JP5375088B2 - Turning behavior control device, turning behavior control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize a turning behavior while preventing the deeri of turning performance. <P>SOLUTION: A difference E1 is calculated (step S1). When the difference E1 exceeds a first prescribed value th1 (a determination of step S3 is "YES"), an estimation value &gamma;e at a point of the time is set as a target value &gamma;* (step S4). A difference E2 is calculated (step S6). When the difference E2 is larger than a second prescribed value th2 (a determination of step S7 is "YES"), correction amount &Delta;&theta; of a turning angle &theta;w is calculated according to the difference E2 (step S8), and counter steering is performed according to the correction amount &Delta;&theta;. Subsequently, when the difference E2 becomes smaller than the second prescribed value th2 and the difference E1 becomes smaller than the first prescribed value th1 (a determination of the step S10 is "YES"), the calculation of the correction amount &Delta;&theta; and the counter steering are finished. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a turning behavior control device and a turning behavior control method.

Conventionally, in a steering structure that can control the steering angle of a steered wheel regardless of the driver's steering operation, when steering tendency of the vehicle is detected, counter-steer is performed, that is, the steered wheel is steered in a direction to suppress spin. Some control the corners to stabilize the turning behavior (see Patent Document 1).
JP-A-4-345575

However, the conventional example described in Patent Document 1 does not disclose a specific method for counter-steering, so details are unknown. However, if excessive counter-steering is performed, the turning performance is rather different. Will be reduced.
The subject of this invention is aiming at stabilization of turning behavior, preventing the fall of turning performance.

The turning behavior control device according to the present invention drives and controls an actuator capable of controlling the steering angle of a steered wheel, calculates an estimated value of the yaw rate, detects an actual value of the yaw rate, and estimates from the actual value. If the difference obtained by subtracting the value is larger than the first predetermined value for determining whether or not an oversteer tendency is reached, the current estimated value is set as the target value of the yaw rate, and this target value setting is retained. Then, actuator drive control is started according to the difference between the target value and the actual measurement value. If the difference between the target value and the actual value is smaller than the second predetermined value, the actuator drive control is temporarily stopped while the target value is maintained. Alternatively, if the difference between the target value and the actual measurement value is larger than the second predetermined value and the actual measurement value is smaller than the target value, the drive control of the actuator is temporarily stopped while maintaining the target value setting.

  According to the turning behavior control device according to the present invention, if the difference between the estimated value and the actually measured value is larger than the first predetermined value, the current estimated value is held as the target value of the yaw rate. Since the actuator is driven and controlled in accordance with the difference between them, it is possible to prevent the turning behavior from being stabilized while preventing the turning performance from being lowered.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
"Constitution"
FIG. 1 is a schematic configuration diagram of a steering-by-wire.
The steering wheel 1 is connected to the steering shaft 2, and the steering wheels 3L and 3R are connected to the pinion shaft 7 through the knuckle arm 4, the tie rod 5, and the rack and pinion 6 in this order. The steering shaft 2 and the pinion shaft 7 are in a mechanically separated and unconnected state, and are respectively held rotatably by a housing or the like (not shown).

The steering shaft 2 is provided with a reaction force motor 8 that generates a pseudo steering reaction force in response to a steering operation by a driver. The pinion shaft 7 has a pinion shaft corresponding to the steering angle of the steering shaft 2. A turning motor 9 for turning 7 is provided.
The steering shaft 2 is provided with a steering angle sensor 11 that detects the steering angle θs, and the pinion shaft 7 is provided with a turning angle sensor 12 that detects the turning angle θw. A hub sensor 13 for detecting the tire lateral force is provided in each of the left and right wheel hub units, and a vehicle speed sensor 14 for detecting the vehicle speed V is mounted on the output side of the transmission. A yaw rate sensor 15 that detects an actual measurement value γs of the yaw rate is provided on the vehicle body that is on the spring. The steering angle sensor 11 and the turning angle sensor 12 are configured to detect positive values when turning right and detect negative values when turning left.

