JP2000275011A - Measuring apparatus and measurement method for mobile body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately obtain a movement amount or a velocity of a mobile body. SOLUTION: A laser light is irradiated to a road face 20 from a laser light source 11, and a pattern of laser speckles reflecting from the road face 20 is detected by a linear image sensor 12. The pattern of laser speckles is sent to an operation device 13. The device 13 calculates a mutual correlation function of patterns of the laser speckles at different time points, whereby a movement amount or velocity of a mobile body is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is mounted on a mobile object,
The present invention relates to a moving object measuring device and a measuring method for measuring a moving amount or a speed of a moving object.

[0002]

2. Description of the Related Art Conventionally, as a measuring device for measuring a moving amount or a speed of a moving body, there is known a measuring apparatus for detecting a rotation speed of a rotating body built in the moving body. However, when the number of rotations is converted into the movement amount or the position, an error due to friction with the floor surface occurs, and the structure is complicated. There is also a method of embedding a scale or an electric wire in a floor or the like as an embedded guide, but in that case, maintenance of a traveling environment is required, and a traveling place is limited.

[0003]

As described above, the conventional moving object measuring apparatus detects the number of rotations of a mechanical member, and has a complicated structure and an error due to a contact state.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a moving object measuring apparatus and a moving object measuring device capable of directly and easily detecting the moving amount or position of the moving object without contact. It is intended to provide a measuring method.

[0005]

According to the present invention, there is provided a laser light source on a road or floor mounted on a moving body, a linear image sensor for detecting a laser speckle pattern reflected from the road, and a linear image sensor. A calculating device for calculating the moving amount or the position of the moving object based on the laser speckle pattern at different times, and a measuring device for the moving object, and a laser light source mounted on the moving object, on a road surface. Irradiating a laser beam;
A step of detecting a laser speckle pattern reflected from a road surface with a linear image sensor, and a step of calculating an amount of movement or a position of the moving object with an arithmetic device based on the laser speckle pattern at different times, This is a method for measuring a moving object that moves.

According to the present invention, a road surface or a floor is irradiated with laser light from a laser light source fixed to a moving body,
The laser speckle pattern reflected from the road surface is detected by a linear image sensor similarly fixed to the moving body. The calculating unit obtains the moving amount or the speed of the moving object calculated as the cross-correlation peak position of the output from the linear image sensor.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a moving object measuring apparatus and a measuring method according to the present invention. As shown in FIG.
And a linear image sensor 12 for detecting a laser speckle pattern included in the reflected light reflected from the road surface 20. Among them, the laser light source 11 and the linear image sensor 1 are mounted on a moving body 10 such as a vehicle or a robot. Further, the linear image sensor 12 is connected to an arithmetic unit 13 for calculating the moving amount and speed of the moving body 10 based on the laser speckle pattern from the linear image sensor 12.

Next, the operation of the present embodiment having the above configuration will be described. First, the road surface 20 is irradiated with laser light from the laser light source 11. The speckled laser speckles appear in the reflected light due to the interference of the light reflected from each point on the road or floor. Next, the pattern of the laser speckle reflected from the road surface 20 is detected by the linear image sensor 12.

[0009] The laser speckle pattern from the linear image sensor 12 is then sent to an arithmetic unit 13, which calculates the moving amount and speed of the moving body 10 as follows.

The output signal of the image sensor is calculated by the arithmetic unit 13
It is led to. First, an output signal at a certain time is stored in a memory and repeatedly read as a reference signal. The cross-correlation between this and the current signal is calculated, and the amount of speckle movement in the axial direction of the image sensor is detected as the peak position. However, since the location of the road surface or floor where the speckles are formed by irradiation with the laser beam is switched, the height of the correlation peak decreases with movement, and the peak position cannot be detected. To prevent this, if the peak falls below a predetermined threshold, the contents of the reference signal memory are updated with the current output signal, and the subsequent peak positions are added to the speckle movement amount before the update. Go. By repeating this procedure, it is possible to obtain any amount of movement. The following relationship exists between the thus detected speckle Ax and the displacement ax of the moving body.

