WO1998024977A1

WO1998024977A1 - Road vertical section profile measuring apparatus

Info

Publication number: WO1998024977A1
Application number: PCT/JP1997/004459
Authority: WO
Inventors: Shawtaro Kato; Junichi Ito
Original assignee: Pasco Corporation; Japan Aviation Electronics Industry Limited
Priority date: 1996-12-05
Filing date: 1997-12-05
Publication date: 1998-06-11
Also published as: AU5137298A; JPH10168810A; JP3074464B2

Abstract

A posture vertical motion sensor (21), a road-to-car distance sensor (22), and an arithmetic unit (23) are mounted on a vehicle, and the vertical section profile is obtained from the distance to the road face measured with the distance sensor (22) and the pitch angle υ, the roll angle ζ, and the displacement H in vertical direction of the vehicle measured with posture vertical motion sensor (21).

Description

Specification

Road profile measurement device

Technical field

The present invention relates to a road profile profile measuring device that is used by being mounted on a vehicle and measures a vertical profile of a road on which the vehicle runs while the vehicle is running. Conventional technology

As a conventional example of this kind of road longitudinal profile measuring device, there is one disclosed in Japanese Patent Application Publication No. 3-78882, for example. This measuring device is equipped with an accelerometer that measures the vertical acceleration of the vehicle body and a distance meter that measures the distance from the vehicle body to the road surface, and integrates the vertical acceleration detected by the accelerometer to calculate the displacement. Is calculated, and the difference δ between the displacement amount and the change amount of the vehicle height detected by the range finder is calculated to obtain a vertical profile of the road. It is said that the difference S allows the user to know the undulation and depression of the road surface due to land subsidence, for example.

However, in the above measuring device, since the input shaft of the accelerometer is fixed in the vertical direction of the vehicle body, it is not possible to measure the acceleration component in the vehicle traveling direction perpendicular to the input shaft. When the vehicle 11 follows the slope 12 as shown in FIG. 8 and is running on a slope, the output of the accelerometer based on the running acceleration becomes zero, and the vehicle on the slope 12 runs. 11 The vertical movement (displacement) in 1 cannot be measured.

In other words, although the measuring device described in the above publication No. 3-7882 can measure the unevenness of the road surface such that the vehicle body moves up and down with respect to the road surface, it is difficult to measure the vehicle traveling along the inclined road surface. If there are large undulations or slopes (longitudinal undulations) on the road surface, the undulations cannot be measured.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks, and to measure a road profile profile accurately, including a undulation or a slope of a road surface in which a vehicle travels along the slope. Is to provide.

Disclosure of the invention

According to the present invention, a road profile measuring apparatus mounted on a vehicle and measuring a profile of a road on which the vehicle travels measures a distance to a road surface Distance measuring means, vertical acceleration measuring means for measuring vertical acceleration, integrating means for integrating vertical acceleration by measuring the acceleration measured by the vertical acceleration measuring means, displacement obtained by the integrating means And a means for obtaining a longitudinal opening file using a difference between the distance measured by the distance measuring means.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2A is a side view of a vehicle equipped with the road profile measurement device of FIG.

Figure 2B is a front view.

FIG. 3 is a block diagram showing details of the posture vertical movement sensor in FIG.

FIG. 4 is a block diagram showing another example of the posture vertical movement sensor.

FIG. 5 is a diagram for explaining a method of measuring a road profile.

FIG. 6 is a GG sectional view of FIG.

Fig. 7 is a diagram showing the trajectory of the vertical displacement of the vehicle in the measurement of the road longitudinal profile.

FIG. 8 is a diagram for explaining a problem with the conventional road profile measurement device. BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a preferred embodiment of the present invention. In this example, the road profile measurement device is assumed to include a posture vertical movement sensor 21, a road-vehicle distance sensor 22, and a calculation device 23. The posture vertical motion sensor 21 is provided with the inclination angle (pitch angle) θ in the longitudinal direction (running direction) of the vehicle with respect to the horizontal plane, the inclination angle (roll angle) in the lateral direction (width direction) φ, and the displacement of the vehicle in the vertical direction. (Vertical movement) Measures Η. For example, it is mounted and fixed inside the vehicle as shown in Figs. 2Α and 2Β.

