JP2016223793A - Road surface unevenness measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a road surface unevenness measuring device that can increase the accuracy of measuring the unevenness of a road surface.SOLUTION: The road surface unevenness measuring device according to the present invention includes: an unmanned travelling body 1 that can travel on a road surface 5 with wheels 11; a gyro 2 equipped to the unmanned travelling body 1; and operating means 4 obtaining, as the unevenness of the road surface 5, a change in attitude angle of the unmanned travelling body 1 calculated based on an angular velocity detected by the gyro 2 when the unmanned travelling body 1 is travelling. The operating means 4 stores a rest-time gyro output, which is the output of the gyro 2 when the unmanned travelling body 1 is resting, subtracts the rest-time gyro output from the output of the gyro 2 when the unmanned travelling body 1 is travelling, and uses the obtained output for measuring the unevenness of the road surface 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a road surface unevenness measuring apparatus for measuring road surface unevenness.

  As this kind of road surface unevenness measuring apparatus conventionally used, for example, the configuration shown in the following Patent Document 1 can be exemplified. That is, in the conventional configuration, a gyroscope and an accelerometer are mounted on an unmanned traveling body that can travel on a road surface by wheels, and a change in the attitude angle of the unmanned traveling body calculated based on the output of the gyroscope and the accelerometer is used as road surface unevenness. Measuring.

JP 2014-186612 A

  In the conventional road surface unevenness measuring apparatus as described above, when a relatively inexpensive gyro such as a MEMS gyro is used, the offset error of the gyro adversely affects the measurement of the road surface unevenness. The offset error is an angular velocity that is erroneously detected as if the unmanned traveling body is displaced even though the unmanned traveling body is stationary. Also, the accelerometer may be installed with a deviation from the reference axis, and its mounting error angle also adversely affects the measurement of road surface unevenness.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a road surface unevenness measuring apparatus capable of improving the road surface unevenness measurement accuracy.

  The road surface unevenness measuring apparatus according to the present invention is calculated based on an unmanned traveling body that can travel on a road surface by wheels, a gyro mounted on the unmanned traveling body, and an angular velocity detected by the gyro when the unmanned traveling body travels. Calculating means for obtaining a change in posture angle of the unmanned traveling body as unevenness of the road surface, and the computing means stores a gyro output at rest, which is an output of the gyro when the unmanned traveling body is stationary, and unmanned The stationary gyro output is subtracted from the gyro output when the traveling body is traveling, and is used to measure the unevenness of the road surface.

The road surface unevenness measuring apparatus according to the present invention is detected by an unmanned traveling body that can travel on a road surface by wheels, an accelerometer and a gyro mounted on the unmanned traveling body, and an accelerometer when the unmanned traveling body travels. And calculating means for obtaining a change in the attitude angle of the unmanned traveling body as unevenness of the road surface calculated based on the measured acceleration, the computing means being an acceleration measured by the acceleration when the unmanned traveling body is placed in the first stationary state. Is ACC ₁ , acceleration measured by acceleration when the unmanned traveling body is placed in the second stationary state rotated by 180 ° from the first stationary state is ACC _2, and gravitational acceleration is g , {Sin ⁻¹ (ACC ₁ / g) + sin ⁻¹ (ACC ₂ / g)} / 2 is stored, and the accelerometer mounting error angle θ _e is stored, and the unmanned vehicle is traveling acceleration Correcting the posture angle obtained by using the acceleration and gyro output meter with mounting error angle theta _e.

According to the road surface unevenness measuring apparatus of the present invention, the calculation means subtracts the stationary gyro output from the gyro output when the unmanned traveling body is traveling, and uses it to measure road surface unevenness, or the unmanned traveling body since corrects the posture angle obtained by using the acceleration of the accelerometer during that traveling by mounting error angle theta _e, it can improve the measurement accuracy of the road surface irregularities.

It is a block diagram which shows the road surface unevenness | corrugation measuring apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the detection angle calculated | required based on the output of the accelerometer when the unmanned traveling body of FIG. 1 is stationary. It is explanatory drawing which shows the 1st deviation | shift angle between the horizontal surface and the detection axis of an accelerometer when the unmanned traveling body of FIG. It is explanatory drawing which shows the 2nd deviation angle between the horizontal surface when the unmanned traveling body of FIG. 1 is made into a 2nd stationary state, and the detection axis of an accelerometer.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing a road surface unevenness measuring apparatus according to Embodiment 1 of the present invention. In the figure, the road surface unevenness measuring apparatus includes an unmanned traveling body 1, a gyro 2, an accelerometer 3 and a calculation means 4.

