JPS60252010A - Posture controller for car - Google Patents

Abstract

PURPOSE:To permit the speedy rolling control by estimating the centrifugal acceleration speed by the signals of a car-speed sensor and a steering sensor on cornering and adjusting the car-height according to the centrifugal acceleration speed and correcting the car-height adjustment amount according to a roll angle sensor. CONSTITUTION:When a car comes to a corner, a car-speed signal supplied from a car-speed sensor 1 and a steering-angle signal supplied from a steering sensor 2 are input into a control means 11, and the centrifugal acceleration speed in the lateral direction which acts onto the chassis is estimated. The output for setting the roll angle of the chassis to zero or close to zero on the basis of the centrifugal acceleration speed is transmitted to a car-height adjusting means 10, and rolling control is started. During the time when the chassis roll angle theta detected by a roll-angle sensor 3 does not reach an aimed value, the car-height adjusting means 10 is allowed to continue to transmit output, and when the chassis roll angle reaches zero or close to zero, the transmission of the output to the car- height adjusting means 10 is suspended and rolling control is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an attitude control device for a vehicle, and more particularly to an attitude control device for obtaining running stability during cornering.

Problems with the Prior Art and Their Solutions Conventionally, when cornering, a centrifugal force acts on the vehicle body, which causes the vehicle body to tilt outward, causing a so-called roll. When roll occurs, not only does the running stability and riding comfort of the vehicle deteriorate, but in extreme cases, there is a risk that the vehicle will overturn.

Therefore, as a method for controlling the vehicle height to be constant regardless of the driving state of the vehicle, for example, as described in Japanese Patent Publication No. 59-14365, a displacement detection means, a displacement signal from the displacement detection means, and a change in displacement are used. A vehicle is known that is equipped with a signal processing circuit that adds the ratio signal and an actuation mechanism that applies a force to the vehicle body in accordance with the output from the signal processing circuit.

However, in the above case, after the vehicle body actually rolls outward during cornering, this is detected by the displacement detection means, and rolling control is started based on the signal, which reduces responsiveness. is slow, making it difficult to obtain the desired cornering performance.

Purpose of the Invention The present invention has been made in view of such conventional problems.
The purpose is to provide a vehicle attitude control device that controls the vehicle height with good responsiveness so that the roll angle is zero or close to zero during cornering, and has excellent cornering performance.

Structure of the Invention In order to achieve the above object, the present invention provides a vehicle speed sensor that detects vehicle speed, a steering sensor that detects the steering direction and amount of steering angle of a steering wheel, and a roll angle sensor that detects the roll angle of a vehicle body. It consists of a vehicle height adjustment means for adjusting the vehicle height on the left and right sides of the vehicle body, and a control means.The control means controls the lateral cardiac acceleration acting on the vehicle body based on the vehicle speed signal from the vehicle speed sensor and the steering angle signal from the steering sensor. is estimated, and based on this cardiac acceleration, an output is transmitted to the vehicle height adjustment means so that the roll angle of the vehicle body becomes zero or close to zero, and the vehicle height adjustment means is corrected and controlled based on the roll angle signal from the roll angle sensor. This is what I did.

DESCRIPTION OF EMBODIMENTS FIG. 1 shows an example of the attitude control device according to the present invention, and the vehicle speed sensor is a conventionally known one, for example, a reed switch or a magnetically sensitive element is driven by a magnet rotated by the rotation of a speedometer cable. There are also devices that optically detect the rotation of the speedometer cable.

The steering sensor 2 is also conventionally known and detects the steering direction, steering angle amount, and steering angular velocity of the steering wheel. One such configuration is, for example, that a slit plate is provided on the steering shaft, and two pairs of photo ink rubbers are attached to the steering column with the slit plate sandwiched therebetween. Then, when the steering shaft rotates, the photo ink labeler transmits light through the slit plate.

Light is repeatedly blocked, thereby detecting the steering direction, steering angle amount, and steering angular velocity.

As the roll angle sensor 3, for example, the Japanese Patent Publication No. 59-143
As described in Publication No. 66, a device that detects the vehicle height using a magnet and a magnetoelectric transducer is installed on each side of the front or rear wheels to measure the difference in vehicle height between the left and right wheels, and the roll angle is determined from this vehicle height difference. I can think of something that would make it look like this. However, in this case, since changes in vehicle height are detected by ON/OFF signals of the magneto-electric transducer, continuous changes in vehicle height cannot be detected.

Therefore, as shown in FIG. 2, a link 6.7 is connected between an unsprung member 4 such as a lower arm or axle beam and a sprung member 5 such as a vehicle body, and a potentiometer 8 is connected to the base end of the link 7. Similarly to the above, one detection device may be provided on each side of the front wheel or the rear wheel. In this case, the relative displacement between the unsprung member 4 and the sprung member 5 is converted into rotation of the link 7, and the potentiometer 8 sequentially outputs an output signal from this rotation angle, and the difference between the outputs of the left and right potentiometers 8 is Just measure the roll angle from

The vehicle height adjustment means 10 is provided independently for each of the four wheels, and is used to adjust the relative height between the unsprung member 4 and the sprung member 5. As for its composition, the above-mentioned special public interest
There are a hydropneumatic system that adjusts the vehicle height using hydraulic pressure as described in Japanese Utility Model Publication No. 365 and Japanese Utility Model Publication No. 59-11767, an air spring system, and a system that uses both an air spring and a coil spring.

