JPS62226074A - Measuring method for three-dimensional position of vehicle - Google Patents

Abstract

PURPOSE:To measure the positions of plural running vehicles by emitting a laser beam for rotating synchronously at constant speed so as to turn in the same direction, in the reference position of 2 parts in a limited area, and photodetecting the laser beam by a laser photodetecting device on the vehicle. CONSTITUTION:Laser light emitting devices 53, 54 for rotating synchronously at constant speed so as to turn in the same direction are provided on a spot of 2 parts. When a vehicle is inclined on a road surface, a signal from an inclinometer 71 operates an attitude control device 32 through an arithmetic circuit 72, and the photodetecting surface of a laser photodetector 31 is always held vertically. Also, a signal by the photodetected 31 laser beam becomes the data of photodetecting timings talpha, tbeta and the photodetecting height position of the photodetector 31, in a photodetection processing circuit 73, inputted to the circuit 72, the data of the photodetecting height position is processed, and the photodetecting position is controlled 32. Also, a radio wave from a non-directional transmitter device 55 is received by a mobile radio equipment member 591, inputted to the circuit 72, and in the circuit 72, three-dimensional positions (x)-(z) of the vehicle are calculated, and sent to a radio equipment 63 installed in a job site management office from a radio equipment member 592.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a method for measuring the three-dimensional position of a vehicle, particularly for construction vehicles at civil engineering work sites where the vehicle travel path changes frequently and the road surface is not leveled. This is suitable for use in position measurement.

(Prior Art) Conventional methods for measuring the position of a running vehicle are classified as follows. That is, (A) a method in which a traveling vehicle detects its position using an external support facility.

(A)-(1) Fixed route method...Guiding the vehicle by a cable buried in the running track or optical tape fixed on the running track, or by a laser beam emitted along the running track. A method of guiding a moving vehicle.

(A)-(2) Semi-fixed route method: A method of guiding the vehicle using marks placed on the road surface of the vehicle.

(A)-(3) Free route method: A method of guiding a free route while measuring the direction and distance from the reference point of an external support facility to the traveling vehicle. Radio waves, laser light, or ultrasonic waves are used, and there are the following two measurement methods. That is, (A)-(3)-(i) Arc method...Figure 8 (
In al, a and b are two reference points on the ground, and p is the position of the vehicle whose position is to be measured.

- As an example, a case using radio waves will be explained.

If a radio wave is transmitted from point P, received at points A and B, and sent back at the same time as the reception, this is received at point P.

The position of point p is determined by measuring the time taken for the radio waves to travel back and forth between pa and pb.

(A) - (3) (ii) Hyperbolic method...
- In FIG. 8(b), a, b, and C are three reference points on the ground, and p is the position of the vehicle whose position is to be measured. - As an example, a case using radio waves will be explained.

If radio waves are transmitted at points a and b at the same time T0 and received at point p at times T8 and Tb, the following equation holds true, where ■ is the propagation speed of the radio waves.

Distance between pa Lll"" V (T, -To)
``'-' (1) Distance between pb L b = V (T
b T o ) −(2) Therefore, La − Lb =
V (T, -'r'b '') - (3) By measuring T-Tb using equation (3), -Lb can be calculated. Then, the locus of the point where the difference in distance from the two fixed points is constant is a hyperbola with its two fixed points as foci, so point p is a
Points P and B are on a single hyperbola (5-b- in Figure 8 (bl)) with focal points. If similar measurements are made for points a and C, point p will be on point a. and point C is on the hyperbola (S, e, in Figure 8 (bl)), and the position of point p is on the hyperbola S abp and 5acl,
is determined as the intersection of (However, there are two points of intersection between the two hyperbolas, but the measurer only has to select one point that is close to the estimated position.) (B) Rotation of the wheels of the traveling vehicle without using external support facilities and mounting on the traveling vehicle A method in which a vehicle can independently measure distance and direction using a gyro.

