JP2009029399A - Steering device, steering reaction force simulating device, and steering reaction force setting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a vibration level when the vibration occurs in a steering wheel when the hysteresis is given to the steering reaction force characteristic when the steering wheel is additionally turned and when the steering wheel is returned. <P>SOLUTION: If the additionally turning/returning direction of a steering wheel is changed when a steering reaction force command value Tp* is on a second characteristic line (for example, B, D), an inclination of the steering reaction force command value Tp* is increased from K2 to K1. If a steering angle θh reaches an angle corresponding to the intersection of the first characteristic line with the second characteristic line, when the steering reaction force command value Tp* is on the first characteristic line (for example, A2), the inclination of the steering reaction force command value Tp* is decreased from K1 to K2. If the steering reaction force command value Tp* is in a set range in a vicinity of 0 when the steering reaction force command value Tp* is on the first characteristic line, the inclination on the first characteristic line is set to be K3 which is smaller than K1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a steering device, a steering reaction force simulation device, and a steering reaction force setting method. More specifically, the present invention relates to a steering device and a steering reaction force simulation device that output a steering reaction force according to the operation of the steering wheel. The present invention relates to a steering reaction force setting method for setting a corresponding steering reaction force.

  Conventionally, as this type of steering device, as disclosed in Patent Document 1 below, a steering reaction force is set with hysteresis characteristics based on the steering angle of the steering wheel and the determination result of the steering wheel turning back and forth. Has been proposed. The hysteresis characteristic here is the first characteristic in which the steering reaction force changes with the first inclination K1 with respect to the change in the steering angle, and the steering reaction force with respect to the change in the steering angle with respect to the first inclination K1. And a second characteristic that changes with a small second inclination K2, and when the steering reaction force with respect to the steering angle is on the second characteristic, the steering angle is increased and the return direction is changed. When the steering reaction force with respect to the steering angle changes from the second inclination K2 to the first inclination K1 and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle is the first characteristic and the second characteristic. When the angle corresponding to the intersection with is reached, the inclination of the steering reaction force with respect to the steering angle changes from the first inclination K1 to the second inclination K2. In this steering apparatus, by increasing the value of the first inclination K1, a hysteresis that approximates Coulomb friction is given to the steering reaction force characteristic by a spring element having a high rigidity (spring constant), and the hysteresis characteristic that does not depend on the steering speed is obtained. It is reproduced.

Japanese Patent No. 3889916

  In the above steering device, when the minimum resolution of the steering angle sensor for detecting the steering angle of the steering wheel is not sufficiently high, self-excited vibration is likely to be generated in the steering wheel. It will make you feel uncomfortable and uncomfortable. For example, self-excited vibration is likely to occur when the handle is released. By reducing the value of the first slope K1 in the hysteresis characteristic, the level of self-excited vibration can be reduced, but on the other hand, the hysteresis characteristic due to Coulomb friction cannot be sufficiently obtained, and the steering feeling is reduced. This is a trade-off relationship of lowering.

  It is an object of the present invention to suppress the level of steering wheel vibration that occurs when the steering wheel is released when hysteresis is given to the steering reaction force characteristics when the steering wheel is increased and turned back.

  The steering device, the steering reaction force simulation device, and the steering reaction force setting method according to the present invention employ the following means in order to achieve the above-described object.

  The steering device according to the present invention is a vehicle-mounted steering device that outputs a steering reaction force corresponding to the operation of the steering wheel, and is based on the steering angle detection means that detects the steering angle of the steering wheel, and the detected steering angle. The target steering reaction force is set with a hysteresis characteristic based on the determination result by the increase / return determination unit and the detected steering angle. Target steering reaction force setting means, and steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output, and the hysteresis characteristic is in response to a change in steering angle. A first characteristic in which the steering reaction force changes with a first inclination; and a second characteristic in which the steering reaction force changes with a second inclination smaller than the first inclination with respect to a change in steering angle. Including a steering reaction force with respect to a steering angle. When the direction of the additional turning back of the steering wheel changes in the case of the characteristic, the inclination of the steering reaction force with respect to the steering angle changes from the second inclination to the first inclination, and the steering reaction force with respect to the steering angle. When the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic, the inclination of the steering reaction force with respect to the steering angle is the first characteristic. The target steering reaction force setting means has a characteristic in which the target steering reaction force is near zero when the steering reaction force with respect to a steering angle is on the first characteristic. When it is within the set range, the gist is to set the inclination of the steering reaction force with respect to the steering angle in the first characteristic to a third inclination smaller than the first inclination.

  In one aspect of the present invention, the steering angle detecting means is means for detecting a steering angle with a predetermined resolution Δθh, and the setting range has K3 × Δθh as its upper limit, where the third inclination is K3. , −K3 × Δθh is preferably in the range of the lower limit. In this aspect, it is preferable that the target steering reaction force setting means sets the third inclination K3 so that the value of K3 × Δθh is smaller than the allowable vibration value that changes according to the vibration frequency of the steering wheel. is there.

  In one aspect of the present invention, the apparatus further includes an inclination setting receiving unit that is operated by an operator of a handle and receives an operation input related to the setting of the third inclination, and the target steering reaction force setting unit is based on the inclination setting receiving unit. It is preferable to set the third inclination based on an operation input related to the setting of the third inclination.

  Further, the steering device according to the present invention is a steering device that outputs a steering reaction force according to the operation of the steering wheel, the steering angle detecting means for detecting the steering angle of the steering wheel with a predetermined resolution Δθh, and the detection Target increase / return determination means for determining whether the steering wheel is increased or decreased based on the steering angle, and the target steering with hysteresis characteristics based on the determination result by the increase / return determination determination means and the detected steering angle A target steering reaction force setting means for setting a reaction force; and a steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output. A first characteristic in which a steering reaction force changes with a first inclination with respect to a change, and a second characteristic in which a steering reaction force changes with a second inclination smaller than the first inclination with respect to a change in steering angle. Characteristics, and operation with respect to the steering angle. When the steering reaction force is on the second characteristic and the direction of turning and turning back the steering wheel changes, the inclination of the steering reaction force with respect to the steering angle changes from the second inclination to the first inclination. When the steering reaction force with respect to the steering angle is on the first characteristic, when the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic, the steering with respect to the steering angle is performed. The reaction force inclination changes from the first inclination to the second inclination, and the target steering reaction force setting means has a value of K1 × Δθh of the steering wheel when the first inclination is K1. The gist is to set the first inclination K1 so as to be smaller than the allowable vibration value that changes in accordance with the vibration frequency.

  The steering device according to the present invention is a steering device that outputs a steering reaction force according to the operation of the steering wheel, and is based on the steering angle detection means that detects the steering angle of the steering wheel and the detected steering angle. A target steering reaction force is set with hysteresis characteristics based on the increase / return determination unit for determining whether the steering wheel is increased or returned, and the determination result of the increase / return determination unit and the detected steering angle. Target steering reaction force setting means, and steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output, and the hysteresis characteristic is steered with respect to a change in steering angle. A first characteristic in which the reaction force changes with a first inclination; and a second characteristic in which the steering reaction force changes with a second inclination smaller than the first inclination with respect to a change in steering angle. , The steering reaction force with respect to the steering angle is When the direction of the additional turning back of the steering wheel changes in the case of the characteristic, the inclination of the steering reaction force with respect to the steering angle changes from the second inclination to the first inclination, and the steering reaction force with respect to the steering angle. When the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic, the inclination of the steering reaction force with respect to the steering angle is the first characteristic. A tilt change receiving unit that is operated by a handle operator and receives an operation input related to the setting of the first tilt, and further includes a target steering reaction force setting unit. The gist is that the first inclination is set based on an operation input related to the setting of the first inclination by the inclination setting receiving means.

