JP3319989B2 - Sensor detection value correction device in vehicle motion control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a motion state detecting sensor for detecting a motion state of a vehicle by continuously changing a detection output according to a change in the motion state of the vehicle.
The present invention relates to an apparatus for correcting a detection value of a movement state detection sensor in a vehicle movement control apparatus capable of controlling the movement of a vehicle based on a detection value of the movement state detection sensor.

[0002]

2. Description of the Related Art In such a vehicle motion control apparatus, a yaw rate sensor for detecting a yaw rate of the vehicle, a lateral acceleration sensor for detecting a lateral acceleration of the vehicle, a steering angle sensor for detecting a steering angle of a steering wheel, and the like. In general, the detection output of the motion state detection sensor in the middle point of the motion state detection sensor, that is, the state in which the vehicle is stopped and stable, varies for each vehicle, and the motion state detection sensor differs for each vehicle. If the midpoint is not confirmed, the output of the motion state detection sensor during running of the vehicle will vary from vehicle to vehicle. For this reason, conventionally, when a vehicle is shipped from a manufacturing factory, the midpoint of the motion state detection sensor is confirmed and stored, and after the vehicle is shipped from the factory, the motion state detection sensor is determined based on the stored midpoint. Is corrected.

[0003]

However, the midpoint of the motion state detecting sensor also changes due to ambient temperature, deterioration over time, and the like. Depending on the traveling environment and the years of use, it is difficult to accurately detect the motion state, and the motion control of the vehicle may be inaccurate.

The present invention has been made in view of the above circumstances, and is capable of always detecting an accurate motion state and performing accurate motion control irrespective of the running environment of the vehicle and the number of years of use. An object of the present invention is to provide a sensor detection value correction device in a vehicle vibration control device.

[0005]

In order to achieve the above object, an invention according to claim 1 comprises a yaw rate sensor for detecting a yaw rate by continuously changing a detection output according to a yaw motion of a vehicle. A lateral acceleration sensor for detecting the lateral acceleration by continuously changing the detection output in accordance with the lateral acceleration of the vehicle, and capable of controlling the motion of the vehicle based on the detection values of both sensors. And a yaw rate sensor based on a detection value of a yaw rate sensor when the halt state determining means determines that the vehicle is stopped. And a yaw rate compensation means for correcting a detection value of the yaw rate sensor based on the midpoint determined by the yaw rate midpoint decision means. Means, a straight running state determining means for determining the straight running state of the vehicle based on the yaw rate corrected by the yaw rate correcting means, and a case where the straight running state determining means determines that the vehicle is running straight. A lateral acceleration midpoint determining means for determining a midpoint of the lateral acceleration sensor based on a detection value of the lateral acceleration sensor; and a lateral acceleration sensor based on the midpoint determined by the lateral acceleration midpoint determining means. And a lateral acceleration correction means for correcting the detection value of

According to such a configuration, when the vehicle is stopped, the midpoint of the yaw rate sensor is determined, and the detection value of the yaw rate sensor is corrected at the determined midpoint, so that the running environment of the vehicle is controlled. Even if the middle point of the yaw rate sensor changes due to the change and the age of use, the detected value of the yaw rate sensor will be corrected at the latest middle point, and the yaw rate used for vehicle motion control will be set as an accurate value for motion control Accuracy can be improved. Moreover, when it is determined that the vehicle is traveling straight based on the yaw rate corrected at the latest midpoint, the midpoint of the lateral acceleration sensor is determined, and the detected value of the lateral acceleration sensor is determined at the determined midpoint. Is corrected, so that even if the midpoint of the lateral acceleration sensor changes due to changes in the traveling environment of the vehicle and the aging of the vehicle, the lateral acceleration sensor can be accurately determined after judging whether the vehicle is traveling straight. Is corrected at the latest midpoint, and the accuracy of the motion control can be improved by setting the lateral acceleration used for the motion control of the vehicle as an accurate value.

[0007]

[0008]

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIGS. 1 to 4 show an embodiment of the present invention. FIG. 1 is a diagram showing a drive system and a brake system of a vehicle, FIG. 2 is a block diagram showing a configuration of a control unit, and FIG. FIG. 4 is a flowchart showing the procedure for determining the midpoint of the yaw rate sensor, and FIG. 4 is a flowchart showing the procedure for determining the midpoint of the lateral acceleration sensor and the steering angle sensor and the procedure for estimating the ratio of the left and right driven wheel diameters.

