JPS60252011A - Roll-angle detector for car - Google Patents

Abstract

PURPOSE:To easily and correctly detect the continuous variation of the chassis roll angle by outputting the voltage corresponding to the chassis roll angle by multiplying the difference of the outputs supplied from the potentiometers installed at the right and left of front wheels by an amplification factor in differential amplifying circuit. CONSTITUTION:The spring lower member 1 of a lower arm and the spring upper member 2 of a chassis are connected through two links 5 and 6, and a potentiometer 7 is installed at the base edge part of the link 6. A certain voltage V is applied onto the right and left potentiometers 7, and the output signals V1 and V2 of the potentiometers 7 are input into a differential amplifying circuit 9 through a low-pass filter 8. Therefore, the final output (Vout) is obtained from the difference between the output signals V1 and V2 of the potentiometers 7 accompanied by the inclination of the chassis, and the roll angle is obtained by inputting the final output into a sequential controller, etc., and thus the continuous variation of the roll angle can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a roll angle detection device for a vehicle, and more particularly to a roll angle detection device for detecting the roll angle of a vehicle body during cornering.

Prior art and its problems Conventionally, a vehicle height detection device that is installed between a sprung member and an unsprung member of a vehicle and detects changes in vehicle height has been developed, for example, by the Japanese Patent Publication Publication No. 5
9=14.366.

However, since centrifugal force acts on the vehicle body during cornering, there is a problem in that the vehicle body tilts outward, resulting in 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, if the vehicle body is always kept horizontal during cornering, or if the vehicle body is forced to roll inward, the difference in the shared load of the tires between the inner and outer wheels can be alleviated and stable cornering performance can be obtained.

For this purpose, it is necessary to accurately detect the roll angle of the vehicle body when cornering, but although the vehicle height detection device described above can detect the vehicle height displacement of each individual wheel, it cannot detect the roll angle. Therefore, it is conceivable to provide one vehicle height detection device on each of the front wheels or the rear wheels to measure the difference in vehicle height between the left and right wheels, and to determine the roll angle from this vehicle height difference. However, in this case, since changes in vehicle height are detected by ON/OFF signals of the magneto-electric transducer, continuous changes in roll angle cannot be detected.

Purpose of the Invention The present invention has been made in view of such conventional problems.
An object of the present invention is to provide a vehicle roll angle detection device that can easily and accurately detect continuous changes in the vehicle body roll angle. A potentiometer is installed on the left and right sides of the vehicle and outputs a voltage corresponding to the relative displacement between the sprung member and the unsprung member, and the difference in output from the potentiometer is multiplied by an amplification factor to output a voltage corresponding to the roll angle of the vehicle body. It is composed of a differential amplifier circuit.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows an example of the sensor portion of the roll angle detection device according to the present invention, where l is an unsprung member such as a lower arm or axle beam, 2 is an unsprung member such as a vehicle body, 3 is a tire,
4 is a suspension.

The unsprung member 1 and the sprung member 2 are connected by two links 5, 6, and a potentiometer 7 is provided at the base end of the link 6. The links 5 and 6 and the potentiometer 7 are installed on each side of the front or rear wheels of the vehicle.
They are provided one by one.

As the potentiometer 7, a non-contact type such as a capacitive optical potentiometer is preferable from the viewpoint of longevity, but a contact type may be used. Also, in the above case,
The relative displacement between the unsprung member l and the sprung member 2 is converted into rotation of the link 6, and the potentiometer 7 is calculated from this rotation angle.
Although a rotary potentiometer that sequentially outputs an output signal is shown, the present invention is not limited to this, and a linear potentiometer may be used.

FIG. 2 shows the configuration of the call angle detection device according to the present invention, in which 8 is a low-pass filter, and left and right potentiometers 7
．． Out of the output signals V, . Reference numeral 9 denotes a differential amplifier circuit which multiplies the difference between the output signals V, V2 by an amplification factor and outputs an output according to the roll angle.

That is, a constant voltage V is applied to the potentiometer 7.7, and when the vehicle body tilts, the left and right potentiometers 7.
．． 7, and when these output signals are input to the differential amplifier circuit 9, the final output ■□ of the differential amplifier circuit 9 becomes ■□ - (V, -V2 )α (α: amplification factor), so that the roll angle θ becomes θ−KVOJ□ (K: coefficient considering the link relationship), and θ can be determined from ■.

As mentioned above, the roll angle detection device determines the final output V from the difference between the output signals V, V2 of the left and right potentiometers 7.7, and sequentially inputs this to a control device etc. to determine the roll angle. Therefore, continuous changes in roll angle can be detected.

Incidentally, if the amplification factor α' of the differential amplifier circuit 9 is set to α''=α, the roll angle θ can be determined directly from the final output.

Effects of the Invention As is clear from the above explanation, according to the present invention, a differential amplifier circuit multiplies the difference in output from the potentiometers provided on the left and right sides of the front or rear wheels by an amplification factor to generate a signal according to the roll angle of the vehicle body. Since the voltages are sequentially output, even if the roll angle of the vehicle changes continuously, it can be detected easily and accurately.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of an example of the present invention, and FIG. 2 is a circuit diagram thereof. 1... Unsprung member, 2... Sprung member, 5.6...
- Link, 7... Potentiometer, 8... Low pass filter, 9-... Differential amplifier circuit. Applicant Daihatsu Motor Co., Ltd. Agent Patent Attorney Hidetaka Tsutsui

Claims (1)

[Claims] (1) A potentiometer is installed on the left and right sides of the front or rear wheels and outputs a voltage according to the relative displacement between the sprung member and the unsprung member, and the roll angle of the vehicle body is determined by multiplying the difference in output from the potentiometer by an amplification factor. A roll angle detection device for a vehicle, comprising: a differential amplifier circuit that outputs a voltage according to the voltage.