  The steering reaction force simulation device according to the present invention is a steering reaction force simulation device that outputs a steering reaction force according to an operation of a steering wheel, a steering angle detection unit that detects a steering angle of the steering wheel, and the detection A turn-up / back-off judging means for judging whether the steering wheel is turned up or down based on the steering angle, and a target having a hysteresis characteristic on the basis of the result of judgment by the turn-up / back-back judging means and the detected steering angle. Target steering reaction force setting means for setting a steering reaction force; and steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output. A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the second angle, and a second characteristic in which the steering reaction force changes with a second inclination smaller than the first inclination with respect to a change in steering angle. And steering with respect to the steering angle When the force is on the second characteristic and the direction of the additional turning back of the steering wheel changes, the inclination of the steering reaction force with respect to the steering angle changes from the second inclination to the first inclination, When the steering reaction force with respect to the steering angle is on the first characteristic, when the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic, the steering reaction force with respect to the steering angle The target steering reaction force setting means is configured to change the target steering when the steering reaction force with respect to a steering angle is on the first characteristic. When the reaction force is within a set range near 0, the gist is to set the inclination of the steering reaction force with respect to the steering angle in the first characteristic to a third inclination smaller than the first inclination.

  The steering reaction force simulation device according to the present invention is a steering reaction force simulation device that outputs a steering reaction force according to the operation of the steering wheel, and detects a steering angle of the steering wheel with a predetermined resolution Δθh. Based on the detected steering angle, a turning increase / return determining means for determining whether the steering wheel is increased or decreased based on the detected steering angle, a determination result by the increased / returned switching determination means, and the detected steering angle. A target steering reaction force setting means for setting a target steering reaction force with hysteresis characteristics, and a steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output. The characteristics include a first characteristic in which a steering reaction force changes with a first inclination with respect to a change in steering angle, and a second inclination in which the steering reaction force with respect to a change in steering angle is smaller than the first inclination. A second characteristic that changes at When the steering reaction force with respect to the steering angle is on the second characteristic and the direction of the steering wheel is increased and turned back, the inclination of the steering reaction force with respect to the steering angle is changed from the second inclination to the first inclination. When the steering angle changes to an inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. The inclination of the steering reaction force with respect to an angle changes from the first inclination to the second inclination, and the target steering reaction force setting means has a value of K1 × Δθh, where K1 is the first inclination. The gist of the invention is to set the first inclination K1 so that is smaller than the allowable vibration value that changes in accordance with the vibration frequency of the steering wheel.

  The steering reaction force simulation device according to the present invention is a steering reaction force simulation device that outputs a steering reaction force according to an operation of a steering wheel, a steering angle detection unit that detects a steering angle of the steering wheel, and the detection A turn-up / back-off judging means for judging whether the steering wheel is turned up or down based on the steering angle, and a target having a hysteresis characteristic on the basis of the result of judgment by the turn-up / back-back judging means and the detected steering angle. Target steering reaction force setting means for setting a steering reaction force; and steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output. A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the second angle, and a second characteristic in which the steering reaction force changes with a second inclination smaller than the first inclination with respect to a change in steering angle. And steering with respect to the steering angle When the force is on the second characteristic and the direction of the additional turning back of the steering wheel changes, the inclination of the steering reaction force with respect to the steering angle changes from the second inclination to the first inclination, When the steering reaction force with respect to the steering angle is on the first characteristic, when the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic, the steering reaction force with respect to the steering angle A tilt setting receiving means that is operated by an operator of a handle and receives an operation input related to the setting of the first tilt, wherein the tilt of the first tilt is changed from the first tilt to the second tilt. The gist of the target steering reaction force setting means is to set the first inclination based on an operation input related to the setting of the first inclination by the inclination setting receiving means.

  The steering reaction force setting method according to the present invention is a steering reaction force setting method for setting a steering reaction force according to an operation of a steering wheel of a vehicle, wherein only the steering wheel is increased based on the steering angle of the steering wheel. In the steering reaction force setting method of determining whether to return and setting a steering reaction force with a hysteresis characteristic based on the determination result and the steering angle of the steering wheel, the hysteresis characteristic is a steering reaction force against a change in the steering angle. A first characteristic that changes with a first inclination, and a second characteristic that a steering reaction force changes with a second inclination that is smaller than the first inclination with respect to a change in steering angle. When the steering reaction force with respect to the angle is on the second characteristic and the direction of the steering wheel turning back and forth changes, the inclination of the steering reaction force with respect to the steering angle changes from the second inclination to the first inclination. To the steering angle When the steering reaction force is on the first characteristic, when the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic, the inclination of the steering reaction force with respect to the steering angle is When the steering reaction force is within the set range near 0 when the steering reaction force with respect to the steering angle is on the first property, the characteristic changes from the first inclination to the second inclination. The gist is to set the inclination of the steering reaction force with respect to the steering angle in the first characteristic to a third inclination smaller than the first inclination.

  The steering reaction force setting method according to the present invention is a steering reaction force setting method for setting a steering reaction force according to the operation of the steering wheel, wherein the steering angle of the steering wheel is detected with a predetermined resolution Δθh, and the detection is performed. In the steering reaction force setting method for determining whether the steering wheel is increased or returned based on the steering angle, and setting the steering reaction force with a hysteresis characteristic based on the determination result and the steering angle of the steering wheel, the hysteresis characteristic Is a first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the steering angle, and a second inclination in which the steering reaction force is smaller than the first inclination with respect to a change in the steering angle. And when the steering reaction force with respect to the steering angle is on the second characteristic, the steering reaction force slope with respect to the steering angle is changed From the second slope When the steering angle is changed to the first inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. Is a characteristic in which the inclination of the steering reaction force with respect to the steering angle changes from the first inclination to the second inclination. When the first inclination is K1, the value of K1 × Δθh is the vibration frequency of the steering wheel. The gist of the present invention is to set the first slope K1 so as to be smaller than the allowable vibration value that changes according to the above.

  According to the present invention, it is possible to suppress the level of handle vibration that occurs when the handle is released when hysteresis is provided to the steering reaction force characteristics when the handle is increased and returned.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

“Embodiment 1”
FIG. 1 is a diagram showing a schematic configuration of a steering device 20 according to Embodiment 1 of the present invention. A steering device 20 according to the present embodiment is mounted on a vehicle. As shown in the figure, a steering wheel 22 operated by a driver, a steering angle sensor 24 for detecting an angle (steering angle) of the steering wheel 22, and A torque sensor 26 for detecting the torque (steering reaction force) of the handle 22 and a reaction force motor 40 for simulating the steering reaction force of the handle 22 by applying a torque to the handle 22 in accordance with the operation of the handle 22 by the driver. And a steering motor 42 that transmits an output torque for changing the turning angle of the steering wheels 30 and 32 according to the steering angle of the steering wheel 22 to the rack 36 via the reduction gear 34 and outputs the output torque to the steering wheels 30 and 32. And an electronic control unit 50 for controlling the entire apparatus.

  The electronic control unit 50 is configured as a microprocessor centered on a CPU 52, and includes a ROM 54 that stores a processing program, a RAM 56 that temporarily stores data, and an input / output port (not shown). A steering angle θh from the steering angle sensor 24, a torque Th from the torque sensor 26, a vehicle speed V from the vehicle speed sensor 58, and the like are input to the electronic control unit 50 through an input port. Further, the electronic control unit 50 outputs drive signals to the reaction force motor 40 and the steering motor 42 through the output port.

