JPH04225403A - Distance measuring device for mobile object - Google Patents

Abstract

PURPOSE:To quickly and correctly track a light wave range finder turned to a reflector regardless of the movement of a cart by measuring the distance between the cart and the reflector set at a subject position with the light wave range finder provided to the cart. CONSTITUTION:The beam transmitting/receiving devices 8a and 8b are provided at both sides of a light wave range meter 7 in such an attitude where the beams of both devices 8a and 8b are in parallel with the beam of the finder 7. Thus these devices 8a and 8b originate the beams and receive the reflected beams respectively. In this case, the space between the devices 8a and 8b is set smaller than the width of a reflector 6. Then both devices 8a and 8b are arranged so that their directions can be changed in a single body to the finder 7. Thus the directions of both devices 8a and 8b are continuously changed until they can receive the beams, that is, each of both devices 8a and 8b is turned in the beam receivable direction if it is unable to receive the beam respectively.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention detects the position of a work vehicle, which is necessary when a work vehicle such as a transport vehicle for transporting materials at a construction site runs autonomously, from the work vehicle to two reference positions. It is a device used when conducting measurements based on distance, etc. Specifically, it is a device that emits a beam of light, radio waves, sound waves, etc. toward an indicator set at a target position such as a reference position, and
A distance meter such as a light wave distance meter that receives the reflected beam from the index tool and measures the distance to the index tool is installed on a moving object such as a work vehicle, and the distance meter is oriented in a direction facing the index tool. The present invention relates to a distance measuring device for a moving object, which is provided with a tracking means for correcting the direction of a beam emitting/receiving section.

0002

2. Description of the Related Art In this type of distance measuring device for a moving object, the positional relationship between the indicator and the distance meter changes as the moving object moves. If such a change in positional relationship causes the beam emitting/receiving section of the range finder to deviate from the direction toward the indicator, it becomes impossible to measure the distance as expected. Therefore, some kind of means is required to perform distance measurement regardless of the movement of the moving object, and one such means is to ensure that the direction of the beam emitting/receiving section is directed toward the index tool regardless of the movement of the moving object. Change the direction of the beam emitting/receiving unit so that the
There is tracking to fix.

[0003] When such a tracking means is used, for example, the beam emitting/receiving section is rotated around the vertical axis to scan the beam, and each time the beam emitting/receiving section faces the indicator and the reflected beam returns. Compared to scanning means that measure distances, this method has the advantage of being able to measure distances with high precision. In other words, when using the scanning means, distance measurement is performed once every rotation of the beam emitting/receiving section, but the distance measuring time during which the beam emitting/receiving section faces the indicator and receives the reflected beam is: Beam emitting/receiving section is 1
This is a very small amount of time during a rotation, and most of the time for one rotation is a waiting time when distance measurement is not being performed. When a long-time light wave distance meter such as front and back is provided, the beam emitting/receiving section needs to rotate until the sum of the distance measuring time for each rotation becomes 4 to 5 seconds. Therefore, actual distance measurement takes several times or several tens of times longer than the distance measurement time, and during that long period of time, the moving object moves considerably, and the difference between when distance measurement starts and when distance measurement is completed. This may result in a non-negligible large difference in the distance from the moving object to the index tool, and a situation where distance measurement may not be possible may occur. Moreover, if there is a reflective object around the moving body in addition to the indexing tool, even if it is not between the moving object and the indexing tool, the reflected beam from that reflective object may also be received as a reflected beam from the indexing tool, causing errors. There is a risk that distance measurement may be performed. This means that
In particular, it is common for materials to be placed on the floor, which serves as the road surface for work vehicles to travel on, and some of these materials can reflect the beam, such as metal materials such as aluminum sash, and glass. This is inconvenient as a distance measuring device for work vehicles at construction sites. On the other hand, when the tracking means is used, the beam emitting/receiving section can be continuously directed toward the index tool, and even if there is another reflective object between the beam emitting/receiving section and the index tool, it will not be affected by it. Never.

Conventionally, as a tracking means for performing such tracking, a television camera is installed in a state where the direction can be changed integrally with the beam emitting/receiving section and facing the same direction as the beam emitting/receiving section. The direction of the beam emitting/receiving unit and the relationship between the indicator and the indicator are determined from the image position of the indicator within the imaging screen, and the beam emitting/receiving unit is moved so that the image of the indicator is at a predetermined position such as the center of the image screen. There is a known method for changing the direction and correcting the direction to face the index tool.

[0005]

However, the above-mentioned conventional technology has the disadvantage that it takes time to process the image and that the mobile device for moving the moving object is limited.