The road-to-vehicle distance sensor 22 measures the distance from the vehicle body to the road surface and is attached to, for example, a part of a bumper. In this example, three distance sensors 22 are mounted on the bumper 24 at the center in the width direction of the vehicle 11 and in front of the left and right tires, as shown in FIG. Distance sensors 22 are arranged opposite to the center of the lane of the road and to the left and right ruts, respectively. For example, a sensor that emits laser light or ultrasonic waves and detects the reflection to measure the distance is used as the distance sensor 22. Pitch angle Θ, mouth angle Φ, vertical displacement H, measured by posture vertical movement sensor 21, and center of lane, left and right lines from vehicle body measured by three distance sensors 22 The distances C, L, and R to the road surface are input to the arithmetic unit 23, which calculates the lane center, left rutting, and right rutting road longitudinal profiles PC, PL, and PR. The arithmetic unit 23 is installed in the vehicle, for example, like the posture vertical movement sensor 21.

Next, the configuration and function of the posture vertical movement sensor 21 in FIG. 1 will be described in detail.

FIG. 3 is a block diagram showing a detailed configuration of the posture vertical movement sensor 21. A 3-axis gyro 25 mounted on the orthogonal 3-axis measures angular velocities around the X, Y, and Z axes. Here, the X-axis direction is the front of the device, the Y-axis direction is rightward, and the Z-axis direction is downward. On the other hand, a three-axis accelerometer 26 attached to three orthogonal axes measures acceleration in the X, Y, and Ζ axis directions.

The coordinate conversion unit 27 converts the X, Υ, and Ζ coordinates into N, E, and D coordinates (inertial coordinates). The X, Υ, and Z accelerations output from the three-axis accelerometer 26 are converted by the coordinate conversion unit 27. Input to 27 and converted to N, E, D acceleration. Here, N is the north direction, E is the east direction, and D is the earth center direction (vertical direction).

The coordinate transformation matrix of the coordinate transformation unit 27 changes every moment as the posture of the device changes. The coordinate transformation matrix update value calculation unit 28 calculates the change that changes the value of this matrix. Since the matrix change corresponds one-to-one with the change in attitude, that is, the angular velocity, the three-axis gyro 2 The matrix change is calculated using the X, Y, and 5 angular velocity data of 5. The calculated change is input to the coordinate conversion unit 27, and the matrix value is updated every moment.

The N, E, and D accelerations output from the coordinate conversion unit 27 are input to the integration unit 29, and the integration unit 29 integrates the N, E, and D accelerations and outputs N, E, and D velocities. Among these [N, E, E] speeds, the D speed is input to the integration unit 31. The integration unit 31 calculates the displacement H in the vertical direction by integrating the D speed.

On the other hand, the N and E velocities are input to the integrator 32, which integrates the N and E velocities and outputs the N and E positions (moving distances). And this N, E position and GPS (G1 The N and E positions output from the obal positioning system 33 are input to the comparison unit 34. The comparison unit 34 calculates the difference between the N and E positions obtained from these accelerations and the N and E positions of the GPS 33.

Here, since the integrators 29 and 32 also integrate the error, the errors of the N and E positions obtained from the acceleration gradually increase, while the error of the GPS 33 can be ignored. Since the error does not increase with time for the N and E positions by the GPS 33, this difference indicates the error of the N and E positions obtained from the acceleration.

The main cause of this error is the error of the coordinate transformation matrix due to the error of the 3-axis gyro port 25. Therefore, the calculated difference (error) is fed back to the coordinate transformation matrix update value calculation unit 28, and the N, E position error Modify the coordinate transformation matrix so that the minute is zero. As a result, the error of the coordinate transformation matrix is suppressed, so that the D acceleration is also corrected, and therefore, the error of the displacement H is also suppressed.