  FIG. 2 is an explanatory diagram illustrating a control block when the electronic control unit 50 of the steering device 20 operates as the steering reaction force command value calculation block 60 for calculating the steering reaction force command value Tp *. As shown in the drawing, the steering reaction force command value calculation block 60 includes an additional switching / returning determination unit 62 that determines whether the steering wheel 22 is increased or decreased based on the input steering angle θh, and an additional switching / returning determination unit. And a steering reaction force command value calculation unit 66 for calculating the steering reaction force command value Tp * based on the determination result of 62, the steering angle θh, and the vehicle speed V. In the electronic control unit 50, the steering reaction force acting on the handle 22 is steered based on the steering reaction force command value Tp * calculated by the steering reaction force command value calculation block 60 and the torque Th detected by the torque sensor 26. The reaction force motor 40 is driven and controlled so that the reaction force command value Tp * is obtained. However, here, the reaction force motor 40 may be driven and controlled based only on the steering reaction force command value Tp * without using the torque sensor 26. The steering angle θh is detected by the steering angle sensor 24 with a predetermined resolution (minimum resolution) Δθh.

  The increase / return determination unit 62 in the steering reaction force command value calculation block 60 determines whether the handle 22 is in the increased state or the reverted state based on the steering angle θh detected by the steering angle sensor 24. Is done. More specifically, the sign of the difference between the steering angle θh input last time and the steering angle θh input this time, that is, whether it is increased or decreased is determined by positive / negative.

  In the steering reaction force command value calculation unit 66, the steering reaction force acting on the steering wheel 22 based on the determination result of the increase / cutback determination unit 62, the steering angle θh, and the vehicle speed V exhibits a hysteresis characteristic as illustrated in FIG. 3. The steering reaction force command value Tp * is calculated so as to hold. In FIG. 3, the horizontal axis is the steering angle θh, and the vertical axis is the steering reaction force Tp. The hysteresis characteristics illustrated in FIG. 3 are characteristic lines A and C (first characteristic lines) in which the steering reaction force Tp changes with a slope K1 with respect to changes in the steering angle θh, and steering with respect to changes in the steering angle θh. This is a characteristic including the characteristic lines B and D (second characteristic line) in which the reaction force Tp changes with the inclination K2 (K2 <K1). In FIG. 3, the intercept of the characteristic line (straight line) B is T0, and the intercept of the characteristic line (straight line) D is -T0. Hereinafter, processing in which the steering reaction force command value calculation unit 66 calculates the steering reaction force command value Tp * will be described. The steering reaction force command value Tp * is calculated in the same way except that the sign differs between when the handle 22 is rotated to the right and when the handle 22 is rotated to the left. In the embodiment, the case where the handle 22 is rotated to the left will be described. For ease of explanation, a process for calculating the steering reaction force command value Tp * without using the vehicle speed V will be described.

  When the steering angle θh at the start of turning of the steering wheel 22 increases from the value 0 to the minimum resolution Δθh of the steering angle sensor 24, the steering reaction force command value Tp * is increased at a gradient of the gradient K3 (K3 <K1). That is, the steering reaction force command value Tp * is calculated as the following equation (1).

  Tp * = K3 · Δθh (1)

  Further, until the steering wheel 22 is increased and the steering angle θh reaches the angle θ1 intersecting the straight line B on the straight line of the inclination K1 from the angle Δθh, the steering angle θh and the steering reaction force Tp are expressed on the horizontal axis and the vertical axis. The steering reaction force command value Tp * is calculated as a straight line relationship passing through the point (Δθh, K3 · Δθh) with the inclination K1 on the coordinates at the time. That is, the steering reaction force command value Tp * is calculated as the following equation (2).

  Tp * = K3 · Δθh + K1 · (θh−Δθh) (2)

  When the steering angle θh is increased after exceeding the angle θ1, every time the steering angle θh is increased by the minimum resolution Δθh, ΔT calculated by the following equation (3) is added. That is, when it is increased by n times the minimum resolution Δθh, the steering reaction force command value Tp * is calculated by the equation (4).

ΔT = K2 · Δθh (3)
Tp * = K3 · Δθh + K1 · (θ1−Δθh) + n · ΔT
= K2 · (θ1 + n · Δθh) + T0 (4)
T0 = (K1-K2) · θ1- (K1-K3) · Δθh

  FIG. 4 shows how the steering reaction force command value Tp * is set when the steering angle θh increases by the minimum resolution Δθh. As shown in the figure, after the steering angle θh exceeds the angle θ1, the calculated steering reaction force command value Tp * is a value on the straight line B (second characteristic line) of the slope K2.

  When the steering wheel 22 is turned back from the state where the steering angle θh is larger than the angle θ1, the steering reaction force command value Tp * decreases with the gradient of the inclination K1 according to the following equation (6) until the following equation (5) is satisfied. To do. Equation (6) represents the steering reaction force command value Tp * when the angle θ2 is switched back by n times the minimum resolution Δθh.

| Tp * | ≦ K3 · Δθh (5)
Tp * = K3 · Δθh + K1 · (θ1−Δθh)
+ K2 · (θ2−θ1) −K1 · n · Δθh (6)

  The steering reaction force command value Tp * immediately before the determination of switching back is the value of the point B2 on the characteristic line B in FIG. When the switchback is started, the steering reaction force command value Tp * is calculated by the equation (6), and the steering reaction force command value Tp * is calculated by the characteristic line A2 (first first) of the slope K1 passing through the point B2 in FIG. (Characteristic line). Then, the steering reaction force command value Tp * is calculated from the expression (6) until the steering angle θh satisfies the expression (5) from the intersection B2 with the characteristic line B on the characteristic line A2. As described above, when the steering reaction force command value Tp * with respect to the steering angle θh is on the second characteristic line (for example, the characteristic line B), the steering reaction force is changed when the direction of the additional turning back of the steering wheel 22 is changed. The command value Tp * becomes a value on the first characteristic line (for example, the characteristic line A2), and the inclination of the steering reaction force command value Tp * with respect to the steering angle θh changes (increases) from K2 to K1. Here, the characteristic line B of the inclination K2 corresponds to the steering reaction force characteristic at the time of addition, and the characteristic line A2 of the inclination K1 corresponds to the steering reaction force characteristic for applying the steering reaction force corresponding to the Coulomb friction. . By increasing the value of the slope K1, it is possible to obtain a hysteresis approximating Coulomb friction by a spring element having a high rigidity (spring constant).

  When the steering wheel 22 is further turned back after the expression (5) is established, until the steering angle θh is turned back twice the minimum resolution Δθh (2 · Δθh) (while the expression (5) is satisfied). ), The steering reaction force command value Tp * is decreased at a gradient of inclination K3 (K3 <K1). As described above, when the steering reaction force command value Tp * with respect to the steering angle θh is on the first characteristic line (for example, the characteristic lines A, A2, and C), the steering reaction force command value Tp * is within the set range near 0. Is set to K3, which is smaller than K1, in the inclination (the inclination of the steering reaction force Tp with respect to the steering angle θh) in the first characteristic line. For example, as shown in FIG. 4, the setting range here may be a range in which −K3 × Δθh is the lower limit and K3 × Δθh is the upper limit.

