WO2018003828A1

WO2018003828A1 - Suspension control device

Info

Publication number: WO2018003828A1
Application number: PCT/JP2017/023679
Authority: WO
Inventors: 隆介平尾; 賢太郎糟谷; 修之一丸
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2016-06-28
Filing date: 2017-06-28
Publication date: 2018-01-04
Also published as: JP2019142244A

Abstract

Provided is a suspension control device with which it is possible to minimize roll acting on a vehicle. This suspension control device is provided with: a damping-force-adjusting shock absorber that is provided between the body of a vehicle and a vehicle wheel and can adjust generated damping force; and a steering torque information acquisition unit that acquires steering torque information of a steering wheel provided to the vehicle. The suspension control device controls the damping force generated by the damping-force-adjusting shock absorber, in accordance with the acquired results from the steering torque information acquisition unit.

Description

Suspension control device

The present invention relates to a suspension control device suitably used for a vehicle such as a four-wheel automobile.

As a vehicle anti-roll control, for example, a configuration is known in which a lateral acceleration is calculated from a vehicle steering angle and a vehicle speed, and a target damping force of each suspension provided in the vehicle is calculated using the lateral acceleration. In addition, there is also known one that compensates for a change in steering torque when vehicle behavior stabilization control is performed (see, for example, Patent Document 1).

JP 2009-173169 A

Incidentally, in the anti-roll control of the vehicle described above, when the steering angle is constant and the frictional force on the road surface changes, the actual lateral acceleration changes and rolls are generated. However, since the steering angle has not changed, the anti-roll control does not operate, and the roll acting on the vehicle may become large.

An object of the present invention is to provide a suspension control device that can suppress a roll acting on a vehicle.

A suspension control apparatus according to an embodiment of the present invention is provided between a vehicle body and a wheel of a vehicle, a damping force adjustment type shock absorber capable of adjusting a generated damping force, and a steering torque of a steering provided in the vehicle. A steering torque information acquisition unit that acquires information, and controls a damping force generated by the damping force adjusting shock absorber according to an acquisition result of the steering torque information acquisition unit.

A suspension control device according to an embodiment of the present invention is provided between a vehicle body and a wheel of a vehicle, and a damping force adjustment type shock absorber capable of adjusting a generated damping force, and a steering provided in the vehicle. A steering torque information acquisition unit that acquires steering torque information; and an unsprung resonance extraction unit that extracts an unsprung resonance frequency component from the acquisition result of the steering torque information acquisition unit, the extraction result of the unsprung resonance extraction unit Based on the above, adjustment control of the damping force generated by the damping force adjusting type shock absorber is performed.

According to one embodiment of the present invention, it is possible to effectively suppress the behavior of the roll acting on the vehicle, thereby improving the ride comfort of the vehicle.

1 is a circuit diagram showing an electric circuit of a four-wheeled vehicle equipped with a suspension control device according to a first embodiment of the present invention. It is a control block diagram which shows the suspension control apparatus in FIG. It is a control block diagram which shows the suspension control apparatus by 2nd Embodiment. It is a control block diagram which shows the suspension control apparatus by 3rd Embodiment.

Hereinafter, a suspension control device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where the suspension control device is applied to a four-wheeled vehicle.

1 and 2 show a first embodiment of the present invention. In FIG. 1, a vehicle body 1 constitutes the body of a four-wheeled vehicle, and a left front wheel 2A, a right front wheel 2B, a left rear wheel 3A, and a right rear wheel 3B are provided on the lower side of the vehicle body 1, for example. ing.

The left front wheel suspension device 4A (hereinafter referred to as FL damper 4A) is provided between the left front wheel 2A side and the vehicle body 1. On the other hand, a right front wheel suspension device 4B (hereinafter referred to as FR damper 4B) is provided between the right front wheel 2B side and the vehicle body 1. These

dampers

4A and 4B are configured as, for example, hydraulic damping force adjustment type shock absorbers capable of adjusting the generated damping force. The

dampers

4A and 4B are provided with actuators (not shown) including damping force adjusting valves, solenoids, etc. in order to continuously adjust the damping force characteristics from hard characteristics (hard characteristics) to soft characteristics (soft characteristics). ) Is attached. At this time, each

damper

4A, 4B is comprised by the semi-active damper which controls the flow of a working fluid with an actuator, for example.

Note that the damping force adjusting actuator is not necessarily configured to continuously change the damping force characteristic, and may be configured to intermittently adjust in two stages or three or more stages. The

dampers

4A and 4B only need to be able to switch the damping force, and may be pneumatic dampers or electromagnetic dampers.