The hub sensor 13 detects a tire lateral force by detecting a change in the displacement difference between the inner ring and the outer ring in the hub unit using, for example, a Hall element and a magnetized encoder. However, the present invention is not limited to this, and a strain gauge may be provided outside the bearing, and the tire lateral force may be detected by detecting deformation of the bearing.
Various signals detected by the steering angle sensor 11, the turning angle sensor 12, the hub sensor 13, the vehicle speed sensor 14, and the yaw rate sensor 15 are input to a controller 20 constituted by, for example, a microcomputer. The tire lateral force detected by the hub sensor 13 is inputted as a total value Yf.

As shown in FIG. 2, the controller 20 calculates a steered angle control unit 21 for driving and controlling the steered motor 9, a steering reaction force control unit 22 for driving and controlling the reaction force motor 8, and an estimated yaw rate value γe. An estimated value calculating unit 23 for controlling the turning behavior of the vehicle.
The turning angle control unit 21 inputs the steering angle θs of the steering shaft 2 and the turning angle θw of the pinion shaft 7 and controls the turning angle θw by driving the turning motor 9 according to the steering angle θw. .

  The steering reaction force control unit 22 inputs the tire lateral force Yf and the vehicle speed V and drives the reaction force motor 8 to control the steering reaction force Tr with respect to the steering operation. Specifically, the steering reaction force Tr is calculated according to the tire lateral force Yf with reference to the map of FIG. This map is set so that the steering reaction force Tr increases in proportion to the tire lateral force Yf.

The estimated value calculation unit 23 calculates an estimated value γe of the yaw rate according to the tire lateral force Yf and the vehicle speed V according to the following equation (1).
γe = {Yf × (L / Lr)} / (m × V) (1)
γe: Estimated value of yaw rate Yf: Tire lateral force of steered wheel L: Wheelbase Lr: Distance between vehicle center of gravity and rear wheel axle m: Vehicle weight V: Vehicle speed However, vehicle speed V is lower than predetermined value V1 of low speed Sometimes, the predetermined value V1 is substituted into the above equation (1). This predetermined value V1 is a value of about 20 km / h, for example.

The above equation (1) will be described.
The vehicle motion equation of a general vehicle is expressed by the following equation (2).
may = Yf + Yr
Iγ = YfLf + YrLr (2)
ay: Lateral acceleration I: Yawing moment of inertia Yr: Rear wheel tire lateral force Lf: Distance between vehicle center of gravity and front wheel axle

At the time of steady turning (stable), it is expressed by the following equation (3).
may = Yf + Yr = mVγ
YfLf = YrLr (3)
If the above formula (3) is arranged, the following formula (4) is derived.
Yf {(Lf + Lr) / Lr} = mVγ (4)
Solving the equation (4) for γ leads to the equation (1).

The turning behavior control unit 24 executes the turning behavior control process of FIG. 5 and corrects the steered angle θw in a direction to counter-steer when the vehicle detects an oversteer tendency, that is, to suppress the oversteer tendency. By doing so, the turning behavior is stabilized. When the turning angle θw is corrected, the steering reaction force Tr may be corrected accordingly.
FIG. 4 is a specific example of the oversteer tendency. For example, when the tire lateral force Yr of the rear wheel is saturated and the tire lateral force Yf of the front wheel is increased due to the load movement due to the brake, the yaw rate is increased and the oversteer tendency is increased. Become.

Next, the turning behavior control process will be described with reference to the flowchart of FIG.
In step S1, as shown below, a difference E1 between the actual measurement value γs and the estimated value γe is calculated.
E1 = γs−γe
In a succeeding step S2, it is determined whether or not the control flag is reset to F = 0. Note that the initial setting is reset to F = 0. Here, if the control flag is reset to F = 0, it is determined that the counter steer has not started yet, and the process proceeds to step S3. On the other hand, if the control flag is set to F = 1, it is determined that the counter steer is already started, and the process proceeds to step S6 described later.

  In step S3, it is determined whether or not the difference E1 is greater than a first predetermined value th1. The first predetermined value th1 is a relatively small value because it is a threshold value for determining the degree of deviation of the actual measurement value γs from the estimated value γe. If the determination result is E1 ≦ th1, it is determined that the vehicle does not have an oversteer tendency and the countersteer is unnecessary, and the process returns to the predetermined main program as it is. On the other hand, if the determination result is E1> th1, it is determined that the vehicle is on the verge of oversteering and there is a possibility that counter-steering is necessary, and the process proceeds to step S4.

