Vehicle steering system, gain determination map creation method

Abstract

To improve a by-wire type vehicular steering system, for example, improve the operability of a driver.SOLUTION: In a vehicular steering system, a gain representing a relation between an operation amount of a steering operation member and a steering angle of a steering wheel is determined on the basis of an operation speed of the steering operation member or the like. This thus improves the operability of a driver and reduces the discomfort of the driver.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a so-called by-wire type vehicle steering system. [Background technology]

[0002] Patent Document 1 describes a by-wire vehicle steering system equipped with a joystick as a steering operation member. In the vehicle steering system described in Patent Document 1, a gain that represents the relationship between the operation amount of the joystick and the steering angle of the steered wheels is determined to be a smaller value when the vehicle travel speed is fast than when it is slow. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-34353 Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to improve the operability of the driver.

[0005] In the vehicle steering system according to the present invention, a gain that represents a relationship between an operation amount of a steering operation member and a steering angle of a steering wheel is determined based on an operation speed of the steering operation member, etc. This improves operability for the driver and reduces discomfort.

[0006] The gain determination map creation method according to the present invention is a method for creating a gain determination map for determining a gain, which is a relationship between an operation amount of an operating member and an operation amount of an in-vehicle device, used in a first vehicle. The operator gets into the second vehicle and operates an operating member independent of the second vehicle while the second vehicle is traveling, as if he or she were driving the vehicle. Then, operator operation information, which is information on the operation state of the operating member by the operator, and second traveling information, which is information on the traveling state of the second vehicle, are acquired (information acquisition step), and a gain determination map is created based on a plurality of pieces of information including these pieces of information (creation step). Therefore, when the driver operates the operating member in the first vehicle and the in-vehicle device is controlled using a gain determined based on the created gain determination map, it is possible to reduce discomfort and improve the operability of the driver. When the in-vehicle device is operated, the traveling state of the vehicle changes. Therefore, the gain creation map can be created based on the second traveling information and the operator operation information. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view showing a steering device which is a component of a vehicle steering system according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view showing a steering operation member which is a component of the vehicle steering system. [Diagram 3] 2 is a diagram conceptually showing a peripheral structure of a control device which is a component of the vehicle steering system. FIG. [Figure 4] 10A is a flow chart showing a steering control program stored in a memory unit of the control device, and FIG. 10B is a flow chart showing a learning program. [Diagram 5] 5A to 5E are diagrams conceptually showing gain determination maps stored in the storage unit. [Figure 6] FIG. 2 is a diagram conceptually showing a gain determination map creating device that creates the gain determination map. [Figure 7]4 is a flowchart showing a gain determination map creating program stored in a storage unit of a personal computer, which is a component of the gain determination map creating device. [Figure 8] 3 is a diagram conceptually showing a relationship between an operation amount of a steering operation member, which is a component of the vehicle steering system, and a target steering angle. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A vehicle steering system according to one embodiment of the present invention will be described below with reference to the drawings. The vehicle steering system is mounted on a first vehicle V1 (see FIG. 3), which is a vehicle, and is of a by-wire type. The vehicle steering system includes a steering device 10 provided on each of a plurality of steered wheels of the first vehicle V1, and a control device 50 that controls the steering device 10 to control the steered angle of the steered wheels. EXAMPLES

[0009] As shown in Fig. 1, the steering device 10 independently steers each of the steered wheels, that is, the left and right front wheels 12. Since these steering devices 10 have the same structure, in this embodiment, the steering device 10 provided for the right front wheel 12 will be described, and the description of the steering device provided for the left front wheel will be omitted.

[0010] A right front wheel (hereinafter sometimes simply referred to as a front wheel or a steering wheel) 12 is rotatably held by a steering knuckle (hereinafter referred to as a knuckle) 16. A lower arm 18 is connected to the knuckle 16, and the lower arm 18 is connected to a vehicle body member (not shown) via a bush so as to be swingable in the vertical direction (around an axis extending in the front-rear direction) and the horizontal direction (around an axis extending in the vertical direction). The knuckle 16 is supported by a vehicle body member (not shown) via a shock absorber 20 and a suspension spring 21.

[0011] The steering device 10 includes the above-mentioned knuckle 16, a steering actuator 24 provided on the lower arm 18, a pitman arm 34 connected to an output shaft (not shown) of the steering actuator 24, and a tie rod 26 connecting the pitman arm 34 to the knuckle arm 22 of the knuckle 16.

