JP2017128155A - Steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To alleviate an incongruity when switching a relationship between a steering angle and a turning angle in accordance with the switching of a traveling mode.SOLUTION: A steering device 13 comprises first calculation means 136 which calculates a target turning angle θtg on the basis of a first function fm when a traveling mode is in a manual mode, and second calculation means 132 which calculates a target steering angle φtg on the basis of a second function fa when the traveling mode is in an automatic mode. When the traveling mode is switched to the manual mode, the first calculation means or the second calculates the target turning angle or the target steering angle on the basis of a third function fm0 or a fourth function fa0 which satisfies a first condition for sufficing a correspondence relationship between a steering angle φ0 and a turning angle θ0 when the traveling mode is switched, a second condition for making a posture of a steering member 134 and a reference posture coincide with each other in a situation that the turning angle becomes zero, and a third condition or a fourth condition that a change tendency of the turning angle with respect to the steering angle becomes most similar to a change tendency in the first function or the second function.SELECTED DRAWING: Figure 4

Description

  The present invention relates to the technical field of steer-by-wire steering devices.

  Steer-by-wire steering devices are known. For example, Patent Literature 1 describes a steering device that can change a rotation ratio of a wheel snake angle relative to a steering angle of a steering member (for example, a steering wheel). In particular, in Patent Document 1, the rotation ratio used when the vehicle is automatically traveling is set to be larger than the rotation ratio used when the vehicle is not automatically traveling, so that the movement of the steering member during automatic traveling is increased. A reduced steering system is described.

JP 2004-224238 A

  The steering device described in Patent Literature 1 switches the rotation ratio when a vehicle that is automatically traveling ends automatic traveling or a vehicle that has not automatically traveled newly starts automatic traveling. However, when the rotation ratio is simply switched, the steering angle is not zero after the rotation ratio is switched, but the snake angle is not zero (or the snake angle is zero). (The steering angle is not zero). For example, assuming that the rotation ratio of the snake angle with respect to the steering angle is 2, the steering angle is +5 degrees, and the rotation ratio is switched to 1 under the condition that the snake angle is +10 degrees, the steering member is only +5 degrees. Although the steering angle becomes 0 degree by returning, the turning angle is not 0 degree (specifically, the turning angle becomes +5 degree by returning the wheel by +5 degrees). The situation occurs. As a result, the passenger who operates the steering member may feel uncomfortable. On the other hand, by changing the tumbling angle or the steering angle at the same time as switching the rotation ratio, the condition that the snake angle is zero when the steering angle becomes zero even after switching the rotation ratio is satisfied. It is theoretically possible to switch the rotation ratio. For example, it is assumed that the rotation ratio is switched to 1 under the situation where the rotation ratio of the snake to the steering angle is 2, the steering angle is +5 degrees, and the snake angle is +10 degrees. In this case, in order to switch the rotation ratio so as to satisfy the condition that the turning angle becomes zero when the steering angle becomes zero even after switching the rotation ratio, the steering angle is changed simultaneously with the switching of the rotation ratio. It is necessary to change from +5 degrees to +10 degrees or to change the snake angle from +10 degrees to +5 degrees. However, such a change in steering angle or rolling angle may also cause the passenger to feel uncomfortable.

  Examples of problems to be solved by the present invention include the above. The present invention is a steer-by-wire system that can alleviate the discomfort given to the passenger when switching the relationship between the steering angle of the steering member and the snake-turning angle of the wheel in accordance with the switching of the driving mode of the vehicle. It is an object to provide a steering device.

  According to a first aspect of the steering apparatus of the present invention, there is provided a vehicle capable of switching a travel mode between a manual mode that travels based on a passenger's operation and an automatic mode that travels automatically without being based on a passenger's operation. A steer-by-wire steering device for steering, the steering member being operable by the occupant to meander the wheels of the vehicle and having the same posture every time the vehicle rotates by a predetermined angle, and the steering A first actuator capable of driving the steering member such that the steering angle of the member becomes a first target angle; and a second actuator capable of driving the wheel such that the rolling angle of the wheel becomes a second target angle. Detecting means for detecting the steering angle and the meandering angle, and a first function that defines a correspondence relationship that the steering angle and the meandering angle should satisfy when the travel mode of the vehicle is the manual mode. On the basis of the The first calculation means for calculating the second target angle corresponding to the steering angle detected by the detection means, and when the vehicle travel mode is the automatic mode, the steering angle and the snake snake angle are Corresponding to the meandering angle detected by the detecting means based on a second function that defines a corresponding relationship to be satisfied and has a smaller amount of change in the steering angle with respect to the meandering angle compared to the first function. Second calculating means for calculating the first target angle, and the first calculating means, based on the first function, when the traveling mode is switched from the automatic mode to the manual mode. Before calculating the second target angle, (i) a first condition that the correspondence relationship between the steering angle detected by the detecting means at the timing when the traveling mode is switched and the snake-turn angle is satisfied, ( ii) The snake angle is A second condition that the attitude of the steering member coincides with the attitude of the steering member when the steering angle is zero, and (iii) the rolling angle of the steering angle with respect to the steering angle. The detecting means is based on a third function that defines a correspondence relationship that the steering angle and the snake-turn angle should satisfy so that the third condition that the change tendency is most similar to the change tendency in the first function is satisfied. The second target angle corresponding to the detected steering angle is calculated, and the second calculation means is based on the second function when the traveling mode is switched from the manual mode to the automatic mode. Before the first target angle is calculated, (i) the first condition, (ii) the second condition, and (iii) the change tendency of the rolling angle with respect to the steering angle is expressed by the second function. The most similar to the change trend in The first target corresponding to the rolling angle detected by the detecting means based on a fourth function that defines a correspondence relationship that the steering angle and the rolling angle should satisfy so as to satisfy the fourth condition of Calculate the corner.

  According to the first aspect of the steering device of the present invention, when the traveling mode is switched from the automatic mode to the manual mode, the third function is calculated before the second target angle is calculated based on the first function. Based on the second target angle is calculated. Therefore, as compared with the case where the calculation of the second target angle based on the first function is started at the same time when the travel mode is switched from the automatic mode to the manual mode, the steering angle and the shift are changed in accordance with the switching of the travel mode of the vehicle. The uncomfortable feeling given to the occupant when switching the function that defines the correspondence between the snake angle is alleviated. Similarly, when the travel mode is switched from the manual mode to the automatic mode, the first target angle is calculated based on the fourth function before the first target angle is calculated based on the second function. . Therefore, as compared with the case where the calculation of the first target angle based on the second function is started at the same time when the travel mode is switched from the manual mode to the automatic mode, the steering member is steered in accordance with the switching of the travel mode of the vehicle. The uncomfortable feeling given to the occupant when the function that defines the correspondence between the corner and the snake-turn angle of the wheel is switched is alleviated.