(Problems to be Solved by the Invention) At civil engineering work sites where construction vehicles operate, (a) the route of the construction vehicles changes frequently; (b) Among the position measurement methods described in 2 above (prior art), there is an adverse condition that the road surface for construction vehicles is not leveled.

The (A)-(1) fixed route method and the (A)-(2) semi-fixed route method cannot be used due to the condition that the route of the construction vehicle (a) changes frequently. In addition, the above (B) position measurement method that relies on the self-reliance of the running vehicle without using external support facilities,
Since the errors accumulate, it is very difficult to apply this method to civil engineering work sites due to the condition that the road surface for construction vehicles is not leveled.

Of the position measurement methods described above (prior technology), the free path method (A)-(3) is practical at civil engineering work sites, but among the measurement methods, conventional methods using radio waves are Although it is suitable for long-distance and large-scale applications such as ships, it is expensive and its positioning accuracy is not very good. Additionally, there are the following problems with the measurement method.

(A)-(3)-(i) The arc method can only perform positioning of one construction vehicle with respect to two reference points.

(A) - (3) - (ii) The hyperbolic method is capable of positioning multiple construction vehicles, but it requires three reference points and between the reference points (point a in Figure 8(b) and This method has the problem of being complicated and expensive because it requires synchronization at point b, point a, and point C).

Furthermore, another problem is that another measuring means is required to measure the position in the height direction, making the overall configuration complicated.

(Means and effects for solving the problems) This invention has been made in view of the above points, and is based on two points on the ground that are the reference points, facing the same direction in the same horizontal plane, and rotating in the same direction. Two laser emitting devices that emit laser light that rotates at a constant speed are installed.

In a visible position on the vehicle whose position is to be measured,
Omnidirectionality 1 For example, a laser emitting device with a light receiving surface of a regular polygonal column is installed, and the light receiving surface is always vertical regardless of the inclination of the vehicle, and the receiving position of the laser beam is almost the same as the light receiving surface. A laser receiver is installed on the vehicle via an attitude control device so that it is at the center height.

Also, a means (for example, a proximity switch) for transmitting a signal to either of the two laser emitting devices described above when the laser beam is directed toward a reference direction (hereinafter, the reference direction is assumed to be north).
In addition, a means for detecting the rotation angle of the laser beam from the north is provided to impart azimuth information to the laser beam. There are two secondary methods for detecting the rotation angle of the laser beam from the north. In other words, ■ With the signal when the laser beam points north as the reset point, a radio wave with a signal (frequency, radio wave intensity, or pulse code) corresponding to the rotation angle of the laser beam is transmitted from an omnidirectional transmitter.

When the vehicle-mounted laser receiver receives two laser beams, the radio wave signals are measured.

(2) Measure two times from the time of the signal when the laser beam points north to the time when the vehicle-mounted laser receiver receives the two laser beams.

In this way, two azimuth angle data can be obtained from the two laser beams received by the on-vehicle laser receiver, and from this and the distances between the two laser emitters, The location can be determined. Furthermore, the height of the vehicle can be determined by measuring the leg length of the attitude control device on which the laser receiver is mounted.

As described above, in this invention, for two reference points,
It is capable of measuring the three-dimensional positions of multiple moving vehicles.

(Example) Examples of the present invention will be described below based on the drawings.

FIG. 2 is a schematic diagram of a specific example of a laser emitting device 20. A laser emitting device 21 is rotatable in a housing 24 having eight legs 25 via a turntable 22 rotated at a constant speed by a pulse motor 23. It is pivoted like this. The pulse motor 23 is for synchronously rotating the two laser emitters.

One oscillator 56 (see FIG. 4) drives two pulse motors. O indicates the rotation center line of the laser emitter 21. FIG. 2 shows one of the two laser emitting devices 20,
Omnidirectional transmitter 41. An electric cable 42 and a proximity switch 43 are shown attached. The proximity switch 43 is activated when the laser beam emitted from the laser emitter 21 faces north.
The proximity switch 43 is set to be turned on, and at that time a pulse transmission trigger is given to the omnidirectional transmission 4ff141. 42 is an electric cable connecting the proximity switch 43 and the omnidirectional transmitter 41.