[0012] The steering actuator 24 includes a steering motor 30 which is an electric motor serving as a drive source, and a reducer 32 which reduces the rotation speed of the steering motor 30. The pitman arm 34 is connected at one end to the output shaft of the reducer 32 which is the output shaft of the steering actuator 24 so as to be rotatable integrally therewith.

[0013] The other end of the pitman arm 34 is connected to one end of the tie rod 26 via a connecting portion 36. The other end of the tie rod 26 is connected to the knuckle arm 22 via a connecting portion 38.

[0014] In the present steering device 10, when the steering actuator 24 is driven in the direction indicated by the arrow X in Fig. 1, the pitman arm 34 is rotated about the axis of the steering actuator 24. As the pitman arm 34 rotates, the tie rod 26 is moved in the direction indicated by the arrow Y, whereby the knuckle arm 22 and the knuckle 16 are rotated about the kingpin axis KP, and the wheels 12 are steered in the direction indicated by the arrow Z.

[0015] In this embodiment, as shown in Fig. 2, the vehicle steering system is provided with a joystick 40 operable by the driver. The joystick 40 can, for example, function as a steering operation member, a braking operation member, and a driving operation member. The joystick 40 is held in a housing 41 so as to be rotatable in the front-rear direction and the left-right direction from an upright state, and can, for example, be rotated in the front-rear direction to instruct driving and braking, and rotated in the left-right direction to instruct steering.

[0016] The upright state of the joystick 40 is a neutral state with no drive, brake, or turn instructions, and it is assumed that, for example, the first vehicle V1 will travel straight ahead at approximately the same speed. The rotation angle of the joystick 40 from the upright state in the forward / backward or left / right direction is referred to as the operation amount. In this embodiment, a drive / braking operation amount sensor 42 that detects the forward / backward operation amount of the joystick 40 (the forward / backward rotation angle from the upright state) and a steering operation amount sensor 44 that detects the left / right operation amount are provided. In this embodiment, either the leftward rotation angle or the rightward rotation angle of the joystick 40 is expressed as a positive value, and the other is expressed as a negative value. The same applies to the steering angle of the steered wheels 12.

[0017] Control device 50 includes steering ECU (Electric Control Unit) 52 and the like, as shown in Fig. 3. Steering ECU 52 is mainly a computer, and has execution section 52c, memory section 52m, input / output section 52f and the like. Also connected to steering ECU 52 are driving / braking operation amount sensor 42, steering operation amount sensor 44, road information acquisition device 54 that acquires road information (such as information representing the shape of the road and information regarding unevenness of the road surface) which is information relating to the road on which first vehicle V1 is traveling, traveling condition detection device 56 that detects the traveling condition of first vehicle V1 and the like, as well as steering devices 10 provided on each of steered wheels 12 and the like.

[0018] The road information acquisition device 54 may include a camera, a radar device, etc., and may acquire information about the road ahead on which the first vehicle V1 is traveling, or may acquire information about the road from a navigation system, etc. The traveling condition detection device 56 detects the traveling speed, longitudinal acceleration, lateral acceleration, yaw rate, etc. of the first vehicle V1, and may include a plurality of sensors such as a speed sensor, an acceleration sensor, a yaw rate sensor, etc. The steering device 10 is provided with a rotation angle sensor 58, etc., that detects the rotation angle of the steering motor 30.

[0019] The operation of the vehicle steering system configured as above will now be described. In this embodiment, a target steering angle δ of the steered wheels 12 is obtained based on the left-right operation amount θ of the joystick 40 detected by the steering operation amount sensor 44 and the gain G, and the steering actuator 24 is controlled so that the actual steering angle of the steered wheels 12 approaches the target steering angle δ. As a result, the steered wheels 12 are steered and the first vehicle V1 turns.

[0020] As shown in Fig. 8, the gain G represents the relationship between the operation amount θ and the target steering angle δ, and in this embodiment, it is a value represented by the ratio (δ / θ) of the target steering angle δ to the operation amount θ. When the operation amount θ is the same, when the gain G is large, the target steering angle δ is determined to be a larger value than when the gain G is small. In addition, the gain G is determined based on the steering operation speed dθ of the driver's joystick 40, the timing of the steering operation, the degree of curvature of the road on which the first vehicle V1 is traveling, the operation history of the driver's joystick 40 (for example, the presence or absence of a braking operation before the steering operation was started), etc.