In step S4, as shown below, the current estimated value γe is set as the target value γ ^* . That is, since the current estimated value γe is the limit of the turning performance just before the oversteer tendency, this estimated value γe is held as the target value γ ^* .
γ ^* ← γe
In the subsequent step S5, the control flag is set to F = 1.
In the subsequent step S6, as shown below, a difference E2 between the actually measured value γs and the target value γ ^* is calculated.
E2 = γs−γ ^*

  In a succeeding step S7, it is determined whether or not the difference E2 is larger than a second predetermined value th2. Since the second predetermined value th2 is a threshold value for determining the deviation degree of the actual measurement value γs with respect to the target value γ *, it is a relatively small value and a value close to the first predetermined value th1 described above. If the determination result is E2> th2, it is determined that the vehicle is in an oversteer tendency and a countersteer is necessary, and the process proceeds to step S8. On the other hand, if the determination result is E2 ≦ th2, it is determined that there is no oversteer tendency at least at the present time and that countersteering is not necessary, and the process proceeds to step S10 described later.

In step S8, with reference to the map of FIG. 6, the correction amount Δθ of the turning angle θw is calculated according to the difference E2. This map is set so that the larger the difference E2, the larger the correction amount Δθ and the upper limit value. Note that any one of the characteristic lines L1, L2, and L3 may be arbitrarily selected until the upper limit is reached. The characteristic line L1 is a characteristic that increases the correction amount Δθ using only one proportional coefficient. The characteristic line L2 is a characteristic that increases the correction amount Δθ by using two different proportional coefficients depending on the magnitude of the difference E2. The characteristic line L3 is a characteristic in which the increase rate of the correction amount Δθ with respect to the addition rate of the difference increase E2 increases as the difference E increases.
In the subsequent step S9, the correction amount Δθ is output to the turning angle control unit 21, and then the process returns to the predetermined main program.

On the other hand, in step S10, it is determined whether or not the difference E1 is smaller than the first predetermined value th1. If the determination result is E1 ≦ th1, it is determined that the oversteer tendency has been eliminated by the counter steer, and the process proceeds to step S11. On the other hand, if the determination result is E1> th1, it is determined that the oversteer tendency may be temporarily reduced, and the process proceeds to step S12.
In step S11, the control flag is reset to F = 0, and then the process returns to a predetermined main program.

  Step S12 determines whether or not the vehicle speed V is smaller than the third predetermined value th3, or whether or not the actual measurement value γs is smaller than the fourth predetermined value th4. The third predetermined value th3 is a threshold value for determining whether or not the vehicle speed V is in the low speed region, and is a value of about 15 km / h, for example. The fourth predetermined value th4 is a threshold value for determining whether or not the actual measurement value γs is sufficiently small, and is a value of, for example, about 10 deg / sec, which is smaller than the target value γ *. If the determination result is V <th3 or γs <th4, it is determined that the counter steer is no longer necessary, and the process proceeds to step S11. On the other hand, if the determination result is V ≧ th3 and γs ≧ th4, it is determined that the oversteer tendency may be temporarily reduced, and the process returns to the predetermined main program as it is.

<Action>
First, calculation of the estimated value γe will be described.
In general, it is known that the yaw rate is estimated based on the vehicle speed V and the steering angle θs. However, since the actual yaw rate is affected by the road surface friction coefficient, the yaw rate is calculated based on the vehicle speed V and the steering angle θs. The estimated value of the yaw rate needs to be corrected according to the friction coefficient. However, since it is difficult to accurately detect the friction coefficient, it is difficult to accurately estimate the yaw rate.

  Therefore, in the present embodiment, an estimated value γe of the yaw rate is calculated according to the tire lateral force Yf and the vehicle speed V according to the equation (1). Thus, by using the tire lateral force Yf, the yaw rate can be accurately estimated without being affected by the road surface friction coefficient. However, when the vehicle speed V is less than or equal to the low predetermined value V1, the predetermined value V1 is substituted into the equation (1) to calculate the estimated value γe. That is, according to the above equation (1), the estimated value γe increases as the vehicle speed V decreases. Therefore, by providing a lower limit value for the vehicle speed V to be substituted, the estimation value γe is prevented from being maximized, and in accordance with the actual situation. An estimated value γe can be calculated.