  Further, when the steering wheel 22 is turned back, the steering reaction force command value Tp * is expressed by the following equation (7) until the steering angle θh is reduced by an angle required to reach the intersection D2 with the straight line D on the characteristic line A2. ) In accordance with the slope of the slope K1. In Equation (7), θ3 is an angle (see FIG. 4) when the steering reaction force command value Tp * is 0 on the characteristic line A2.

  Tp * = − K3 · Δθh−K1 · (θ3−Δθh−θh) (7)

  Next, consider the case where the steering angle θh is cut back to an angle θ4 corresponding to the intersection D2 of the characteristic line A2 and the characteristic line D in FIG. When further turning back is performed from this angle θ4, every time the steering angle θh is turned back by the minimum resolution Δθh, ΔT calculated by the above equation (3) is subtracted. That is, when the angle θ3 is switched back by m times the minimum resolution Δθh, the steering reaction force command value Tp * is calculated by the following equation (8).

  Tp * = − T0 + K2 · (θ4−m · Δθh) (8)

  FIG. 4 shows how the steering reaction force command value Tp * is set when the steering angle θh decreases by the minimum resolution Δθh. As shown in the figure, after the steering angle θh is decreased from the angle θ4, the calculated steering reaction force command value Tp * is a value on the straight line D (second characteristic line) of the slope K2. Thus, when the steering reaction force command value Tp * for the steering angle θh is on the first characteristic line (for example, characteristic line A2), the steering angle θh is the intersection of the first characteristic line and the second characteristic line. Is reached (for example, the angle θ4 corresponding to the intersection D2 between the characteristic line A2 and the characteristic line D), the steering reaction force command value Tp * is on the second characteristic line (for example, the characteristic line D). The slope of the steering reaction force command value Tp * with respect to the steering angle θh changes (decreases) from K1 to K2. The characteristic line D of the inclination K2 here corresponds to the steering reaction force characteristic at the time of switching back. In the present embodiment, the steering reaction force command value Tp * is set based on the steering angle θh and the determination result of the additional turning back, whereby the current state of the hysteresis characteristic (the steering angle θh and the steering reaction force Tp are characteristic). It is possible to reproduce the hysteresis characteristic due to Coulomb friction that does not depend on the steering speed while accurately grasping the positions of the lines A, B, C, and D).

  When the minimum resolution Δθh of the steering angle sensor 24 is not sufficiently high, self-excited vibration is likely to occur in the steering wheel 22, and when the level of the self-excited vibration increases, the driver feels uncomfortable and uncomfortable. In particular, self-excited vibration is likely to occur when the absolute value of the steering reaction force Tp is small and close to 0, such as when the handle 22 is released or when the steering wheel 22 is lightly held. Therefore, in the present embodiment, the steering reaction force command value calculation unit 66 determines that the steering reaction force command value Tp * is within a setting range near 0 (for example, −K3 × Δθh ≦ Tp * ≦ K3 × Δθh). The inclination (inclination of the steering reaction force Tp with respect to the steering angle θh) in the first characteristic line (for example, characteristic lines A, A2, and C) is set to K3 smaller than K1. This suppresses the level of self-excited vibration of the handle 22 that occurs when the steering reaction force Tp is near zero. On the other hand, when the steering reaction force command value Tp * is out of the setting range near 0, the steering reaction force command value calculation unit 66 sets the slope of the first characteristic line to K1.

  When the driver releases the handle 22 when the steering angle θh is the angle θ2, the steering angle θh converges to the angle θ3 (see FIG. 4) according to the equation of motion of the handle 22 expressed by the following equation (9). However, since the inclination (rigidity) K1 of the steering reaction force Tp with respect to the steering angle θh is a large value, the handle 22 vibrates. In equation (9), Jh is the moment of inertia of the handle 22, and ch is the viscous friction coefficient of the handle 22.

  When the stiffness in the vicinity of the angle θ3 (the inclination of the steering reaction force Tp with respect to the steering angle θh) is set to K1, the minimum unit K1 · Δθh of the steering reaction force command value Tp * is large as shown in FIG. Therefore, the steering angle θh causes hunting by the control, and the vibration of the handle 22 becomes difficult to attenuate. On the other hand, in this embodiment, the rigidity in the vicinity of the angle θ3 (for example, the range in which θ3−Δθh is the lower limit and θ3 + Δθh is the upper limit), that is, the inclination of the steering reaction force Tp with respect to the steering angle θh is set to K3 smaller than K1. Therefore, as shown in FIG. 6, the minimum unit of the steering reaction force command value Tp * can be reduced to K3 · Δθh. As a result, the vibration of the handle 22 can be quickly suppressed without causing the hunting by the control of the steering angle θh. Further, since the minimum unit of the steering reaction force command value Tp * is small, there is an effect that the torque fluctuation of the steering wheel 22 is not concerned even when the driver is touching the steering wheel 22. For this purpose, it is preferable to set the value of the slope K3 so that the torque fluctuation K3 · Δθh is smaller than the torque fluctuation that the driver can feel. On the other hand, when the steering reaction force command value Tp * deviates from the vicinity of 0, the inclination of the steering reaction force Tp with respect to the steering angle θh is set to K1, which is larger than K3. A feeling of friction due to friction can be sufficiently felt. Even when the driver releases the steering wheel 22 from the state where the steering angle θh is the angle θ4, the steering angle θh converges to the angle θ3 according to the equation of motion of the above equation (9), and the vibration suppressing effect similar to FIG. Is obtained.

  As described above, according to the present embodiment, it is possible to reproduce the hysteresis characteristic due to Coulomb friction that does not depend on the steering speed, and vibration when self-excited vibration occurs in the handle 22 when the handle 22 is released. The level can be quickly suppressed. As a result, a good steering feeling can be obtained.

  In the present embodiment, the value of the slope K3 can be set so that the torque variation K3 · Δθh is slightly smaller than the torque vibration amplitude that the driver feels uncomfortable. However, human torque vibration perception characteristics change according to the vibration frequency, and the torque vibration amplitude that the driver feels uncomfortable changes according to the vibration frequency. Therefore, the steering reaction force command value calculation unit 66 determines the value of the inclination K3 so that the torque fluctuation amount K3 · Δθh is smaller than the allowable vibration value TL that changes according to the vibration frequency of the handle 22. Hereinafter, the process in that case will be described with reference to the flowchart shown in FIG.

  In step S101 of the flowchart shown in FIG. 7, an initial value of the slope K3 is set. Here, the initial value of the slope K3 can be set to a high value that provides a sufficient feeling of friction, and can be set to a value of about 50 to 100 N · m / deg, for example. In step S102, the torque amplitude and frequency of the self-excited vibration of the handle 22 that occurs when the steering reaction force Tp is near zero are calculated. The torque amplitude of the self-excited vibration of the handle 22 is represented by K3 · Δθh. The frequency of the self-excited vibration of the handle 22 can be expressed by the resonance frequency of the handle 22, and the resonance frequency (angular frequency) ω of the handle 22 is expressed by the following equation (10). In Expression (10), Jh is the moment of inertia of the handle 22. As shown in Expression (10), the resonance frequency (the frequency of self-excited vibration) of the handle 22 changes according to the value of the slope K3.