  The unmanned traveling body 1 includes a traveling body main body 10, a plurality of wheels 11, and a handle 12. The traveling body main body 10 is a housing on which the gyro 2 and the accelerometer 3 are mounted. The wheels 11 are attached to the lower part of the traveling body main body 10. The handle 12 protrudes upward from the rear part of the traveling body main body 10. The unmanned traveling body 1 is configured such that the operator can travel on the road surface 5 with the wheels 11 without the operator getting on the vehicle by pressing the handle 12. That is, the unmanned traveling body 1 is a traveling body on which an operator does not get on. The rotating shaft of the wheel 11 is rotatably supported by a shaft support body 10 a provided at the lower part of the traveling body main body 10. The shaft support body 10a is fixed to the traveling body main body 10, and the unmanned traveling body 1 is configured to be able to travel only in a straight line.

  The gyro 2 and the accelerometer 3 are mounted on the unmanned traveling body 1. The gyro 2 detects angular velocities about three axes orthogonal to each other, and the accelerometer 3 detects acceleration in a direction along the three axes.

  The calculation means 4 is a computer connected to the gyro 2 and the accelerometer 3 by wire or wirelessly. When the unmanned traveling body 1 travels, the angular velocity detected by the gyro 2 and when the unmanned traveling body 1 travels. A change in posture angle (pitch angle and roll angle) of the unmanned traveling body 1 calculated based on the acceleration detected by the accelerometer 3 is obtained as unevenness of the road surface 5. Although FIG. 1 shows that the calculation means 4 is provided at a position away from the unmanned traveling body 1, the calculation means 4 may be mounted on the unmanned traveling body 1.

  The calculation means 4 has an offset cancel function and a boresight correction processing function. The offset cancel function is intended to cancel the angular velocity erroneously detected by the gyro 2 as if the unmanned traveling body 1 is displaced even though the unmanned traveling body 1 is stationary. That is, the calculation means 4 stores the stationary gyro output, which is the output of the gyro 2 when the unmanned traveling body 1 is stationary, and is stationary from the output of the gyro 2 when the unmanned traveling body 1 is traveling. The gyro output is subtracted and used to measure road surface irregularities. When a storage command is input from the outside, the calculation means 4 determines that the unmanned traveling body 1 is stationary, and stores the output of the gyro 2 at that time as a stationary gyro output.

The boresight correction processing function is intended to correct the mounting displacement of the accelerometer 3 with respect to the reference axis. The calculation means 4 stores the mounting error angle θ _e of the accelerometer 3 represented by {sin ⁻¹ (ACC ₁ / g) + sin ⁻¹ (ACC ₂ / g)} / 2, and the unmanned traveling body 1 the attitude angle is determined using accelerometer 3 of acceleration when that traveling is corrected by mounting error angle theta _e. ACC ₁ is the acceleration measured by the accelerometer 3 when the unmanned vehicle 1 is placed in the first stationary state, and ACC ₂ is the _second stationary state in which the azimuth angle is rotated 180 ° from the first stationary state. Is an acceleration measured by the accelerometer 3 when the unmanned traveling body 1 is placed on g, and g is a gravitational acceleration. The calculation means 4 stores the accelerations ACC ₁ and ₂ of the accelerometer 3 when a storage command is input from the outside, and stores the mounting error angle θ _e calculated from the accelerations ACC ₁ and ₂ .

Next, the boresight correction processing function will be described in more detail with reference to FIGS. FIG. 2 is an explanatory diagram showing the detected angle θ obtained based on the output of the accelerometer 3 when the unmanned traveling body 1 of FIG. 1 is stationary. As shown in FIG. 2, when the unmanned traveling body 1 is stationary, the gravitational acceleration g acts on the accelerometer 3. At this time, when the deviation angle between the detection axis of the accelerometer 3 and the horizontal direction is θ, the acceleration ACC detected by the accelerometer 3 can be expressed as the following Expression 1.
ACC = g × sin θ (1)
By changing Equation 1, the deviation angle θ can be expressed as Equation 2 below.
θ = sin ⁻¹ (ACC / g) Equation 2

FIG. 3 is an explanatory diagram showing a first deviation angle θ ₁ between the horizontal plane and the detection axis of the accelerometer 3 when the unmanned traveling body 1 of FIG. 1 is in a first stationary state, and FIG. It is explanatory drawing which shows 2nd shift | offset | difference angle (theta) ₂ between the horizontal surface when the unmanned traveling body 1 is made into a 2nd stationary state, and the detection axis of the accelerometer 3. FIG.

As shown in FIGS. 3 and 4, the road surface 5 on which the unmanned traveling body 1 is placed is not always parallel to the horizontal plane. That is, the deviation angle theta obtained on the basis of the output of the acceleration ACC detected by the acceleration meter 3, not only the mounting error angle theta _e, are also included deviation angle theta _t between the road surface 5 and the horizontal plane .