The pitch angle e and the wail angle 0 are output from the pitch / whale calculation unit 35. Since the coordinate conversion matrix in the coordinate conversion unit 27 indicates the relationship between the X, Υ, and Z coordinates and the N, E, and D coordinates, the pitch angle θ and the roll angle φ are obtained from this relationship. FIG. 4 shows an example in which a velocity sensor 36 is used in place of the GPS 33 in the posture vertical movement sensor 21.

In this example, the coordinate conversion unit 27 converts the X, Υ, Ζ coordinates into ΧΗ, ΥΗ, D coordinates. The X, Υ, and Ζ accelerations output from the three-axis accelerometer 26 are converted into ΧΗ, YH, and D accelerations by the coordinate conversion unit 27. Here, ΧΗ is the front of the vehicle on the horizontal plane, YH is the right side of the vehicle on the horizontal plane, and D is the direction of the center of the earth.

The coordinate conversion matrix update value calculation unit 28 uses the X, Y, and Ζ angular velocity data of the three-axis gyro 25 to calculate a change in the coordinate conversion matrix, and the calculated change is input to the coordinate conversion unit 27. The matrix value is updated every moment.

The 加速度_Η , Υ _Η , and D acceleration output from the coordinate conversion unit 27 are input to the integration unit 29. The integration unit 29 integrates the X _H , Υ _，, and D acceleration to output X _H , YH, and D speeds. I do. Of the XH, YH, and D speeds, the D speed is input to the integration unit 31. The integration unit 31 calculates the vertical displacement H by integrating the D speed.

The XH speed and the speed output from the speed sensor 36 are input to the comparison unit 34, Comparator 3 4 and X _H speed obtained from acceleration, the difference between the speed sensor 3 6 speed of that calculation. Since the integration unit 29 also integrates the error, the error of the XH speed obtained from the acceleration gradually increases, while the error of the speed sensor 36 can be ignored. Since the error does not increase with time, this difference indicates the error in the XH speed obtained from the acceleration.

As described above, the main cause of this error is the error of the coordinate conversion matrix due to the error of the three-axis gyro 25. Therefore, the calculated difference (XH error) is fed back to the coordinate conversion matrix update value calculation unit 28. and, error of chi _Eta rate so zero corrects the coordinate transformation matrix. On the other hand, YH speed because it is the vehicle Ri as error Der, the Y _H error component is also fed back to the coordinate transformation matrix updating value calculating unit 2 8 similarly. Thereby, the error of the coordinate transformation matrix is suppressed.

The pitch angle θ and the roll angle 0 are output from the pitch / roll calculator 35. Since the coordinate conversion matrix in the coordinate conversion unit ₂₇ shows the relationship between the X, Υ, Ζ coordinates and Χ _Η , YH, D coordinates, the pitch angle 6 and the roll angle φ are obtained from this relationship. The speed sensor 36 determines the speed from the number of rotations of the wheels of the vehicle, for example. An optical speedometer may be used as the speed sensor 36, or a GPS may be used to obtain the speed from the GPS.

According to the above-described configuration, an accurate coordinate transformation matrix can be obtained, that is, the vertical acceleration (E) acceleration can be accurately measured, so that an accurate vertical displacement H can be obtained, and Accurate pitch angle θ and roll angle φ can be obtained. In order to minimize error divergence due to integration, as shown by the broken lines in FIGS. 3 and 4, an HPF (high-pass filter) 30 is provided in front of the integration section 31 to cut the DC component. Is also good. In this case, a more accurate vertical displacement Η can be obtained.

Next, the content of the calculation in the calculation device 23 will be described.