Next, the control of the turning behavior will be described according to the time chart of FIG.
When the difference E1 is calculated (step S1) and the difference E1 is smaller than the first predetermined value th1 (determination in step S3 is “No”), that is, when the actual measurement value γs approximates the estimated value γe, Since the vehicle is not in an oversteer tendency and no countersteer is required, the control of the turning behavior is turned off as shown by the section T1 of the time chart.

When the actually measured value γs increases from this state and the difference E1 exceeds the first predetermined value th1 (determination in step S3 is “Yes”), the estimated value γe at that time is set as the target value γ ^* (step S4). ). Since the present estimated value γe is the limit of the turning performance just before the tendency toward oversteer, this estimated value γe is held as the target value γ ^* .
Then, the difference E2 is calculated (step S6), and when the difference E2 is larger than the second predetermined value th2 (determination in step S7 is “Yes”), the correction amount Δθ of the turning angle θw according to the difference E2 Is calculated (step S8), and counter steering is performed according to the correction amount Δθ, so that the control of the turning behavior is turned on as shown by the section T2 of the time chart.

As described above, the yaw rate as a limit of turning performance of the verge of reaching the oversteer, and set as a target value gamma ^*, according to the difference E2 between the target value gamma ^* and the measured value gamma] s, performs counter-steering Thereby, stabilization of turning behavior can be prevented while preventing deterioration of turning performance. That is, when the actual measurement value γs approaches the target value γ ^* , the correction amount Δθ is reduced, and when the actual measurement value γs is far from the target value γ ^* , the correction amount Δθ is increased, so You can steer.

Thereafter, when the actual measurement value γs approximates the target value γ ^* and the difference E2 becomes smaller than the second predetermined value th2 (determination in step S7 is “No”), the calculation of the correction amount Δθ is stopped and the counter steer is stopped. The vehicle is temporarily stopped and the turning behavior control is set to standby as indicated by a time chart section T3. This is because the estimated value γe is not stable at this time, and the actually measured value γs may increase again. In general, the stronger the first oversteer tendency (first wave), the oversteer tendency (second wave) may appear again due to inertia, even if the oversteer tendency once weakens by a single counter-steer operation. is there. Therefore, if the difference E2 is smaller than the second predetermined value th2, the control of the turning behavior is not immediately ended, and the vehicle is on standby for a case where an oversteer tendency appears again. In this way, by temporarily stopping the control of the turning behavior while maintaining the setting of the target value γ ^* , when the oversteer tendency appears again, the turning behavior is immediately controlled based on the same target value γ ^* . Control can be resumed.

In the standby state, the actually measured value γs may temporarily become smaller than the target value γ ^* , but the counter steer in the increasing direction is not performed, and the standby state is maintained as it is.
Then, when an oversteer tendency appears again and the difference E2 becomes larger than the second predetermined value th2 (determination in step S7 is “Yes”), the countersteer is restarted according to the correction amount Δθ, so that the time chart As indicated by the section T4, the turning behavior control is once again turned ON.

Thereafter, when the difference E2 becomes smaller than the second predetermined value th2 again and the difference E1 becomes smaller than the first predetermined value th1 (determination in Step S10 is “Yes”), the calculation of the correction amount Δθ and the counter steer are performed. The control of the turning behavior is turned off as shown in the section T5 of the time chart. At this time, the setting of the target value γ ^* is canceled by resetting the control flag to F = 0 (step S11). Therefore, thereafter, when the difference E1 becomes larger than the first predetermined value th1, the target value γ ^* is set again.

  On the other hand, if the difference E1 is larger than the predetermined value th1, the difference E2 is smaller than the second predetermined value th2 and the vehicle speed V is smaller than the third predetermined value th3 (determination in step S11 is “Yes”). The calculation of the amount Δθ and the counter steer are finished, and the control of the turning behavior is finished. This is because the turning behavior does not become a big problem when the vehicle is traveling at a low speed.