[0021] 5(a), when the steering operation speed dθ, which is the left / right turning speed of the joystick 40, is fast, the gain G is made larger than when it is slow (when the absolute value |dθ| of the steering operation speed is large compared to when it is small), for the same operation amount θ. This is because it is presumed that when the steering operation speed dθ is fast, the driver feels a greater need to turn quickly than when it is slow. The steering operation speed dθ can be obtained as the amount of change per unit time of the operation amount θ detected by the steering operation amount sensor 44.

[0022] As shown in Fig. 5(b), when the steering operation timing is early, the gain is determined to be a smaller value than when it is late. Based on road information, the traveling speed of the first vehicle V1, etc., when the margin time, which is the time from when the steering operation of the joystick 40 starts until the point where the steering of the steered wheels 12 is reached, is long, the operation timing can be considered to be earlier than when it is short. When the margin time is long and the steering operation timing is early, it is presumed that the driver feels less need to turn quickly than when the margin time is short and the steering operation timing is late, so the gain is made large.

[0023] The margin time may be a negative value, for example, when the steering operation of the joystick 40 is started after passing a curved point. In addition, when the detection value of the steering operation amount sensor 44 is read in for each cycle time, if the absolute value of the operation amount θ read in last time was 0 and the absolute value of the operation amount θ read this time is greater than 0, the time when the operation amount θ was detected this time by the steering operation amount sensor 44 is determined to be the time when the steering operation started.

[0024] As shown in Figure 5 (c), when the road information indicates that the curvature of the road on which the first vehicle V1 is traveling is sharp (when the curvature is large and the radius of curvature is small), the gain G is determined to be a larger value for the same operating amount θ than when the curvature is determined to be gentle.

[0025] As shown in Fig. 5(d), when there is a braking history, the gain G is determined to be a larger value than when there is no braking history. For example, when a braking operation is performed within a set time before the start of steering operation of the joystick 40, it can be considered that there is a braking history. When there is a braking history, it is presumed that the driver feels a greater need to increase the steering angle than when there is no braking history, so the gain G is determined to be a larger value. If the steering operation amount sensor 44 detects that the joystick 40 has been operated by steering before a set time has elapsed from the time when the driving / braking operation amount sensor 42 detects that the joystick 40 has been operated by braking, it is detected that there is a braking history.

[0026] 5(e), when the traveling speed of the first vehicle V1 detected by the traveling condition detection device 56 is fast, the gain G is set to a smaller value than when it is slow (when the absolute value of the traveling speed is large, it is smaller than when it is small). This is to improve the driving stability of the first vehicle V1.

[0027] 5(a)-(e) are created in advance and stored in the storage unit 52m of the control device 50. The gain determination map is constantly learned and appropriately changed.

[0028] The steering control program shown in the flowchart of FIG. 4(a) is executed in the steering ECU 52 at predetermined cycle times. In step 1 (hereinafter abbreviated as S1, the same applies to the other steps), the operation amount of the joystick 40 is detected and stored by the driving / braking operation amount sensor 42 and the steering operation amount sensor 44, and in S2, road information is acquired and stored by the road information acquisition device 54. Also, in S3, the running state of the first vehicle V1 is detected and stored by the running state detection device 56.

[0029] Next, in S4, it is determined whether or not a steering operation of joystick 40 has been performed, and in S5, it is determined whether or not this is the first time that the determination in S4 has become YES. If the determination in S5 is YES, the time is obtained and stored in S6. In S7, the steering operation speed, margin time, presence or absence of braking history, traveling speed, curvature of curved parts of the road, etc. are obtained. In S8, gain G is determined based on one or more of the gain determination maps shown in Figures 5(a)-(e), and in S9, target steering angle δ is obtained and steering actuator 24 is controlled.

[0030] The gain G can be determined based on one of the gain determination maps shown in Figures 5(a)-(e), or based on two or more of the gain determination maps shown in Figures 5(a)-(e). When the gain G is determined based on two or more of the gain determination maps shown in Figures 5(a)-(e) (for example, Figures 5(a) and 5(b)), the average value of the gains Ga and Gb determined in the respective gain determination maps can be used as the gain G (hereinafter, sometimes referred to as the control gain) used when determining the target steering angle δ, or a value obtained by weighting the gains Ga and Gb can be used as the control gain G.

[0031] On the other hand, if the determination in S5 is NO, S6 is not executed and S7 and subsequent steps are executed.

[0032] As described above, in this embodiment, the gain G is determined based on the steering operation speed, the steering operation timing, the presence or absence of braking history, the traveling speed, the degree of curvature of the road, etc., so that the operability for the driver can be improved and the sense of discomfort can be reduced.

