JPS60174912A - Detection of centripetal acceleration and inclination angle of car - Google Patents

Abstract

PURPOSE:To make it possible to separately calculate the centripetal acceleration of a car during accelerated motion and the inclination angle of a car body, by using two simple inclination angle sensors utilizing gravity and separating the outputs thereof into a centripetal acceleration component and an inclination angle component. CONSTITUTION:A pair of left and right gravity utilizing inclination angle sensors 2, 3 are provided to the proper part of a car body so as to be arranged in the car width direction at a constant interval and the car speed data (v) from a car speed sensor 7, the output data VOL from the left inclination angle sensor 2, the output data VOR from the right inclination angle sensor 3, the output data VOL' of LPF8 connected to the sensor 2 and the output data VOR of LPF9 connected to the sensor 3 are inputted to CPU through a multiplexer 10 and an A/D converter 11 controlled by CPU. Further, the data from a revolving direction sensor 12 attached to a steering column is directly inputted to CPU and these data is operated to output centripetal acceleration data, inclination data and vibration data from CPU.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting cardiac acceleration and tilt angle of an automobile, and relates to a method for detecting cardiac acceleration and tilt angle of an automobile. The feature is that the data and slope angle data can be displayed instead of being output separately.

Examples of tilt angle sensors that use gravity include:
Utility Model Application Publication No. 57-116815 and Utility Model Application No. 57-116
There is one shown in Publication No. 816. These inclination angle sensors have a basic configuration that mechanically or electrically outputs the amount of movement of the movable mass point from the reference position due to the inclination of the reference plane. However, although such a tilt angle sensor can detect the tilt angle of a stationary object or an object that is moving in a straight line at a constant velocity, it can detect the tilt angle of an object that is moving with acceleration, such as a car. It is not possible to output the inclination angle independently.

When an object is in accelerated motion, a force due to the accelerated motion acts on the movable mass point in the tilt angle sensor in addition to the force due to the acceleration of gravity, and as a result, the output of this tilt angle sensor is the same as that of the object. This is because a component due to the tilt (tilt component) and a component due to the accelerated motion of the object (acceleration component) are superimposed.

On the other hand, if the acceleration and tilt angle of a moving vehicle can be detected separately, the detected acceleration data can be used to activate an anti-skid device, and the detected tilt angle data can be used to issue a rollover warning. , various applications are possible.

The method of this invention collects cardiac acceleration data when a car is turning and vehicle body inclination angle data using two left and right inclination angle sensors placed a certain distance apart in the vehicle width direction, and a vehicle speed sensor. By performing specific calculations using data from the turning direction sensor, it is intended to output each separately.

Hereinafter, the method of the present invention will be specifically explained with reference to the drawings.

In the present invention, as shown in FIG. 1, a pair of left and right tilt angle sensors 2 and 3 are used to energize a vehicle body 1 of an automobile, which are arranged at a constant interval in the vehicle width direction. As shown in FIG. 2, the tilt sensors 2 and 3 include a support frame 4
When a circular arc-shaped resistor 6 is brought into contact with an inclined movable body 5 made of a conductor that is swingably suspended in the vehicle width direction, and a constant voltage is applied to both ends 6a and 6b of this resistor 6. A WIR gravity-utilizing tilt sensor that outputs the potential difference between one end 6a of the resistor and the movable tilting body 5 can be used.

Now, consider the case where the automobile 1 is turning clockwise or counterclockwise, as shown in FIG.

In the figure, rR is the rotation radius of the right sensor 2 with respect to the left and right turning centers 01 and 02, and ri is the left and right turning center 01.02.
r is the rotation radius of the left sensor 3 with respect to the left and right turning centers 01 and 02, n is the distance between the left and right sensors, and the values other than 2 change from time to time.Here, , rL+ rR in case of clockwise turn are rL-r+ 1w...-Il) 'rR=r --
1, - (2) 2 In the case of a counterclockwise turn, it becomes.

Now, the output VOL of the left sensor and the output VOR of the right sensor are a superposition of a tilt component caused by the tilt of the vehicle body, an acceleration component caused by centripetal acceleration, and a vibration component caused by vibration of the vehicle body, respectively. Therefore, it can be expressed as follows.

