JPH07122666B2 - Vehicle three-dimensional position measurement method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle position measuring method, and particularly to measuring the position of a construction vehicle at a civil engineering work site where the traveling path of the vehicle changes frequently and the road surface is not leveled. It is suitable for use.

(Prior Art) Conventional position measurement methods for traveling vehicles are classified as follows. That is, (A) a method in which a traveling vehicle detects a position by using an external support facility.

(A)-(1) Fixed path system: A running vehicle is guided by a cable embedded in the running path of the running vehicle or an optical tape fixed on the running surface, or is guided by a laser beam emitted along the running path. Method to do.

(A)-(2) Semi-fixed path system ... A system that guides the traveling vehicle by using marks placed on the traveling surface of the traveling vehicle.

(A)-(3) Free path method: A method of guiding a free path while measuring the direction and distance from the reference point of the external support facility to the traveling vehicle, and the measuring means is radio wave, laser or Ultrasonic waves are used, and there are the following two measurement methods. That is, (A)-(3)-(i) circular arc method ... In FIG. 8 (a), a and b are two reference points on the ground, and p is the position of the traveling vehicle whose position is to be measured. The case of using radio waves will be described as an example. If radio waves are transmitted from point p, received at points a and b, returned at the same time as reception, and received at point p, the time it takes for the radio waves to travel back and forth between pa and pb is measured to obtain p points. The position of is determined.

(A)-(3)-(ii) Hyperbolic method ... In Fig. 8 (b), a, b and c are the three reference points on the ground, and p is the position of the traveling vehicle that is the object of position measurement. is there. The case of using radio waves will be described as an example. Same time T ₀ at points a and b
If a radio wave is transmitted to and received at times T _a and T _b at point p, the following equation holds with V as the propagation velocity of the radio wave.

The distance between the _{pa L a = V (T a} -T 0) ...... (1) Distance _{L b = V (T a -T} 0) between pb ...... (2) thus L _a -L _b = V (T _{a -T b) ...... (3)} (3) L a -L b can be calculated by measuring the T _a -T _b by equation. Since the locus of points where the difference in distance from the two fixed points is constant is a hyperbola whose focal points are the two fixed points, the p point is one hyperbola whose focal points are the points a and b (Fig. 8 ( b) on S _abp ). If the same measurement is performed for points a and c, the point p lies on the hyperbola (S _{acp in} Fig. 8 (b)) whose focal points are points a and c, and the position of the point p Is determined as the intersection of the hyperbolas S _abp and S _acp . (However, there are two intersections of the two hyperbolas, but the measurer only needs to select one that is close to the estimated position.) (B) The wheel of the traveling vehicle is rotated without using an external support facility, and it is mounted on the traveling vehicle. A method in which a traveling vehicle independently measures the distance and direction by the gyro (the problem to be solved by the invention) At the civil engineering work site where the construction vehicle operates, (a) the traveling path of the construction vehicle changes frequently. , (B) There is a bad condition that the road surface of the construction vehicle is not leveled, and among the position measurement methods described in the above (Prior Art), (A)-(1) fixed path method and (A)-( 2) The semi-fixed route system cannot be used due to the condition (a) that the running path of the construction vehicle changes frequently. Further, since the error is accumulated in the position measurement method in which the (B) external support facility is not used and the traveling vehicle is independent, from the condition (b) that the road surface of the construction vehicle is not leveled,
It is very difficult to apply to civil engineering work sites.

Of the position measurement methods described in (Prior Art) above, the free path method (A)-(3) is practically applicable to civil engineering work sites. Is suitable for long-distance and large-scale vessels such as ships, but it is expensive and its positioning accuracy is not so good. In addition, the measurement method has the following problems.

The (A)-(3)-(i) circular arc method can only position one construction vehicle for two reference points.

(A)-(3)-(ii) The hyperbolic method is capable of positioning a plurality of construction vehicles, but it requires three reference points and is located between the reference points (point a in FIG. 8 (b)). There is a problem that it becomes complicated and expensive because it is necessary to synchronize at points b and a and c).

Further, another measuring means is required to measure the position in the height direction, and there is also a problem that the entire configuration becomes complicated.