FIG. 1 is a block diagram illustrating a configuration of a vehicle according to the first embodiment. FIG. 2 is a graph showing a steering function used in the first embodiment. FIG. 3 is a block diagram illustrating a configuration of the vehicle according to the second embodiment. FIG. 4 is a graph showing a steering function used in the second embodiment. FIG. 5 is a graph showing a steering function used in the second embodiment. FIG. 6 is a graph showing a steering function used in the second embodiment. FIG. 7 is a graph showing a steering function used in the second embodiment. FIG. 8 is a graph showing a steering function used in the second embodiment. FIG. 9 is a graph showing a steering function used in the second embodiment. FIG. 10 is a graph showing a steering function used in the second embodiment. FIG. 11 is a graph showing a steering function used in the second embodiment. FIG. 12 is a graph showing a steering function used in the second embodiment. FIG. 13 is a block diagram illustrating a configuration of a vehicle according to the third embodiment. FIG. 14 is a graph showing a steering function used in the third embodiment. FIG. 15 is a graph showing a steering function used in the third embodiment. FIG. 16 is a graph showing a steering function used in the third embodiment. FIG. 17 is a graph showing a steering function used in the third embodiment. FIG. 18 is a graph showing a steering function used in the third embodiment. FIG. 19 is a graph showing a steering function used in the third embodiment. FIG. 20 is a graph showing a steering function used in the third embodiment. FIG. 21 is a graph showing a steering function used in the third embodiment.

(1) First Embodiment Hereinafter, a vehicle 1 to which a first embodiment of a steering apparatus of the present invention is applied will be described with reference to FIG. As shown in FIG. 1, the vehicle 1 includes a wheel (a snake ring) 11 and a steer-by-wire steering device 13 that can snake the wheel 11 (that is, the vehicle 1 can be steered).

  The steering device 13 includes a turning angle monitoring device 131, which is a specific example of “detection means”, a target steering angle calculation unit 132, which is a specific example of “second calculation means”, and a “first actuator”. A specific example of the steering actuator 133, a steering wheel 134 as a specific example of the “steering member”, a steering angle monitoring device 135 as a specific example of the “detection means”, and a specific example of the “first calculation means” A target meandering angle calculation unit 136 as an example, a meandering actuator 137 as a specific example of a “second actuator”, a travel mode determination unit 138, and a function setting unit 139 are provided.

  The tumbling angle monitoring device 131 detects the tumbling angle θ of the wheel 11. The meandering angle monitoring device 131 sends the detected meandering angle θ (hereinafter, the meandering angle θ detected by the meandering angle monitoring device 131 is referred to as “the meandering angle θd”) to the target steering angle calculation unit 132. Output. The target steering angle calculation unit 132 calculates a target steering angle φtg, which is a target value of the steering angle φ of the steering wheel 134, based on the meander angle θd. In particular, the target steering angle calculation unit 132 corresponds to the snake snake angle θd based on a steering function f (especially, a steering function fa described later) that defines a correspondence relationship that the steering angle φ and the snake snake angle θ should satisfy. A target steering angle φtg is calculated. The target steering angle calculation unit 132 outputs the calculated target steering angle φtg to the steering actuator 133. The steering actuator 133 rotates the steering wheel 134 so that the steering angle φ of the steering wheel 134 matches the target steering angle φtg.

  The steering wheel 134 is an operation member that can be operated (specifically, can be rotated) by the occupant in order to control the snake direction of the vehicle 1. The steering wheel 134 has a shape that assumes the same posture every time the steering wheel 134 is rotated by a predetermined angle. As an example of such a shape, there is a shape in which the steering wheel 134 is axisymmetric with respect to a predetermined reference line passing through the center of rotation of the steering wheel 134. An example of a shape that is line symmetric is a shape such as the letter “H” of the alphabet. In this case, the attitude of the steering wheel 134 becomes the same every time the steering wheel 134 rotates 180 degrees. As an example of a shape that is line symmetric, there is a shape such as an alphabet “T”. In this case, the attitude of the steering wheel 134 becomes the same every time the steering wheel 134 rotates 360 degrees.

  The steering angle monitoring device 135 detects the steering angle φ of the steering wheel 134. The steering angle monitoring device 135 outputs the detected steering angle φ (hereinafter, the steering angle φ detected by the steering angle monitoring device 135 is referred to as “steering angle φd”) to the target rolling angle calculation unit 136. The target rolling angle calculator 136 calculates a target rolling angle θtg that is a target value of the rolling angle θ based on the steering angle φd. In particular, the target rolling angle calculation unit 136 corresponds to the steering angle φd based on a steering function f (in particular, a steering function fm described later) that defines the correspondence relationship that the steering angle φ and the rolling angle θ should satisfy. The target roll angle θtg is calculated. The target roll angle calculator 136 outputs the calculated target roll angle θtg to the roll lever actuator 137. The snake-turning actuator 137 snakes the wheel 11 so that the snake-turning angle θ matches the target snake-turning angle θtg.

  The travel mode determination unit 138 determines whether the travel mode of the vehicle 1 is an automatic mode or a manual mode. Therefore, the vehicle 1 can travel in the automatic mode and can travel in the manual mode. Traveling mode determination unit 138 outputs the determination result to function setting unit 139.

  The automatic mode is a travel mode in which the vehicle 1 automatically travels without being based on a passenger's operation (for example, an operation using a steering wheel 134, an unillustrated accelerator pedal, an unillustrated brake pedal, or the like). When the vehicle 1 is traveling in the automatic mode, the rolling angle θ of the wheel 11 is set so that the vehicle 1 appropriately travels the desired travel route (travel locus) regardless of whether the steering wheel 134 is operated by the passenger. The vehicle is controlled by an automatic travel control unit (not shown) (for example, a controller) so as to travel to Therefore, when the vehicle 1 is traveling in the automatic mode, the target rolling angle calculating unit 136 does not have to calculate the target rolling angle θtg based on the steering angle φd. Therefore, the snake-turn actuator 137 snakes the wheel 11 under the control of the automatic travel control unit, instead of turning the wheel 11 based on the target snake angle of θtg. On the other hand, when the vehicle 1 is traveling in the automatic mode, the target steering angle calculation unit 132 calculates the target steering angle φtg based on the rolling snake angle θd. Further, the steering actuator 134 rotates the steering wheel 134 based on the target steering angle φtg. As a result, the occupant can recognize the snake direction (traveling direction) of the vehicle 1 traveling in the automatic mode relatively easily from the movement of the steering wheel 134.