VOL=VSL”VGL+VVL=-(3)
-VOR= VSR"VGR"VVR-(') Here, VSL is the tilt component of the left sensor, VSR is the tilt component of the right sensor, VGL is the acceleration component of the left sensor, VGR is the acceleration component of the right sensor, and VVL is the left sensor. Vibration component of the sensor, V
VR is the vibration component of the right sensor.

Since the left and right sensors 2.3 tilt in the same way in the vehicle width direction, the tilt components VSL and VSR of the respective sensor outputs VOL and VOR should be equal to each other. Also, assuming that the vibration components VVL and VVR of the left and right sensors are equal to each other, the tilt components VSL and VSR and the vibration components VVL and VVR can be eliminated from the above equations (3) and (4) and expressed as follows. I can do it.

VOL - VaR = VGL -, VGR° - (s) In other words, the difference between the left sensor output VOL and the right sensor output VOR is the acceleration-skin component VGL, VGRc7)
expressed as a difference.

Here, the acceleration component VGL of the output of the left and right sensors 2 and 3
, think about VGH. The output of sensors 2 and 3 is
As shown in the figure, if there is a potential difference between the right end 6a of the resistor 6 and the tiltable movable body 5, the acceleration component when the car turns to the right has a positive value, and conversely, the acceleration component when the car turns to the left has a positive value. The component will be a negative value. On the other hand, the acceleration component vcr,
VGR is expressed as 1*6L1=krLω2 (6) l VGRl = krLω2−(7). Here, k is a proportionality constant and ω is the turning angular velocity of the vehicle.

Here, the difference between the left and right sensor outputs when turning counterclockwise is VGL = -k rLω2'+ VGR = -k r
Since RIJ32, the formulas (l, (2)' and (5
), VOL−VOR= (−krLω') −(−
krRω2)=kω2(rR−rL)=]w2((r+Zw)−(r−Zw))2=bottle 2′1w (8).

On the other hand, the difference between the left and right sensor outputs VOL and VOR when turning right is VGL = krLω2. Since VGR month ηω2, formula +11. (From 23 and (5)・■OL−■0
R=krLω2-krRω2=kn+2(rL-rR
) = kω2((r ” 2 Zw) −(r −, Zw
))=ω2Zw...(9)

Furthermore, when the vehicle speed is V, the turning angular velocity of the vehicle body is expressed as
O), the turning radius at the center of the vehicle body is expressed as follows, regardless of the turning direction of the vehicle.

VOL”-VOR=k (”-)2ZwThis formula (1
1) means that when the left and right sensor outputs VOLI VOR and the vehicle speed V are given, the turning radius around the center of the vehicle body can be determined.

Then, using equations (11', (2), u (2)', and (10), the acceleration component V.lj VGR of the left and right sensor output during counterclockwise turning and clockwise turning is expressed as follows. Therefore, by substituting the value of r calculated by the above equation (11) into these equations, each acceleration component VGL, VG
R is calculated.

v2. .

VGR= krRω2= k (r −j Zw),
2' (15) Here, VGL for the case of clockwise rotation
, VGR calculation formulas (14) and (15) for both left and right rotations.

Typical formulas for calculating VGH are: for clockwise rotation, formulas (14) and (15) are used as is, and for counterclockwise rotation, formulas (14) and (15) are used.
Calculations can be made by reversing the sign of k to -k and Zw to -~.

In this way, the acceleration component VGL of the tilt angle sensor output
, When VGR is set, the slope component VSL (= VS
R).

and the vibration component VVL'"VVR) can be determined as follows.

That is, assuming that the vibration components VVL and VVR of the sensor output can be completely removed by passing the sensor output through a low-pass filter, the output of the low-pass filter (2). 1′, ■. ,' is VOL−=VSL”V
GL-(16)VOR'=VSR"VGR-07
1, so the slope component VSL (= VSR)
It is calculated as VSL = Voi, -VGL -ns+.

Also, the vibration component VVL (=VVR) is vvr,
It will be calculated as =VOL-VOL''+191.