ω = (K3 / Jh) ^0.5 (10)

  In step S103, it is determined whether or not the torque amplitude K3 · Δθh of the self-excited vibration is smaller than the allowable vibration value TL at the frequency ω of the self-excited vibration calculated in step S102. Since the torque vibration amplitude that the driver feels uncomfortable changes according to the vibration frequency of the handle 22, the allowable vibration value TL here corresponds to the self-excited vibration frequency as a threshold value that makes the driver feel uncomfortable with the torque vibration. For example, it has a frequency weighted characteristic as shown in FIG. As frequency weighting here, for example, frequency weighting disclosed in ISO 5349-1 “Measurement standard for hand-arm vibration” can be used. Moreover, the frequency characteristic (frequency weighting) of the allowable vibration value TL can also be set from the result obtained in the sensory evaluation experiment of the subject. More specifically, by giving a sine wave torque whose amplitude gradually increases from 0 to the steering wheel as an evaluation input, it is presented to the driver (subject), and the driver gives the presented evaluation input (sine wave torque). The amplitude value of the sine wave torque at the time when the user feels uncomfortable for the first time is examined for each frequency while changing the frequency, and the frequency characteristic (frequency weighting) of the allowable vibration value TL is obtained from the sine wave torque amplitude value for each frequency. You can also. The frequency characteristics of the allowable vibration value TL as shown in FIG. 8 are stored in advance in a storage device in the electronic control unit 50. The steering reaction force command value calculation unit 66 determines whether or not the torque amplitude K3 · Δθh is smaller than the vibration allowable value TL corresponding to the given frequency ω of the self-excited vibration in the stored frequency characteristic of the vibration allowable value TL. Determine whether. For example, as indicated by a point P1 in FIG. 8, when the value of the torque amplitude K3 · Δθh is equal to or greater than the vibration allowable value TL corresponding to the frequency ω of the self-excited vibration (when the determination result in step S103 is NO), In S104, the value of the slope K3 is changed to a value smaller than the current value, and the process returns to Step S102. On the other hand, when the value of the torque amplitude K3 · Δθh is smaller than the allowable vibration value TL corresponding to the frequency ω of the self-excited vibration (when the determination result in step S103 is YES), for example, as indicated by a point P2 in FIG. In step S105, the value of the slope K3 is determined as the current value. Note that the processing in the flowchart of FIG. 7 can be performed in advance before the processing for calculating the steering reaction force command value Tp * is started, or is performed during the processing for calculating the steering reaction force command value Tp *. You can also.

  According to the process of the flowchart of FIG. 7, the value of the slope K3 is determined so that the torque amplitude K3 · Δθh of the self-excited vibration becomes a value slightly smaller than a threshold that makes the driver feel uncomfortable. Therefore, the self-excited vibration level of the handle 22 generated when the steering reaction force Tp is close to 0 can be suppressed without impairing the feeling of friction due to Coulomb friction.

  Further, in the present embodiment, as shown in FIG. 9, an inclination setting reception unit 65 that receives a driver's operation input related to the setting of the inclination K3 is provided, and the steering reaction force command value calculation unit 66 is based on the inclination setting reception unit 65. The value of the inclination K3 can also be determined based on an operation input related to the setting of the inclination K3. The inclination setting accepting unit 65 here can be configured to include, for example, a switch or a scale adjustment dial operated by the driver to change the value of the inclination K3. Is output to the electronic control unit 50 (steering reaction force command value calculator 66). Then, the steering reaction force command value calculation unit 66 sets the value of the inclination K3 so as to match the target value of the inclination K3 from the inclination setting reception unit 65. According to this configuration example, the driver does not lose the feeling of friction due to Coulomb friction, and does not feel uncomfortable the self-excited vibration of the handle 22 that occurs when the steering reaction force Tp is near zero. The value can be adjusted.

“Embodiment 2”
Next, the steering device 20 according to Embodiment 2 of the present invention will be described. In the present embodiment, the steering reaction force command value calculation unit 66 illustrates the steering reaction force acting on the steering wheel 22 based on the determination result of the additional increase / return determination unit 62, the steering angle θh, and the vehicle speed V in FIG. The steering reaction force command value Tp * is calculated so as to have such hysteresis characteristics. In FIG. 10, the horizontal axis represents the steering angle θh, and the vertical axis represents the steering reaction force Tp. The hysteresis characteristic illustrated in FIG. 10 also includes the straight lines A and C (first characteristic lines) in which the steering reaction force Tp changes with the inclination K1 with respect to the change in the steering angle θh, and the steering reaction with respect to the change in the steering angle θh. This is a characteristic including straight lines B and D (second characteristic lines) in which the force Tp changes with a slope K2 (K2 <K1). In FIG. 10, the intercept of the straight line B is T0, and the intercept of the straight line D is -T0. Hereinafter, processing in which the steering reaction force command value calculation unit 66 calculates the steering reaction force command value Tp * will be described. Also in the following description, the direction in which the steering angle θh is positive (when the steering wheel 22 is rotated to the left in the embodiment) will be described, and the processing for calculating the steering reaction force command value Tp * without using the vehicle speed V will be described.

  When the steering angle θh at the start of turning of the steering wheel 22 reaches the angle θ1 that intersects the straight line B on the straight line with the inclination K1 from the value 0, the steering angle θh and the steering reaction force Tp are set as the horizontal axis and the vertical axis. A steering reaction force command value Tp * is calculated as a straight line relationship passing through the origin with an inclination K1 on the coordinates. That is, the steering reaction force command value Tp * is calculated as the following equation (11).

  Tp * = K1 · θh (11)

  When the steering angle θh is increased after exceeding the angle θ1, every time the steering angle θh is increased by the minimum resolution Δθh, ΔT calculated by the following equation (12) is added. That is, when it is increased by n times the minimum resolution Δθh, the steering reaction force command value Tp * is calculated by the equation (13).

ΔT = K2 · Δθh (12)
Tp * = K1 · θ1 + n · ΔT
= K2 · (θ1 + n · Δθh) + (K1−K2) · θ1 (13)

  FIG. 11 shows how the steering reaction force command value Tp * is set when the steering angle θh increases by the minimum resolution Δθh. As shown in the figure, after the steering angle θh exceeds the angle θ1, the calculated steering reaction force command value Tp * is a value on the straight line B (second characteristic line) of the slope K2. Note that (K1−K2) · θ1 in the second term on the right side in the equation (13) is the intercept T0 of the straight line B in FIG.

  When the steering wheel 22 is turned back from the state where the steering angle θh is larger than the angle θ1, the steering reaction force command value Tp * is calculated by the following equation (14).

  Tp * = K1 · θh− (K1−K2) · (θ2−θ1) (14)

  The steering reaction force command value Tp * immediately before the determination of switching back is the value of the point B2 on the straight line B in FIG. When the switchback is started, the steering reaction force command value Tp * is calculated by the equation (14), and the steering reaction force command value Tp * is a straight line A2 (first characteristic) of the slope K1 passing through the point B2 in FIG. Value on line). Then, the steering reaction force command value Tp * is calculated by the equation (14) until the steering angle θh becomes smaller by the angle required to reach the intersection D2 with the straight line D from the intersection B2 with the straight line B on the straight line A2. The As described above, when the steering reaction force command value Tp * with respect to the steering angle θh is on the second characteristic line (for example, the straight line B), the steering reaction force command is changed when the direction of the additional turning back of the handle 22 is changed. The value Tp * becomes a value on the first characteristic line (for example, the straight line A2), and the inclination of the steering reaction force command value Tp * with respect to the steering angle θh changes (increases) from K2 to K1.

  Next, a case where the steering angle θh is cut back to an angle θ3 corresponding to the intersection D2 between the straight line A2 and the straight line D in FIG. When further turning back is performed from this angle θ3, every time the steering angle θh is turned back by the minimum resolution Δθh, ΔT calculated by the above equation (12) is subtracted. That is, when the angle θ3 is switched back by m times the minimum resolution Δθh, the steering reaction force command value Tp * is calculated by the following equation (15).