First, in FIG. 1, this vehicle is a front engine / front drive vehicle. A power unit P including an engine E and a transmission T is provided at a front portion of a vehicle body 1 with a left front wheel W _{FL as} a drive wheel and a right front wheel W _FL. Installed to drive front wheels W _FR . Left and right front wheel brakes B _FL and B _FR are attached to the left and right front wheels W _FL and W _FR, and left and right rear wheel brakes B are applied to driven left and right rear wheels W _RL and W _{RR. RL} and B _RR are mounted, and each wheel brake B _FL , B _FR and B
_RL and B _RR are, for example, disc brakes.

The tandem type master cylinder M has the
Brake pedals from the first and second output ports 2A and 2B
The brake fluid pressure is output in accordance with the depressing operation of
And both output ports 2A and 2B are brake fluid pressure control.
The brake fluid pressure control device 4 is connected to the brake fluid pressure control device 4.
Rake hydraulic pressure is applied to each wheel brake B_FL, B_FR, B_RL, B_RRTo
It works. In the brake fluid pressure control device 4,
Each wheel brake is controlled by the control unit 5.
B_FL, B_FR, B_RL, B_RRBrake fluid pressure acting on
The control unit 5 includes
W_FL, W_FR, W _RL, W_RRDetect the wheel speed of each
Wheel speed sensor 6_FL, 6_FR, 6_RL, 6_RR, Steering
A steering angle sensor for detecting a steering angle δ operated by the steering wheel H
7, a yaw rate sensor for detecting the yaw rate γ of the vehicle
8 and a lateral acceleration for detecting the lateral acceleration α of the vehicle.
The detection value of the speed sensor 9 is input.

In FIG. 2, the control unit 5 includes
Brake B_FL, B_FR, B_RL, B_RRControls brake fluid pressure
Lock to eliminate wheel lock during brake operation
Brake control and drive wheels left and right front wheels W_FL, W_FR
Left and right front wheel brake B mounted on_FL, B_FRBlur
The left and right front wheels during non-braking operation by controlling the brake fluid pressure
W _FL, W_FRThat eliminates excessive slippage in vehicles
Control during braking and non-braking operations
Left and right front wheel brakes B_FL, B_FRBrake fluid pressure
Control to achieve directional stability control by yaw motion of the vehicle.
Control for controlling the brake fluid pressure control device 4
A control amount calculating means 11 for calculating a control amount is provided.

The control amount calculating means 11 detects the wheel speeds detected by the wheel speed sensors 6 _FL , 6 _FR , 6 _RL , 6 _RR , the steering angle δ detected by the steering angle sensor 7, and the yaw rate sensor 8. The control amount is calculated based on the detected yaw rate γ and the lateral acceleration α detected by the lateral acceleration sensor 9. The detection values of the steering angle sensor 7, the yaw rate sensor 8, and the lateral acceleration sensor 9 are calculated. Is corrected based on a change in the midpoint of the sensors 7, 8, and 9, and the corrected steering angle δ ′, yaw rate γ ′, and lateral acceleration α ′ are input to the control amount calculating means 11.

In order to correct the detection values of the steering angle sensor 7, the yaw rate sensor 8 and the lateral acceleration sensor 9, the control unit 5 comprises a stop state judging means 12, a yaw rate midpoint determining means 13, a yaw rate correcting means. 14, a straight traveling state determining means 15, a lateral acceleration midpoint determining means 16, a lateral acceleration correcting means 17, a steering angle midpoint determining means 18, and a steering angle correcting means 19.

The stop state judging means 12 determines whether or not the vehicle is stopped by each of the wheel speed sensors 6 _FL , 6 _FR , 6 _RL ,
The determination is made based on the wheel speed detected by 6 _RR . The yaw rate midpoint determining means 13 is adapted to determine when the stop state determining means 12 determines that the vehicle is stopped.
The midpoint of the yaw rate sensor 8 is learned and determined based on the output of the yaw rate sensor 8, and the yaw rate correction unit 14 determines the midpoint of the yaw rate sensor 8 based on the midpoint of the yaw rate sensor 8 determined by the yaw rate midpoint determination unit 13. The detection value of the yaw rate sensor 8 is corrected, and the yaw rate correction means 1
The yaw rate γ ′ obtained by the correction in step 4 is input to the control amount calculating means 11.