[0033] In this embodiment, learning is performed and the gain determination map is changed as appropriate. The learning program shown in the flowchart of Fig. 4(b) is executed at set time intervals. The set time can be longer than the cycle time. In S11 to S13, operation information relating to the operation state of joystick 40 is acquired and stored, road information is acquired and stored, and traveling information relating to the traveling state of first vehicle V1 is acquired and stored. Also, in S14, control information relating to the control content of steering actuator 24 up to now (rotation angle of steering motor 30, driving start time of steering motor 30, etc.) is acquired and stored. Then, in S15, learning is performed by AI (Artificial Intelligence) or the like based on this information. Through the learning, one or more of the gain determination maps of Figures 5(a)-(e) are appropriately changed.

[0034] In this way, the gain determination map used when determining the gain is appropriately corrected in accordance with the characteristics of the driver, so that the operability for the driver can be further improved.

[0035] The gain determination map is not limited to the five maps shown in Fig. 5(a)-(e). For example, it is possible to include a map that determines the gain to be a small value when a driving operation is performed within a set time before the start of a steering operation, or a map that determines the gain by taking into account the unevenness of the road. Also, it is not always necessary to store the five maps shown in FIGS. 5(a)-(e), and some of the five maps may be stored and used. Furthermore, the structure of the steering device is not important, and any structure may be used as long as the vehicle is a steer-by-wire type.

[0036] As described above, in this embodiment, the actuator control device is constituted by a part of the control device 50 that stores the steering control program shown in Fig. 4(a), a part that executes it, etc. Among them, the gain determination map storage part is constituted by a part that stores the maps shown in Fig. 5(a)-(d), etc., and the gain determination part is constituted by the gain determination map storage part and the part that stores and executes S8, etc. Furthermore, the steering operation amount sensor 44, the part that stores and executes S7 of the control device 50, etc. constitute a steering operation speed detection device, the steering operation amount sensor 44, the part that stores and executes S4, 5, 6 of the control device 50, etc. constitute a steering operation start detection device, and the driving / braking operation amount sensor 42 etc. correspond to a braking operation state detection device. Furthermore, the part that stores and executes the learning program of Fig. 4(b) of the control device 50 constitutes a learning device.

[0037] Next, a method for creating the gain determination map will be described. For example, the gain determination maps shown in Figures 5(a)-(e) are used in a first vehicle V1, which is a vehicle equipped with a joystick 40 as an operating member and a vehicle steering system as a by-wire type in-vehicle device, but the gain determination maps are created away from the first vehicle V1.

[0038] For example, as shown in Fig. 6, an operator sits in a passenger seat or the like of a second vehicle V2 different from the first vehicle V1, and while the second vehicle V2 is traveling, operates a joystick 82 independent of the second vehicle V2 as if he or she were driving the vehicle. The joystick 82 is similar to the joystick 40, and a steering operation amount sensor 84 and a driving / braking operation amount sensor 86 provided for the joystick 82 are connected to a storage device 88. The storage device 88 acquires and stores the steering operation amount of the joystick 82, the steering operation start time, the braking operation start time, and the like. The storage device 88 can be, for example, a personal computer.

[0039] The second vehicle V2 may be an automatic driving vehicle or a manually driven vehicle, but if it is a manually driven vehicle, it is driven by an experienced driver such as a test driver and drives in an exemplary manner. In addition, the vehicle steering system installed in the second vehicle V2 may be of a steer-by-wire type or may be of a type in which the steering wheel as a steering operation member and the steering wheels are mechanically connected.

[0040] In this embodiment, the second vehicle V2 is a manually operated vehicle, and is driven by a test driver when the gain determination map is created. The vehicle steering system mounted on the second vehicle V2 has a steering wheel and steered wheels mechanically connected to each other, and the test driver operates the steering wheel, brake pedal, accelerator pedal, etc. (not shown).

[0041] A steering ECU 92 of the vehicle steering system mounted on the second vehicle V2 is connected to a steering operation amount sensor 94 for detecting the operation amount of the steering wheel, a driving / braking operation detection device 96 including an accelerator operation state detection device for detecting the depression amount of the accelerator pedal and a brake operation state detection device for detecting the depression amount of the brake pedal, a road information acquisition device 98, a running state detection device 100 for detecting the running state of the second vehicle V2, etc., and is also connected to a power steering motor 102, a storage device (which may be, for example, a drive recorder, etc.) 104, etc. The road information acquisition device 98, the running state detection device 100, etc. may be similar to the road information acquisition device 54, the running state detection device 56, etc. provided in the above-mentioned first vehicle.

