JP4655913B2 - Wheel vertical acceleration detection device for posture correction of detection value of vertical acceleration sensor - Google Patents

Description

  The present invention relates to a device for detecting the vertical acceleration of a wheel suspended on a vehicle body by a wheel suspension device in a vehicle such as an automobile.

  The vertical acceleration of a wheel in a vehicle such as an automobile is important information for various vehicle travel control as one of the parameters affecting the various vehicle travel performance including the ground contact load of the wheel.

In the technical field of analyzing a vehicle as a vibration system in which the vehicle body and wheels are arranged up and down via springs, the vehicle body and wheels are referred to as “sprung” and “unsprung”, respectively. These are referred to as sprung vertical acceleration and unsprung vertical acceleration, respectively, but in Patent Document 1 below, the sprung vertical acceleration detected by the sprung vertical acceleration sensor is equal to or greater than a first predetermined value. When the absolute value of the difference between the left and right unsprung acceleration detected by the unsprung vertical acceleration sensor provided for the left and right wheels is equal to or greater than a second predetermined value, the road surface on which the vehicle travels is a bad road. Is described.
JP 2005-170242 A

  In order to detect the vertical acceleration of the wheel with the acceleration sensor, it is preferable that the vertical acceleration sensor is attached to the part that moves up and down as closely as possible to the vertical movement of the axle, but from the viewpoint of convenience of installation and stability The vertical acceleration sensor is usually attached to a movable member of a part of a wheel suspension device such as a suspension arm. However, the movable member of the wheel suspension device is essentially a member that is attached to the vehicle body at one end portion and mounted to the wheel bearing portion at the other end portion by a rotating joint, and tilts as the wheel moves up and down relative to the vehicle body. For this reason, the vertical acceleration sensor attached thereto tilts with the vertical movement of the wheel relative to the vehicle body.

  For example, if the vertical acceleration sensor is attached to the suspension arm and the vehicle body receives lateral acceleration and tilts in the roll direction, the left and right suspension arms will tilt accordingly, and the vertical acceleration sensor tilts accordingly. However, since it moves up and down, its output decreases as the tilt of the vertical acceleration sensor increases. As an example, FIG. 13 shows a state in which the vertical acceleration output of the wheel vertical acceleration sensor mounted on the suspension arm decreases as the lateral acceleration acting on the vehicle body increases.

  The present invention pays attention to the situation in which the above-described deviation occurs in the detection of the vertical acceleration of the wheel in a vehicle such as an automobile, and further improves the accuracy of the detection of the vertical acceleration of the wheel by correcting for it. It is an issue.

  In order to solve the above problems, the present invention provides a wheel vertical acceleration detecting device for detecting vertical acceleration of the wheel in a vehicle in which a wheel is suspended from a vehicle body by a wheel suspension device. The vertical acceleration sensor attached to the movable part of the sensor and the vertical acceleration detected by the vertical acceleration sensor are corrected according to the attitude of the movable part so as to cancel the influence of the attitude on the detected vertical acceleration value of the vertical acceleration sensor. The present invention proposes a wheel vertical acceleration detecting device characterized by having a posture influence correcting means.

  The posture of the movable part may be estimated based on the running state of the vehicle.

  The traveling state of the vehicle for estimating the posture of the movable part is a combination of a vehicle speed and a steering angle, a yaw rate of the vehicle body, a roll angle of the vehicle body, a pitch angle of the vehicle body, a vehicle height at a plurality of wheel positions, a lateral acceleration of the vehicle body, It may include at least one of longitudinal accelerations of the vehicle body.

  As described above, the wheel vertical acceleration detecting device for detecting the vertical acceleration of the wheel in a vehicle in which the wheel is suspended from the vehicle body by the wheel suspension device includes: a vertical acceleration sensor mounted on a movable portion of the wheel suspension device; And a posture influence correction means for correcting the vertical acceleration detected by the vertical acceleration sensor so as to cancel the influence of the posture on the vertical acceleration detection value of the vertical acceleration sensor according to the posture of the movable part. For example, even if the vertical acceleration sensor mounted on the movable part of the wheel suspension device tilts as the wheel moves up and down, the deviation of the output value of the wheel vertical acceleration sensor caused by the tilting is canceled by the posture effect correcting means. It is possible to accurately grasp the vertical acceleration of the wheel.