The left rear wheel suspension device 5A (hereinafter referred to as RL damper 5A) is provided between the left rear wheel 3A side and the vehicle body 1. On the other hand, the right rear wheel suspension device 5B (hereinafter referred to as the RR damper 5B) is provided between the right rear wheel 3B side and the vehicle body 1. These

dampers

5A and 5B are configured as hydraulic damping force adjusting shock absorbers that can adjust the generated damping force. The

dampers

5A and 5B are provided with actuators (not shown) including damping force adjusting valves, solenoids, etc., in order to continuously adjust the damping force characteristics from hard characteristics (hard characteristics) to soft characteristics (soft characteristics). ) Is attached. At this time, each

damper

5A, 5B is comprised by the semi-active damper which controls the flow of a working fluid with an actuator, for example.

dampers

5A and 5B only need to be able to switch the damping force, and may be pneumatic dampers or electromagnetic dampers.

The steering angle sensor 6 detects a steering operation amount of the vehicle. That is, the steering angle sensor 6 detects a steering angle (corresponding to a front wheel steering angle δf described later) when the driver of the vehicle operates the steering 7 (steering wheel) during turning. Then, the steering angle sensor 6 outputs a detection signal (steering angle signal) to the control device 12 described later.

The vehicle speed sensor 8 detects a traveling speed of the vehicle (corresponding to a vehicle speed V described later). The vehicle speed sensor 8 outputs a detection signal (vehicle speed signal) to the control device 12 described later.

The torque sensor 9 detects the steering torque (steering torque M described later) of the shaft 10 that is twisted by the steering force when the driver of the vehicle operates the steering 7. Then, the torque sensor 9 outputs the detection signal (torque signal) to the control device 12 described later. The torque sensor 9 constitutes a steering torque information acquisition unit of the present invention. Note that the steering torque information acquisition unit may acquire and use information from a steering control device that controls the steering, in addition to the control device having means for detecting steering torque.

The vehicle height sensors 11A to 11D are for detecting the height dimension of the vehicle body 1. The vehicle height sensor 11A is provided, for example, in the vicinity of the FL damper 4A, and the vehicle height sensor 11B is provided in the vicinity of the FR damper 4B. Further, the vehicle height sensor 11C is provided, for example, in the vicinity of the RL damper 5A, and the vehicle height sensor 11D is provided in the vicinity of the RR damper 5B. Then, the vehicle height sensors 11A to 11D output detection signals (height signal) to the control device 12 described later.

Next, the control device 12 that performs anti-roll control of the vehicle body 1 will be described.

The control device 12 is configured by a microcomputer or the like and is mounted on the vehicle body 1. When it is determined that the vehicle is in a roll state, the control device 12 performs control to increase the damping force generated by the FL damper 4A, the FR damper 4B, the RL damper 5A, and the RR damper 5B. On the input side of the control device 12, a steering angle sensor 6, a vehicle speed sensor 8, a torque sensor 9, and vehicle height sensors 11A to 11D are connected. On the other hand, the output side of the control device 12 is connected to an actuator (not shown) of the FL damper 4A, the FR damper 4B, the RL damper 5A, the RR damper 5B, and the like.

As shown in FIG. 2, the control device 12 includes a first roll rate calculation unit 13, a second roll rate calculation unit 16, a roll rate selection unit 20, a target damping force calculation unit 21, and a relative speed calculation unit 30. It is configured to include. In this case, the second roll rate calculation unit 16, the roll rate selection unit 20, and the target damping force calculation unit 21 constitute a roll suppression control unit of the present invention.

First, the first roll rate calculation unit 13 for calculating the first roll rate R1 will be described.

The first roll rate calculation unit 13 estimates and calculates the first roll rate R1 from the detection result (steering torque M) of the torque sensor 9. The first roll rate calculation unit 13 constitutes a first roll rate calculation unit of the present invention. The first roll rate calculation unit 13 includes a lateral acceleration estimation unit 14 and a differentiation unit 15.

The lateral acceleration estimator 14 stores (stores) a map (not shown) indicating the correspondence between steering torque and lateral acceleration calculated by, for example, experiments. Therefore, the lateral acceleration estimation unit 14 can calculate the first lateral acceleration αy1 by inputting the torque signal (steering torque M) output from the torque sensor 9 to this map.

The differentiation unit 15 calculates a lateral jerk by differentiating the first lateral acceleration αy1. This lateral jerk almost coincides with the roll rate. In this way, the first roll rate calculation unit 13 can calculate the first roll rate R1 estimated from the steering torque M. The first roll rate R1 is output to the roll rate selection unit 20 described later.

Next, the second roll rate calculation unit 16 that estimates and calculates the second roll rate R2 will be described.

The second roll rate calculation unit 16 estimates and calculates the second roll rate R2 from the steering angle (front wheel steering angle δf) detected by the steering angle sensor 6 and the vehicle speed V detected by the vehicle speed sensor 8. is there. The second roll rate calculation unit 16 constitutes a second roll rate calculation unit of the present invention. The second roll rate calculation unit 16 includes a vehicle model unit 17, a phase adjustment filter 18, and a differentiation unit 19.