An object of the present invention is to perform accurate and high-speed tracking.

[0007]

[Means for Solving the Problems] A first feature of the distance measuring device for a moving object according to the present invention is that the tracking means includes the indicator tool located on one side of the direction change direction from the beam emitting/receiving section. At a location separated by a first set distance smaller than the width of
One of the two beam transmitting/receiving devices for detecting correction directions in which the beam transmitting direction and the receiving direction are the same is arranged in a posture such that its transmitting beam is parallel to the transmitting beam of the beam transmitting/receiving section. , the other beam transmitter/receiver is placed at a location separated from the one beam transmitter/receiver on the other side in the direction change direction by a second set distance that is equal to or greater than the first set distance and smaller than the width of the index tool. , a driving device for integrally changing the direction of the beam emitting/receiving unit and the beam emitting/receiving device, the beam emitting/receiving unit being arranged in a posture such that its emitting beam is parallel to the emitting beam of one beam emitting/receiving device; and the beam emitting/receiving device. Based on the detection results of these sensors, two sensors are installed on the other side when one sensor detects no reception, and two on one side when the other sensor detects no reception. A direction correction control means is provided for operating the drive device to change the direction until the sensor detects the presence.

[0008] A second characteristic configuration of the distance measuring device for a moving body according to the present invention is that in the first characteristic configuration, the other beam transmitter/receiver is moved from the beam transmitter/receiver to the other side in the direction change direction. They are located at points located one set distance apart.

A third characteristic configuration of the ranging device for a moving body according to the present invention is that in the second characteristic configuration, each of the two beam transmitting and receiving units is a beam transmitting and receiving unit of a distance meter different from the above. The point is that it is made up of.

0010

[Operation] According to the first characteristic configuration, the interval between the direction change directions of the two beam transmitters and receivers for detecting correction direction is smaller than the width of the index tool, and the beam transmitter and receiver for distance measurement is located at a first set distance from one beam emitter/receiver in the direction of change of orientation to the other beam emitter/receiver, and
Since the beams from the beam emitting/receiving section and the beam emitting/receiving section are parallel to each other, if the two beam emitting/receiving devices both receive the reflected beam from the indexing device, the beam emitting/receiving section receives the reflected beam from the indexing device. This means that the beam is being received. If one of the beam emitters/receivers does not receive the beam, it means that the two beam emitters/receivers and the beam emitter/receiver section have all deviated from the proper direction in which they are receiving the beam, and the other beam is not receiving the beam. Failure to receive a beam is a deviation from the proper orientation to the other side, which is detected by the sensor. Based on the detection result of this sensor, the driving device operates the orientation correction control means to correct the orientation to an appropriate orientation. As described above, the direction is corrected based on the presence or absence of beam reception by the beam emitter/receiver for detecting the corrected direction, that is, the direction is tracked, which takes time to capture images that would otherwise be required if a television camera was used for tracking. No processing required.

According to the second characteristic configuration, since the distances from the distance measuring beam emitting/receiving unit to the two correcting direction detecting beam emitting/receiving units are equal, if the direction is shifted to one side and the other side The characteristics of direction correction can be made the same as when the direction is shifted.

According to the third characteristic configuration, even if the direction of the moving body deviates so much that the distance measuring beam emitting/receiving unit cannot receive the beam due to a sudden change in direction, the beam emitting/receiving unit for correcting direction detection can There is a possibility that one is maintaining reception, so
Discontinuities in distance measurement can be reduced.

[0013]

[Effects of the Invention] Therefore, according to the present invention, regardless of the movement of the moving object, the beam emitting/receiving section can be directed to the index tool for tracking.
To perform accurate and high-speed measurement without limiting the movement speed of a moving object, and to accurately measure the desired distance even at a construction site where there are materials that may cause a decrease in distance measurement accuracy. be able to. In particular, according to the second aspect of the present invention, it is possible to accurately and accurately track a deviation in orientation in any direction, thereby further improving distance measurement accuracy. Furthermore, according to the third aspect of the present invention, the distance measurement time can be lengthened to further improve the distance measurement accuracy.

[0014]

[Example] Examples of the present invention are shown below.

[0015] Autonomous transport vehicle 1 which is an example of a mobile object
As shown in Figs. 1 and 3, the XY
A position detecting means 2 for detecting the position P of the transport vehicle 1 on the coordinates, a direction detecting means 3 for detecting the moving direction of the transport vehicle 1, and a target based on the detection results of the position detecting means 2 and the direction detecting means 3. The vehicle is equipped with an automatic travel control means 5 for autonomous travel which operates the travel means 4 so as to arrive at the position P0.