  If the posture of the movable part is estimated based on the running state of the vehicle, the posture of the vertical acceleration sensor, in particular, there is no need to provide any means such as a sensor to detect it. It is possible to grasp indirectly based on the running state, and the present invention can be implemented without requiring substantial additional cost for the posture influence correcting means.

  The tilting of the movable member of the wheel suspension device accompanying the vertical movement of each wheel with respect to the vehicle body in a four-wheeled vehicle such as a normal automobile depends on the motion state of the vehicle body with respect to the wheel, which depends on the type of motion state. For wheels, at least one of a combination of vehicle speed and steering angle, vehicle yaw rate, vehicle body roll angle, vehicle body pitch angle, vehicle height at multiple wheel positions, vehicle body lateral acceleration, or vehicle body longitudinal acceleration Therefore, it is possible to effectively operate the attitude influence correction means by estimating the attitude of the movable part of the wheel suspension apparatus to which the vertical acceleration sensor is attached according to at least one of these parameters. Can do.

  FIG. 1 is a schematic diagram showing a wheel vertical acceleration detecting device according to the present invention in a general configuration in which several possible configurations are implemented simultaneously. As shown in the figure, the wheel vertical acceleration detecting device according to the present invention is a wheel vertical acceleration sensor and a wheel vertical acceleration sensor obtained as a part of its function by a vehicle electronic control unit (ECU) mainly composed of a microcomputer. It consists of a combination with a correction unit. The wheel vertical acceleration sensor may be of any known configuration, and the electronic control device is of any known configuration, and is configured to perform computer control of various already known vehicles. It may be a thing.

  The electronic control device is supplied with a signal indicating a detection value from the wheel vertical acceleration sensor, a signal indicating a vehicle speed from a vehicle speed sensor not shown in the figure, a signal indicating a steering angle from a steering angle sensor, A signal indicating the yaw rate of the vehicle body from the yaw rate sensor, a signal indicating the roll angle of the vehicle body from the vehicle body roll angle sensor, a signal indicating the pitch angle of the vehicle body from the vehicle body pitch angle sensor, and the vehicle height from the vehicle height sensor at a plurality of wheel positions. A signal indicating the lateral acceleration of the vehicle body is supplied from the lateral acceleration sensor, and a signal indicating the longitudinal acceleration of the vehicle body is supplied from the longitudinal acceleration sensor.

  However, the signals other than the signal from the wheel vertical acceleration sensor are not all required, and the signal for correcting the signal from the wheel vertical acceleration sensor according to the inclination of the sensor is as described above. Indicates at least one of a combination of vehicle speed and steering angle, body yaw rate, body roll angle, body pitch angle, vehicle height at multiple wheel positions, body lateral acceleration, body longitudinal acceleration If the signal is supplied, the combination of vehicle speed and steering angle, vehicle body yaw rate, vehicle body roll angle, vehicle body pitch angle, vehicle height at multiple wheel positions, vehicle body lateral acceleration, vehicle body The output deviation accompanying the inclination of the wheel vertical acceleration sensor according to the longitudinal acceleration can be corrected as it is, and the wheel by the wheel vertical acceleration sensor is compared with the case where neither of these corrections is performed. It can improve the accuracy of the lower acceleration detection.

  FIG. 2 is a signal correction diagram showing a procedure for correcting the detection value of the wheel vertical acceleration sensor based on these signals according to the present invention when a combined signal of the vehicle speed and the steering angle is obtained. In a four-wheeled vehicle, there are four wheels: a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel. Here, as an example, detection of vertical acceleration for the left front wheel will be described. The same applies hereinafter. In this case, the wheel vertical acceleration signal generated by the wheel vertical acceleration sensor attached to one of the movable members of the wheel suspension device such as the suspension arm for the left front wheel is a map as illustrated in FIG. 7 based on the vehicle speed and the steering angle. Is corrected by a correction coefficient obtained with reference to FIG. In FIG. 7, a positive steering angle is when turning left, and a negative steering angle is when turning right.