  Tp * = − T0 + K2 · (θ3−m · Δθh) (15)

  FIG. 11 shows how the steering reaction force command value Tp * is set when the steering angle θh decreases by the minimum resolution Δθh. As shown in the drawing, after the steering angle θh is decreased from the angle θ3, the calculated steering reaction force command value Tp * becomes a value on the straight line D (second characteristic line) of the slope K2. Thus, when the steering reaction force command value Tp * with respect to the steering angle θh is on the first characteristic line (for example, the straight line A2), the steering angle θh is at the intersection of the first characteristic line and the second characteristic line. When the corresponding angle (for example, the angle θ3 corresponding to the intersection D2 of the straight line A2 and the straight line D) is reached, the steering reaction force command value Tp * becomes a value on the second characteristic line (for example, the straight line D), and the steering is performed. The inclination of the steering reaction force command value Tp * with respect to the angle θh changes (decreases) from K1 to K2.

  For example, when the absolute value of the steering reaction force Tp is small and close to 0, such as when the steering wheel 22 starts to be turned, when the handle 22 is released, or when the steering wheel is kept lightly attached, the steering angle sensor is detected by a slight change in the steering angle θh. A torque fluctuation of K1 · Δθh (minimum unit of the steering reaction force command value Tp *) corresponding to the minimum resolution Δθh of 24 occurs. Such a change in the steering angle θh may be caused by a driver's steering operation, but the handle 22 may be moved by the above torque fluctuation. When the handle 22 is moved by torque fluctuation, the steering angle θh causes hunting by control when the steering reaction force Tp is near 0, and self-excited vibration is generated in the handle 22. If the value of the inclination K1 is set to be large, the driver can be given a sufficient feeling of friction due to Coulomb friction, but the minimum unit K1 · Δθh of the steering reaction force command value Tp * becomes large. For this reason, the torque amplitude of the self-excited vibration when the steering angle θh causes hunting by the control also increases, and the driver feels uncomfortable and uncomfortable. Therefore, in this embodiment, the value of the slope K1 is set so that the torque fluctuation K1 · Δθh is slightly smaller than the torque vibration amplitude that the driver feels uncomfortable. However, since the torque vibration amplitude that the driver feels uncomfortable changes according to the vibration frequency, the steering reaction force command value calculation unit 66 determines that the torque variation K1 · Δθh varies according to the vibration frequency of the steering wheel 22. The value of the slope K1 is determined so as to be smaller than TL. Hereinafter, the process in that case will be described with reference to the flowchart shown in FIG.

  In step S201 of the flowchart shown in FIG. 12, an initial value of the slope K1 is set. Here, the initial value of the inclination K1 can be set to a high value that provides a sufficient friction feeling, and can be set to a value of, for example, about 50 to 100 N · m / deg. In step S202, the torque amplitude and frequency of the self-excited vibration of the handle 22 that occurs when the steering reaction force Tp is near zero are calculated. The torque amplitude of the self-excited vibration of the handle 22 is represented by K1 · Δθh. The frequency of the self-excited vibration of the handle 22 can be expressed by the resonance frequency of the handle 22, and the resonance frequency (angular frequency) ω of the handle 22 is expressed by the following equation (16). As shown in Expression (16), the resonance frequency of the handle 22 (the frequency of self-excited vibration) changes according to the value of the slope K1.

ω = (K1 / Jh) ^0.5 (16)

  In step S203, it is determined whether or not the torque amplitude K1 · Δθh of the self-excited vibration is smaller than the allowable vibration value TL at the frequency ω of the self-excited vibration calculated in step S202. The vibration allowable value TL here is also set according to the frequency of the self-excited vibration as a threshold value that makes the driver feel uncomfortable with the torque vibration, similarly to step S103 in the flowchart of FIG. 7, for example, as shown in FIG. Has weighted characteristics. Regarding the frequency weighting here, for example, the frequency weighting disclosed in ISO 5349-1 “Measurement standard of hand-arm vibration” can be used, or the frequency weighting obtained in the sensory evaluation experiment of the subject can also be used. The steering reaction force command value calculation unit 66 has a torque characteristic higher than the vibration allowable value TL corresponding to the given frequency ω of the self-excited vibration in the frequency characteristic of the vibration allowable value TL stored in the storage device in the electronic control unit 50. It is determined whether or not the amplitude K1 · Δθh is small. For example, as shown at a point P1 in FIG. 8, when the value of the torque amplitude K1 · Δθh is equal to or greater than the vibration allowable value TL corresponding to the frequency ω of the self-excited vibration (when the determination result in step S203 is NO), In S204, the value of the slope K1 is changed to a value smaller than the current value, and the process returns to Step S202. On the other hand, for example, as indicated by a point P2 in FIG. 8, when the value of the torque amplitude K1 · Δθh is smaller than the allowable vibration value TL corresponding to the frequency ω of the self-excited vibration (when the determination result in step S203 is YES). In step S205, the value of the slope K1 is determined as the current value. Note that the processing of the flowchart of FIG. 12 can also be performed in advance before starting the processing of calculating the steering reaction force command value Tp *, or performed during the processing of calculating the steering reaction force command value Tp *. You can also.

  When the value of the inclination K1 is set large, as shown in FIG. 13, the minimum unit Tmin = K1 · Δθh of the steering reaction force command value Tp * becomes large, the steering angle θh causes hunting by the control, and the steering wheel 22 The self-excited vibration is difficult to attenuate. On the other hand, according to the process of the flowchart of FIG. 12, as shown in FIG. 14, the minimum unit Tmin = K1 · Δθh of the steering reaction force command value Tp * can be reduced, so that the steering angle θh is controlled. Hunting can be suppressed and self-excited vibration of the handle 22 can be suppressed. Then, since the value of the slope K1 is determined so that the torque amplitude K1 · Δθh of the self-excited vibration is slightly smaller than the threshold that makes the driver feel uncomfortable, it occurs when the steering reaction force Tp is near zero. The self-excited vibration level of the handle 22 can be suppressed without impairing the feeling of friction due to Coulomb friction.

  Also in the present embodiment, as shown in FIG. 9, an inclination setting reception unit 65 that receives a driver's operation input related to the setting of the inclination K <b> 1 is provided, and the steering reaction force command value calculation unit 66 is based on the inclination setting reception unit 65. The value of the inclination K1 can also be determined based on the operation input related to the setting of the inclination K1. The inclination setting accepting unit 65 here can also be configured to include, for example, a switch or a scale adjustment dial operated by the driver to change the value of the inclination K1, and the operation state of the switch or the scale adjustment dial. Is output to the electronic control unit 50 (steering reaction force command value calculator 66). Then, the steering reaction force command value calculation unit 66 sets the value of the inclination K1 so as to match the target value of the inclination K1 from the inclination setting reception unit 65. According to this configuration example, the driver does not lose the feeling of friction due to Coulomb friction and does not feel uncomfortable with the self-excited vibration of the handle 22 that occurs when the steering reaction force Tp is near zero. The value can be adjusted.

  In the above description, for easy explanation, the steering reaction force command value Tp * is calculated without considering the vehicle speed V. However, in the steering device 20 according to the first and second embodiments, the inclination K1 of the characteristic lines A, A2, and C, the inclination K2 of the characteristic lines B and D, and the intercepts T0 and -T0 in FIGS. The steering reaction force command value Tp * can be calculated as changing according to the vehicle speed V.