The straight traveling state judging means 15 judges the straight traveling state of the vehicle based on the yaw rate γ 'corrected by the yaw rate correcting means 14. The midpoint determining means 16 for lateral acceleration includes a straight traveling state determining means 15.
Is determined by learning the midpoint of the lateral acceleration sensor 9 based on the output of the lateral acceleration sensor 9 when it is determined that the vehicle is traveling straight ahead. The detection value of the lateral acceleration sensor 9 is corrected based on the midpoint of the lateral acceleration sensor 9 determined by the lateral acceleration midpoint determination means 16, and is obtained by the correction by the lateral acceleration correction means 17. Lateral acceleration α '
Is input to the control amount calculating means 11.

The steering angle midpoint determining means 18 determines the midpoint of the steering angle sensor 7 based on the output of the steering angle sensor 7 when the straight traveling state determining means 15 determines that the vehicle is traveling straight. The steering angle correction means 19 corrects the detection value of the steering angle sensor 7 based on the midpoint of the steering angle sensor 7 determined by the steering angle midpoint determination means 18, The steering angle δ ′ obtained by the correction by the steering angle correction unit 19 is input to the control amount calculation unit 11.

The stop state determining means 12, the yaw rate midpoint determining means 13, the straight traveling state determining means 15,
The processing procedure of the lateral acceleration midpoint determining means 16 and the steering angle midpoint determining means 18 and the procedure of estimating the ratio of the left and right driven wheel diameters are set as shown in FIGS.

In step S1 of FIG. 3, it is determined whether or not the vehicle has stopped. That is, the stop state determining means 12
, It is determined whether or not the vehicle is stopped based on the detected values of the wheel speed sensors 6 _FL , 6 _FR , 6 _RL , 6 _RR . If it is determined that the vehicle is stopped, step S
Proceed to 2.

Steps S2 to S10 are processes executed by the yaw rate midpoint determining means 13, and are executed in step S2.
Then, it is determined whether or not the input value from the yaw rate sensor 8 is stable in the middle point guarantee range. The midpoint guarantee range is set including individual variations, temperature characteristic variations, variations due to aging, and the like. When the input value from the yaw rate sensor 8 changes within a small fluctuation range within the midpoint guarantee range for a certain period of time. When it is determined that the distance is within the range, step S
After counting the stopped midpoint learning timer in step 3, the input value from the yaw rate sensor 8 is integrated in step S4, and it is determined in step S5 whether a specified time has elapsed. When it is determined at step S5 that the specified time has elapsed, the integrated value of the detected values of the yaw rate sensor 8 during the specified time is averaged at step S6, whereby the midpoint of the yaw rate sensor 8 is obtained. Will be determined. At step S7 after the midpoint is determined, the stopped midpoint learning timer is cleared, and then at step S8, the integrated value of the input value from the yaw rate sensor 8 is cleared.

On the other hand, in step S2, the yaw rate sensor 8
If it is determined that the detection value input from the CPU is out of the middle point guarantee range or that the fluctuation range is large even within the middle point guarantee range, the timer is cleared in step S9,
In step S10, the integrated value up to that point is cleared and the process returns to step S1, and when the specified time has not elapsed in step S5, the process returns from step S5 to step S1.

When the middle point of the yaw rate sensor 8 is determined in this way, the determined middle point is input from the yaw rate determination means 13 to the yaw rate correction means 14,
The yaw rate correction means 14 corrects the yaw rate γ detected by the yaw rate sensor 8. That is, when the detected value of the yaw rate sensor 8 is γ and the midpoint determined by the yaw rate determining means 13 is γ _C , the next correction operation γ ′ = γ−γ _C is executed by the yaw rate correcting means 14, The corrected yaw rate γ ′ is input from the yaw rate correction unit 14 to the straight traveling state determination unit 15 and is input to the control amount calculation unit 11.

When it is determined in step S1 that the vehicle has not stopped, the flow proceeds from step S1 to step S1 in FIG.
In step S11, it is determined whether or not the vehicle is traveling at or above the specified speed. When it is determined that the vehicle is traveling at or above the specified speed, in step S12, it is determined that the vehicle is stopped. Yaw rate correction means 14 based on midpoint
It is determined whether or not the yaw rate γ ′ corrected in the above is stable in a state indicating the straight running state, and this determination is executed by the straight running state determining means 15.