  The manual mode is a travel mode in which the vehicle 1 travels based on a passenger's operation. When the vehicle 1 is traveling in the manual mode, the target rolling angle calculation unit 136 calculates the target rolling angle θtg based on the steering angle φd reflecting the operation result of the passenger. Further, the snake-turn actuator 137 snakes the wheel 11 based on the target snake-turn angle θtg. As a result, the rolling angle θ of the wheel 11 is controlled according to the operation of the steering wheel 134 by the passenger. On the other hand, when the vehicle 1 is traveling in the manual mode, the target steering angle calculation unit 132 does not have to calculate the target steering angle φtg based on the snake serpentine angle θd. Further, the steering actuator 134 may not rotate the steering wheel 134 based on the target steering angle φtg.

  The function setting unit 139 sets the steering function f. In particular, the function setting unit 139 sets the steering function f based on the determination result of the travel mode determination unit 138.

  Specifically, when the vehicle 1 is traveling in the automatic mode, the function setting unit 139 uses the steering angle φ and the snake angle as the steering function f under the situation where the vehicle 1 is traveling in the automatic mode. A steering function fa that defines the correspondence that θ should satisfy is set. As described above, when the vehicle 1 is traveling in the automatic mode, the target steering angle φtg is calculated based on the rolling angle θd, while the target rolling angle θtg is calculated based on the steering angle φd. Is not calculated. Therefore, it can be said that the steering function fa is the steering function f that defines the correspondence between the rolling snake angle θd and the target steering angle φtg. That is, it can be said that the steering function fa is the steering function f that the target steering angle calculation unit 132 should refer to in order to calculate the target steering angle φtg. When the function setting unit 139 sets the steering function fa as the steering function f, the target steering angle calculation unit 132 calculates the target steering angle φtg based on the steering function fa and the snake-turn angle θd.

  On the other hand, when the vehicle 1 is traveling in the manual mode, the function setting unit 139 sets the steering angle φ and the snake serration angle θ as the steering function f under the situation where the vehicle 1 is traveling in the manual mode. The steering function fm that defines the correspondence that should be satisfied is set. As described above, when the vehicle 1 is traveling in the manual mode, the target turning angle θtg is calculated based on the steering angle φd, while the target steering angle φtg is calculated based on the turning angle θd. Is not calculated. Therefore, it can be said that the steering function fm is the steering function f that defines the correspondence between the steering angle φd and the target rolling angle θtg. That is, it can be said that the steering function fm is the steering function f to be referred to in order for the target rolling angle calculation unit 136 to calculate the target rolling angle θtg. When the function setting unit 139 sets the steering function fm as the steering function f, the target rolling angle calculation unit 136 calculates the target rolling angle θtg based on the steering function fm and the steering angle φd.

  The function setting unit 139 may store each of the steering functions fa and fm in advance. The steering functions fa and fm may be appropriately calculated (generated) by the function setting unit 139.

Hereinafter, the steering functions fa and fm will be described in more detail with reference to FIG. As shown in FIG. 2, the steering function fa is specified by a relational expression “φ = fa (θ)”. Accordingly, the target steering angle φtg is calculated from the relational expression “φtg = fa (θd)”. The steering function fm is specified by the relational expression “φ = fm (θ)”. Therefore, the target turning angle θtg is calculated from the relational expression “θtg = fm ⁻¹ (φd)”. In the present embodiment, the unit of the angle is “degree”.

  In the example shown in FIG. 2, the steering function fa is a linear function. Specifically, in the example illustrated in FIG. 2, the relational expression “φ = fa (θ)” is the relational expression “φ = (180 / θmax) × θ”. Note that “θmax” is the maximum value (upper limit value) of the meander angle θ. Therefore, this relational expression means that when the vehicle 1 is traveling in the automatic mode, the steering wheel 134 rotates halfway (rotates 180 degrees) when the wheel 11 is snaked to the maximum. Yes. However, the steering function fa shown in FIG. 2 is merely an example. For this reason, a steering function fa different from the steering function fa shown in FIG. 2 may be used. For example, a steering function fa specified by a relational expression “φ = (Ka / θmax) × θ (where Ka is an arbitrary constant)” may be used. For example, a steering function fa that is a nonlinear function may be used.

  In the example shown in FIG. 2, the steering function fm is a linear function. Specifically, in the example illustrated in FIG. 2, the relational expression “φ = fm (θ)” is a relational expression “φ = (540 / θmax) × θ”. This relational expression shows that, when the vehicle 1 is traveling in the manual mode, when the passenger turns the steering wheel 134 one and a half times (rotates 540 degrees), the wheels 11 are snaked to the maximum extent. Means. However, the steering function fm shown in FIG. 2 is merely an example. For this reason, a steering function fm different from the steering function fm shown in FIG. 2 may be used. For example, a steering function fm specified by a relational expression “φ = (Km / θmax) × θ (where Km is an arbitrary constant)” may be used. For example, a steering function fm that is a nonlinear function may be used.

  Particularly in the first embodiment, as shown in FIG. 2, the change amount of the steering angle φ with respect to the snake angle θ in the steering function fa is smaller than the change amount of the steering angle φ with respect to the snake angle θ in the steering function fm. . That is, the amount of change Δφa of the steering angle φ with respect to the predetermined amount of change Δθ of the snake angle θ in the steering function fa is smaller than the amount of change Δφm of the steering angle φ with respect to the predetermined amount of change ∆θ of the snake angle θ in the steering function fm . In other words, the gradient of the steering function fa (that is, Δφa / Δθ) is smaller than the gradient of the steering function fm (that is, Δφm / Δθ). As a result, when the vehicle 1 is traveling in the automatic mode, the amount of rotation of the steering wheel 134 is smaller than when the vehicle 1 is traveling in the manual mode. For this reason, when the vehicle 1 is traveling in the automatic mode, the occupant can recognize the snake direction from the movement of the steering wheel 134 without being bothered by the movement of the steering wheel 134.

(2) Second Embodiment Next, a vehicle 2 to which a second embodiment of the steering apparatus of the present invention is applied will be described.