In addition, the legs 25 of the two laser emitting devices 20 are adjusted so that the rotation center lines O of the laser emitting devices 21 are vertical, and the heights of the 22 laser beams from the ground are the same. Two laser emitting devices 20 are installed on the ground so that.

FIG. 3 is a schematic diagram of a specific example of the laser light receiving device 30. In the figure, a laser receiver 31 is constructed by forming a light-receiving element made of, for example, amorphous silicon into a plate shape.
n≧3), and FIG. 9 shows a regular triangular prism structure. Since this laser receiver 31 may have any shape as long as it can receive light in all directions, it goes without saying that it may have a cylindrical shape in addition to a regular n-prism. The light receiving surface constituting the laser light receiving device 331 is mounted on the attitude control device 32 so that when the laser light receiving device 30 is mounted on a vehicle, it is always vertical regardless of the inclination of the vehicle or the unevenness of the ground. Ru.

FIG. 1 is an explanatory diagram of a method for calculating a vehicle position in a horizontal plane according to the present invention. In the figure, A and B indicate the positions of the laser emitting device 20 installed at two reference points on the ground, and each corresponds to O in FIG. 2. P is a laser light receiving device 3 installed on the vehicle whose position is to be measured
0, which corresponds to the axial center of the regular triangular prism of the laser receiver 31 in FIG. In Figure 1, the orthogonal coordinate axis with point A as the origin is A-xy, the negative direction of the X axis is north, and if α and β are determined, the negative direction of the , y is sin (π-(π-α)-β)
Because of sin β.

X = τ / cos (π - α) y - 1 / 5 in (π - α) sxnL α - μ The specific method for determining the angles α and β in the above equations (4) and (5) will be described later. . (See Figures 5 and 6) The height direction coordinate value 2 of point P is obtained in a quadratic manner. That is, the center position in the height direction of the laser receiver (31 in Fig. 3) is set in advance to ho, and points A and B are set in advance.
The two emitted laser beams from the point are at the same height from the ground as explained in Fig. 2, and at point P, the receiving laser beam is received at the center of the height direction of the laser receiver.
Since the leg length of the posture control device (32 in FIG. 3) is adjusted, let the amount of change in the leg length be h (more specifically, the average value of the length adjustment amounts of the four legs of the posture control device).

z=h0+h −・−・・−・・−−1−−=−1−−
−−・・・−−Ichiichi −−−−−−・−・=−・−−−
--- It is determined by (6).

FIG. 4 is a schematic explanatory diagram of a specific example of the present invention at a civil engineering work site. In the figure, 51 and 52 are both construction vehicles undergoing civil engineering work, and 53 and 54 are the laser emitting devices explained in FIG. 2.

It is installed at two points that serve as the reference for position measurement on the ground.

In addition, the two light emitting lasers are installed with their respective leg lengths adjusted so that their heights above the ground are the same. Reference numeral 55 indicates the omnidirectional transmitter 41.55 described in FIG. A combination of an electric cable 42 and a proximity switch 43 is shown as a representative combination, and will hereinafter be simply referred to as a transmitter device. 56 is a pulse motor (
This is for synchronously driving 23) in FIG. 57
and 5th are the laser light receiving devices explained in FIG. 3, and 59 and 60 are both radio devices.

It receives radio signals from the transmitter device 55 and performs transmission and reception with a radio device 63 installed in the work site management office 61. 62 is a vehicle position management device installed in the work site management office 61.