  Further, even if the difference E1 is larger than the predetermined value th1, if the difference E2 is smaller than the second predetermined value th2 and the measured value γs is smaller than the fourth predetermined value th4 (determination in step S11 is “Yes”). The calculation of the correction amount Δθ and the counter steer are finished, and the control of the turning behavior is finished. This is also because the turning behavior does not become a big problem when the vehicle has a low yaw rate, as in the case of traveling at a low speed.

《Application example》
In the present embodiment, the tire lateral force Yf is detected using a Hall element and a magnetized encoder. However, this type of hub sensor 13 can accurately detect the tire lateral force when the vehicle speed is extremely low. There is a possibility that Yf cannot be detected. Therefore, when the vehicle speed V is equal to or lower than the low speed predetermined value V1, the drive current of the steered motor 9 is detected, the rack axial force is detected, the pinion torque is detected, and these are used instead. The estimated value γe may be calculated. Thereby, even if the vehicle speed V is low, the estimation of the yaw rate can be continued.

  In this embodiment, the yaw rate estimated value γe is calculated according to the tire lateral force Yf and the vehicle speed V, but the present invention is not limited to this. That is, according to the equation (1), the vehicle weight m is also a variable element. Therefore, instead of setting the vehicle weight m as a fixed value, the vehicle weight m is detected based on the suspension stroke detected by the stroke sensor or the pitching state of the vehicle detected by the acceleration sensor, and this is also substituted into the above (1). The estimated value γe may be calculated. Similarly, since the distance Lr between the vehicle center of gravity and the rear axle is also a variable element, the vehicle center of gravity is detected based on the suspension stroke detected by the stroke sensor and the vehicle pitching state detected by the acceleration sensor. The estimated distance γe may be calculated by calculating the distance Lr from the wheel axle and also substituting it into (1). Thus, more accurate estimation can be performed by detecting the vehicle weight m and the vehicle gravity center point and reflecting them in the calculation of the estimated value γe.

In the present embodiment, the estimated value γe of the yaw rate is calculated according to the equation (1), but the present invention is not limited to this. For example, a first-order lag low-pass filter may be added to the process of calculating the estimated value γe, and the estimated value γe of the yaw rate may be calculated according to the following equation (5).
γe = {{Yf × (L / Lr)} / (m × V)}
× (1/1 + Ts) ………… (5)

  The hub sensor 13 is attached to a hub unit that is unsprung, while the yaw rate sensor 15 is attached to a vehicle body that is sprung. Therefore, strictly speaking, a phase delay occurs in the actual yaw rate value γs detected by the yaw rate sensor 15 with respect to the estimated yaw rate value γe calculated according to the tire lateral force Yf. That is, this phase shift affects the determination of the turning behavior. Therefore, according to the equation (4), the phase of the estimated value γe coincides with the phase of the actually measured value γs by adding a first-order lag low-pass filter to the estimated value γe calculation process. Thereby, the phase shift between the estimated value γe and the actually measured value γs can be eliminated, and the determination accuracy of the turning behavior can be improved.

  Further, in the present embodiment, the control of the turning behavior is finished when the difference E2 is smaller than the second predetermined value th2 and the difference E1 is smaller than the first predetermined value th1. It is not limited. For example, the control of the turning behavior may be terminated when a predetermined time elapses in a state where the difference E2 is smaller than the second predetermined value th2 and the difference E1 is smaller than the first predetermined value th1. According to this, ON / OFF of control can be switched more carefully.

In this embodiment, the control of the turning behavior is terminated when the difference E2 is smaller than the second predetermined value th2 and the difference E1 is smaller than the first predetermined value th1, but the present invention is limited to this. It is not a thing. For example, the standby mode may be omitted, and the turning behavior control may be immediately terminated when the difference E2 becomes smaller than the second predetermined value th2. According to this, ON / OFF of control can be switched more simply.
In the present embodiment, the steering-by-wire has been described. However, the present invention is not limited to this, and any steering wheel can be controlled by a steering angle ratio variable mechanism (VGR) as long as it detects an oversteer tendency and controls the turning behavior. The present invention can also be applied to those that control the turning angle θw.