Now, it is assumed that the running vehicle 11 is on a road surface 37 as shown in FIGS. The road surface 37 has an ascending slope, and the left and right ruts 37a and 37b have uneven steps with respect to the center part 37c of the lane. Accordingly, the vehicle 11 has a pitch angle θ and a roll angle of 0. Fig. 6 shows the GG section in Fig. 5, and the vehicle Only the bumper 24 of 11 is schematically shown.

Here, the distance between the distance sensors 22 (indicated by points in FIGS. 5 and 6) in the vehicle coordinate system is represented by t. On the other hand, the posture vertical movement sensor 21 (similarly indicated by a dot) is assumed to be located at the center of the vehicle in the width direction similarly to the center distance sensor 22, and the distance m and the height in the front-rear direction of the vehicle and the distance sensor 22. It is assumed that the position is shifted by a distance n in the direction.

The vertical displacement H obtained by the posture vertical movement sensor 21 is expressed as the height of the posture vertical movement sensor 21 with respect to the reference plane 38 as shown in FIG. The reference plane 38 is, for example, a level plane at the measurement starting point of the road. Each of the longitudinal profiles PC, PL, and PR in the center, left rut, and right rut of the road expresses the height of each road surface from the reference plane 38, and FIG. The longitudinal profile PC at the center of the lane measured under the condition is shown.

Each longitudinal profile PC, PL, PR is obtained by subtracting the vertical distance from the attitude vertical movement sensor 21 to the distance measuring road surface of each distance sensor 22 from H, respectively. If the vertical distances at the center of the lane, the left rut and the right rut are F C, FL and F R, respectively,

FC = (C + n-mtan) cos θ cos φ

FL = (then + η- m · tan Θ-· tan φ) cos Θ cos φ

FR = (R + n-m · tan Θ + t · tan φ) cos Θ cos φ

It is represented as Therefore, each longitudinal profile PC, PL, PR can be obtained by the following equation.

PC = H-FC = H- (C + n-m-tan)) cos θ cos φ…)

PL == Η— FL = Η ~ (L + n-m · tan Θ -t · tan φ) cos Θ cos… (2)

PR = H- FR = H- (R + n-m · tan Θ + t · tan) cos Θ cos φ… (3)

In addition, the fluctuation profiles D L and D R of the left rutting part and the right rutting part with respect to the lane center part are as follows.

DL = PC-PL = (L-C-t ■ tan φ) cos θ cos φ

DR = PC-PR = (R-C + t tan φ) cos Θ cos φ

Is represented by FIG. 7 shows a state in which the vehicle 11 travels on the road for which the longitudinal profile is to be measured. In the figure, the broken line indicates the trajectory of the displacement H in the vertical direction measured by the posture vertical movement sensor 21. Is shown. In addition, H. , Hi, z, to Hi schematically show data measured sequentially.

As described above, an accurate road profile can be obtained by mounting the road profile measuring device shown in FIG. 1 on a vehicle and sequentially measuring the vehicle while traveling. Although not shown in FIG. 1, the longitudinal profiles PC, PL, and PR obtained by the arithmetic unit 23 are recorded by, for example, a recording device. The preferred embodiment of the present invention has been described above. However, the basic principle of the present invention is that even when a vehicle travels along a road surface and leans in the front-rear direction (running direction) along a road surface, By measuring the acceleration in the direction, the displacement H in the vertical direction of the vehicle can be obtained, and the longitudinal profile of the road can be measured accurately.

Similarly to the orientation vertical movement sensor 2 1, for example, the distance sensor 2 2, if any on Pampa one ² 4, from m = 0, n = 0, (1) to (3), the

PC = H-C-cos Θ cos </>… hi),

PL = H- (L-t-tan ø) cos Θ cos φ… (2) '

PR = H- (R + t · tan) cos Θ cos φ… (3) '

These are to determine the longitudinal profiles PC, PL and PR from the difference between the vertical distance from the attitude vertical motion sensor 21 to the road surface and the vertical displacement Η of the vehicle. Also, if the pitch angle θ and the lip angle ø are relatively small, and cos6 = l, cos (> ^ 1, tan φ0), these equations (1) 'to (3)'

P C = H-C ■■■ (!) "

P L = H- L ... (2) "

P R = H-R '

That is, the longitudinal profiles PC, PL, and PR are obtained from the difference between the vertical displacement Η and the distances C, L, and R.