First, the vehicle model unit 17 estimates the yaw rate r by using the vehicle model of the following equation 1 from the steering angle (front wheel rudder angle δf) and the vehicle speed V. Here, the yaw rate r can be obtained by the equation (1) when a linear model of the vehicle is assumed and dynamic characteristics are ignored. Where V is the vehicle speed (m / s), A is the stability factor (S2 / m2), δf is the front wheel steering angle (rad), Gf is the steering gear ratio, and L is the wheelbase (m).

Further, the relationship between the second lateral acceleration αy2 and the yaw rate r can be obtained by the following equation (2). That is, the second lateral acceleration αy2 is calculated by multiplying the calculated yaw rate r by the vehicle speed V.

Then, the phase adjustment filter 18 is used to compensate for the dynamics from the vehicle steering angle to the occurrence of lateral acceleration. At this time, the phase adjustment filter 18 is constituted by a secondary filter represented by, for example, a second-order lag equation. Next, the differentiation unit 19 differentiates the second lateral acceleration αy2 to calculate the lateral jerk. The lateral jerk almost coincides with the roll rate. In this way, the second roll rate calculation unit 16 can calculate the second roll rate R2 estimated from the front wheel steering angle δf and the vehicle speed V. The second roll rate R2 is output to the roll rate selection unit 20 described later.

The roll rate selection unit 20 has a larger value between the first roll rate R1 calculated by the first roll rate calculation unit 13 and the second roll rate R2 calculated by the second roll rate calculation unit 16. The roll rate (R1 or R2) is selected. This roll rate selection unit 20 constitutes a roll rate selection unit of the present invention.

That is, when the steering angle is constant and the frictional force of the road surface changes while the vehicle is running, the actual lateral acceleration changes and rolls are generated. However, since the steering angle has not changed, for example, in a configuration in which the first roll rate calculation unit 13 and the roll rate selection unit 20 are omitted, the anti-roll control does not operate and the roll acting on the vehicle becomes large. There is a fear.

On the other hand, in the first embodiment, the control device 12 includes a first roll rate calculation unit 13 and a roll rate selection unit 20. For this reason, the first roll rate calculation unit 13 estimates and calculates the first roll rate R1 from the steering torque M acting on the steering 7 when the frictional force of the road surface changes. Then, the control device 12 uses the larger roll rate of the first roll rate R1 and the second roll rate R2 estimated and calculated based on the vehicle steering angle δf and the vehicle speed V to It is configured to perform roll control.

Next, the target damping force calculation unit 21 that calculates the target damping force of each

damper

4A, 4B, 5A, 5B will be described.

The target damping force calculation unit 21 calculates the target damping force of each

damper

4A, 4B, 5A, 5B using the roll rate (R1 or R2) selected by the roll rate selection unit 20. The target damping force calculation unit 21 constitutes a target damping force calculation unit of the present invention. The target damping force calculation unit 21 includes target damping

force calculation units

22 and 23,

sign inversion units

24 and 25, and damper command

value calculation units

26, 27, 28, and 29.

The target damping

force calculation units

22 and 23 multiply the roll rate (R1 or R2) selected by the roll rate selection unit 20 by the Fr gain for the right front wheel 2B and the Rr gain for the right rear wheel 3B to suppress the roll. The target damping force. The

sign reversing units

24 and 25 multiply “−1” in order to reverse the roll damping target damping force between the left front wheel 2A and the left rear wheel 3A with the right front wheel 2B and the right rear wheel 3B.

After calculating the target damping force of each wheel in this way, the damper command

value calculation units

26, 27, 28, and 29 store the target damping force and the relative speed estimated by the relative speed calculation unit 30 in advance. The necessary current value is output from the characteristic map of the damper.

In this case, the relative speed calculation unit 30 can calculate the relative speed of the

front wheels

2A and 2B by differentiating the difference between the detection value of the vehicle height sensor 11A and the detection value of the vehicle height sensor 11B, for example. Further, the relative speed calculation unit 30 can calculate the relative speed on the

rear wheels

3A and 3B side by differentiating the difference between the detection value of the vehicle height sensor 11C and the detection value of the vehicle height sensor 11D, for example.

Accordingly, the damper command

value calculation units

26, 27, 28, and 29 use, as current values, damper command values to be output to the actuators (not shown) of the FL damper 4A, FR damper 4B, RL damper 5A, and RR damper 5B. calculate. The

dampers

4A, 4B, 5A, and 5B are controlled so that the damping force characteristics are continuously variable between hardware and software, or variable in multiple stages, according to the current value (damper command value) supplied to the actuator.

The suspension control device according to the present embodiment has the above-described configuration, and next, an anti-roll control process for the vehicle body 1 by the control device 12 will be described.