"effect"
From the above, the steered motor 9 corresponds to the “actuator”, the estimated value calculation unit 23 corresponds to the “estimated value calculation unit”, the yaw rate sensor 15 corresponds to the “actual value detection unit”, and the turning behavior control unit 24. Corresponds to “control means”.
(1) An actuator capable of controlling the steering angle of the steered wheels, an estimated value calculating means for calculating an estimated value of the yaw rate, an actual value detecting means for detecting an actual value of the yaw rate, and an estimation estimated by the estimated value calculating means If the difference between the value and the actual value detected by the actual value detection means is greater than the first predetermined value, the current estimated value is set as the target value of the yaw rate, and the difference between the target value and the actual value is set as the target value. And a control means for starting drive control of the actuator in response.
Thus, if the difference between the estimated value and the actually measured value is larger than the first predetermined value, the current estimated value is held as the target value of the yaw rate, and thereafter the actuator is driven according to the difference between the target value and the actually measured value. Since the control is performed, it is possible to prevent the turning behavior from being stabilized while preventing the turning performance from being deteriorated.

(2) The estimated value calculating means calculates the estimated value of the yaw rate according to the vehicle speed and the tire lateral force of the steered wheels.
Thus, since the tire lateral force is used when calculating the estimated value of the yaw rate, it can be accurately estimated without being affected by the road surface friction coefficient, and the turning behavior of the vehicle can be detected accurately. it can.

(3) The estimated value calculating means calculates an estimated value of the yaw rate according to the vehicle speed detected by the vehicle speed detecting means and the tire lateral force detected by the lateral force detecting means, according to the following equation. The turning behavior detection device according to claim 1.
γe = {Yf × (L / Lr)} / (m × V)
γe: Estimated value of yaw rate Yf: Tire lateral force of steered wheel L: Wheelbase Lr: Distance between vehicle center of gravity and driven wheel axle m: Vehicle weight V: Vehicle speed When calculating the estimated value of yaw rate in this way Since the tire lateral force is used, it can be accurately estimated without being influenced by the road surface friction coefficient, and the turning behavior of the vehicle can be detected with high accuracy.

(4) When the vehicle speed detected by the vehicle speed detecting means is equal to or less than a predetermined value, the estimated value calculating means estimates the yaw rate according to the predetermined value and the tire lateral force detected by the lateral force detecting means. Is calculated.
Thus, by providing the lower limit value for the vehicle speed to be substituted, it is possible to prevent the estimated value from being maximized and to calculate the estimated value in accordance with the actual situation.
(5) If the difference between the target value and the actually measured value is smaller than a second predetermined value, the control means temporarily stops the drive control of the actuator while maintaining the setting of the target value.
As a result, when the oversteer tendency appears again, the drive control of the actuator can be resumed immediately based on the same target value.

(6) If the difference between the target value and the measured value is greater than a second predetermined value and the measured value is smaller than the target value, the control means maintains the setting of the target value, The actuator drive control is temporarily stopped.
As a result, the actuator drive control can be performed only when the oversteer tendency is suppressed without performing the actuator drive control in the direction of additional cutting.

(7) If the difference between the target value and the actually measured value is greater than the second predetermined value and the actually measured value is greater than the target value, the control means resumes drive control of the actuator.
Thereby, the oversteer tendency that appears again can be suppressed, and the turning behavior can be stabilized.
(8) When the difference between the target value and the actual measurement value is smaller than a second predetermined value, the control means cancels the setting of the target value and ends the drive control of the actuator. The turning behavior control device according to claim 1 or 2.
Thereby, ON / OFF of drive control can be switched simply.

(9) If the difference between the target value and the measured value is smaller than a second predetermined value and the difference between the measured value and the estimated value is smaller than the first predetermined value, The setting of the target value is canceled, and the drive control of the actuator is ended.
Thereby, ON / OFF of drive control can be switched accurately.
(10) The control means cancels the setting of the target value if the difference between the target value and the actually measured value is smaller than the second predetermined value and the vehicle speed is smaller than a third predetermined value in the low speed region. At the same time, the drive control of the actuator is terminated.
In general, when the vehicle speed is running at a low speed, the turning behavior does not become a big problem, so the drive control can be simply turned off.