As shown in FIGS. 1 to 3, the position detection means 2 sets the origin of the XY coordinates to a first target position P1 of the position detection reference, and sets a set distance L0 in the X-axis direction from the origin.
The second target position P2 of the position detection reference is the position separated by
A first distance measuring device A1 that measures the distance LP1 from the position P of the transport vehicle 1 to the first target position P1, and a first distance measuring device A1 that measures the distance LP1 from the position P of the transport vehicle 1 to the second target position A second distance measuring device A2 measures the distance LP2 to P2, and the coordinate values (X, Y ).

[0017] The first and second distance measuring devices A1 and A2
As shown in FIGS. 1 and 2, respectively, the target position P1
, P2, and receives the reflected infrared beam from the indicator, and calculates the distance to the indicator based on the time from transmission to reception. A light wave distance meter 7 that measures as LP1 and LP2, and a tracking means 8 that corrects the direction of the entire light wave distance meter 7 to face the index tool 6 so as to transmit an infrared beam to the target index tool 6. Become.

The index tool 6 is a reflecting mirror using a corner cube that reflects an incident (received) infrared beam in a direction parallel to the direction of incidence of the infrared beam.

As shown in FIG. 2, the means for attaching the light wave distance meter 7 is to support two turntables 9 on the transport vehicle 1 so as to be rotatable around the same vertical axis y, and to attach the turntables 9 to the vehicle 1. The support frame 10 is supported swingably around the horizontal axis x, and the light wave distance meter 7 corresponding to each of the support frames 10 is attached to the support frame 10. In other words, the direction of the optical distance meter 7 is changed by the rotation of the turntable 9 and the swinging of the support frame 10.

The tracking means 8 is capable of transmitting and receiving beams for distance measurement of the light wave range meter 7, regardless of the relative displacement in the horizontal direction between the light wave range meter 7 and the reflecting mirror 6 as the transport vehicle 1 moves. Part 7
This is a means for directing a to the reflecting mirror 6 and performing distance measurement. As shown in FIG. 4, there are two
a stepping motor 8A (an example of a driving device) that rotates the turntable 9 to change the direction of the optical distance meter 7, and beam transmitters and receivers 8a and 8b for detecting the corrected direction, respectively. It consists of sensors Sa and Sb that detect the presence or absence of reception, and direction correction control means 8B.

Beam transmitter/receiver 8a for detecting the correction direction
, 8b, as shown in FIGS. 6 to 8, the emitted beams are emitted from the beam emitting/receiving unit 7a for distance measurement at a first set distance L1 on both sides of the direction change direction. The beam emitting/receiving section 7a for distance measurement is arranged in a posture parallel to the emitted beam of the beam emitting/receiving section 7a, and is attached to the turntable 9 so as to be changed in direction integrally with the beam emitting/receiving section 7a for distance measurement. The first set distance L1 and the width L of the reflecting mirror 6 are set to have a relationship of 2L1 <L. In other words, 2
Interval between two beam transmitters and receivers 8a and 8b (second set distance)
L2 is 2L1.

As shown in FIG. 6, the direction correction control means 8B is means for operating the stepping motor 8A so that the two sensors Sa and Sb both detect presence. When one sensor Sa detects no detection as shown in FIG. 7, the other sensor Sa and Sb move to the other side as shown in FIG. 8 until both sensors Sa and Sb detect presence. When no detection is detected, the stepping motor 8A is actuated to rotate the turntable 9 to one side, respectively, until both sensors Sa and Sb detect presence, as shown in FIG.

As shown in FIG. 1, the calculation means B calculates the coordinate values (X,
Y).

[0024]

[Equation 1] cosλ=(L02+LP12-LP22)/2・L0
・LP1 X=LP1 ・cosλ Y=LP1 ・sinλ

The direction detecting means 3 is shown in FIGS. 1, 2, and 5.
As shown in FIG. 2, a rotary encoder 3A is provided to detect the inclination angle α of the direction of the beam emitting/receiving unit 7a with respect to the moving direction of the carrier vehicle 1, specifically, to detect the rotation angle of the turntable 9 with respect to the carrier vehicle 1. , the moving direction of the transport vehicle 1 is determined from the inclination angle α detected by the rotary encoder 3A, the measured distances LP1, LP2 of the first and second distance measuring devices A1, A2, and the set distance L0. A calculation means 3B is provided to calculate the inclination angle θ with respect to the Y-axis direction. Then, θ is determined from the equations shown in Equations 2 and 3.