When the vehicle approaches the corner of the road and turns, the steering 7 is operated in the order of, for example, straight ahead → transient turn → steady turn → transient turn → straight forward. When the vehicle is traveling straight, the steering angle is kept almost neutral, and when the vehicle reaches a transient turn, the steering angle is increased by a necessary angle. When the vehicle turns into a steady turn, the steering angle is maintained at a substantially constant angle so as to maintain the required angle. When the subsequent transient turn is reached, an operation to return the steering angle to neutral is performed. Become neutral. In this case, the lateral acceleration generated in the vehicle increases or decreases so as to be substantially proportional to the steering angle. Further, the roll angle of the vehicle body 1 is also increased or decreased so as to be substantially proportional to the steering angle and the lateral acceleration.

By the way, in the prior art, the lateral acceleration is calculated from the steering angle and the vehicle speed of the vehicle, and the target damping force of each suspension provided in the vehicle is calculated using the lateral acceleration, thereby controlling the ride comfort of the vehicle (anti-antistatic). Roll control).

In this case, if the frictional force of the road surface changes while the vehicle is turning, the actual lateral acceleration changes, and the vehicle rolls. However, since there is no change in the steering angle, the anti-roll control does not operate, and the roll acting on the vehicle may become large. Moreover, since the actual lateral acceleration signal includes the influence of road surface input, it is necessary to apply a low pass filter strongly, and it is difficult to use it for anti-roll control.

Therefore, in the first embodiment, in addition to calculating the roll rate (second roll rate R2) from the vehicle steering angle δf and the vehicle speed V, the roll rate (from the steering torque M acting on the steering 7) ( The first roll rate R1) is calculated. The control device 12 controls the damping force generated by the FL damper 4A, the FR damper 4B, the RL damper 5A, and the RR damper 5B according to the magnitude of the steering torque M.

That is, for example, when the frictional force on the road surface increases while the vehicle is running, the steering torque M increases, and therefore the first roll rate R1 changes. Then, the control device 12 selects a roll rate having a larger value from the first roll rate R1 and the second roll rate R2 by the roll rate selection unit 20, and based on the roll rate (R1 or R2). The damping force generated by the FL damper 4A, the FR damper 4B, the RL damper 5A, and the RR damper 5B is increased.

As a result, even if the vehicle steering angle δf and the vehicle speed V do not change when the road frictional force changes and the vehicle rolls while the vehicle is running, the steering torque M acting on the steering 7 If the calculated first roll rate R1 is greater than the second roll rate R2, the anti-roll control of the vehicle can be performed using the first roll rate R1. Further, by controlling the torque change caused by the road surface vertical input and output in the same manner, it is possible to suppress the sprung vibration caused by the road surface input. Therefore, it is possible to effectively suppress the behavior of the roll acting on the vehicle, thereby improving the riding comfort of the vehicle.

Next, FIG. 3 shows a second embodiment of the present invention. The feature of the second embodiment resides in that a target damping force of each damper is calculated by extracting a signal of the unsprung resonance frequency from the steering torque signal. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

The control device 31 is configured by a microcomputer or the like and is mounted on the vehicle body 1. The control device 31 performs control to increase the damping force generated by the FL damper 4A and the FR damper 4B based on the vertical speed of the wheel in the roll direction. On the input side of the control device 31, the steering angle sensor 6, the vehicle speed sensor 8, the torque sensor 9, and the

vehicle height sensors

11A and 11B are connected. On the other hand, the output side of the control device 31 is connected to an actuator (not shown) of the FL damper 4A and the FR damper 4B.

In this case, the control device 31 shown in FIG. 3 is mounted on a two-wheel steering (2WS) vehicle and controls the FL damper 4A for the left front wheel 2A and the FR damper 4B for the right front wheel 2B. It is said. In the case of a four-wheel steering (4WS) vehicle, the control of the RL damper 5A for the left rear wheel 3A and the RR damper 5B for the right rear wheel 3B may be performed separately in the same manner.

The unsprung resonance extraction unit 32 performs a band-pass filter process on the torque signal (steering torque M) output from the torque sensor 9 to thereby generate a signal (unsprung resonance) of an unsprung resonance frequency (for example, about 10 to 16 Hz). Frequency component). In other words, the unsprung resonance frequency component is a frequency component at which the vibration in the vertical direction of the wheel becomes the largest. The unsprung resonance extracting unit 32 constitutes the unsprung resonance extracting unit of the present invention. This unsprung resonance frequency component is output to the wheel vertical speed difference extraction unit 33.

The wheel vertical speed difference extraction unit 33 calculates the vertical speed difference in the roll direction of the

front wheels

2A and 2B based on the unsprung resonance frequency component. That is, the vertical speed difference between the left front wheel 2A and the right front wheel 2B can be calculated by converting the steering torque M to a force applied to the steering 7 by multiplying the gain and integrating the value.