  In the first embodiment described above, when the traveling mode of the vehicle 1 is switched from the automatic mode to the manual mode, the steering function f is also switched from the steering function fa to the steering function fm at the same time. Similarly, when the traveling mode of the vehicle 1 is switched from the manual mode to the automatic mode, the steering function f is also switched from the steering function fm to the steering function fa at the same time. In this case, simply by switching the steering function f, after the steering function f is switched, the steering angle φ is not zero although the steering angle φ is zero (or the rolling angle θ There is a possibility that the steering angle φ is not zero even though is zero). Such a situation occurs when the steering function f is switched under a situation where the steering angle φ and the snake angle θ are not zero. In other words, such a situation occurs when the steering function f is switched under a situation where the steering angle φ and the snake-turning angle θ are different from the values corresponding to the intersections of the steering function fa and the steering function fm. Arise. For example, in the example shown in FIG. 2, the steering function f switches from the steering function fa to the steering function fm under the situation where the steering angle φ is φa (≠ 0) and the meander angle θ is θa (≠ 0). Is assumed. In this case, in order to maintain the continuity of the steering angle φ and the meander angle θ before and after the switching of the steering function f, the steering function f has the same inclination as the steering function fm as an operation of switching the steering function f to the steering function fm. And the operation of switching to the steering function fmp (see the dotted line relational expression in FIG. 2) passing through the coordinates (φa, θa) is performed. Therefore, as apparent from FIG. 2, the steering angle φ is not zero even though the steering angle φ is zero (or the steering angle φ is zero when the steering angle θ is zero). Is not zero). Therefore, there is a possibility that a technical problem that a passenger operating the steering wheel 134 has a great sense of incongruity. In order to avoid the occurrence of such a situation, the steering angle f is switched from the steering function fa to the steering function fm at the same time as the steering angle φ is φa and the snake angle θ is θa. A countermeasure for switching the steering function from the steering angle φa corresponding to the steering function fa and the meander angle θa to the steering angle φm corresponding to the steering function fm and the meander angle θa can be considered. However, as the steering function f is switched, the steering angle φ changes suddenly (that is, the steering wheel 134 rotates suddenly), and thus there is a technical problem that the passenger operating the steering wheel 134 has a great sense of incongruity. It can still happen.

  The second embodiment of the steering device of the present invention suppresses the occurrence of such a technical problem that may occur when the steering function f is switched. Hereinafter, the vehicle 2 to which the second embodiment of the steering apparatus of the present invention is applied will be described with reference to FIG. In addition, about the component same as the component with which the vehicle 1 mentioned above is provided, the detailed description is abbreviate | omitted by providing the same referential mark.

  As shown in FIG. 3, the vehicle 2 of the second embodiment is different from the vehicle 1 of the first embodiment in that the steering device 23 includes a function setting unit 239 instead of the function setting unit 139. Is different. Other components of the vehicle 2 may be the same as other components of the vehicle 1.

  When the travel mode of the vehicle 1 is switched from the manual mode to the automatic mode, the function setting unit 239 replaces the steering function f from the steering function fm to the steering function fa and replaces the steering function f with the steering function fm. To the steering function fa0. When the travel mode of the vehicle 1 is switched from the automatic mode to the manual mode, the function setting unit 239 replaces the steering function f from the steering function fa to the steering function fm, and replaces the steering function f with the steering function fa. Is switched to the steering function fm0. Hereinafter, the steering functions fa0 and fm0 will be described in more detail with reference to FIGS.

  FIG. 4 shows the steering function fm0. The steering function fm0 is a steering function f that satisfies the following three conditions (first condition, second condition, and third condition). That is, the steering function fm0 is a steering function f that defines a correspondence relationship that the steering angle φ and the snake-turn angle θ should satisfy so as to satisfy the following three conditions.

  The first condition is a correspondence relationship between the snake angle θd detected by the snake angle monitoring device 131 when the travel mode is switched and the steering angle φd detected by the steering angle monitoring device 135 when the travel mode is switched. It is a condition that can be satisfied. In the following description, the meandering angle θd detected by the meandering angle monitoring device 131 when the travel mode is switched is referred to as “reference meandering angle θ0”. Further, the steering angle φd detected by the steering angle monitoring device 135 when the traveling mode is switched is referred to as “reference steering angle φ0”. Therefore, the first condition is a condition that φ0 = fm0 (θ0) is satisfied. In other words, the first condition is a condition that the steering function fm0 is a function that passes the coordinates P1 (φ0, θ0).

  The second condition is a condition that makes it possible to match the attitude of the steering wheel 134 with the attitude of the steering wheel 134 when the steering angle φ is zero under a situation where the snake angle θ is zero. Hereinafter, the attitude of the steering wheel 134 when the steering angle φ is zero is referred to as a “first reference attitude”. Specifically, it is assumed that the posture of the steering wheel 134 becomes the same every time the steering wheel 134 rotates by a predetermined angle R. In this case, the attitude of the steering wheel 134 when the steering angle φ is zero, and the attitude and steering angle φ of the steering wheel 134 when the steering angle φ is + k × R (where k is an integer of 1 or more) are −. Each of the postures of the steering wheel 134 when k × R is the first reference posture. Therefore, the second condition is a condition that 0 = fm0 (0), + k × R = fm0 (0), or −k × R = fm0 (0) is satisfied. In other words, the second condition is a condition that the steering function fm0 becomes a function that passes the coordinates (0, 0), the coordinates (+ k × R, 0), or the coordinates (−k × R, 0).

  FIG. 4 shows an example in which the attitude of the steering wheel 134 becomes the same every time the steering wheel 134 rotates 360 degrees. In this case, the attitude of the steering wheel 134 when the steering angle φ becomes zero, the attitude of the steering wheel 134 when the steering angle φ becomes +360 degrees, and the attitude of the steering wheel 134 when the steering angle φ becomes −360 degrees Each of these is the first reference posture. Therefore, in the example illustrated in FIG. 4, the second condition is a condition that 0 degree = fm0 (0), +360 degrees = fm0 (0), or −360 degrees = fm0 (0) is satisfied. In other words, the second condition is a condition that the steering function fm0 becomes a function that passes through the coordinate P2 ″ (0, 0), the coordinate P2 ′ (+360, 0), or the coordinate P2 (−360, 0).

  The third condition is that the change tendency of the snake angle θ with respect to the steering angle φ in the steering function fm0 is most similar to the change tendency of the snake angle θ with respect to the steering angle φ in the steering function fm. The “change tendency” here typically means the inclination of the steering function f. Therefore, “the state in which the change tendency of the steering function fm0 is most similar to the change tendency of the steering function fm” typically means that “the sign of the inclination of the steering function fm0 matches the sign of the inclination of the steering function fm. Means that the inclination of the steering function fm0 is closest to the inclination of the steering function fm. More specifically, “the state in which the change tendency of the steering function fm0 is most similar to the change tendency of the steering function fm” typically indicates that the sign of the inclination of the steering function fm0 is the sign of the inclination of the steering function fm. This means a state in which a steering angle φ2 described later is closest to a steering angle φ1 described later under a situation where the condition of matching is satisfied.