When it is determined in step S12 that the vehicle is running straight, steps S13 to S25 are performed.
, The midpoint determination means 1 for lateral acceleration
6 and a middle point determining process in the steering angle middle point determining means 18;
In addition, the outer diameter ratio of the left and right driven wheels is estimated.

In step S13, the middle point learning timer during running is counted, and in step S14, the input values from the lateral acceleration sensor 9 and the steering angle sensor 7 are integrated. In step S15, the left and right driven wheels, ie, left and right Rear wheel W _RL ,
Calculate the speed ratio of W _RR , and in step S16,
After integrating the speed ratios of the right rear wheels W _RL and W _RR , step S
At 17, it is determined whether the specified time has elapsed. If it is determined in step S17 that the specified time has elapsed, the integrated value of the detected values of the lateral acceleration sensor 9 and the steering angle sensor 7 during the elapsed specified time is averaged in step S18. The midpoints of the sensor 9 and the steering angle sensor 7 are respectively determined. In step S19, the left and right rear wheels W while the specified time elapses
By averaging the integrated values of the speed ratios of _RL and W _RR ,
The outer diameter ratio of the left and right rear wheels W _RL , W _RR is estimated.

In step S20 after the midpoints of the lateral acceleration sensor 9 and the steering angle sensor 7 have been determined and the outer diameter ratios of the left and right rear wheels W _RL and W _RR have been estimated, in step S20, the midpoint learning during traveling is performed. After the timer is cleared, the integrated values of the input values from the lateral acceleration sensor 9 and the steering angle sensor 7 are cleared in step S21, and the speed ratio integrated values of the left and right rear wheels W _RL and W _RR are further cleared in step S22. clear.

On the other hand, when it is determined in step S11 that the vehicle is not traveling at a speed higher than the specified speed, and when it is determined in step S12 that the corrected yaw rate γ 'is not stable in a straight traveling state, a timer is determined in step S23. Is cleared, the lateral acceleration sensor 9 is determined in step S24.
After clearing the integral value of the input value from the steering angle sensor 7 and clearing the speed ratio integral value of the left and right rear wheels W _RL and W _RR in step S25, the process returns to step S1 in FIG. 3, and returns to step S17. Even when the specified time has not elapsed, the process returns from step S17 to step S1.

When the midpoints of the lateral value acceleration sensor 9 and the steering angle sensor 7 are determined in this way, the determined midpoints are determined by the lateral acceleration determining means 16 and the steering angle midpoint determining means 18. Lateral acceleration correction means 17
The lateral acceleration α and the steering angle δ detected by the lateral acceleration sensor 9 and the steering angle sensor 7 are input to the lateral acceleration correction unit 17 and the steering angle correction unit 19, respectively. Done.
That is, the detection value of the lateral acceleration sensor 9 is α, the midpoint determined by the lateral acceleration midpoint determination means 16 is α _C , the detection value of the steering angle sensor 7 is δ, and the steering angle midpoint determination is Assuming that the midpoint determined by the means 18 is δ _C , the following correction calculation α ′ = α−α _C δ ′ = δ−δ _C is obtained by the lateral acceleration correction means 17 and the steering angle correction means 19.
The corrected lateral acceleration α ′ is input from the lateral acceleration correcting means 17 to the control amount calculating means 11, and the corrected steering angle δ ′ is calculated by the steering angle correcting means 1.
9 to the control amount calculation means 11.

The estimated outer diameter ratios of the left and right rear wheels W _RL and W _RR are used to more accurately calculate the vehicle body speed based on the detection values of the wheel speed sensors 6 _FL , 6 _FR , 6 _RL and 6 _RR. Therefore, it is used for the vehicle speed estimation by the control amount calculating means 11.

Next, the operation of this embodiment will be described. When the stop state determining means 12 determines that the vehicle is stopped, the middle point of the yaw rate sensor 8 is determined by the yaw rate middle point determining means 13. Since the detected value of the yaw rate sensor 8 is corrected at the determined midpoint in the yaw rate correction means 14, even if the midpoint of the yaw rate sensor 8 changes due to a change in the traveling environment of the vehicle and the aging of the vehicle, the yaw rate The detection value of the sensor 8 is corrected at the latest midpoint, and the control amount calculating means 11
The accuracy of the vehicle motion control can be improved by setting the yaw rate? '