[0026]

[Formula 2] cosλ=(L02+LP12-LP22)/2・L0
・LP1
From λ=cos-1 {(L02+LP12-LP22)/2
・L0 ・LP1 }

[0027]

[Equation 3] λ = (π/2) - (α + θ) 11 and 12 are a stepping motor that swings the support frame 10 around the horizontal axis X to change the direction of the distance meter 7 up and down, and detects the direction. It is an encoder.

[Another Example] Another example of the present invention will be shown below.

[1] In the above embodiment, the distance meter 7 measures the distance to the reflector 6 from the time required from transmitting the beam to receiving the beam. The distance may be measured based on the phase difference between the beam and the received beam.

[2] In the above embodiment, the beams of the beam emitting/receiving section 7a and the beam emitting/receiving devices 8a, 8b are as follows:
Although infrared light, which is one type of electromagnetic waves, is shown, the beam may be electromagnetic waves other than infrared light, sound waves, or ultrasonic waves.

[3] In the above embodiment, as shown in FIG. 9, by providing the third sensor Sc for detecting the presence or absence of reception by the beam emitting/receiving section 7a for distance measurement, the reflecting mirror 6
When the width L and the first set distance L1 are L<2L1, the beam emitting/receiving section 7a for distance measurement is used as one of the beam emitting/receiving devices 8a, 8b for detecting the correction direction,
Detect the correction direction. Note that the figure shows a mode in which it is used as the beam emitting/receiving section 8b on the other side.

[4] In the above embodiment, as shown in FIG. 10, the beam emitting/receiving section 7a for ranging is used also as one of the beam emitting/receiving devices 8a, 8b for detecting correction direction. In this case, the second set distance L2 is
The set distance is L1.

[5] In the above embodiment, a transport vehicle is shown as the moving body 1, but the moving body 1 may also include various working vehicles such as a concrete floor finishing machine.

[6] In the above embodiment, the beam transmitters/receivers 8a, 8b for detecting the correction direction are constituted by optical distance meters.

[7] Note that although reference numerals are written in the claims for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by these entries.

[Brief explanation of the drawing]

[Figure 1] Plan view

[Figure 2] Schematic configuration diagram

[Figure 3] Block diagram

[Figure 4] Block diagram

[Figure 5] Block diagram

[Figure 6] Schematic plan view

[Figure 7] Schematic plan view

[Figure 8] Schematic plan view

[Fig. 9] Schematic plan view showing another embodiment

FIG. 10 is a schematic plan view showing another embodiment.

[Explanation of symbols]

6 Indicator 1 Moving object 7 Distance meter 8 Tracking means 7a Beam emitting/receiving unit 8a, 8 for distance measurement
b Beam transmitter/receiver Sa, Sb for detecting correction direction
Sensor 8A drive device

Claims (3)

[Claims] [Claim 1] A beam is emitted toward an index tool (6) provided at a target position, and a reflected beam from the index tool (6) is received to measure the distance to the index tool (6). A distance meter (7) is attached to the moving body (1), and the indicator tool (
6) A distance measuring device for a moving body, comprising a tracking means (8) for correcting the direction of a beam emitting/receiving unit (7a) for distance measurement of the range finder (7), the tracking means (8) is a location separated from the beam emitting/receiving section (7a) by a first set distance (L1) smaller than the width (L) of the index tool (6) on one side in the direction change direction. Then, one (8a) of the two beam transmitting/receiving devices (8a), (8b) for detecting correction directions in which the beam transmitting direction and the receiving direction are the same is connected to the beam transmitting/receiving section. (7a) in a posture parallel to the transmitting beam, and the indexing device (6 ) width (L)
The other beam transmitter/receiver (8b) is placed at a location separated by a second set distance (L2) that is smaller than a driving device (8A) for integrally changing the direction of the beam emitting/receiving section (7a) and the beam emitting/receiving devices (8a), (8b);
) sensors (Sa) and (Sb) that detect the presence or absence of reception of each
), and based on the detection results of these sensors (Sa) and (Sb), when one sensor (Sa) does not detect, the other side, and when the other sensor (Sb) does not detect, one side A distance measuring device for a moving body, which is provided with a direction correction control means (8B) that operates a drive device (8A) to change the direction until two sensors (Sa) and (Sb) detect the presence of the object. 2. The other beam transmitter/receiver (8b) is provided at a location separated from the beam transmitter/receiver (7a) by a first set distance (L1) on the other side in the direction change direction. 1. The distance measuring device for a moving object according to 1. 3. The two beam transmitters/receivers (8a),
3. The distance measuring device for a moving body according to claim 2, wherein each of (8b) is constituted by a beam emitting/receiving section of a distance meter different from the above.