[0042] While the second vehicle V2 is traveling, the drive recorder 104 is supplied with and stores road information acquired by the road information acquisition device 98, second traveling information which is information regarding the traveling state of the second vehicle V2 detected by the traveling state detection device 100, and second operation information which is information regarding the operation states of the steering wheel, accelerator pedal, and brake pedal detected by the steering operation amount sensor 94 and the driving / braking operation detection device 96.

[0043] After the driving ends, the information stored in the drive recorder 104 and the information stored in the storage device 88 are supplied to an external device 110 mainly composed of a computer. In the external device 110, machine learning is performed by AI based on the information and the like, and a gain determination map shown in Fig. 5(a)-(e) is created. The created gain determination map is then supplied to and stored in the first vehicle V1, which is a vehicle equipped with the joystick 40 and a by-wire type in-vehicle device.

[0044] FIG. 7 shows an example of a procedure for creating a gain determination map. A plurality of operators take turns riding in the second vehicle V2 driven by a test driver and operate the joystick 82 as if they were driving the vehicle. For a first operator, during a series of travels of the second vehicle V2 (for example, during travels along a predetermined course or for a predetermined period of time), (A) the storage device 88 stores operator operation information, which is information representing the operation state of the joystick 82 detected by the driving / braking operation amount sensor 86 and the steering operation amount sensor 84. Also, (B) the second operation information, (C) road information, (D) the second travel information, etc. are stored in the drive recorder 104. When a series of travels is completed, the operator is changed.

[0045] Similarly, for the second operator, during a series of travels of the second vehicle V2, (A) operator operation information is stored in the storage device 88, and (B)-(D) second operation information, road information, second travel information, etc. are stored in the drive recorder 104. Then, when a series of travels of the second vehicle V2 is completed, the next operator is handed over.

[0046] When the planned number of operators finish operating the joysticks 82, (E) the operator operation information stored in the storage device 88, the second operation information stored in the drive recorder 104, the road information, the second driving information, etc. are supplied to the external device 110. (F) In the external device 110, machine learning is performed by AI based on this information, and a gain determination map shown in Fig. 5(a)-(e) is created. (G) The created gain determination map is supplied to the first vehicle V1 and stored therein.

[0047] In this way, the gain determination map is created based on information regarding the operation of the joystick 82 by a plurality of operators, etc. Therefore, in the first vehicle V1, the steering actuator is controlled based on the gain determined using the gain determination map, thereby reducing the discomfort felt by the driver and improving operability.

[0048] In this embodiment, the external device corresponds to a gain determination map creating device. Also, the execution of (A)-(D) corresponds to an information acquisition step, and the execution of (E) and (F) corresponds to a creating step.

[0049] In the above embodiment, the gain determination map is created in the external device 110, but the present invention is not limited to this. For example, the gain determination map can be created in a personal computer equipped with the storage device 88 brought into the second vehicle V2. In this case, the steering ECU 92 can be connected to the personal computer wirelessly or via a wire so as to be able to communicate with each other, and the second operation information, road information, second traveling information, and the like can be sequentially supplied to the personal computer. Also, the gain determination map can be created in the steering ECU 92. Furthermore, the information stored in the storage device 88 and the drive recorder 104 may be stored in the external device 110 every time an operator is changed.

[0050] In addition, in the gain determination map creation device, not only the gain determination map for determining the gain representing the relationship between the operation amount of the steering operation member and the steering angle of the steering wheel, but also the gain determination map for determining the gain representing the relationship between the operation amount of the operation member provided in the vehicle and the operation amount of the on-board device can be created. For example, the gain determination map for determining the gain representing the relationship between the braking operation amount and the operation amount of the braking device as the on-board device, and the gain representing the relationship between the drive operation amount and the operation amount of the drive device as the on-board device based on the road information, the braking operation speed, the drive operation speed, etc. Also, when the operation amount of the on-board device such as the braking device and the drive device is determined, the deceleration and acceleration of the vehicle change, and the state of the vehicle changes. Therefore, the gain can be considered to represent the relationship between the operation amount of the operation member and the state of the vehicle.

[0051] Also, the operator can operate the joystick 82 while watching the image of the driving simulator, instead of getting in the second vehicle V2 and operating the joystick 82. In this embodiment, the operator operates the joystick 82 while the driving simulator is being operated by an experienced driver. Similarly, a gain determination map is created in the external device 110 based on the operator operation information, operation information stored in the driving simulator as second operation information, image information of the driving simulator as road information, driving information assumed in the driving simulator as second driving information, and the like.