  There may be a plurality of steering functions fm0 that satisfy both the first and second conditions described above. The third condition can specify one steering function fm0 that is actually used to calculate the target rolling angle θtg from such a plurality of steering functions fm0. For example, in the example illustrated in FIG. 4, the steering function fm0-1 that passes through the coordinates P1 (φ0, θ0) and the coordinates P2 (−360, 0) as the steering function fm0 that satisfies both the first and second conditions, the coordinates Steering function fm0-2 passing through P1 (φ0, θ0) and coordinate P2 ′ (+360, 0), and steering function fm0− passing through coordinate P1 (φ0, θ0) and coordinate P2 ″ (0, 0) 3 (= steering function fa) exists. Here, the change tendency of the steering function fm0-1 is more similar to the change tendency of the steering function fm than the change tendency of the steering functions fm0-2 and fm0-3. Therefore, in the example shown in FIG. 4, the steering function fm0-1 is the steering function fm0 that is actually used to calculate the target rolling angle θtg.

  The steering function fm0 that satisfies these three conditions is calculated by the function setting unit 239 through the following procedure. First, the function setting unit 239 calculates a linear steering function fm ′ that passes the coordinates P1 (φ0, θ0) and has the same inclination as the steering function fm. Thereafter, the function setting unit 239 calculates a steering angle φ1 that satisfies φ1 = fm ′ (0). That is, the function setting unit 239 calculates the steering angle φ1 corresponding to the coordinates of the intersection point of the steering function fm ′ and the straight line that defines the rolling snake angle θ = 0. After that, the function setting unit 239 calculates the steering angle φ2 that is closest to the steering angle φ1 and at which the posture of the steering wheel 134 becomes the first reference posture. In the example shown in FIG. 4, the steering angle φ2 is −360 degrees. Thereafter, the function setting unit 239 calculates a steering function fm0 that passes through the coordinates P1 (φ0, θ0) and the coordinates P2 (φ2, 0).

  However, the steering function fm0 passing through the coordinates P1 (φ0, θ0) and the coordinates P2 (φ2, 0) reliably satisfies the first and second conditions described above, but does not satisfy the third condition (particularly, steering). The sign of the slope of the function fm0 may not be the same as the sign of the slope of the steering function fm). If the calculated steering function fm0 does not satisfy the third condition, the function setting unit 239 newly sets the steering angle φ2 that is the second closest to the steering angle φ1 and the posture of the steering wheel 134 becomes the first reference posture. calculate. Thereafter, the function setting unit 239 newly sets the steering function fm0 based on the newly calculated steering angle φ2. Thereafter, the function setting unit 239 repeats the same operation until the steering function fm0 that satisfies the third condition is calculated.

  When the travel mode of the vehicle 1 is switched from the automatic mode to the manual mode, the target snake angle calculator 136 first calculates the target snake angle θtg based on the steering function fm0. As a result, at the timing when the steering angle φ becomes φ2 (−360 degrees in FIG. 4), the attitude of the steering wheel 134 becomes the first reference attitude and the meander angle θ becomes zero. For this reason, there is no situation where the steering wheel 134 is not in the first reference posture even though the snake serpentine angle θ is zero. The state in which the posture of the steering wheel 134 is the first reference posture is substantially equivalent to a state in which the steering angle φ is zero. Therefore, there is no situation where the steering angle θ is not zero although the steering angle φ is zero (that is, the attitude of the steering wheel 134 is the first reference attitude). In other words, there is no situation in which the steering angle φ is not zero (that is, the attitude of the steering wheel 134 is not in the first reference attitude) even though the meander angle θ is zero. Therefore, the steering device 23 can alleviate the uncomfortable feeling that the passenger may hold when the traveling mode is switched from the automatic mode to the manual mode (that is, the steering function f is switched).

  While the target rolling angle calculation unit 136 calculates the target rolling angle θtg based on the steering function fm0, the rolling angle θ may become zero. In this case, as shown in FIG. 5, the function setting unit 239 changes the steering function f from the steering function fm0 to the steering function having the same inclination as the steering function fm and passing the coordinate P2 (φ2, 0). You may switch to fm0 ′. The operation of switching the steering function f to the steering function fm0 'substantially corresponds to the operation of switching the steering function f to the steering function fm. This is because the state in which both the steering angle φ and the tumbling angle θ are zero in the steering function fm is substantially the same as the state in which the steering angle Φ is φ2 and the snake angle θ is zero in the steering function fm0 ′. This is because they are the same. Therefore, the target snake squeezing angle calculator 136 can calculate the target snake snake angle θtg substantially based on the steering function fm. That is, in the second embodiment, when the travel mode of the vehicle 1 is switched from the automatic mode to the manual mode, the target rolling angle calculation unit 136 first calculates the target rolling angle θtg based on the steering function fm0. After that, an operation for calculating the target rolling angle θtg based on the steering function fm is performed.

  FIG. 6 shows the steering function fm0 calculated under a situation where the coordinates P1 (φ0, θ0) are different from those of the steering function fm0 shown in FIG. However, in the example shown in FIG. 6, the steering angle φ2 is zero. For this reason, the steering function fm0 coincides with the steering function fa.

  FIG. 7 shows the steering function fa0. Similarly to the steering function fm0, the steering function fa0 is also a steering function f that satisfies the first to third conditions described above. However, in the third condition that the steering function fa0 satisfies, compared to the third condition that the steering function fm0 satisfies, the change tendency of the snake angle θ with respect to the steering angle φ in the “steering function fa0” is the “steering function fa”. The difference is that the condition is the most similar to the change tendency of the snake angle θ with respect to the steering angle φ. Accordingly, in the steering function fa0, the change tendency of the snake angle θ with respect to the steering angle φ in the steering function fa is the change tendency of the snake angle θ with respect to the steering angle φ in the steering function fa0. It can be said that the steering function f satisfies the fourth condition of being most similar to.

  The function setting unit 239 calculates the steering function fa0 by following the same procedure as that to be performed when calculating the steering function fm0. Specifically, the function setting unit 239 calculates a linear steering function fa ′ that passes the coordinate P1 (φ0, θ0) and has the same inclination as the steering function fa. Thereafter, the function setting unit 239 calculates a steering angle φ1 that satisfies φ1 = fa ′ (0). After that, the function setting unit 239 calculates the steering angle φ2 that is closest to the steering angle φ1 and at which the posture of the steering wheel 134 becomes the first reference posture. Thereafter, the function setting unit 239 calculates a steering function fa0 that passes through the coordinates P1 (φ0, θ0) and the coordinates P2 (φ2, 0).