Figures 5 ta) and 5 (b) are explanatory diagrams of a specific example of the method for determining the angles α and β in the above formulas (4) and (5), and Figures 1, 2, and 4 are also diagrams. I will explain while referring to it. The signal from the proximity switch 43 that detects that the emitted laser light of the laser emitting device 53 is directed north is set as the reset point 1, and increases linearly according to the rotation angle from the north of the emitted laser light (2). Radio waves having the frequency shown in FIG. 5 (see al) are transmitted from the omnidirectional transmitter device 55, and the radio waves are received by the radio device 59 (the case where the position of the vehicle 51 is measured will be described below).

Generation of radio waves with a frequency that increases linearly in accordance with the rotation angle may be achieved using a sawtooth generator, such as a Vf converter (voltage-to-frequency converter). Note that T is the rotation period of the laser emitter 21. FIG. 5 fb) shows laser emitting devices 53 and 5.
4 is an explanatory diagram of the timing at which the laser light receiving device 57 receives the laser light from the laser beam receiving device 57. FIG. Laser emitting devices 53 and 54 (
points A and B in FIG. 1), and the laser receiver 57
If (point P in Figure 1) is arranged as shown in Figure 1, α
>β, so in Fig. 5 (bl), the laser beam from point B reaches the laser receiver 5 before the laser beam from point A.
The light is received at 7. In Fig. 1, if point P is below one block, α<β, and in Fig. 5 (the timing of light reception at bl is opposite from that from point A and from point B. To explain it with a diagram, the vehicle 51 is at the position of point P in FIG. 1, and the vehicle 52 is at the bottom of the first street in FIG. 1. If you set the position of the car so that it runs only above or below the 1st block in Figure 1.

The two received laser beams in Fig. 5 (bl) can be easily correlated with the emitted laser beams from points A and B. Referring to Fig. 5 (a) and (b), angles α and β
is calculated using the following formula.

In this embodiment, a linearly changing frequency was used as shown in FIG. 5(a), but a linearly changing radio wave intensity or pulse sign may be used instead.

6(a) and (bl) are explanatory diagrams of another example of a method for determining the angles α and β in the above equations (4) and (5).The emitted laser light from the laser emitting device 53 is A signal from the proximity switch 43 that detects that the user is facing the camera is transmitted from the omnidirectional transmitter device 55, and the waveform of the received radio wave received by the radio 59 with respect to time is shown in FIG. 6(a).Period T is the same as T explained in Fig. 5 (al). Fig. 6 (bl is the same as Fig. 5 (b), so the explanation is omitted. Fig. 6 (a) and (b) If tα and tβ are measured for 9 hours with reference, the angles α and β in FIG. 1 can be obtained by the following equations.

FIG. 7 is a block diagram of a specific example in which the position of the vehicle 51 shown in FIG. 4 is measured.

When the vehicle 51 tilts due to the slope or unevenness of the road surface, the inclinometer 7
1 (consisting of two sets, one for the front and rear directions of the vehicle and one for the left and right directions) is sent to the attitude control device 3 via the arithmetic circuit 72.
2 actuate the actuating member.

The light receiving surface of the laser receiver 31 is always held vertically. In addition, the signal from the laser beam that has entered the laser receiver 31 is transmitted to the arithmetic circuit 72 as data on the light reception timing tα, tβ and the light reception height position in the laser receiver in the 9 light reception processing circuit 73. The laser receiver 31 determines the light receiving position by processing the data.
Attitude control device 3
Issue a control command to 2. Further, the radio waves from the transmitter device 55 are received at 59°, which is a part of the vehicle-mounted radio device 59, and the frequencies fα and fβ explained in FIG.
It enters the arithmetic circuit 72 as pulse signal data indicating the north direction explained in FIG.

The arithmetic circuit 72 calculates the three-dimensional positions x, y, and 2 of the vehicle and sends them from a member 59□ of the radio device 59 to a radio a63 installed in the work site management office 61.

(Effects of the Invention) Since the present invention is constructed as described above, it is possible to avoid problems such as at a civil engineering work site where construction vehicles operate (a) where the vehicle travels frequently, and (b) where the vehicle travels on an uneven surface.