[0052] In this way, by using a driving simulator, the gain determination map can be easily created.

[0053] In addition, the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0054] 24: Steering actuator 40, 82: Joystick 42, 84: Steering operation amount sensor 44, 86: Driving / braking operation amount sensor 52: Steering ECU 54: Road information acquisition device 56: Driving state detection device 88: Storage device 104: Drive recorder 110: External device Patentable invention

[0055] (1) A vehicle steering system that is provided in a vehicle and steers the vehicle's steering wheels based on an amount of operation of a steering operation member operated by a driver, comprising: A steering actuator for steering the steering wheels of the vehicle; a steering actuator control device that controls the steering actuator so that the steering angle of the steered wheels approaches a target steering angle determined based on an operation amount of the steering operation member and a gain; Including, The vehicle steering system includes a steering operation speed detection device that detects an operation speed of the steering operation member, The steering actuator control device includes an operation speed dependent gain determiner that determines the gain to be a larger value when the operation speed of the steering operation member detected by the steering operation speed detection device is fast than when the operation speed is slow.

[0056] (2) A vehicle steering system that is provided in a vehicle and steers the vehicle's steering wheels based on an operation amount of a steering operation member operated by a driver, comprising: A steering actuator for steering the steering wheels of the vehicle; a steering actuator control device that controls the steering actuator so that the steering angle of the steered wheels approaches a target steering angle determined based on an operation amount of the steering operation member and a gain; Including, The vehicle steering system, A steering operation start detection device for detecting a start of operation of the steering operation member, The actuator control device, A vehicle steering system including a timing-based gain determination unit that determines the gain to be a smaller value when the time from the time when the steering start detection device detects the start of operation of the steering operation member to the time when the vehicle reaches a curved point on a road on which the vehicle is traveling is long than when the time is short.

[0057] A turning point may be, for example, a point where a turning of the steering wheels is deemed necessary in order for the vehicle to travel along the road.

[0058] (3) The vehicle steering system comprises: a road information acquisition device for acquiring information about a road on which the vehicle is traveling; a vehicle speed detection device for detecting the vehicle speed; Including, The vehicle steering system described in item (2), wherein the timing-dependent gain determination unit obtains the time from when the start of operation of the steering operation member is detected by the operation start detection device to when the vehicle reaches a curved point on the road, based on information regarding the road on which the vehicle is traveling, obtained by the road information acquisition device, and the traveling speed of the vehicle detected by the traveling speed detection device, and determines the gain to be a smaller value when the time is longer than when the time is shorter.

[0059] The information relating to the road includes information relating to the shape of the road, information relating to the unevenness of the road, and the like.

[0060] (4) A vehicle steering system that is provided in the vehicle and steers the steering wheels of the vehicle based on an operation amount of a steering operation member operated by a driver, comprising: A steering actuator for steering the steering wheels of the vehicle; a steering actuator control device that controls the steering actuator so that the steering angle of the steered wheels approaches a target steering angle determined based on an operation amount of the steering operation member and a gain; Including, The vehicle steering system, a road information acquisition device for acquiring information about a road on which the vehicle is traveling; The actuator control device, A vehicle steering system including a road shape-dependent gain determination unit that determines the gain to be a larger value when the curvature of the road on which the vehicle is traveling, acquired by the road information acquisition device, is large than when the curvature is small.

[0061] (5) A vehicle steering system that is provided in a vehicle and steers the vehicle's steering wheels based on an operation amount of a steering operation member operated by a driver, comprising: A steering actuator for steering the steering wheels of the vehicle; a steering actuator control device that controls the steering actuator so that the steering angle of the steered wheels approaches a target steering angle determined based on an operation amount of the steering operation member and a gain; Including, the vehicle steering system includes a brake operation state detection device that detects an operation state of a brake operation member that can be operated by a driver, The actuator control device of the vehicle steering system includes an operation history-based gain determination unit that determines the gain to be a larger value when the brake operation state detection device detects that the brake operation member has been operated within a set time before the steering operation member is operated, compared to when this is not detected.

[0062] The set time is a time period that can be considered to have a relationship between a braking operation and a steering operation, and refers to a time period that can be estimated as being highly likely to result in a steering operation following a braking operation in order to make a turn.

[0063] (6) A vehicle steering system as described in any one of (1) to (5), wherein the steering operation member is a joystick, and the steering direction and steering amount are indicated by rotating the joystick left and right.