(11) If the difference between the target value and the measured value is smaller than the second predetermined value and the measured value is smaller than a fourth predetermined value smaller than the target value, the control means The setting of the value is cancelled, and the drive control of the actuator is ended.
In general, when the yaw rate is small, the turning behavior does not become a big problem, so that the drive control can be simply turned off.

(12) A turning behavior control method for driving and controlling an actuator capable of controlling a steering angle of a steered wheel, calculating an estimated value of a yaw rate, detecting an actual value of a yaw rate, and calculating the estimated value and the measured value If the difference is larger than the first predetermined value, the current estimated value is set as the target value of the yaw rate, and drive control of the actuator is started according to the difference between the target value and the actually measured value.
Thus, if the difference between the estimated value and the actually measured value is larger than the first predetermined value, the current estimated value is held as the target value of the yaw rate, and thereafter the actuator is driven according to the difference between the target value and the actually measured value. Since the control is performed, it is possible to prevent the turning behavior from being stabilized while preventing the turning performance from being deteriorated.

It is a schematic structure of a steering-by-wire. It is a block diagram of a controller. It is a map used for calculation of steering reaction force. It is a specific example of an oversteer tendency. It is a flowchart which shows a turning behavior control process. It is a map used for calculation of correction amount (DELTA) (theta). It is a time chart which shows the operation | movement of a turning behavior control process.

Explanation of symbols

3L, 3R Steering wheel 8 Reaction force motor 9 Steering motor 11 Steering angle sensor 12 Steering angle sensor 13 Hub sensor 14 Vehicle speed sensor 15 Yaw rate sensor 20 Controller 21 Steering angle control unit 22 Steering reaction force control unit 23 Estimated value calculation unit 24 Turning behavior control unit

Claims (12)