As described below, the mounting error angle θ _e can be obtained from the detected accelerations ACC ₁ and ACC _{2 of the} accelerometer 3 when the unmanned traveling body 1 is placed in the first and second stationary states shown in FIGS. In the situation as shown in FIG. 3, the first deviation angle θ ₁ obtained based on the output of the detected acceleration ACC ₁ of the accelerometer 3 is the deviation angle θ _t between the road surface 5 and the horizontal plane as the mounting error angle θ _e. The angle is obtained by adding
θ ₁ = sin ⁻¹ (ACC ₁ / g) = θ _e + θ _t Equation 3

On the other hand, as shown in FIG. 4, the second deviation angle θ ₂ obtained based on the output of the detected acceleration ACC ₂ of the accelerometer 3 when the azimuth direction of the unmanned traveling body 1 is rotated 180 ° from the first stationary state is an angle obtained by subtracting the deviation angle theta _t between the mounting error angle theta _e between the road surface 5 and the horizontal plane.
θ ₂ = sin ⁻¹ (ACC ₂ / g) = θ _e −θ _t Expression 4

The addition formula of the first deviation angle θ ₁ and the second deviation angle θ ₂ shown in the expressions 3 and 4 is expressed as the following expression 5.
θ ₁ + θ ₂ = sin ⁻¹ (ACC ₁ / g) + sin ⁻¹ (ACC ₂ / g) = 2θ _e Formula 5
By arranging this equation 5 for the mounting error angle θ _e , {sin ⁻¹ (ACC ₁ / g) + sin ⁻¹ (ACC ₂ / g)} / 2 representing the mounting error angle θ _e is obtained. As described above, the calculation means 4 stores the mounting error angle θ _e of the accelerometer 3 represented by {sin ⁻¹ (ACC ₁ / g) + sin ⁻¹ (ACC ₂ / g)} / 2. The attitude angle obtained by using the acceleration of the accelerometer 3 when the unmanned traveling body 1 is traveling is corrected by the mounting error angle θ _e .

  In such a road surface unevenness measuring apparatus, the calculation means 4 subtracts the stationary gyro output from the output of the gyro 2 when the unmanned traveling body 1 is traveling and uses it to measure the unevenness of the road surface. The error can be canceled and the measurement accuracy of the road surface unevenness can be improved.

Further, since the calculation means 4 corrects the attitude angle obtained by using the acceleration of the accelerometer 3 when the unmanned traveling body 1 is traveling with the mounting error angle θ _e , the mounting error angle θ _e can be canceled out. This can improve the measurement accuracy of road surface unevenness.

  In the embodiment, the calculation means 4 has been described as having both the offset cancellation function and the boresight correction function. However, the calculation means 4 has only one of the offset cancellation function and the boresight correction function. May be performed.

DESCRIPTION OF SYMBOLS 1 Unmanned traveling body 11 Wheel 2 Gyro 3 Accelerometer 4 Calculation means 5 Road surface

Claims (3)

An unmanned vehicle that can run on the road surface with wheels,
A gyro mounted on the unmanned vehicle,
Calculating means for obtaining a change in posture angle of the unmanned traveling body as unevenness on the road surface, which is calculated based on an angular velocity detected by the gyro when the unmanned traveling body travels,
The calculating means stores a stationary gyro output, which is an output of the gyro when the unmanned traveling body is stationary, and calculates the stationary state from the output of the gyro when the unmanned traveling body is traveling. A road surface unevenness measuring apparatus characterized by subtracting the gyro output and measuring the unevenness of the road surface. An accelerometer mounted on the unmanned vehicle;
The computing means sets the acceleration measured by the acceleration when the unmanned traveling body is placed in the first stationary state as ACC _1, and changes the azimuth angle from the first stationary state to the second stationary state by 180 °. Accel ₂ measured by the acceleration when an unmanned traveling body is placed is ACC ₂ and gravitational acceleration is g, {sin ⁻¹ (ACC ₁ / g) + sin ⁻¹ (ACC ₂ / g)} / The accelerometer mounting error angle θ _e represented by 2 is stored, and the attitude angle obtained using the acceleration of the accelerometer and the output of the gyroscope when the unmanned traveling body is traveling is mounted. road irregularities measuring apparatus according to claim 1, wherein the correcting the error angle theta _e. An unmanned vehicle that can run on the road surface with wheels,
An accelerometer and a gyro mounted on the unmanned vehicle,
Calculating means for obtaining a change in posture angle of the unmanned traveling body as unevenness of a road surface calculated based on an acceleration detected by the accelerometer when the unmanned traveling body travels,
The computing means sets the acceleration measured by the acceleration when the unmanned traveling body is placed in the first stationary state as ACC _1, and changes the azimuth angle from the first stationary state to the second stationary state by 180 °. Accel ₂ measured by the acceleration when an unmanned traveling body is placed is ACC ₂ and gravitational acceleration is g, {sin ⁻¹ (ACC ₁ / g) + sin ⁻¹ (ACC ₂ / g)} / The accelerometer mounting error angle θ _e represented by 2 is stored, and the attitude angle obtained using the acceleration of the accelerometer and the output of the gyroscope when the unmanned traveling body is traveling is mounted. road unevenness measuring device and correcting the error angle theta _e.

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