The control means 11 includes the vehicle speed sensor 1. It processes signals from the steering sensor 2 and roll angle sensor 3, and controls the vehicle height adjustment means 10 so that the roll angle is approximately constant during cornering.

Here, the operation of the attitude control device having the above configuration will be explained. First, when the vehicle approaches a corner, the vehicle speed signal from the vehicle speed sensor 1 and the steering angle signal from the steering sensor 2 are sent to the control means 11, and the control means 11 calculates the lateral cardiac acceleration acting on the vehicle body from these signals. presume. That is, the control means 11 stores in advance data obtained by experimentally determining the correlation between the vehicle speed and steering angle and the cardiac acceleration acting on the vehicle body at that time, and the cardiac acceleration is estimated using this data.

Based on the centripetal acceleration, the control means 11 transmits an output that makes the roll angle of the vehicle body zero or close to zero to the vehicle height adjustment means 10, and promptly starts rolling control. Note that the control means 11 stores in advance data obtained experimentally on the correlation between the requested center acceleration and the amount of vehicle height adjustment to make the roll angle zero when this center acceleration acts on the vehicle body. , the above output is achieved using this data.

Next, the roll angle sensor 3 detects the actual vehicle body roll angle and sequentially sends the signal to the control means 11.
continues to transmit an output to the vehicle height adjustment means 10 while the vehicle body roll angle θ detected by the roll angle sensor 3 has not reached the target value (θ slope 0), and the vehicle body roll angle reaches zero or its vicinity. At this time, the output transmission to the vehicle height adjustment means XO is stopped. In other words, if rolling control is performed using only the signals from the vehicle speed sensor 1 and steering sensor 2, there is a risk that an error will occur between the target value and the roll angle sensor 3. It is controlled so that

Note that since the rolling control described above is not necessary when the vehicle is parked or traveling at low speed, the rolling control can be performed only at a predetermined vehicle speed or higher based on the vehicle speed signal from the vehicle speed sensor 1.

In the above embodiment, the vehicle height adjusting means 10 is provided independently for each of the four wheels, but the invention is not limited to this, and as shown in FIG. In order to adjust the vehicle height in pairs, a left wheel height adjusting means 12 and a right wheel height adjusting means 13 may be provided. In this case, there is an advantage that the adjustment variation between the front and rear wheels is reduced compared to the case where the four wheels are independent.

Further, since it is possible to perform considerable rolling control by controlling only the two front wheels, for example, the vehicle height adjustment means 12 and 13 shown in FIG. 3 may be provided only on the two front wheels.

Effects of the Invention As is clear from the above explanation, according to the present invention, cardiac acceleration is estimated from the signals from the vehicle speed sensor and steering sensor during cornering, and the roll angle of the vehicle body is adjusted to be zero or close to zero based on this cardiac acceleration. In addition to adjusting the vehicle height, the roll angle sensor also corrects the amount of vehicle height adjustment, which stabilizes the vehicle body posture during cornering.
The difference in the load shared between the inner and outer wheels of the tires is alleviated, allowing for excellent cornering performance (M).Also, instead of starting rolling control only after the vehicle body actually begins to roll outward, the vehicle speed signal and steering angle signal Since the cardiac acceleration is estimated from the heart acceleration and the rolling control is immediately started based on the cardiac acceleration, the response speed is fast.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an attitude control device according to the present invention, FIG. 2 is an explanatory diagram of an example of a roll angle sensor, and FIG. 3 is a block diagram of another embodiment of the present invention. 1... Vehicle speed sensor, 2... Steering sensor, 3
... Roll angle sensor, 10.12.13 ... Vehicle height adjustment means, 11 ... Control means. Applicant Daihatsu Motor Co., Ltd. Agent Patent Attorney Hidetaka Tsutsui Figure 2

Claims (1)

[Claims] (1) A vehicle speed sensor that detects vehicle speed, a steering sensor that detects the steering direction and steering angle of the steering wheel, a roll angle sensor that detects the roll angle of the vehicle body, and a vehicle height that adjusts the vehicle height on the left and right sides of the vehicle body. The adjusting means estimates the lateral cardiac acceleration acting on the vehicle body based on the vehicle speed signal from the vehicle speed sensor and the steering angle signal from the steering sensor, and adjusts the roll angle of the vehicle body to be zero or close to it based on the cardiac acceleration. 1. A vehicle attitude control device comprising: control means for transmitting an output to a vehicle height adjustment means, and for correcting and controlling the vehicle height adjustment means based on a roll angle signal from a roll angle sensor.