  FIG. 7 shows an example in which the attitude of the steering wheel 134 becomes the same every time the steering wheel 134 rotates 360 degrees. In the example shown in FIG. 7, the steering angle φ2 that is closest to the steering angle φ1 and the attitude of the steering wheel 134 is the first reference attitude should be +360 degrees originally. However, the sign of the inclination of the steering function fa0 passing through the coordinates P1 (φ0, θ0) and the coordinates P2 (+360, 0) is not the same as the sign of the inclination of the steering function fa. For this reason, 0 degree is used as the steering angle φ2 that is second closest to the steering angle φ1 and in which the posture of the steering wheel 134 becomes the first reference posture. Therefore, the steering function fa0 is the steering function f that passes through the coordinates P1 (φ0, θ0) and the coordinates P2 (0, 0). In the example shown in FIG. 7, the steering function fa0 matches the steering function fm.

  When the travel mode of the vehicle 1 is switched from the manual mode to the automatic mode, the target steering angle calculation unit 132 first calculates the target steering angle φtg based on the steering function fa0. As a result, at the timing at which the steering angle φ becomes φ2 (0 degree in FIG. 7), the steering wheel 134 is in the first reference posture and the snake angle θ is zero. For this reason, there is no situation where the steering wheel 134 is not in the first reference posture even though the snake serpentine angle θ is zero. Therefore, the steering device 23 can alleviate the uncomfortable feeling that the passenger may have when the traveling mode is switched from the manual mode to the automatic mode (that is, the steering function f is switched).

  While the target steering angle calculation unit 132 calculates the target steering angle φtg based on the steering function fa0, the turning angle θ may become zero. In this case, the function setting unit 239 may switch the steering function f from the steering function fa0 to the steering function fa0 ′ having the same inclination as the steering function fa and passing through the coordinates P2 (φ2, 0). . The operation of switching the steering function f to the steering function fa0 'substantially corresponds to the operation of switching the steering function f to the steering function fa. Therefore, the target steering angle calculator 132 can substantially calculate the target steering angle φtg based on the steering function fa. That is, in the second embodiment, when the travel mode of the vehicle 1 is switched from the manual mode to the automatic mode, the target steering angle calculation unit 132 first calculates the target steering angle φtg based on the steering function fa0. After that, the operation of calculating the target steering angle φtg based on the steering function fa is performed.

  FIG. 8 shows the steering function fa0 calculated under the situation where the coordinates P1 (φ0, θ0) are different from those of the steering function fa0 shown in FIG. FIG. 9 shows a situation where the coordinates P1 (φ0, θ0) are different from the steering function fm0 shown in FIG. 4, and the attitude of the steering wheel 134 is the same every time the steering wheel 134 rotates 180 degrees. The steering function fm0 calculated under the situation becomes. FIG. 10 shows the steering function fm0 calculated in a situation where the coordinates P1 (φ0, θ0) are different from those of the steering function fm0 shown in FIG. 11 shows a situation where the coordinates P1 (φ0, θ0) are different from the steering function fa0 shown in FIG. 7, and the attitude of the steering wheel 134 is the same every time the steering wheel 134 rotates 180 degrees. The steering function fa0 calculated under the situation becomes. FIG. 12 shows the steering function fa0 calculated under a situation where the coordinates P1 (φ0, θ0) are different from those of the steering function fa0 shown in FIG.

(3) Third Embodiment Next, a vehicle 3 to which a third embodiment of the steering apparatus of the present invention is applied will be described.

  In 2nd Embodiment mentioned above, the discomfort which a passenger may hold | maintain with the switching of driving modes (switching of the steering function f) is relieved. On the other hand, in the second embodiment, the wheel 11 rotates to the maximum in a situation where the target rolling angle θtg is calculated based on the steering function fm0 or the target steering angle φtg is calculated based on the steering function fa0. When snaked (that is, when the snake angle θ becomes θmax), the posture of the steering wheel 134 is different from the posture that the steering wheel 134 should originally take when the wheel 11 is snaked to the maximum. There is a possibility of becoming. For example, in the example shown in FIG. 4, when the wheel 11 is snaked to the maximum, the steering angle φ should be 540 degrees. However, in the situation where the target rolling angle θtg is calculated based on the steering function fm0, the steering angle φ is 540 degrees (or 540 degrees ± 360 degrees × k) when the wheel 11 is swung to the maximum. ) Does not. Therefore, there is a possibility that a technical problem that a passenger operating the steering wheel 134 has a great sense of incongruity.

  The third embodiment of the steering device of the present invention suppresses the occurrence of such technical problems that may occur when the wheels 11 are snaked to the maximum. Hereinafter, the vehicle 3 to which the third embodiment of the steering apparatus of the present invention is applied will be described with reference to FIG. In addition, about the component same as the component with which the vehicle 2 mentioned above is provided, the detailed description is abbreviate | omitted by providing the same referential mark.

  As shown in FIG. 13, the vehicle 3 of the third embodiment is different from the vehicle 2 of the second embodiment in that the steering device 33 includes a function setting unit 339 instead of the function setting unit 239. Is different. Other components of the vehicle 3 may be the same as the other components of the vehicle 2.

  The function setting unit 339 differs from the function setting unit 239 in that the steering functions fm0 and fa0 to be set are different from the steering functions fm0 and fa0 of the second embodiment, respectively. Hereinafter, the steering functions fa0 and fm0 of the third embodiment will be described in more detail with reference to FIGS.

  FIG. 14 shows the steering function fm0. A steering function fm2 that defines a correspondence relationship that the steering angle φ and the snake angle θ should satisfy within a range of the steering function fm0 that is equal to or smaller than the reference snake angle θ0 is the same as the steering function fm0 of the second embodiment described above. . Therefore, the steering function fm2 is a function that passes through the coordinate P1 (φ0, θ0) and the coordinate P2 (φ2, 0). On the other hand, the steering function fm4 that defines the correspondence relationship that the steering angle φ and the snake angle θ should satisfy within the range of the reference snake angle θ0 or more of the steering function fm0 includes the first condition described above and the following: The steering function f satisfies the two conditions (fifth condition and sixth condition).

