other (performing a lock-to-lock operation). If the steered wheels are turned when the road load of the steered wheels is large, friction between the steered wheels and the road surface can increase damage to the steered wheels and power consumption of the steering mechanism can also increase.

[0005] An object of the present disclosure is to suppress damage to the steered wheels and power consumption of the steering mechanism when the steered wheels are steered to learn the neutral position of the steered wheels. [Means for solving the problem]

[0006] One aspect of the present disclosure is a vehicle control device characterized by having a steering device that steers steered wheels, an estimation unit that estimates the ground load of the steered wheels based on at least one of vehicle information that indicates the state of the vehicle and peripheral information that indicates information about the surroundings of the vehicle, a change unit that changes the position of the vehicle or the state of the vehicle so that the ground load of the steered wheels becomes smaller, and a learning unit that learns the neutral position of the steered wheels after the position of the vehicle or the state of the vehicle is changed.

[0007] According to the above configuration, when learning the neutral position of the steered wheels, the position or state of the vehicle is changed so that the ground load of the steered wheels is reduced. This makes it possible to reduce damage to the steered wheels compared to when the steered wheels are steered in a position or state where the ground load is greater. Also, it is possible to reduce power consumption of the steering mechanism that steers the steered wheels. [Effects of the Invention]

[0008] According to the present disclosure, when the steered wheels are steered to learn the neutral position of the steered wheels, damage to the steered wheels and power consumption of the steering mechanism can be suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a configuration of a vehicle control device according to an embodiment; [Figure 2] 1 is a diagram schematically illustrating a vehicle according to a first embodiment as viewed from the left side of the vehicle. [Figure 3] 1 is a diagram schematically illustrating a vehicle according to a first embodiment as viewed from the left side of the vehicle. [Figure 4] FIG. 10 is a diagram schematically illustrating a vehicle according to a second embodiment as viewed from the left side of the vehicle. [Figure 5] FIG. 10 is a diagram schematically illustrating a vehicle according to a second embodiment as viewed from the left side of the vehicle. [Figure 6] FIG. 10 is a diagram schematically illustrating a vehicle according to a third embodiment as viewed from the left side of the vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0010] A vehicle control device according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing a vehicle control device according to an embodiment.

[0011] A vehicle control device 10 according to the embodiment is a steering device mounted on a vehicle, and is a device for steering steered wheels 12 mounted on the vehicle. The vehicle control device 10 includes an operation device 14 and a steering device 16.

[0012] The operation device 14 includes a steering wheel and the like, and is a device used by the driver to perform steering operations. A known device is used as the operation device 14. The steering device 16 is a device that steers each of the steerable wheels 12. A known device is used as the steering device 16.

[0013] The vehicle control device 10 also includes a surrounding information acquisition unit 18, an estimation unit 20, a change unit 22, and a learning unit 24.

[0014] The surrounding information acquisition unit 18 includes a detection device (for example, a radar, a camera, various sensors) mounted on the vehicle, and acquires surrounding information indicating the surroundings of the vehicle. For example, the surrounding information acquisition unit 18 detects the state (for example, shape) of the road surface and objects on the road surface by irradiating the road surface with a laser or capturing an image of the road surface with a camera.

[0015] The estimation unit 20 estimates the ground contact load of the steered wheels 12 based on at least one of vehicle information indicating the state of the vehicle and peripheral information. The vehicle information includes stroke information indicating the stroke amount of a suspension mounted on the vehicle, and information obtained from an inertial measurement unit (IMU) (e.g., information indicating the position and attitude of the vehicle). The ground contact load is the vertical component of the force acting from the road surface to the steered wheels 12. For example, it is estimated that the force acting from the road surface to the steered wheels 12 when the suspension is compressed is greater than the force acting from the road surface to the steered wheels 12 when the suspension is extended. In other words, it can be estimated that the ground contact load when the suspension is compressed is greater than the ground contact load when the suspension is extended. For example, the estimation unit 20 estimates the ground contact load for each of the steered wheels 12.

[0016] The change unit 22 changes the position or state of the vehicle so that the ground load estimated by the estimation unit 20 becomes smaller. For example, the change unit 22 drives a motor or engine mounted on the vehicle to move the vehicle to a position where the ground load becomes smaller. As another example, the change unit 22 moves objects such as equipment mounted on the vehicle within the vehicle so that the ground load becomes smaller. As yet another example, the change unit 22 moves the steered wheels 12 upward on the vehicle so that the steered wheels 12 do not contact the road surface. Each steered wheel 12 is connected to the vehicle via a suspension unit. Each suspension unit includes a suspension and an electric shock absorber that can move the suspension up and down. The change unit 22 moves the steered wheels 12 upward on the vehicle by controlling the electric shock absorber to move the suspension up and down.