FIG. 3 shows an example of an apparatus for calculating cardiac acceleration data, inclination angle data, and vibration data of an automobile through each of the above calculation steps, and a flowchart of data processing performed by the central processing unit CPU of the apparatus shown in FIG. is shown in Figure 4.

Vehicle speed data V from vehicle speed sensor 7, left tilt angle sensor 2
■ Output data from. L, Output data of the right tilt angle sensor VOR1 Output data of the low pass filter 8 connected to the left tilt angle sensor ■. 1' and the output data VOR' of the low-pass filter 9 connected to the right tilt angle sensor are sent to the multiplexer 10 controlled by the central processing unit CPU.
and the central processing unit C via the A/D converter 11.
Input to PU. In addition, the data of the turning direction sensor 12 force applied to the steering link column etc. is directly input to the central processing unit. The data output from the
VR' is displayed on the display device 13 or stored in the memory M as it is or after further appropriate processing.

The central processing unit CPU performs the following processing.

That is, as shown in FIG. 4, first, in step S1, the output data VOL of the left tilt angle sensor 2 and the output data VOL of the right tilt angle sensor 2 are obtained. Output data VOL' of the R1 left low-pass filter 8, output data VOR1 of the useful low-pass filter 9, vehicle speed data V, and turning direction data are input. Next, in step S2, it is determined whether the vehicle speed data V is 0 or not. If it is 0, the process proceeds to step S3, and if it is not 0, the process proceeds to step S4. In step S4, it is determined whether the vehicle is turning right, turning left, or going straight. If it is turning right, the process goes to step S5; if it is turning left, the process goes to step S6; if it is going straight, the process goes to step S4. is step S3
Proceed to. In step S5, the turning radius r around the vehicle center is calculated using equation (11), and further in step S7, the left tilt angle sensor 2 is calculated using equations (14) and (15).
The acceleration component VGL of the right tilt angle sensor 3 and the acceleration component VGR of the right tilt angle sensor 3 are calculated.

Furthermore, in step S8, the tilt component VSL (= VSR) of the tilt angle sensor is calculated using equations (18) and (19).
and the vibration component VVL (=VVR) is calculated.

When the vehicle speed is determined to be O in step S2, and
When it is determined in step S4 that the direction of travel of the vehicle is straight ahead, the claimed center acceleration should be 0, so in step S3 VGL is set to “VGR=0” and the process jumps to step S8. If it is determined that it is a left turn, the formula (
14) and (15) to correspond to equations (12) and (13) (In step S6, the distance between the left and right sensors 2
．． , I and the proportionality constant k, then step
Proceed to step 7 S5.

Finally, in step S9, the claimed center acceleration data, inclination angle data, and vibration data are output, and the process returns to step S1. By repeating the processes from step S1 to step S9 in this way, it is possible to output cardiac acceleration data or inclination angle data that change from moment to moment.

In addition, the acceleration data can be displayed digitally by adding appropriate calibration to the data.
Various methods can be considered, such as increasing or decreasing the number of lit lamps arranged in a row depending on the magnitude of acceleration, so that changes in acceleration can be recognized quantitatively. In addition, various measures can be considered for the tilt data, such as appropriately calibrating the data and displaying it digitally as an angle, or rotating an indicator indicating the horizontal direction. Of course, the acceleration data, e.g.
It is also possible to use each data independently, for example, by using it to detect when an anti-skid device is activated, or by applying the tilt angle data to, for example, a rollover warning device. Also,
The acceleration data to be displayed will be closer to the actual situation if the results calculated using equations (14) and (15) are averaged and output. Furthermore, since the turning radius r around the center of the vehicle body is determined in the process of calculating the acceleration data, it is also possible to display this separately.

As explained above, the method for detecting cardiac acceleration and tilt angle of an automobile according to the present invention uses two simple tilt angle sensors that utilize gravity.
By simply using these devices, the cardiac acceleration and inclination angle of the vehicle body during acceleration motion can be determined separately, and furthermore, the turning radius of the vehicle can be determined, which is a special effect. .