  The fifth condition is a condition that makes it possible to make the attitude of the steering wheel 134 coincide with the second reference attitude under the situation where the rolling angle θ is θmax. The second reference posture is the posture of the steering wheel 134 when the turning angle θ becomes θmax under the condition where the target turning angle θtg is calculated based on the steering function fm. Specifically, it is assumed that the posture of the steering wheel 134 becomes the same every time the steering wheel 134 rotates by a predetermined angle R. Here, in a situation where the target snake angle θtg is calculated based on the steering function fm, it is assumed that the steering angle φ becomes φmax when the snake angle θ is θmax. In this case, the attitude of the steering wheel 134 when the steering angle φ becomes φmax, the attitude of the steering wheel 134 when the steering angle φ becomes φmax + k × R, and the steering wheel when the steering angle φ becomes φmax−k × R. Each of the 134 postures is the second reference posture. Accordingly, the fifth condition is that φmax = fm4 (θmax), φmax + k × R = fm4 (θmax), or φmax−k × R = fm4 (θmax) is satisfied. In other words, the second condition is a condition that the steering function fm4 becomes a function that passes the coordinates (φmax, θmax), (φmax + k × R, θmax) or the coordinates (φmax−k × R, θmax).

  FIG. 14 shows an example in which the attitude of the steering wheel 134 becomes the same every time the steering wheel 134 rotates 360 degrees. Further, FIG. 14 shows an example in which the steering angle φ is 540 degrees when the wheel 11 is snaked to the maximum in a situation where the target rolling angle θtg is calculated based on the steering function fm. In this case, the attitude of the steering wheel 134 when the steering angle φ is 540 degrees, the attitude of the steering wheel 134 when the steering angle φ is +180 degrees, and the steering wheel 134 when the steering angle φ is −180 degrees. Each of the postures of the steering wheel 134 when the posture and the steering angle φ are −540 degrees is the second reference posture. Therefore, in the example shown in FIG. 14, the fifth condition satisfies +540 degrees = fm4 (θmax), +180 degrees = fm4 (θmax), −180 degrees = fm4 (θmax), or −540 degrees = fm4 (θmax). This is the condition. In other words, the fifth condition is that the steering function fm4 is coordinate P3 (+180, θmax), coordinate P3 ′ (−180, θmax), coordinate P3 ″ (+540, θmax) or coordinate P3 ′ ″ (−540, θmax). ).

  The sixth condition is that the change tendency of the snake angle θ with respect to the steering angle φ in the steering function fm4 is most similar to the change tendency of the snake angle θ with respect to the steering angle φ in the steering function fm. There may be a plurality of steering functions fm4 that satisfy both the first and fifth conditions described above. The sixth condition can specify one steering function fm4 that is actually used to calculate the target rolling angle θtg from such a plurality of steering functions fm4. For example, in the example shown in FIG. 14, the steering function fm4-1 that passes through the coordinates P1 (φ0, θ0) and the coordinates P3 (+180, θmax), the coordinates P1 as the steering function fm4 that satisfies both the first and fifth conditions. Steering function fm4-2 passing through (φ0, θ0) and coordinate P3 ′ (−180, θmax), steering function fm4-3 passing through coordinate P1 (φ0, θ0) and coordinate P3 ″ (+540, θmax), In addition, there is a steering function fm4-4 that passes through the coordinate P1 (φ0, θ0) and the coordinate P3 ′ ″ (−540, θmax). Here, the change tendency of the steering function fm4-1 is more similar to the change tendency of the steering function fm than the change tendency of the steering functions fm4-2 to fm4-4. Therefore, in the example shown in FIG. 14, the steering function fm4-1 is the steering function fm4 that is actually used to calculate the target rolling angle θtg.

  The steering function fm4 that satisfies these three conditions is calculated by the function setting unit 339 according to the following procedure. First, the function setting unit 339 calculates the steering function fm ′ described above. Thereafter, the function setting unit 339 calculates a steering angle φ3 that satisfies φ3 = fm ′ (θmax). After that, the function setting unit 339 calculates the steering angle φ4 that is closest to the steering angle φ3 and at which the attitude of the steering wheel 134 becomes the second reference attitude. That is, the function setting unit 339 calculates the coordinates P3 (φ4, θmax). In the example shown in FIG. 14, the steering angle φ4 is +180 degrees. Thereafter, the function setting unit 339 calculates a steering function fm4 that passes through the coordinates P1 (φ0, θ0) and the coordinates P3 (φ4, θmax).

  However, the steering function fm4 that passes through the coordinates P1 (φ0, θ0) and the coordinates P3 (φ4, θmax) reliably satisfies the first and fifth conditions described above, but does not satisfy the sixth condition (in particular, steering). The sign of the slope of the function fm4 may not be the same as the sign of the slope of the steering function fm). If the calculated steering function fm4 does not satisfy the sixth condition, the function setting unit 339 newly sets the steering angle φ4 that is second closest to the steering angle φ3 and the posture of the steering wheel 134 becomes the second reference posture. calculate. Thereafter, the function setting unit 339 newly sets the steering function fm4 based on the newly calculated steering angle φ4. Thereafter, the function setting unit 339 repeats the same operation until the steering function fm4 that satisfies the sixth condition is calculated.

  When the travel mode of the vehicle 1 is switched from the automatic mode to the manual mode, the target squeeze angle calculation unit 136 first sets the target sway angle θtg based on the steering function fm0 composed of the steering functions fm2 and fm4. Is calculated. As a result, the attitude of the steering wheel 134 becomes the second reference attitude at the timing when the wheel 11 is snaked to the maximum. Therefore, the steering device 33 can relieve the uncomfortable feeling that the passenger may hold when the wheel 11 is snaked to the maximum.

  FIG. 15 shows the steering function fm0 calculated under a situation where the coordinates P1 (φ0, θ0) are different from those of the steering function fm0 shown in FIG.

  FIG. 16 shows the steering function fa0. The steering function fa2 that defines the correspondence relationship that the steering angle φ and the snake angle θ should satisfy within the range of the reference snake angle θ0 within the steering function fa0 is the same as the steering function fa0 of the second embodiment described above. . Therefore, the steering function fa2 is a function that passes through the coordinate P1 (φ0, θ0) and the coordinate P2 (φ2, 0). On the other hand, the steering function fa4 that defines the correspondence relationship that the steering angle φ and the snake angle θ should satisfy within the range of the reference snake angle θ0 of the steering function fa0 is the same as the first steering function fm4 described above. , The steering function f that satisfies the fifth and sixth conditions. However, in the fifth condition that the steering function fa4 satisfies, the second reference attitude is calculated based on the “steering function fa” and the “target steering angle φtg” as compared with the fifth condition that the steering function fm4 satisfies. The difference is that the steering wheel 134 is in a posture in the case where the meander angle θ is θmax under the circumstances. Further, in the sixth condition that the steering function fa4 satisfies, as compared with the sixth condition that the steering function fm4 satisfies, the change tendency of the snake angle θ with respect to the steering angle φ in the “steering function fa4” is the “steering function fa”. The difference is that the condition is the most similar to the change tendency of the snake angle θ with respect to the steering angle φ. Therefore, the steering function fa4 has the above-described first and fifth conditions, and the change tendency of the snake angle θ with respect to the steering angle φ in the steering function fa4 is the change in the snake angle θ with respect to the steering angle φ in the steering function fa. The steering function f satisfies the seventh condition of being most similar to the tendency.