In this case, when the left front wheel 2A and the right front wheel 2B move up and down in phase, the force applied to the steering 7 is canceled out, and the steering torque M does not change. On the other hand, when the left front wheel 2A and the right front wheel 2B move up and down in opposite phases, a force is applied to the steering wheel 7. Therefore, the vertical speed difference between the left front wheel 2A and the right front wheel 2B can be calculated based on the value of the steering torque M.

The sign reversing unit 34 multiplies “−1” in order to reverse the wheel vertical speed difference between the left front wheel 2A and the right front wheel 2B. The target damping force calculation units 35 and 36 multiply the wheel vertical speed difference by the Fr gain for the right front wheel 2B and the Fl gain for the left front wheel 2A to obtain the target damping force for roll suppression.

value calculation units

37 and 38 store the dampers stored in advance from the target damping force and the relative speed estimated by the relative speed calculation unit 39. The necessary current value is output from the characteristic map. In this case, the relative speed calculation unit 39 is configured in substantially the same manner as the relative speed calculation unit 30, and calculates the relative speed of the

front wheels

2A and 2B from the detection signal of the vehicle height sensor 11A and the detection signal of the vehicle height sensor 11B. .

Thereby, the damper command

value calculation units

37 and 38 calculate the damper command value to be output to the actuators (not shown) of the FL damper 4A and the FR damper 4B as the current value. Each of the

dampers

4A and 4B is controlled so that the damping force characteristic is continuously variable between hardware and software according to the current value (damper command value) supplied to the actuator, or variable in a plurality of stages.

Thus, even in the second embodiment configured as described above, the anti-roll control of the vehicle can be performed using the steering torque M acting on the steering 7. In particular, in the second embodiment, the damping force can be increased as early as possible from the occurrence of the steering kickback. Further, vibration can be detected without providing a sensor under the spring (under the damper).

Next, FIG. 4 shows a third embodiment of the present invention. A feature of the third embodiment is that a larger lateral acceleration is selected from the first lateral acceleration estimated by the steering torque and the second lateral acceleration estimated by the steering angle and the vehicle speed. Then, based on the lateral acceleration, there is a configuration in which control is performed to increase the damping force generated in each

damper

4A, 4B, 5A, 5B. Note that in the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

The left front wheel suspension device 41A (hereinafter referred to as FL damper 41A) is provided between the left front wheel 2A side and the vehicle body 1. On the other hand, the right front wheel suspension device 41B (hereinafter referred to as FR damper 41B) is provided between the right front wheel 2B side and the vehicle body 1. Each of the

dampers

41A and 41B is configured as a hydraulic damping force adjusting buffer that can adjust the generated damping force.

Each of the

dampers

41A and 41B is provided with a hydraulic actuator (not shown) using hydraulic oil, for example. The actuator may be a pneumatic actuator using compressed air, an electric actuator using an electric actuator, or an electromagnetic actuator using electromagnetic force such as a linear motor. That is, each of the

dampers

41A and 41B is configured as an active damper that can actively generate a thrust (vibration suppression force) by an actuator.

The left rear wheel suspension device 42A (hereinafter referred to as the RL damper 42A) is provided between the left rear wheel 3A side and the vehicle body 1. On the other hand, the right rear wheel suspension device 42B (hereinafter referred to as the RR damper 42B) is provided between the right rear wheel 3B side and the vehicle body 1. Each of the

dampers

42A and 42B is configured as a hydraulic damping force adjusting shock absorber capable of adjusting the generated damping force.

Each of the

dampers

42A and 42B is provided with a hydraulic actuator (not shown) using hydraulic oil, for example. The actuator may be a pneumatic actuator using compressed air, an electric actuator using an electric actuator, or an electromagnetic actuator using electromagnetic force such as a linear motor. That is, each of the

dampers

42A and 42B is configured as an active damper that can actively generate a thrust (vibration suppression force) by an actuator.

The control device 43 is constituted by a microcomputer or the like and is mounted on the vehicle body 1. The control device 43 performs control to increase the damping force generated by the FL damper 41A, the FR damper 41B, the RL damper 42A, and the RR damper 42B when it is determined that the vehicle is in a roll state. On the input side of the control device 43, a steering angle sensor 6, a vehicle speed sensor 8, a torque sensor 9, and vehicle height sensors 11A to 11D are connected. On the other hand, an output side of the control device 43 is connected to an actuator (not shown) of the FL damper 41A, the FR damper 41B, the RL damper 42A, the RR damper 42B, and the like.

As shown in FIG. 4, the control device 43 includes a lateral acceleration estimation unit 44, a lateral acceleration calculation unit 45, a lateral acceleration selection unit 48, a target damping force calculation unit 49, and a relative speed calculation unit 59. . In this case, the lateral acceleration calculation unit 45, the lateral acceleration selection unit 48, and the target damping force calculation unit 49 constitute a roll suppression control unit of the present invention.