  FIG. 3 is a signal correction diagram showing a procedure for correcting the detection value of the wheel vertical acceleration sensor based on the signal according to the present invention when a signal indicating the yaw rate of the vehicle body is obtained. Also in this case, the wheel vertical acceleration signal generated by the wheel vertical acceleration sensor attached to one of the movable members of the wheel suspension device such as the suspension arm for the left front wheel has a map as illustrated in FIG. 8 based on the yaw rate. Correction is performed by a correction coefficient obtained by reference. Also in FIG. 8, the yaw rate is positive when turning left, and the yaw rate is negative when turning right.

  FIG. 4 is a signal correction diagram showing a procedure for correcting the detection values of the wheel vertical acceleration sensor based on these signals according to the present invention when signals indicating the roll angle and the pitch angle of the vehicle body are obtained. Also in this case, the wheel vertical acceleration signal generated by the wheel vertical acceleration sensor attached to one of the movable members of the wheel suspension device such as the suspension arm for the left front wheel is based on the roll angle and pitch angle of the vehicle body. And it correct | amends with the correction coefficient obtained with reference to a map as illustrated in FIG. In this case, the correction based on the roll angle of the vehicle body and the correction based on the pitch angle of the vehicle body may be overlapped. Also in FIG. 9, a positive roll angle of the vehicle body is a clockwise roll angle toward the traveling direction of the vehicle as it occurs when turning left, and a negative roll angle of the vehicle body occurs when turning right. The roll angle in the counterclockwise direction toward the traveling direction of the vehicle. In FIG. 10, a positive vehicle body pitch angle is a pitch angle in the direction in which the front of the vehicle body rises with respect to the rear as generated during acceleration, and a negative vehicle body pitch angle is generated during braking. Is the pitch angle in the direction in which the front of the sinks with respect to the rear.

  FIG. 5 is a signal correction showing a procedure for correcting the detection value of the wheel vertical acceleration sensor based on these signals when the vehicle height is detected by the vehicle height sensor at the positions of the front, rear, left and right four wheels. FIG. In this case, the roll angle of the vehicle body and the pitch angle of the vehicle body are calculated from the difference in vehicle height at the positions of the four wheels on the front, rear, left and right. Based on these roll angles and pitch angles, FIG. 9 and FIG. A correction coefficient corresponding to the roll angle and the pitch angle is obtained with reference to the map as illustrated in FIG. 10, and the wheel vertical acceleration signal generated by the wheel vertical acceleration sensor is corrected by the correction coefficient in the above manner.

  FIG. 6 is a signal correction diagram showing a procedure for correcting the detection values of the wheel vertical acceleration sensor based on these signals according to the present invention when signals indicating the lateral acceleration and the longitudinal acceleration of the vehicle body are obtained. Also in this case, the wheel vertical acceleration signal generated by the wheel vertical acceleration sensor attached to one of the movable members of the wheel suspension device such as the suspension arm for the left front wheel is based on the lateral acceleration and the longitudinal acceleration of the vehicle body. And it correct | amends with the correction coefficient obtained with reference to a map as illustrated in FIG. Also in this case, the correction based on the lateral acceleration of the vehicle body and the correction based on the longitudinal acceleration of the vehicle body may be added together. Also in FIG. 11, the positive lateral acceleration of the vehicle body is a lateral acceleration that rolls the vehicle body in the clockwise direction toward the traveling direction of the vehicle, and the negative lateral acceleration of the vehicle body is directed toward the traveling direction of the vehicle. This is the lateral acceleration that rolls the vehicle body in the counterclockwise direction. In FIG. 12, the longitudinal acceleration of the vehicle body is positive when the vehicle body is urged backward, and the longitudinal acceleration of the vehicle body is negative when the vehicle body is urged forward.