  In the steering device 20 according to the first and second embodiments, the characteristic of drawing the parallelogram in FIGS. 3 and 10 has been described as the hysteresis characteristic of the steering reaction force command value Tp *. However, the steering angle θh and the steering reaction force command are illustrated. As long as the hysteresis characteristic is obtained in relation to the value Tp *, various shapes as illustrated in FIGS. 15 and 16 may be drawn. Further, the slopes K1 and K2 in the hysteresis characteristic do not necessarily have to be constant values, and can be changed according to the steering angle θh.

  Further, in the steering apparatus 20 according to the first and second embodiments, the reaction force motor 40 is driven and controlled based on the calculated steering reaction force command value Tp *. However, as shown in the control block illustrated in FIG. Alternatively, a value obtained by multiplying the steering angular velocity, which is a time derivative of the steering angle θh, by a damper gain may be added to the steering reaction force command value Tp *, and the reaction force motor 40 may be driven and controlled based on this value. In this way, the convergence characteristic to the equilibrium point when the hand is released from the handle 22 can be improved.

  In the steering device 20 according to the first and second embodiments, the steering reaction force is applied to the handle 22 by the torque of the reaction motor 40. However, the steering reaction force is applied to the handle 22 using an actuator other than the motor. You can also.

  In the above description of the first and second embodiments, the case where the present invention is applied to the vehicle-mounted steering device 20 has been described. However, the present invention can also be applied to a steering reaction force simulator used in a driving simulator or the like. In that case, the steering reaction force simulation according to the first or second embodiment including the handle 22, the steering angle sensor 24, the reaction force motor 40, and the electronic control unit 50 described in the first or second embodiment. A device can be configured.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

It is a figure showing a schematic structure of steering device 20 concerning Embodiments 1 and 2 of the present invention. FIG. 5 is an explanatory diagram illustrating a control block when the electronic control unit 50 of the steering device 20 according to the first and second embodiments of the present invention operates as a steering reaction force command value calculation block 60 that calculates a steering reaction force command value Tp *. is there. It is explanatory drawing which shows an example of the relationship between steering angle (theta) h and steering reaction force Tp. It is explanatory drawing explaining a mode that steering reaction force command value Tp * is calculated from steering angle (theta) h. It is a figure which shows an example of the vibration characteristic of the handle | steering-wheel 22 when maintaining the inclination of a 1st characteristic line at K1. It is a figure which shows an example of the vibration characteristic of the handle | steering-wheel 22 in the steering apparatus 20 which concerns on Embodiment 1 of this invention. 4 is a flowchart for explaining processing executed by the electronic control unit 50 in the steering device 20 according to the first embodiment of the present invention. It is a figure which shows an example of the frequency characteristic of vibration allowable value TL. It is explanatory drawing which shows an example of the control block of a modification. It is explanatory drawing which shows an example of the relationship between steering angle (theta) h and steering reaction force Tp. It is explanatory drawing explaining a mode that steering reaction force command value Tp * is calculated from steering angle (theta) h. It is a flowchart explaining the process performed by the electronic control unit 50 in the steering apparatus 20 which concerns on Embodiment 2 of this invention. It is a figure which shows an example of the vibration characteristic of the handle | steering-wheel 22 in case the inclination K1 of a 1st characteristic line is set to a big value. It is a figure which shows an example of the vibration characteristic of the handle | steering-wheel 22 in the steering apparatus 20 which concerns on Embodiment 2 of this invention. It is explanatory drawing which shows an example of the shape of the hysteresis characteristic of a modification. It is explanatory drawing which shows an example of the shape of the hysteresis characteristic of a modification. It is explanatory drawing which shows an example of the control block of a modification.

Explanation of symbols

  20 Steering device, 22 Handle, 24 Steering angle sensor, 26 Torque sensor, 30, 32 Steering wheel, 34 Reducer, 36 Rack, 40 Reaction force motor, 42 Steering motor, 50 Electronic control unit, 52 CPU, 54 ROM, 56 RAM, 58 Vehicle speed sensor, 60 Steering reaction force command value calculation block, 62 Increase / return switching determination unit, 65 Inclination setting reception unit, 66 Steering reaction force command value calculation unit

Claims (14)