First, the lateral acceleration estimation unit 44 that calculates the first lateral acceleration αy1 will be described.

The lateral acceleration estimator 44 estimates and calculates the first lateral acceleration αy1 from the detection result (steering torque M) of the torque sensor 9. The lateral acceleration estimation unit 44 constitutes a first lateral acceleration calculation unit of the present invention. The lateral acceleration estimation unit 44 stores (stores) a map (not shown) indicating the correspondence between the steering torque and the lateral acceleration calculated by, for example, experiments. Therefore, the lateral acceleration estimation unit 44 can calculate the first lateral acceleration αy1 by inputting the torque signal (steering torque M) output from the torque sensor 9 to this map. The first lateral acceleration αy1 is output to a lateral acceleration selection unit 48 described later.

Next, the lateral acceleration calculation unit 45 that estimates and calculates the second lateral acceleration αy2 will be described.

The lateral acceleration calculation unit 45 estimates and calculates the second lateral acceleration αy2 from the steering angle (front wheel steering angle δf) detected by the steering angle sensor 6 and the vehicle speed V detected by the vehicle speed sensor 8. The lateral acceleration calculation unit 45 constitutes a second lateral acceleration calculation unit of the present invention. The lateral acceleration calculation unit 45 includes a vehicle model unit 46 and a phase adjustment filter 47.

In the vehicle model unit 46, the yaw rate r is estimated by using the vehicle model of the above equation 1 based on the steering angle (front wheel steering angle δf) and the vehicle speed V, as in the vehicle model unit 17 of the first embodiment. To do. Next, the second lateral acceleration αy2 is calculated by multiplying the calculated yaw rate r by the vehicle speed V. Further, the phase adjustment filter 47 is used to compensate for the dynamics from the vehicle steering angle to the occurrence of lateral acceleration. The second lateral acceleration αy2 is output to a lateral acceleration selection unit 48 described later.

The lateral acceleration selection unit 48 has a larger value of the lateral acceleration (αy1 or αy1) calculated from the first lateral acceleration αy1 calculated by the lateral acceleration estimation unit 44 and the second lateral acceleration αy2 calculated by the lateral acceleration calculation unit 45. αy2) is selected. The lateral acceleration selection unit 48 constitutes a lateral acceleration selection unit of the present invention.

That is, when the steering angle is constant and the frictional force of the road surface changes while the vehicle is running, the actual lateral acceleration changes and rolls are generated. However, since the steering angle has not changed, the anti-roll control does not operate, and the roll acting on the vehicle may become large.

Therefore, in the third embodiment, the first lateral acceleration αy1 is estimated and calculated from the steering torque M acting on the steering wheel 7 when the frictional force on the road surface changes. Then, the control device 43 uses the larger lateral acceleration of the first lateral acceleration αy1 and the second lateral acceleration αy2 estimated and calculated based on the vehicle steering angle δf and the vehicle speed V to perform anti-rolling. It is set as the structure which performs control.

Next, the target damping force calculation unit 49 that calculates the target damping force of each of the

dampers

41A, 41B, 42A, and 42B will be described.

The target damping force calculation unit 49 calculates the target damping force of each of the

dampers

41A, 41B, 42A, and 42B using the lateral acceleration (αy1 or αy2) selected by the lateral acceleration selection unit 48. The target damping force calculation unit 49 constitutes a target damping force calculation unit of the present invention. The target damping force calculation unit 49 includes a roll angle calculation unit 50, target damping

force calculation units

51 and 52,

sign inversion units

53 and 54, and damper command

value calculation units

55, 56, 57, and 58. Yes.

The roll angle calculation unit 50 calculates the roll angle from the lateral acceleration (αy1 or αy2) selected by the lateral acceleration selection unit 48. The roll angle can be calculated by multiplying the lateral acceleration by the roll angle per unit lateral acceleration.

Then, the target damping

force calculation units

51 and 52 multiply the roll angle calculated by the roll angle calculation unit 50 by the Fr gain for the right front wheel 2B and the Rr gain for the right rear wheel 3B, thereby achieving the target damping for roll suppression. Power. The

sign reversing units

53 and 54 multiply “−1” in order to reverse the roll damping target damping force between the left front wheel 2A and the left rear wheel 3A with the right front wheel 2B and the right rear wheel 3B.

After the target damping force is calculated by adding or subtracting the target damping force in this way, the damper command

value calculation units

55, 56, 57, and 58 use the target damping force and the relative speed calculation unit 59 to calculate the target damping force. A necessary current value is output from a damper characteristic map stored in advance from the estimated relative speed.