[Brief explanation of the drawing]

FIG. 1 is a conceptual explanatory diagram of the present invention, FIG. 2 is a sectional view showing an example of an inclination angle sensor, FIG. 3 is a configuration diagram showing an example of a device for carrying out the method of the present invention, and FIG. The figure is a flowchart showing an example of the method of the present invention. 2.3... Tilt angle sensor, 7... Vehicle speed sensor, 8°9... Low pass filter, CPU... Central processing unit, 12... Turning direction sensor Applicant Daihatsu Motor Co., Ltd. Agent Patent attorney Toyoharu Higuchi (Chief) 2 Procedural Amendment (October 5, 1982, Manabu Shiga, Commissioner of the Japan Patent Office 2, Title of Invention: Method for Detecting Cardiac Acceleration and Inclination Angle of a Motor Vehicle 3, Relationship with the Person Who Makes the Amendment Case) Patent Applicant Address 1-1 Daihatsu-cho, Ikeda-shi, Osaka Name Daihatsu Motor Co., Ltd. Representative Tomohiro Shuguchi 4, Agent ■543 Address 2-31 Tamatsukuri Motomachi, Tennoji-ku, Osaka City Contents of the amendment (1) Specification amend the claims column as follows: ``(1) provided at a predetermined interval 'Lw in the vehicle width direction
Output data VOL, VOR1 from a pair of left and right tilt angle sensors capable of detecting tilt in the vehicle width direction; output data VOL, VOR from a low-pass filter connected to the pair of left and right tilt angle sensors; output data V from the vehicle speed sensor.
The cardiac acceleration and tilt angle of the vehicle are calculated by inputting the output data from the turning direction sensor and the turning direction sensor to a central processing unit, and outputting the cardiac acceleration data and vehicle body tilt angle data at each tilt angle sensor position through the following steps. Determine the turning radius r at the center of the vehicle body using the detection method, tb+ Formula VGL = k ・(r +!-z,) 'v22
r2 and the formula VGR=k・(・−↓Zw) ”” Substitute the above turning radius into r2 to obtain the cardiac acceleration component Ver for the left tilt angle sensor output, and the cardiac acceleration component VGR for the right tilt angle sensor output. To calculate, fcl If the turning direction of the car is opposite, use the above steps (reverse the signs of k and Zw in bl, d1 by the formula ■8L=■.F, -VGL or by the formula VSR=VOR-VGR Tilt component VSL or VS of tilt angle sensor output
(e) each centripetal acceleration component VGL, VGR calculated in steps (b) and (C) above and step ld above;
outputting the slope component VSL or VSR calculated in step 1 as acceleration data and slope data; (U) The detailed description of the invention in the specification is amended as follows. +11 [l VGRI = krlW2. on the second line from the bottom of page 7 of the specification. ,',(71' as l
v,,1=...,...(・)'? ili correct. (DI) Replace Figure 3 of the drawings with the attached corrected Figure 3.

Claims (1)

[Claims] (1) Output data from a pair of left and right tilt angle sensors that are provided at a predetermined interval Zw in the vehicle width direction and can detect tilt in the vehicle width direction VOL, VOR1 Low pass connected to the above pair of left and right tilt angle sensors. Output data from the filter VOL, VOR1 Output data from the vehicle speed sensor V
The cardiac acceleration and tilt angle of the vehicle are calculated by inputting the output data from the turning direction sensor and the turning direction sensor to a central processing unit, and outputting the cardiac acceleration data and vehicle body tilt angle data at each tilt angle sensor position through the following steps. (b) By substituting the above turning radius V into and, the cardiac acceleration component VGL for the left tilt angle sensor output and the cardiac acceleration component VGL for the right tilt angle sensor output are obtained. Cardiac acceleration Calculate the component VGR once, (If the turning direction of the C1 car is opposite, invert the signs of k, Z, and j in step (b) above, (dl formula VSL = VOL'- VGL or the slope component of the slope sensor output VSL or VS by the formula VSR=VOR'-VGR
(61 above step (bl, each centripetal acceleration component VGL, VGR calculated in (C1) and above step (d
) to output the calculated slope component VSL or VSR as acceleration data and around 1 oblique angle data.