The invention's effect

As described above, according to the present invention, the vehicle body moves up and down with respect to the road surface. In addition to measuring the unevenness of the road surface, it is also possible to accurately measure the vertical undulations of the road surface where the vehicle runs along the road surface and on an incline, and thus, it is possible to obtain an accurate road profile profile.

By providing a plurality of road-to-vehicle distance sensors (distance measuring units), it is possible to simultaneously measure the longitudinal profiles of the same reference plane, for example, at the center of the lane of the road, and at the left and right rutting parts. It is also possible to accurately measure profiles in the cross-road direction such as rutting.

Claims

The scope of the claims

1. A device mounted on a vehicle to measure the longitudinal profile of the road on which the vehicle travels,

Distance measuring means for measuring the distance to the road surface,

Vertical acceleration measuring means for measuring vertical acceleration,

Integrating means for calculating the vertical displacement by integrating the acceleration measured by the vertical acceleration measuring means;

Means for obtaining the longitudinal profile by using a difference between the displacement obtained by the integrating means and the distance measured by the distance measuring means;

A road profile measurement device, comprising:

2. A device that is mounted on a vehicle and measures the longitudinal profile of the road on which the vehicle travels,

Distance measuring means for measuring the distance to the road surface,

Vertical acceleration measuring means for measuring vertical acceleration,

Attitude measuring means for measuring the attitude angle of the vehicle,

A vertical distance to the road surface is calculated from the attitude angle measured by the attitude measuring means and the distance measured by the distance measuring means, and a difference between the calculated vertical distance and the displacement obtained by the integrating means is used. Means for obtaining the profile file by using

A road profile measurement device, comprising:

3. The road profile measurement device according to claim 2,

A road profile profile measuring device, wherein a plurality of the distance measuring means are arranged in the width direction of the vehicle.

4. The road profile profile measuring device according to claim 2 or 3,

A road longitudinal profile measuring apparatus, wherein the attitude measuring means uses a three-axis gyro.

5. The road profile measurement device according to claim 2 or 3, The attitude measuring means uses a three-axis gyro, a three-axis accelerometer, and a GPS.The acceleration measured by the three-axis accelerometer is calculated by using the angular velocity measured by the three-axis gyro. A configuration in which coordinates are converted into acceleration in an inertial coordinate system, and an error of the three-axis gyro is corrected to obtain an attitude angle based on a difference between an inertial position obtained from the coordinate-converted acceleration and an inertial position obtained from the GPS. Road profile profile measuring device characterized in that:

6. The road profile profile measuring device according to claim 2 or 3,

The attitude measuring means uses a three-axis gyro, a three-axis accelerometer, and a speed sensor, and calculates the acceleration measured by the three-axis accelerometer in an inertial coordinate system using the angular velocity measured by the three-axis gyro. The coordinate is converted into acceleration, and the error of the three-axis gyro is corrected based on the difference between the inertial speed obtained from the coordinate-converted acceleration and the speed obtained from the speed sensor to obtain the attitude angle. Road profile profile measuring device characterized by the fact that

7. The road profile profile measuring device according to claim 6,

A road profile profile measuring device, wherein the speed sensor is configured to calculate a speed from a wheel rotation speed of the vehicle.

8. The road longitudinal profile measuring device according to claim 6,

The above-mentioned speed sensor is constituted using GPS, The road profile opening file measuring device characterized by the above-mentioned.

9. The road profile measuring apparatus according to claim 1, 2 or 3, wherein the vertical acceleration measuring means comprises a three-axis accelerometer and a three-axis gyro. .