[0017] The learning unit 24 learns the neutral position of the steered wheels 12 after the vehicle position or vehicle state has been changed by the change unit 22. For example, after the vehicle position or vehicle state has been changed by the change unit 22, the steering wheel mounted on the vehicle is rotated from one end to the other end (lock-to-lock is performed), and the neutral position of the steered wheels 12 is identified. The learning unit 24 learns the identified neutral position. Artificial intelligence (AI) may be used for learning by the learning unit 24. For example, machine learning such as deep learning is used.

[0018] Hereinafter, the embodiment will be described with reference to Figures 2 to 6. Figures 2 to 6 are diagrams that schematically show the vehicle as viewed from the left side of the vehicle.

[0019] For example, the vehicle 26 is a six-wheel vehicle. That is, the vehicle 26 has a total of six steerable wheels 12, three on each side. Of course, this is just an example, and the number of steerable wheels 12 is not particularly limited in this disclosure. For example, the vehicle 26 may be a four-wheel vehicle.

[0020] 2 and 3, the first embodiment will be described. For ease of explanation, the steerable wheels 12 (front wheels) in the first row from the front of the vehicle 26 will be referred to as "steerable wheels 12A," the steerable wheels 12 in the second row will be referred to as "steerable wheels 12B," and the steerable wheels 12 (rear wheels) in the third row will be referred to as "steerable wheels 12C."

[0021] For example, suppose that lock-to-lock is performed with steerable wheel 12B as the target. Because steerable wheel 12B is in contact with the road surface, friction between steerable wheel 12B and road surface 28 will cause damage to steerable wheel 12B and increase power consumption of the steering mechanism. For example, if steerable wheel 12 is turned while steerable wheel 12 is in contact with a road surface with a high friction coefficient, such as a paved road, damage to steerable wheel 12 will increase and power consumption of the steering mechanism will also increase.

[0022] In this embodiment, the estimation unit 20 estimates the ground contact load of the steered wheels 12B. For example, the estimation unit 20 estimates the ground contact load of the steered wheels 12B based on the stroke amount of a suspension provided on the steered wheels 12B.

[0023] The change unit 22 changes the position or state of the vehicle 26 so as to reduce the ground contact load estimated by the estimation unit 20. For example, as shown in FIG. 3, the change unit 22 controls the electric shock absorbers of the steered wheels 12B to move the steered wheels 12B upward on the vehicle 26. In the example shown in FIG. 3, the change unit 22 moves the steered wheels 12B upward on the vehicle 26 to a position where the steered wheels 12B do not contact the road surface. In this way, the ground contact load of the steered wheels 12B becomes smaller than the ground contact load when the steered wheels 12B are in contact with the road surface 28. This makes it possible to suppress damage that could occur if a lock-to-lock transition were to be performed in this state, and also to suppress an increase in power consumption.

[0024] The estimation unit 20 may estimate the ground contact load of each steered wheel 12, and determine the steered wheel 12 for which the ground contact load may be small as the steered wheel 12 for executing lock-to-lock. In the example shown in FIGS. 2 and 3, a convex portion 30 is formed on a road surface 28, and the steered wheel 12A is placed on the convex portion 30 while in contact with the convex portion 30. Furthermore, the steered wheels 12B and 12C are placed on the road surface 28 while in contact with the road surface 28. As a result, the front side of the vehicle 26 is positioned higher than the rear side, and the entire vehicle 26 is tilted. In this state, by moving the steered wheel 12B upward on the vehicle 26, the steered wheel 12B is no longer in contact with the road surface 28, and the ground contact load of the steered wheel 12B is reduced. On the other hand, even if the steered wheels 12A, 12C are moved upward on the vehicle 26, the steered wheel 12A remains in contact with the convex portion 30, and the steered wheel 12C remains in contact with the road surface 28. Therefore, the ground contact loads of the steered wheels 12A, 12C do not decrease. In this case, the estimation unit 20 estimates that the steered wheel 12B, which may have a smaller ground contact load, is the target for executing lock-to-lock, and the change unit 22 moves the steered wheel 12B upward on the vehicle 26.