In this case, the relative speed calculation unit 59 calculates the relative speed of the

front wheels

2A and 2B from the detection signal of the vehicle height sensor 11A and the detection signal of the vehicle height sensor 11B. In addition, the relative speed calculation unit 59 calculates the relative speed on the

rear wheels

3A and 3B side from the detection signal of the vehicle height sensor 11C and the detection signal of the vehicle height sensor 11D.

Thereby, the damper command

value calculation units

55, 56, 57, and 58 use the damper command value to be output to the actuators (not shown) of the FL damper 41A, the FR damper 41B, the RL damper 42A, and the RR damper 42B as a current value. calculate. Each of the

dampers

41A, 41B, 42A, and 42B is controlled so that the damping force characteristic is continuously variable between hardware and software or in a plurality of stages according to the current value (damper command value) supplied to the actuator.

Thus, also in the third embodiment configured as described above, the anti-roll control of the vehicle can be performed using the steering torque M as in the first embodiment. In particular, in the third embodiment, the roll angle is controlled by using the lateral acceleration, so that it can be suitably used for, for example, an active suspension and an air suspension that can generate thrust.

In the above-described first embodiment, the case where the relative speed calculation unit 30 calculates the relative speed by differentiating the detection values of the vehicle height sensors 11A to 11D has been described as an example. However, the present invention is not limited to this. For example, the relative acceleration is calculated from the detection values of the vertical acceleration sensors attached to the unsprung side and the unsprung side of each damper, and this value is integrated to obtain the relative speed. May be calculated, and it is not particularly necessary to limit the calculation method. Further, the relative speed may be handled as a constant value. The same applies to the second and third embodiments.

In the second embodiment described above, the value calculated from the

vehicle height sensors

11A and 11B is used as the relative speed. Based on the calculation result of the wheel vertical speed difference extraction unit 33, the following equation (3) You may make it calculate based on.

In the second embodiment described above, the wheel vertical speed difference extraction unit 33 multiplies the steering torque M by a gain to convert it into a force applied to the steering wheel 7 and integrates the value to the left front wheel 2A. The case where the vertical speed difference with the right front wheel 2B is calculated has been described as an example. However, the present invention is not limited to this. For example, the steering torque M may be converted into a force applied to the steering wheel 7 by multiplying the gain, and the anti-roll control may be performed using a differential value or a proportional value. The calculation method is not particularly limited.

As a suspension control device based on the embodiment described above, for example, the following modes can be considered.

As a first aspect of the suspension control device, there is provided a damping force adjusting type shock absorber that is provided between a vehicle body and a wheel of the vehicle and that can adjust a generated damping force, and steering torque information of a steering provided in the vehicle. A steering torque information acquisition unit to acquire, and controls the damping force generated by the damping force adjusting shock absorber according to the acquisition result of the steering torque information acquisition unit.

As a second aspect, in the first aspect, a roll for controlling a damping force generated by the damping force adjusting buffer so as to suppress the roll by using a lateral acceleration estimated from the speed and steering angle of the vehicle. A suppression control unit is further provided, and the control by the roll suppression control unit is changed according to the acquisition result of the steering torque information acquisition unit.

As a 3rd mode, in the 2nd mode, it further has the 1st roll rate calculating part which carries out an estimation calculation of the 1st roll rate from the acquisition result of the steering torque information acquisition part, The roll control control part is A second roll rate calculation unit for estimating and calculating a second roll rate from the steering angle and the speed of the vehicle, and a roll having a larger value among the first roll rate and the second roll rate. A roll rate selecting unit that selects a rate; and a target damping force calculating unit that calculates a target damping force of the damping force adjusting shock absorber using the roll rate selected by the roll rate selecting unit.

As a fourth aspect, in the second aspect, the apparatus further comprises a first lateral acceleration calculation unit that estimates and calculates the first lateral acceleration from the acquisition result of the steering torque information acquisition unit, and the roll suppression control unit includes: A second lateral acceleration computing unit that estimates and computes a second lateral acceleration from the steering angle and the speed of the vehicle; and a lateral acceleration having a larger value of the first lateral acceleration and the second lateral acceleration. And a target damping force calculation unit that calculates a target damping force of the damping force adjusting shock absorber using the lateral acceleration selected by the lateral acceleration selection unit.

As a fifth aspect of the suspension control device, a damping force adjustment type shock absorber that is provided between the vehicle body and the wheel of the vehicle and that can adjust the generated damping force, and steering torque information of the steering provided in the vehicle are provided. A steering torque information acquisition unit to acquire, and an unsprung resonance extraction unit to extract an unsprung resonance frequency component from the acquisition result of the steering torque information acquisition unit, and based on the extraction result of the unsprung resonance extraction unit, Adjusting and controlling damping force generated by damping force adjustment type shock absorber.