From the actuator that can control the steering angle of the steered wheel, the estimated value calculating means for calculating the estimated value of the yaw rate, the measured value detecting means for detecting the measured value of the yaw rate, and the measured value detected by the measured value detecting means If the difference obtained by subtracting the estimated value estimated by the estimated value calculating means is larger than the first predetermined value for determining whether or not an oversteer tendency is reached, the current estimated value is set as the target value of the yaw rate. Control means for holding the setting of the target value and starting drive control of the actuator in accordance with a difference between the target value and the actual measurement value ,
If the difference between the target value and the measured value is smaller than a second predetermined value, the control means temporarily stops the drive control of the actuator while maintaining the setting of the target value. Behavior control device. From the actuator that can control the steering angle of the steered wheel, the estimated value calculating means for calculating the estimated value of the yaw rate, the measured value detecting means for detecting the measured value of the yaw rate, and the measured value detected by the measured value detecting means If the difference obtained by subtracting the estimated value estimated by the estimated value calculating means is larger than the first predetermined value for determining whether or not an oversteer tendency is reached, the current estimated value is set as the target value of the yaw rate. Control means for holding the setting of the target value and starting drive control of the actuator in accordance with a difference between the target value and the actual measurement value ,
If the difference between the target value and the measured value is larger than a second predetermined value and the measured value is smaller than the target value, the control means maintains the setting of the target value while maintaining the setting of the target value. A turning behavior control device characterized by temporarily stopping drive control . From the actuator that can control the steering angle of the steered wheel, the estimated value calculating means for calculating the estimated value of the yaw rate, the measured value detecting means for detecting the measured value of the yaw rate, and the measured value detected by the measured value detecting means If the difference obtained by subtracting the estimated value estimated by the estimated value calculating means is larger than the first predetermined value for determining whether or not an oversteer tendency is reached, the current estimated value is set as the target value of the yaw rate. Control means for holding the setting of the target value and starting drive control of the actuator in accordance with a difference between the target value and the actual measurement value ,
If the difference between the target value and the measured value is smaller than a second predetermined value, the control means cancels the setting of the target value and ends the drive control of the actuator. Control device. From the actuator that can control the steering angle of the steered wheel, the estimated value calculating means for calculating the estimated value of the yaw rate, the measured value detecting means for detecting the measured value of the yaw rate, and the measured value detected by the measured value detecting means If the difference obtained by subtracting the estimated value estimated by the estimated value calculating means is larger than the first predetermined value for determining whether or not an oversteer tendency is reached, the current estimated value is set as the target value of the yaw rate. Control means for holding the setting of the target value and starting drive control of the actuator in accordance with a difference between the target value and the actual measurement value ,
If the difference between the target value and the measured value is smaller than a second predetermined value and the difference between the measured value and the estimated value is smaller than the first predetermined value, the control means A turning behavior control device characterized by canceling the setting and terminating the drive control of the actuator . From the actuator that can control the steering angle of the steered wheel, the estimated value calculating means for calculating the estimated value of the yaw rate, the measured value detecting means for detecting the measured value of the yaw rate, and the measured value detected by the measured value detecting means If the difference obtained by subtracting the estimated value estimated by the estimated value calculating means is larger than the first predetermined value for determining whether or not an oversteer tendency is reached, the current estimated value is set as the target value of the yaw rate. Control means for holding the setting of the target value and starting drive control of the actuator in accordance with a difference between the target value and the actual measurement value ,
The control means has a difference between the target value and the measured value smaller than the second predetermined value, and
If the vehicle speed is smaller than a third predetermined value in the low speed region, the setting of the target value is canceled and the drive control of the actuator is terminated . From the actuator that can control the steering angle of the steered wheel, the estimated value calculating means for calculating the estimated value of the yaw rate, the measured value detecting means for detecting the measured value of the yaw rate, and the measured value detected by the measured value detecting means If the difference obtained by subtracting the estimated value estimated by the estimated value calculating means is larger than the first predetermined value for determining whether or not an oversteer tendency is reached, the current estimated value is set as the target value of the yaw rate. Control means for holding the setting of the target value and starting drive control of the actuator in accordance with a difference between the target value and the actual measurement value ,
The control means sets the target value if the difference between the target value and the actual value is smaller than the second predetermined value and the actual value is smaller than a fourth predetermined value smaller than the target value. And the turning control of the actuator is terminated . The turning behavior control device according to any one of claims 1 to 6, wherein the estimated value calculating means calculates the estimated value of the yaw rate according to a vehicle speed and a tire lateral force of a steered wheel. The estimated value calculation means, according to the following equation, according to claim 7, characterized in that the vehicle speed detected by the detecting means and the lateral force detecting means for calculating an estimated value of the yaw rate in accordance with the tire lateral force detected The turning behavior detection device according to 1.
γe = {Yf × (L / Lr)} / (m × V)
γe: Estimated yaw rate Yf: Steering wheel tire lateral force L: Wheelbase Lr: Distance between vehicle center of gravity and driven wheel axle m: Vehicle weight V: Vehicle speed 9. The turning behavior detecting device according to claim 7, wherein the estimated value calculating means includes a filter that matches a phase of the estimated value to be calculated with a phase of the actually measured value detected by the actual value detecting means. . The control means restarts the drive control of the actuator if the difference between the target value and the measured value is greater than the second predetermined value and the measured value is greater than the target value. The turning behavior control device according to claim 1 or 2 . A turning behavior control method for driving and controlling an actuator capable of controlling a steering angle of a steered wheel,
While calculating the estimated value of the yaw rate according to the vehicle speed and the tire lateral force of the steered wheel, detecting the actual value of the yaw rate, and if the difference obtained by subtracting the estimated value from the actual value is greater than the first predetermined value, The current estimated value is set as the target value of the yaw rate, and the actuator is controlled to be driven according to the difference between the target value and the measured value .
If the difference between the target value and the actually measured value is smaller than a second predetermined value , the turning behavior control method is characterized in that the drive control of the actuator is temporarily stopped while the setting of the target value is maintained . A turning behavior control method for driving and controlling an actuator capable of controlling a steering angle of a steered wheel,
While calculating the estimated value of the yaw rate according to the vehicle speed and the tire lateral force of the steered wheel, detecting the actual value of the yaw rate, and if the difference obtained by subtracting the estimated value from the actual value is greater than the first predetermined value, The current estimated value is set as the target value of the yaw rate, and the actuator is controlled to be driven according to the difference between the target value and the measured value .
If the difference between the target value and the measured value is larger than a second predetermined value and the measured value is smaller than the target value, the drive control of the actuator is paused while maintaining the setting of the target value. A turning behavior control method characterized by:

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