[0064] (7) A vehicle steering system that is provided in a vehicle and steers a steering wheel of the vehicle based on an operation amount of a steering operation member operated by a driver, comprising: A steering actuator for steering the steering wheels of the vehicle; a steering actuator control device that controls the steering actuator so that the steering angle of the steered wheels approaches a target steering angle determined based on an operation amount of the steering operation member and a gain; Including, The vehicle steering system, a steering operation state detection device that detects an operation state of the steering operation member; a road information acquisition device that acquires road information that is information about a road on which the vehicle is traveling; a brake operation state detection device that detects an operation state of a brake operation member that can be operated by a driver; Including, The steering actuator control device includes a gain determination unit that determines the gain based on one or more of: (a) the operation speed of the steering operation member detected by the steering operation state detection device; (b) the operation start timing of the steering operation member; (c) the curvature of the curved portion of the road acquired by the road information acquisition device; and (d) an operation history determined by the operation state of the braking operation member detected by the braking operation state detection device and the operation state of the steering operation member detected by the steering operation state detection device.

[0065] The vehicle steering system described in this section may employ any of the technical features described in (1) to (6).

[0066] (8) A vehicle steering system as described in any one of (1) to (7), wherein the steering actuator control device includes a memory unit that stores a gain determination map that determines the gain, and determines the gain using the gain determination map stored in the memory unit.

[0067] (9) A vehicle steering system as described in any one of (1) to (8), including a learning device that learns about the gain based on a plurality of pieces of information including actuator operation information relating to the operating state of the steering actuator and steering operation information representing the operation state of the steering operation member by the driver.

[0068] (10) A gain determination map creation device that is provided in a first vehicle and creates a gain determination map that determines a gain that represents a relationship between an operation amount of an operating member that can be operated by a driver and an operation amount of an in-vehicle device of the first vehicle, A gain determination map acquisition device that creates the gain determination map based on a plurality of pieces of information including information about the operation state of an independent operating member, which is an operating member independent of the second vehicle that is operated by an operator while the second vehicle, which is a vehicle different from the first vehicle, is traveling, and information about the traveling state of the second vehicle.

[0069] It is desirable for the operator to get in the second vehicle and operate the independent operating member while the second vehicle is traveling, as if he were driving the vehicle. The operating member may be any of a steering operating member, a braking operating member, a driving operating member, etc. The operation amount of the in-vehicle device corresponds to the steering angle of the steering wheel of the vehicle (operation amount of the steering device), the operation amount of the braking device or the driving device of the vehicle, etc. In the above embodiment, the joystick 82 corresponds to the independent operating member.

[0070] (11) The gain determination map acquisition device, an independent operation state detection device that is provided independently of the second vehicle and detects an operation state of the independent operation member operated by the operator while the second vehicle is traveling; A running condition detection device provided in the second vehicle and capable of detecting a running condition of the second vehicle; A road information acquisition device provided in the second vehicle and acquiring information about a road on which the second vehicle is traveling; an independent map creation device that is provided independently of the second vehicle and that creates the gain determination map by performing learning based on information about the operation state of the independent operation member detected by the independent operation state detection device, information about the traveling state detected by the traveling state detection device, and information about the road acquired by the road information acquisition device; The gain determination map creating device according to claim 10, further comprising:

[0071] The independent operation state detection device, the running state detection device, the road information acquisition device and the independent map creation device can be communicatively connected wirelessly or by wire so that information can be sequentially supplied from the independent operation state detection device, the running state detection device and the road information acquisition device to the independent map creation device, or information acquired by the independent operation state detection device, the running state detection device and the road information acquisition device can be temporarily stored in a storage device and this information can be supplied to the independent map creation device via the storage device, etc. In the above embodiment, the external device 110 corresponds to the independent map creation device.