  The signal correction as shown in FIGS. 2 to 6 is a combination of the vehicle speed and the steering angle, the vehicle body yaw rate, the vehicle body roll angle, the vehicle body pitch angle, the vehicle height at a plurality of wheel positions, and the lateral force acting on the vehicle body. When several signals indicating acceleration and longitudinal acceleration acting on the vehicle body are obtained in parallel, they may be combined in an appropriate manner. The degree of correction by the parameter may be appropriately reduced. By doing so, the state in which the movable member of the wheel suspension device to which the wheel vertical acceleration sensor is attached tilts with the vertical movement of the wheel relative to the vehicle body is grasped from various aspects by more parameters, and the output of the wheel vertical acceleration sensor is obtained. The value can be corrected to detect the wheel vertical acceleration with higher accuracy.

  While the present invention has been described in detail with respect to several embodiments thereof, it will be apparent to those skilled in the art that various modifications can be made to these embodiments within the scope of the present invention. .

1 is a schematic view showing a wheel vertical acceleration detecting device according to the present invention in a general configuration in which several possible configurations are simultaneously performed. FIG. The signal correction figure which shows the point which correct | amends the detection value of a wheel vertical acceleration sensor based on these signals by this invention, when the combined signal of a vehicle speed and a steering angle is obtained. The signal correction figure which shows the point which correct | amends the detection value of a wheel vertical acceleration sensor based on this signal by this invention, when the signal which shows the yaw rate of a vehicle body is obtained. The signal correction figure which shows the point which correct | amends the detection value of a wheel vertical acceleration sensor based on these signals by this invention, when the signal which shows the roll angle and pitch angle of a vehicle body is obtained. The signal correction figure which shows the point which correct | amends the detection value of a wheel vertical acceleration sensor based on these signals by this invention, when vehicle height is detected by the vehicle height sensor in the position of four wheels of front and rear, right and left. The signal correction figure which shows the point which correct | amends the detection value of a wheel vertical acceleration sensor based on these signals by this invention, when the signal which shows the lateral acceleration and longitudinal acceleration of a vehicle body is obtained. The figure which shows an example of the map referred in the signal correction | amendment shown in FIG. The figure which shows an example of the map referred in the signal correction | amendment shown in FIG. The figure which shows an example of the map referred in the signal correction | amendment shown in FIG. 4 and FIG. The figure which shows an example of the map referred in the signal correction | amendment shown in FIG. 4 and FIG. The figure which shows an example of the map referred in the signal correction | amendment shown in FIG. The figure which shows an example of the map referred in the signal correction | amendment shown in FIG. The figure which illustrates the state which the vertical acceleration output value of the wheel vertical acceleration sensor with which the suspension arm was mounted | worn is influenced by the lateral acceleration which acts on a vehicle body.

Claims (8)

A vertical acceleration sensor mounted on a movable part of the wheel suspension device, the vertical acceleration sensor for detecting the vertical acceleration of the wheel in a vehicle in which a wheel is suspended from a vehicle body by a wheel suspension device, and the vertical acceleration sensor It possesses the attitude influence correcting means for correcting such attitude in accordance with vertical acceleration of the acceleration sensor detects the attitude of the movable portion cancels the effect of the vertical acceleration detection value of the vertical acceleration sensor, the movable portion A wheel vertical acceleration detection device characterized in that an attitude is estimated based on a running state of a vehicle .   The wheel vertical acceleration detection device according to claim 1, wherein the traveling state of the vehicle for estimating the attitude of the movable portion includes a combination of a vehicle speed and a steering angle.   The wheel vertical acceleration detection device according to claim 1, wherein the traveling state of the vehicle for estimating the attitude of the movable part includes a yaw rate of the vehicle body.   The wheel vertical acceleration detection device according to claim 1, wherein the running state of the vehicle for estimating the attitude of the movable part includes a roll angle of the vehicle body.   The wheel vertical acceleration detection device according to claim 1, wherein the running state of the vehicle for estimating the attitude of the movable part includes a pitch angle of the vehicle body.   The wheel vertical acceleration detection device according to claim 1, wherein the traveling state of the vehicle for estimating the attitude of the movable part includes vehicle heights at a plurality of wheel positions.   The wheel vertical acceleration detection device according to claim 1, wherein the traveling state of the vehicle for estimating the posture of the movable part includes a lateral acceleration of the vehicle body.   The wheel vertical acceleration detection device according to claim 1, wherein the traveling state of the vehicle for estimating the posture of the movable part includes a longitudinal acceleration of the vehicle body.

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