The straight traveling state judging means 15 judges whether or not the vehicle is traveling straight based on the highly accurate yaw rate γ 'obtained by the yaw rate correcting means 14. Can be determined more accurately. Moreover, when it is determined by the straight traveling state judging means 15 that the vehicle is traveling straight, the midpoint of the lateral acceleration sensor 9 and the steering angle sensor 7 is set to the midpoint determining means 16 for lateral acceleration and the midpoint for steering angle. Point determination means 18
In the lateral acceleration correction means 17 and the steering angle correction means 19, the respective midpoint determination means 16, 1
Since the detection values of the lateral acceleration sensor 9 and the steering angle sensor 7 are corrected at the midpoint determined in step 8, the lateral acceleration sensor 9 and the steering angle sensor 7 change depending on the change in the traveling environment of the vehicle and the aging of the vehicle. Even if the midpoint changes,
After accurately determining the state in which the vehicle is traveling straight, the detection values of the lateral acceleration sensor 9 and the steering angle sensor 7 are corrected at the latest midpoint, and the lateral acceleration used for the motion control of the vehicle is determined. The accuracy of the motion control can be improved by setting α ′ and the steering angle δ ′ as accurate values.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

[0034]

As described above, according to the first aspect of the invention, the detection value of the yaw rate sensor is corrected at the midpoint determined when the vehicle is stopped, and the vehicle is traveling straight. After accurately determining the midpoint of the lateral acceleration sensor, the detection value of the lateral acceleration sensor is corrected, and the yaw rate sensor and the lateral acceleration sensor Even if the midpoint changes, the accuracy of the motion control can be improved by setting the yaw rate and the lateral acceleration used for the motion control of the vehicle to accurate values.

[0035]

[Brief description of the drawings]

FIG. 1 is a diagram showing a drive system and a brake system of a vehicle.

FIG. 2 is a block diagram illustrating a configuration of a control unit.

FIG. 3 is a flowchart illustrating a procedure for determining a midpoint of a yaw rate sensor.

FIG. 4 is a flowchart showing a procedure for determining a middle point of a lateral acceleration sensor and a steering angle sensor and a procedure for estimating a ratio between left and right driven wheel diameters.

[Explanation of symbols]

 7 ... steering angle sensor 8 ... yaw rate sensor 9 ... lateral acceleration sensor 12 ... stop state determination means 13 ... middle point determination means for yaw rate 14 ... yaw rate correction means 15 ... Straight running state determination means 16 ... Midpoint determination means for lateral acceleration 17 ... Lateral acceleration correction means 18 ... Midpoint determination means for steering angle 19 ... Steering angle correction means H ... Steering handle

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI // B62D 137: 00 G01P 15/00 J (56) References JP-A-2-144262 (JP, A) JP-A-4-108083 (JP) JP-A-2-48211 (JP, A) JP-A-3-282370 (JP, A) JP-A-4-135976 (JP, A) JP-A-4-213067 (JP, A) 2-284069 (JP, A) JP-A-64-26161 (JP, A) JP-A-3-22910 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01P 21/00 G01P 15/00-15/18 G01C 19/00-19/72 G01C 21/00-21/18 B62D 6/00-6/04 B62D 137: 00

Claims (1)

(57) [Claims] 1. A yaw rate sensor for detecting a yaw rate by continuously changing a detection output in accordance with a yaw motion of a vehicle, and continuously changing a detection output in accordance with a lateral acceleration of the vehicle. A lateral acceleration sensor (9) for detecting the lateral acceleration as described above, and a vehicle motion control device capable of controlling the vehicle motion based on the detection values of the two sensors (8, 9). And a yaw rate sensor based on a detection value of a yaw rate sensor when the vehicle is stopped by the stop state determining means. (8) A yaw rate midpoint determining means (13) for determining a midpoint, and the yaw rate midpoint determining means (1).
A yaw rate correction means (14) for correcting the detection value of the yaw rate sensor (8) based on the midpoint determined in 3), and a straight running state of the vehicle is determined based on the yaw rate corrected by the yaw rate correction means (14). A straight traveling state determining means (15) to perform the lateral direction based on a detection value of a lateral acceleration sensor (9) when the straight traveling state determining means (15) determines that the vehicle is traveling straight. A lateral acceleration midpoint determining means (16) for determining a midpoint of the acceleration sensor (9) and a lateral acceleration sensor (9) determined by the midpoint determined by the lateral acceleration midpoint determining means (16). sensor detection value correction equipment in a vehicle motion control apparatus which comprises a lateral acceleration correction means (17) for correcting the detected value.