[0072] (14) A method for creating a gain determination map used when determining a gain that represents a relationship between an amount of operation of an operating member that is provided in a first vehicle and that can be operated by a driver, and an amount of operation of an in-vehicle device of the first vehicle, comprising: an information acquisition process for acquiring information on an operation state of an independent operation member, which is an operation member independent of the second vehicle, when an operator riding in the second vehicle operates the independent operation member while the second vehicle is traveling, and information on a traveling state of the second vehicle; a generating step of generating a gain determination map based on a plurality of pieces of information including the information acquired in the information acquiring step; A method for creating a gain determination map comprising:

Claims

1. A vehicle steering system that is provided in a vehicle and steers the steering wheels of the vehicle based on an operation amount of a steering operation member operated by a driver, a steering operation speed detection device for detecting an operation speed of the steering operation member; A steering operation start detection device that detects the start of operation of the steering operation member; a road information acquisition device for acquiring information about a road on which the vehicle is traveling; a vehicle speed detection device for detecting a vehicle speed; A steering actuator for steering the steering wheels of the vehicle; a steering actuator control device that controls the steering actuator so that the steering angle of the steered wheels approaches a target steering angle determined based on an operation amount of the steering operation member and a gain; Including, The steering actuator control device determines the gain to be a larger value when the operation speed of the steering operation member detected by the steering operation speed detection device is fast than when the operation speed is slow, and obtains the time from when the steering operation start detection device detects that operation of the steering operation member has started to when the vehicle reaches a curved point on the road based on the shape of the road on which the vehicle is traveling acquired by the road information acquisition device and the traveling speed of the vehicle detected by the traveling speed detection device, and determines the gain to be a smaller value when the time is long than when the time is short.

2. A vehicle steering system that is provided in a vehicle and steers the vehicle's steering wheels based on an amount of operation of a steering operation member operated by a driver, comprising: a road information acquisition device for acquiring information about a road on which the vehicle is traveling; a steering operation speed detection device for detecting an operation speed of the steering operation member; A steering actuator for steering the steering wheels of the vehicle; a steering actuator control device that controls the steering actuator so that the steering angle of the steering wheel approaches a target steering angle determined based on an operation amount of the steering operation member and a gain, The steering actuator control device determines the gain to be a larger value when the operation speed of the steering operation member detected by the steering operation speed detection device is fast than when it is slow, and determines the gain to be a larger value when the curvature of the road on which the vehicle is traveling, acquired by the road information acquisition device, is large than when it is small.

3. A vehicle steering system that is provided in a vehicle and steers the vehicle's steering wheels based on an amount of operation of a steering operation member operated by a driver, comprising: a steering operation speed detection device for detecting an operation speed of the steering operation member; a brake operation state detection device provided in the vehicle and configured to detect an operation state of a brake operation member operable by the driver; A steering actuator for steering the steering wheels of the vehicle; a steering actuator control device that controls the steering actuator so that the steering angle of the steering wheel approaches a target steering angle determined based on an operation amount of the steering operation member and a gain, a gain determination section which determines the gain to be a larger value when the operation speed of the steering operation member detected by the steering operation speed detection device is fast than when the operation speed is slow, and which determines the gain to be a larger value when operation of the brake operation member is detected by the brake operation state detection device before the steering operation member is operated than when operation of the brake operation member is not detected.

4. A vehicle steering system that is provided in a vehicle and steers the vehicle's steering wheels based on an amount of operation of a steering operation member operated by a driver, comprising: a steering operation speed detection device for detecting an operation speed of the steering operation member; A steering actuator for steering the steering wheels of the vehicle; a steering actuator control device that controls the steering actuator so that the steering angle of the steering wheel approaches a target steering angle determined based on an operation amount of the steering operation member and a gain, the steering actuator control device includes a gain determination unit that determines the gain to be a larger value when the operation speed of the steering operation member detected by the steering operation speed detection device is fast than when the operation speed is slow, the gain determiner includes a gain determination map storage unit that stores one or more gain determination maps for determining the gain, and determines the gain using the one or more gain determination maps stored in the gain determination map storage unit, each of the one or more gain determination maps is generated by a gain determination map generating device external to the vehicle; A vehicle steering system in which the gain determination map creation device creates the gain determination map based on a plurality of pieces of information including information about the operation state of an independent operating member, which is an operating member including the steering operating member independent of the second vehicle, operated by an operator aboard the second vehicle, which is a vehicle different from the first vehicle, while the second vehicle is traveling, information about the traveling state of the second vehicle, and information about the road on which the second vehicle is traveling.

5. 1. A method for creating a gain determination map used when determining a gain that represents a relationship between an operation amount of an operating member that is provided in a first vehicle and that can be operated by a driver, and an operation amount of an in-vehicle device of the first vehicle, comprising: an information acquisition process for acquiring information on an operation state of an independent operation member, which is an operation member independent of the second vehicle, when an operator riding in the second vehicle operates the independent operation member while the second vehicle is traveling, and information on a traveling state of the second vehicle; a generating step of generating a gain determination map based on a plurality of pieces of information including the information acquired in the information acquiring step; A method for creating a gain determination map comprising:

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