  The function setting unit 339 calculates the steering function fa4 by following the same procedure as that to be followed when calculating the steering function fm4. Specifically, the function setting unit 339 calculates the steering function fa ′ described above. Thereafter, the function setting unit 339 calculates a steering angle φ3 that satisfies φ3 = fa ′ (θmax). After that, the function setting unit 339 calculates the steering angle φ4 that is closest to the steering angle φ3 and at which the posture of the steering wheel 134 becomes the third reference posture. Thereafter, the function setting unit 339 calculates the steering function fa4 that passes through the coordinates P1 (φ0, θ0) and the coordinates P3 (φ4, θmax).

  FIG. 16 shows an example in which the attitude of the steering wheel 134 becomes the same every time the steering wheel 134 rotates 360 degrees. Further, FIG. 16 shows an example in which the steering angle φ is 180 degrees when the wheel 11 is snaked to the maximum while the target rolling angle θtg is calculated based on the steering function fa. In the example shown in FIG. 16, the steering angle φ4 that is closest to the steering angle φ3 and the posture of the steering wheel 134 is the second reference posture is +540 degrees. Therefore, the steering function fa4 is the steering function f that passes through the coordinate P1 (φ0, θ0) and the coordinate P3 (+540, θmax).

  When the travel mode of the vehicle 1 is switched from the manual mode to the automatic mode, the target steering angle calculation unit 132 first calculates the target steering angle φtg based on the steering function fa0 configured by the steering functions fa2 and fa4. To do. As a result, the attitude of the steering wheel 134 becomes the second reference attitude at the timing when the wheel 11 is snaked to the maximum. Therefore, the steering device 33 can relieve the uncomfortable feeling that the passenger may hold when the wheel 11 is snaked to the maximum.

  FIG. 17 shows the steering function fa0 calculated under a situation where the coordinates P1 (φ0, θ0) are different from those of the steering function fa0 shown in FIG. FIG. 18 shows a situation where the coordinates P1 (φ0, θ0) are different from the steering function fm0 shown in FIG. 14, and the attitude of the steering wheel 134 is the same every time the steering wheel 134 rotates 180 degrees. The steering function fm0 calculated under the situation becomes. FIG. 19 shows the steering function fm0 calculated in a situation where the coordinates P1 (φ0, θ0) are different from those of the steering function fm0 shown in FIG. FIG. 20 shows a situation where the coordinates P1 (φ0, θ0) are different from the steering function fa0 shown in FIG. 16, and the attitude of the steering wheel 134 is the same every time the steering wheel 134 rotates 180 degrees. The steering function fa0 calculated under the situation becomes. FIG. 21 shows the steering function fa0 calculated under a situation where the coordinates P1 (φ0, θ0) are different from those of the steering function fa0 shown in FIG. In the example shown in FIG. 21, the steering angle φ4 that is closest to the steering angle φ3 and the posture of the steering wheel 134 becomes the second reference posture is supposed to be +360 degrees originally. However, the sign of the inclination of the steering function fa4 is not the same as the sign of the inclination of the steering function fa4 with the coordinate P1 (φ0, θ0) and the coordinate P3 (+360, θmax). Therefore, as the steering angle φ4, +540 degrees that is second closest to the steering angle φ3 and the attitude of the steering wheel 134 becomes the second reference attitude is used. Therefore, the steering function fa4 is the steering function f that passes through the coordinate P1 (φ0, θ0) and the coordinate P3 (+540, θmax).

  The present invention can be appropriately changed without departing from the gist or concept of the present invention that can be read from the claims and the entire specification, and a steering apparatus that includes such a change is also included in the technical concept of the present invention. It is.

1, 2, 3 Vehicle 11 Wheel 13 Steering device 131 Rolling angle monitoring device 132 Target steering angle calculation unit 133 Steer actuator 134 Steering wheel 135 Steering angle monitoring device 136 Target rolling angle calculation unit 137 Rolling actuator 139, 239, 339 Function setting unit f, fm, fa, fm0, fa0 Steering function φ Steering angle φtg Target steering angle φ0 Standard steering angle θ Tail angle θtg Target tread angle θ0 Standard tread angle

Claims (1)

A steer-by-wire steering device for steering a vehicle that can be switched between a manual mode that travels based on a passenger's operation and an automatic mode that travels automatically without being based on a passenger's operation. And
A steering member that can be operated by the occupant to meander the wheels of the vehicle and that has the same posture every time it rotates a predetermined angle;
A first actuator capable of driving the steering member such that a steering angle of the steering member becomes a first target angle;
A second actuator capable of driving the wheel such that the rolling angle of the wheel becomes a second target angle;
Detecting means for detecting the steering angle and the snake angle;
When the traveling mode of the vehicle is the manual mode, the vehicle corresponds to the steering angle detected by the detection unit based on a first function that defines a correspondence relationship that the steering angle and the snake-turning angle should satisfy. First calculating means for calculating the second target angle;
When the traveling mode of the vehicle is the automatic mode, a change in the steering angle with respect to the snake angle is defined with respect to the snake angle, which defines a correspondence relationship that the steering angle and the snake angle need to satisfy Second calculating means for calculating the first target angle corresponding to the meandering angle detected by the detecting means based on a second function with a small amount;
When the travel mode is switched from the automatic mode to the manual mode, the first calculation means may calculate (i) the travel mode before calculating the second target angle based on the first function. The first condition that the correspondence between the steering angle detected by the detection means at the timing when the detection means is switched and the rolling angle is satisfied, and (ii) the steering is performed under the situation where the rolling angle is zero. The second condition that the attitude of the member matches the attitude of the steering member when the steering angle is zero, and (iii) the change tendency of the snake angle with respect to the steering angle is expressed in the first function Corresponding to the steering angle detected by the detection means based on a third function that defines a correspondence relationship that the steering angle and the snake-turning angle should satisfy so as to satisfy the third condition of being most similar to the change tendency. Second eye To calculate the corner,
When the travel mode is switched from the manual mode to the automatic mode, the second calculation means (i) the first target before calculating the first target angle based on the second function. The steering angle so as to satisfy a condition that (ii) the second condition, and (iii) the change tendency of the snake angle with respect to the steering angle is most similar to the change tendency in the second function. And a first target angle corresponding to the rolling angle detected by the detecting means, based on a fourth function that defines a correspondence relationship to be satisfied by the rolling angle and the rolling angle.

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