[0025] A second embodiment will be described with reference to Figures 4 and 5. For example, assume that a lock-to-lock transition is performed with the steered wheel 12C as the target. For example, as shown in Figure 4, a detection device 32 is provided on the roof or the like of a vehicle 26. The detection device 32 is an example of a surrounding information acquisition unit 18, and acquires surrounding information of the vehicle 26. For example, the detection device 32 detects the state of a road surface 28 around the vehicle 26 (for example, depressions 34 and protrusions formed on the road surface 28). The estimation unit 20 estimates an estimated load at each position based on the state of the road surface 28. The change unit 22 moves the vehicle 26 to a position where the estimated load is smaller.

[0026] For example, if the ground contact load at the position where recessed portion 34 is formed is smaller than the ground contact load at the current position of vehicle 26, as shown in Fig. 5, changing portion 22 moves vehicle 26 so that steered wheel 12C is positioned at the position of recessed portion 34. As a result, steered wheel 12C floats within recessed portion 34 and does not come into contact with road surface 28, and the ground contact load of steered wheel 12C becomes smaller. Alternatively, changing portion 22 may control an electric shock absorber of steered wheel 12C to move steered wheel 12C upward on vehicle 26 at the position of recessed portion 34. In this way, contact of steered wheel 12C with road surface 28 can be more reliably prevented.

[0027] A third embodiment will be described with reference to FIG. 6. An object 36 such as equipment is mounted on the vehicle 26. The ground contact load of each steerable wheel 12 varies depending on the position of the object 36. The ground contact load of a steerable wheel 12 located directly below the object 36 is greater than the ground contact load of a steerable wheel 12 that is not located directly below the object 36. Therefore, the change unit 22 moves the object 36 within the vehicle 26 so that the object 36 is not located above the steerable wheel 12 that is the target of lock-to-lock execution. For example, rails are provided within the vehicle 26, and the object 36 is provided on the rails. The change unit 22 moves the object 36 on the rails using a motor or the like.

[0028] For example, when lock-to-lock is performed with the steered wheel 12C as the target, if an object 36 is mounted above the steered wheel 12C, the change unit 22 moves the object 36 from the position above the steered wheel 12C to another position (for example, a position in front of the vehicle 26). By doing so, the load on the portion above the steered wheel 12C becomes lighter, and the ground contact load of the steered wheel 12C becomes smaller.

[0029] In the example shown in Figure 6, the change unit 22 moves the vehicle 26 so that the steered wheel 12C is positioned at the position of the recess 34, but the change unit 22 may also change the position of the object 36 without moving the vehicle 26.

[0030] A combination of two or more of the above-described embodiments 1 to 3 may be used. That is, the change unit 22 may perform one or more combinations of the movement of the vehicle 26, the movement of the steered wheels 12 of the vehicle 26 upward, and the movement of the object 36.

[0031] The vehicle control device 10 includes, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), other programmable logic devices, or electronic circuits.

[0032] The functions of the vehicle control device 10 are realized by the cooperation of hardware resources and software resources. For example, each function is realized by the CPU reading and executing a program stored in a storage device. The program is stored in the storage device via a recording medium such as a CD or DVD, or via a communication path such as a network. As another example, the functions of the vehicle control device 10 may be realized by hardware resources such as electronic circuits.

[0033] Furthermore, some of the functions of the vehicle control device 10 may be realized by an external device (for example, a server) other than the vehicle control device 10. For example, some of the functions of the vehicle control device 10 may be realized by a device mounted on the vehicle, and the remaining functions of the vehicle control device 10 may be realized by an external device. In this case, the entire functions of the vehicle control device 10 are realized by communication between the vehicle and the external device. [Explanation of symbols]

[0034] 10 vehicle control device, 12, 12A, 12B steering wheels, 14 operation device, 16 steering device, 18 surrounding information acquisition unit, 20 estimation unit, 22 change unit, 24 learning unit, 26 vehicle, 28 road surface, 30 convex portion, 32 detection device, 34 concave portion, 36 object.

Claims

1. a steering device for steering the steered wheels; an estimation unit that estimates a ground contact load of the steered wheels based on at least one of vehicle information indicating a state of the vehicle and peripheral information indicating information about the periphery of the vehicle; a change unit that changes the position or state of the vehicle so as to reduce the ground contact load of the steered wheels; a learning unit that learns the neutral position of the steered wheels after a position or a state of the vehicle is changed; A vehicle control device comprising:

2. 2. The vehicle control device according to claim 1, the change unit moves the steered wheels, the neutral position of which is to be learned, to an upper position of the vehicle. A vehicle control device characterized by:

3. 2. The vehicle control device according to claim 1, the change unit moves the vehicle to a position where the steered wheels that are to be learned as a neutral position do not contact a road surface. A vehicle control device characterized by:

Images