[0011]

(Equation 1) Where L is the distance from the road surface to the sensor, LS is the radius of curvature of the laser beam wavefront, and θS is the angle of incidence. In the case of a parallel beam, the first term in each parenthesis is 0, and the speckle movement and displacement amount are equal.

As described above, according to the present embodiment, it is possible to easily and easily determine the moving amount and speed of the moving body 10.

Next, another embodiment will be described with reference to FIG. FIG. 2 is a plan view showing an embodiment of two-dimensional movement and position measurement of a moving object.

As shown in FIG. 2, a pair of linear image sensors 12, 12 are provided on a moving body 10, and each of the linear image sensors 12, 12 has an arithmetic unit 13, 1,
3 are connected.

In FIG. 2, since the pair of linear image sensors 12, 12 are orthogonal to each other, the amount of movement and the speed of the moving body 10 in two directions on a plane can be obtained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A moving table 21 driven by a ball screw (not shown) shown in FIG.
FIG. 4 shows the output of the displacement sensor when it is moved by mm.
The movement error is about 2mm. The motor with encoder 24 is controlled by a controller 25, and the controller 25 and the arithmetic unit 13 are controlled by a computer 26.

FIG. 5A shows an arrangement of a preliminary experiment for measuring two-dimensional movement. An angle Φ was given between the linear image sensor 12 and the moving direction. Linear image sensor 1
FIG. 5B shows the amount of movement detected when a movement of 200 mm was given in the direction of 2. The movement amount detected as expected is a movement component co in the direction of the linear image sensor.
It is proportional to sΦ. This proves that the two-dimensional movement amount can be obtained with the arrangement shown in FIG.

[0018]

As described above, according to the present invention, the moving amount or the position of the moving object can be easily and accurately measured in a non-contact manner by using the laser speckle pattern generated by the reflection of the laser light on the road surface or the floor surface. You can ask.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of a moving object measuring apparatus and a measuring method thereof according to the present invention.

FIG. 2 is a plan view showing another embodiment of the moving object measuring apparatus and the measuring method according to the present invention.

FIG. 3 is a diagram showing an example of an embodiment of the present invention.

FIG. 4 is a diagram showing a measurement result of a movement amount in a direction of a linear image sensor.

FIG. 5 is a diagram showing a measurement result of a moving amount inclined with respect to the linear image sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Moving body 11 Laser light source 12 Linear image sensor 13 Arithmetic unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA07 AA09 BB15 CC11 FF32 FF56 GG04 JJ02 JJ05 JJ07 JJ25 MM07 PP02 PP22 PP25 QQ23 QQ29 QQ41 UU02 UU05 5H301 AA02 AA09 BB05 CC03 GG01 GG11 GG11 GG11 GG11 GG11 GG11 GG11 GG11

Claims (5)

[Claims] 1. A laser light source mounted on a moving body and irradiating a laser beam to a road surface, a linear image sensor for detecting a laser speckle pattern reflected from the road surface, and a floor linear image sensor and connected at different times. A moving device and a measuring method for measuring the moving device, comprising: a calculation device for calculating a moving amount or a position of the moving object based on a speckle pattern. 2. The moving object measuring apparatus according to claim 1, wherein the calculating device calculates a cross-correlation function of the laser speckle pattern at different times to obtain a moving amount or a position of the moving object. 3. The moving object measuring apparatus according to claim 1, wherein a pair of linear image sensors is provided on the moving object, and the respective linear image sensors are arranged orthogonal to each other. 4. A step of irradiating a laser beam from a laser light source mounted on a moving body to a road surface, a step of detecting a laser speckle pattern reflected from the road surface by a linear image sensor, Obtaining a moving amount or a position of the moving object based on the calculation device based on the calculation method. 5. The moving amount or position of the moving body is calculated by calculating a cross-correlation function of a laser speckle pattern at different times when calculating the moving amount or position of the moving body in the arithmetic unit. 4. The method for measuring a moving object according to 4.