Even under these adverse conditions, simply installing laser emitting devices at two reference points makes it possible to easily and inexpensively measure the positions of a plurality of vehicles equipped with laser light receiving devices.

Furthermore, the information in the height direction of the work vehicle is directly related to the flatness of the leveled surface especially in civil engineering work, and the progress status of the work can be grasped, so it can be expected to improve the efficiency of vehicle allocation work. Furthermore, 1
At each work site management office, we can grasp the location of multiple work vehicles over a wide area, so we can issue appropriate work instructions.

This has excellent effects in that it is possible to significantly improve work efficiency and ensure safety, and furthermore, unmanned work can be expected.

In addition, one inventor previously proposed a "three-dimensional vehicle position measurement system" (patent application No. 61-02008) that achieves the same purpose as this invention.
No. 7), this invention has the following superior effects compared to the previously filed invention. Namely.

In the previous invention, in order to distinguish between the laser beams from two laser emitting devices, each laser beam was modulated separately, but in this invention, the two laser beams are synchronized so that they point in the same direction. Since we decided to take and rotate the two laser beams, we were able to geometrically distinguish between the two laser beams, resulting in a very simple structure for both the light-emitting device and the light-receiving device. Also, for the same reason as mentioned above, a radio device that transmits a direction signal indicating the rotational direction of the laser beam is also used.
The previous invention required two radios that emitted radio waves at different frequencies.

With this invention, only one radio device is required.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the vehicle position calculation method of the present invention, FIG. 2 is a schematic diagram of a specific example of a laser emitting device, FIG. 3 is a schematic diagram of a specific example of a laser receiving device, and FIG. 4 is a schematic diagram of a specific example of a laser light receiving device. A schematic explanatory diagram of an example of the invention at a civil engineering work site, Figure 5 (al
and (b) is an explanatory diagram showing the relationship between the received laser beam and the frequency of radio waves received by the in-vehicle radio and time, and FIG. 6(a)
and fb) are explanatory diagrams showing the relationship between the received laser beam, the pulse signal received by the in-vehicle radio, and time, and FIG.
FIGS. 8(a) and 8(b), which are block diagrams of a specific example of position measurement for the construction vehicle 51 shown in the figure, show the free path method, the arc method, and the hyperbolic method, respectively, among the position measurement methods of the prior art. It is an explanatory diagram. 20, 53.54...Laser light emitting device. 21... Rede light emitter, 22... Turntable. 25...Legs, 30,57.58...Laser light receiving device. 31... Laser receiver, 32... Attitude control device. 41... Omnidirectional transmitter, 43... Proximity switch. 55... Omnidirectional transmitter device, 56... Oscillator. 59, 60... (in-vehicle) radio. Patent Applicant Komatsu Ltd. Agent (Patent Attorney) Osamu Matsuzawa 1 Figure 2 @ 8 Figure (a) Figure 8 (b)

Claims (3)

[Claims] (1) A predetermined position on the vehicle to be measured by emitting laser beams that rotate at a constant speed synchronously in the same horizontal plane and facing the same direction at two reference positions within the limited area. By receiving the laser beam with a laser light receiving device capable of receiving light in all directions placed at A vehicle position measurement method characterized by measuring a three-dimensional position of a vehicle. (2) By transmitting a signal (frequency, intensity, or code) corresponding to the emission direction of the laser beam from an omnidirectional transmitter and receiving it with a radio installed on the vehicle whose position is to be measured, A method for measuring a three-dimensional position of a vehicle according to claim 1, characterized in that information on two directions in the horizontal plane is obtained. (3) A pulse signal obtained from a device that detects that the laser beam is directed toward the reference direction is transmitted from an omnidirectional transmitter and received by a radio installed on the vehicle whose position is to be measured. A method for measuring a three-dimensional position of a vehicle according to claim 1, characterized in that information on two directions in the horizontal plane is obtained.