A steering device that outputs a steering reaction force according to the operation of a steering wheel,
Steering angle detection means for detecting the steering angle of the steering wheel;
An increase / return determination means for determining whether to increase or decrease the steering wheel based on the detected steering angle;
Target steering reaction force setting means for setting a target steering reaction force with hysteresis characteristics based on the determination result by the increase / decrease / return determination means and the detected steering angle;
Steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output;
With
The hysteresis characteristic is
A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the steering angle, and a steering reaction force with a second inclination smaller than the first inclination with respect to a change in the steering angle. A second characteristic;
When the steering reaction force with respect to the steering angle is on the second characteristic and the direction of the steering wheel is increased and turned back, the inclination of the steering reaction force with respect to the steering angle is changed from the second inclination to the first inclination. When the steering angle changes to an inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. The inclination of the steering reaction force with respect to an angle is a characteristic that changes from the first inclination to the second inclination,
The target steering reaction force setting means is configured to perform steering in the first characteristic when the target steering reaction force is within a set range near 0 when the steering reaction force with respect to a steering angle is on the first characteristic. A steering apparatus that sets a tilt of a steering reaction force with respect to an angle to a third tilt smaller than the first tilt. The steering apparatus according to claim 1,
The steering angle detecting means is means for detecting the steering angle with a predetermined resolution Δθh,
The setting range is a steering apparatus in which the upper limit is K3 × Δθh and the lower limit is −K3 × Δθh, where K3 is the third inclination. The steering apparatus according to claim 2,
The steering apparatus, wherein the target steering reaction force setting means sets the third inclination K3 so that a value of K3 × Δθh is smaller than an allowable vibration value that changes in accordance with a vibration frequency of the steering wheel. The steering apparatus according to claim 1 or 2,
A tilt setting receiving means that is operated by an operator of the handle and receives an operation input related to the setting of the third tilt;
The target steering reaction force setting means sets the third inclination based on an operation input related to the setting of the third inclination by the inclination setting reception means. A steering device that outputs a steering reaction force according to the operation of a steering wheel,
Steering angle detection means for detecting the steering angle of the steering wheel with a predetermined resolution Δθh;
An increase / return determination means for determining whether to increase or decrease the steering wheel based on the detected steering angle;
Target steering reaction force setting means for setting a target steering reaction force with hysteresis characteristics based on the determination result by the increase / decrease / return determination means and the detected steering angle;
Steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output;
With
The hysteresis characteristic is
A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the steering angle, and a steering reaction force with a second inclination smaller than the first inclination with respect to a change in the steering angle. A second characteristic;
When the steering reaction force with respect to the steering angle is on the second characteristic and the direction of the steering wheel is increased and turned back, the inclination of the steering reaction force with respect to the steering angle is changed from the second inclination to the first inclination. When the steering angle changes to an inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. The inclination of the steering reaction force with respect to an angle is a characteristic that changes from the first inclination to the second inclination,
The target steering reaction force setting means sets the first inclination K1 so that the value of K1 × Δθh is smaller than the allowable vibration value that changes according to the vibration frequency of the steering wheel, where the first inclination is K1. Steering device to set. A steering device that outputs a steering reaction force according to the operation of a steering wheel,
Steering angle detection means for detecting the steering angle of the steering wheel;
An increase / return determination means for determining whether to increase or decrease the steering wheel based on the detected steering angle;
Target steering reaction force setting means for setting a target steering reaction force with hysteresis characteristics based on the determination result by the increase / decrease / return determination means and the detected steering angle;
Steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output;
With
The hysteresis characteristic is
A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the steering angle, and a steering reaction force with a second inclination smaller than the first inclination with respect to a change in the steering angle. A second characteristic;
When the steering reaction force with respect to the steering angle is on the second characteristic and the direction of the steering wheel is increased and turned back, the inclination of the steering reaction force with respect to the steering angle is changed from the second inclination to the first inclination. When the steering angle changes to an inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. The inclination of the steering reaction force with respect to an angle is a characteristic that changes from the first inclination to the second inclination,
A tilt setting receiving means that is operated by an operator of the handle and receives an operation input related to the setting of the first tilt;
The target steering reaction force setting means sets the first inclination based on an operation input related to the setting of the first inclination by the inclination setting reception means. A steering reaction force simulation device that outputs a steering reaction force according to a steering operation,
Steering angle detection means for detecting the steering angle of the steering wheel;
An increase / return determination means for determining whether to increase or decrease the steering wheel based on the detected steering angle;
Target steering reaction force setting means for setting a target steering reaction force with hysteresis characteristics based on the determination result by the increase / decrease / return determination means and the detected steering angle;
Steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output;
With
The hysteresis characteristic is
A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the steering angle, and a steering reaction force with a second inclination smaller than the first inclination with respect to a change in the steering angle. A second characteristic;
When the steering reaction force with respect to the steering angle is on the second characteristic and the direction of the steering wheel is increased and turned back, the inclination of the steering reaction force with respect to the steering angle is changed from the second inclination to the first inclination. When the steering angle changes to an inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. The inclination of the steering reaction force with respect to an angle is a characteristic that changes from the first inclination to the second inclination,
The target steering reaction force setting means is configured to perform steering in the first characteristic when the target steering reaction force is within a set range near 0 when the steering reaction force with respect to a steering angle is on the first characteristic. A steering reaction force simulation device that sets the inclination of the steering reaction force with respect to an angle to a third inclination smaller than the first inclination. The steering reaction force simulator according to claim 7,
The steering angle detecting means is means for detecting the steering angle with a predetermined resolution Δθh,
The steering reaction force simulation device, wherein the setting range is a range in which the upper limit is K3 × Δθh and the lower limit is −K3 × Δθh, where K3 is the third inclination. The steering reaction force simulator according to claim 8,
The target steering reaction force setting means sets the third inclination K3 so that the value of K3 × Δθh is smaller than a vibration allowable value that changes according to the vibration frequency of the steering wheel. The steering reaction force simulator according to claim 7 or 8,
A tilt setting receiving means that is operated by an operator of the handle and receives an operation input related to the setting of the third tilt;
The target steering reaction force setting means is a steering reaction force simulation device that sets the third inclination based on an operation input related to the setting of the third inclination by the inclination setting receiving means. A steering reaction force simulation device that outputs a steering reaction force according to a steering operation,
Steering angle detection means for detecting the steering angle of the steering wheel with a predetermined resolution Δθh;
An increase / return determination means for determining whether to increase or decrease the steering wheel based on the detected steering angle;
Target steering reaction force setting means for setting a target steering reaction force with hysteresis characteristics based on the determination result by the increase / decrease / return determination means and the detected steering angle;
Steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output;
With
The hysteresis characteristic is
A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the steering angle, and a steering reaction force with a second inclination smaller than the first inclination with respect to a change in the steering angle. A second characteristic;
When the steering reaction force with respect to the steering angle is on the second characteristic and the direction of the steering wheel is increased and turned back, the inclination of the steering reaction force with respect to the steering angle is changed from the second inclination to the first inclination. When the steering angle changes to an inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. The inclination of the steering reaction force with respect to an angle is a characteristic that changes from the first inclination to the second inclination,
The target steering reaction force setting means sets the first inclination K1 so that the value of K1 × Δθh is smaller than the allowable vibration value that changes according to the vibration frequency of the steering wheel, where the first inclination is K1. Steering reaction force simulation device to be set. A steering reaction force simulation device that outputs a steering reaction force according to a steering operation,
Steering angle detection means for detecting the steering angle of the steering wheel;
An increase / return determination means for determining whether to increase or decrease the steering wheel based on the detected steering angle;
Target steering reaction force setting means for setting a target steering reaction force with hysteresis characteristics based on the determination result by the increase / decrease / return determination means and the detected steering angle;
Steering reaction force output means for outputting a steering reaction force so that the set target steering reaction force is output;
With
The hysteresis characteristic is
A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the steering angle, and a steering reaction force with a second inclination smaller than the first inclination with respect to a change in the steering angle. A second characteristic;
When the steering reaction force with respect to the steering angle is on the second characteristic and the direction of the steering wheel is increased and turned back, the inclination of the steering reaction force with respect to the steering angle is changed from the second inclination to the first inclination. When the steering angle changes to an inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. The inclination of the steering reaction force with respect to an angle is a characteristic that changes from the first inclination to the second inclination,
A tilt setting receiving means that is operated by an operator of the handle and receives an operation input related to the setting of the first tilt;
The target steering reaction force setting means is a steering reaction force simulation device that sets the first inclination based on an operation input related to the setting of the first inclination by the inclination setting receiving means. A steering reaction force setting method for setting a steering reaction force according to an operation of a steering wheel,
Based on the steering angle of the steering wheel, it is determined whether the steering wheel is increased or not,
In a steering reaction force setting method for setting a steering reaction force with hysteresis characteristics based on the determination result and the steering angle of the steering wheel,
The hysteresis characteristic is
A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the steering angle, and a steering reaction force with a second inclination smaller than the first inclination with respect to a change in the steering angle. A second characteristic;
When the steering reaction force with respect to the steering angle is on the second characteristic and the direction of the steering wheel is increased and turned back, the inclination of the steering reaction force with respect to the steering angle is changed from the second inclination to the first inclination. When the steering angle changes to an inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. The inclination of the steering reaction force with respect to an angle is a characteristic that changes from the first inclination to the second inclination,
When the steering reaction force with respect to the steering angle is on the first characteristic and the steering reaction force is within a set range near 0, the inclination of the steering reaction force with respect to the steering angle in the first characteristic is set to the first characteristic. A steering reaction force setting method for setting a third inclination smaller than an inclination of 1. A steering reaction force setting method for setting a steering reaction force according to an operation of a steering wheel,
Detecting the steering angle of the steering wheel with a predetermined resolution Δθh, and determining whether the steering wheel is turned back or not based on the detected steering angle;
In a steering reaction force setting method for setting a steering reaction force with hysteresis characteristics based on the determination result and the steering angle of the steering wheel,
The hysteresis characteristic is
A first characteristic in which the steering reaction force changes with a first inclination with respect to a change in the steering angle, and a steering reaction force with a second inclination smaller than the first inclination with respect to a change in the steering angle. A second characteristic;
When the steering reaction force with respect to the steering angle is on the second characteristic and the direction of the steering wheel is increased and turned back, the inclination of the steering reaction force with respect to the steering angle is changed from the second inclination to the first inclination. When the steering angle changes to an inclination and the steering reaction force with respect to the steering angle is on the first characteristic, the steering angle reaches an angle corresponding to the intersection of the first characteristic and the second characteristic. The inclination of the steering reaction force with respect to an angle is a characteristic that changes from the first inclination to the second inclination,
A steering reaction force setting method, wherein the first inclination K1 is set so that a value of K1 × Δθh is smaller than a vibration allowable value that changes according to a vibration frequency of a steering wheel, where K1 is the first inclination.

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