In the above embodiment, an example has been shown in which the roll rate and lateral acceleration obtained from the steering angle and the vehicle speed and the roll rate and lateral acceleration obtained from the steering torque are selectively selected. When the steering torque changes the roll rate and lateral acceleration obtained from the angle and vehicle speed, a control signal is created by correcting the roll rate and lateral acceleration obtained from the steering angle and vehicle speed according to the amount of change. May be.

For example, when the steering torque decreases, the control signal is corrected so as to increase the damping force in the direction in which the roll returns, and when the steering torque increases, the control signal is increased so as to increase the damping force in the direction in which the roll increases. It may be corrected. In this case, a control signal may be obtained linearly by applying a correction coefficient, or stepwise correction such as two steps or three steps may be performed.

Although several embodiments of the present invention have been described above, the above-described embodiments of the present invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention can be changed and improved without departing from the spirit thereof, and the present invention includes equivalents thereof. In addition, any combination or omission of each constituent element described in the claims and the specification is possible within a range where at least a part of the above-described problems can be solved or a range where at least a part of the effect is achieved. It is.

This application claims priority based on Japanese Patent Application No. 2016-127942 filed on June 28, 2016. The entire disclosure including the specification, claims, drawings and abstract of Japanese Patent Application No. 2016-127942 filed on June 28, 2016 is incorporated herein by reference in its entirety.

1 body, 2A left front wheel, 2B right front wheel, 3A left rear wheel, 3B right rear wheel, 4A, 41A left front wheel suspension device (damping force adjustable shock absorber), 4B, 41B right front wheel suspension device (damping force adjustment) 5A, 42A Left front wheel suspension device (damping force adjustment type shock absorber), 5B, 42B Suspension device for right rear wheel (damping force adjustment type shock absorber), 6 Steering angle sensor, 7 Steering, 9 Torque Sensor (steering torque information acquisition unit), 12, 31, 43 control device, 13 first roll rate calculation unit (first roll rate calculation unit), 16 second roll rate calculation unit (second roll rate calculation) Part), 20 roll rate selection part (roll rate selection part), 21 target damping force calculation part (target) Damping force calculation unit), 32 unsprung resonance extraction unit (unsprung resonance extraction unit), 33 wheel vertical speed difference extraction unit, 44 lateral acceleration estimation unit (first lateral acceleration calculation unit), 45 lateral acceleration calculation unit (first 2 lateral acceleration calculation unit), 48 lateral acceleration selection unit (lateral acceleration selection unit), 49 target damping force calculation unit (target damping force calculation unit)

Claims

A suspension control device,
A damping force adjustable shock absorber provided between the vehicle body and the wheel of the vehicle and capable of adjusting the generated damping force;
A steering torque information acquisition unit for acquiring steering torque information of steering provided in the vehicle;
With
A suspension control device that controls a damping force generated by the damping force adjusting shock absorber according to an acquisition result of the steering torque information acquisition unit.
The suspension control device according to claim 1,
A roll suppression control unit that controls a damping force generated by the damping force adjusting shock absorber so as to suppress a roll using a lateral acceleration estimated from a speed and a steering angle of the vehicle;
A suspension control device that changes control by the roll suppression control unit in accordance with an acquisition result of the steering torque information acquisition unit.
The suspension control device according to claim 2,
A first roll rate calculation unit that estimates and calculates a first roll rate from the acquisition result of the steering torque information acquisition unit;
The roll suppression control unit
A second roll rate calculation unit that estimates and calculates a second roll rate from the steering angle and the speed of the vehicle;
A roll rate selecting unit for selecting a roll rate having a large value from the first roll rate and the second roll rate;
A target damping force calculation unit that calculates a target damping force of the damping force adjusting shock absorber using the roll rate selected by the roll rate selection unit;
A suspension control device comprising:
The suspension control device according to claim 2,
A first lateral acceleration calculation unit that estimates and calculates the first lateral acceleration from the acquisition result of the steering torque information acquisition unit;
The roll suppression control unit
A second lateral acceleration calculator that estimates and calculates a second lateral acceleration from the steering angle and the speed of the vehicle;
A lateral acceleration selection unit that selects a lateral acceleration having a larger value from the first lateral acceleration and the second lateral acceleration;
A target damping force calculation unit that calculates a target damping force of the damping force adjusting buffer using the lateral acceleration selected by the lateral acceleration selection unit;
A suspension control device comprising:
A suspension control device,
A damping force adjustable shock absorber provided between the vehicle body and the wheel of the vehicle and capable of adjusting the generated damping force;
A steering torque information acquisition unit for acquiring steering torque information of steering provided in the vehicle;
An unsprung resonance extraction unit that extracts an unsprung resonance frequency component from the acquisition result of the steering torque information acquisition unit;
With
A suspension control device that performs adjustment control of a damping force generated by the damping force adjustment type shock absorber based on an extraction result of the unsprung resonance extraction unit.