(Means and Actions for Solving Problems) The present invention has been made in view of the above points, and is installed at two reference positions, and the laser light emitter and the laser light are respectively moved at a constant speed in a horizontal plane. Rotating legs and turntables,
And a laser emitting device comprising an omnidirectional transmitter for transmitting a reference azimuth signal; a laser having a laser receiving plate attached on a polygonal prism surface so that laser light from the laser emitting device can be received in all directions. An in-vehicle laser light receiving device comprising a light receiving part and an attitude control device for keeping the laser light receiving part vertical regardless of the attitude of the vehicle and for keeping the height of the laser light receiving part constant from the ground; An on-vehicle arithmetic device that calculates the vehicle position from two emission angles obtained by the light receiving device and a known distance between reference points; and information on the vehicle position and height obtained from the on-vehicle arithmetic device is transmitted to the ground station. It is equipped with a laser light receiving device by simply installing a laser emitting device at two reference points even under adverse conditions such as the vehicle's running path changes frequently and the running surface of the vehicle is uneven. Running multiple vehicles Both positions can be measured easily and inexpensively, and the information in the height direction of the work vehicle is directly related to the flatness of the ground level, especially in civil engineering work, and the progress status of the work can be grasped. In addition to being able to expect higher efficiency, it is possible to grasp the positions of multiple work vehicles in a wide range at one work site management office, so it is possible to issue appropriate work instructions, greatly improve work efficiency and ensure safety. Is possible.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic view of a specific example of the laser emitting device 20,
A laser emitter 21 is rotatably attached to a housing 24 having legs 25 via a turntable 22 which is rotated at a constant speed by a motor 23. O indicates the center line of rotation of the laser emitter 21. A proximity switch 28 is set so that the proximity switch 28 is turned on when the laser light emitted from the laser emitter 21 faces the reference direction, for example, north, and at that time, pulse transmission is performed to the omnidirectional transmitter 26. Made to give a trigger. 27 is an electric cable connecting the proximity switch 28 and the omnidirectional transmitter 26. Incidentally, the laser light and the pulse signal emitted from the two laser emitting devices set at the two reference positions are changed in frequency, phase, wavelength and intensity so that they can be discriminated from each other. Also, the legs 25 of the two laser light emitting devices 20 are adjusted so that the rotation center lines O of the laser light emitting devices 21 are vertical and the heights of the two laser beams are the same from the ground. Therefore, two laser light emitting devices 20 are installed on the ground.

FIG. 3 is a schematic view of a specific example of the laser light receiving device 30.
In the figure, the laser light receiving portion 31 has a plate-shaped light receiving element made of, for example, amorphous silicon, and has a regular n-shaped prism (n ≧ n
3), and the figure shows the structure of a regular triangular prism. The light receiving surface that constitutes the laser light receiving section 31 is
The attitude control device 32 is configured such that when the laser light receiving device 30 is mounted on a vehicle, the laser light receiving device 30 is always vertical regardless of the inclination of the vehicle and the unevenness of the ground.

FIG. 1 is an explanatory diagram of a vehicle position calculation system of the present invention.
In the figure, A and B show the positions of the laser light emitting device 20 installed at two points on the ground which are reference points, and each corresponds to O in FIG. P indicates the position of the laser light receiving device 30 installed on the vehicle whose position is to be measured.
It corresponds to the axial center of the regular triangular prism of the laser receiving unit 31 in the figure. In Fig. 1, the Cartesian coordinate axis with point A as the origin is A-xy, the negative direction of the x axis is north, and if the symbols L, α, and β are set as shown in the figure, the coordinate x , y is calculated by the following equation.

Therefore, FIG. 4 is an illustration of a specific example of a method for measuring α and β from the time when the laser light and the pulse signal from points A and B in FIG. 1 are received at point P. In FIG. 4A, the horizontal axis represents the time when the laser light and pulse signal from point A was received at point P, and the vertical axis represents the electrical waveform of the laser light and pulse signal. Now, the time from the reception of the pulse signal to the rise and fall of the received laser waveform is t _a1 and t, respectively.
Assuming that _a2 and the time until the next pulse signal is received are T _a , T _a is the rotation period of the laser emitter at point A as explained in FIG. A pulse signal is emitted when the light is emitted to the north.

FIG. 4 (b) shows the laser light and pulse signal from point B as P
The points t _b1 , t _b2 and T _b correspond to t _a1 , t _a2 and T _a in FIG. 4 (a), respectively.

From the above, the azimuth angles α and β in FIG. 1 can be obtained by the following equations.

Therefore, the coordinates x and y of P point are the values of α and β above.
It is obtained by putting it into the equations (4) and (5).

The height direction coordinate value Z of the point P is obtained as follows. That is, the center position in the height direction of the laser receiving part (31 in FIG. 3) is set to h _o in advance, and the two emitted laser beams from points A and B are described in FIG. As described above, since the height from the ground is the same, and at point P, the leg length of the attitude control device (32 in Fig. 3) is adjusted so that the received laser is received at the center in the height direction of the laser receiver. If the amount of change in the leg length is h (in detail, the average value of the adjustment amounts of the lengths of the four legs of the posture control device), then Z = _ho + h (8).

FIG. 5 is a specific example of a light receiving laser calculation processing block diagram of the present invention. The laser light entering the laser receiving point is converted into a current by the light receiving element, and the upper portion (H) of the laser receiving section 31
And current values corresponding to the length of the lower part (L) enter the current-voltage converters 51 and 52, respectively, and are converted into corresponding voltage values, and the BPFs (band-pass filters) 53, 54, 55
Enter 56. 53 and 55 are BPFs that process laser light from point A, and 54 and 56 process lasers from point B
Indicates BPF. It should be noted that, as described in the description of FIG. 2, the laser light and the pulse signal emitted from the points A and B can be discriminated from each other. It is designed so that only the discriminated voltage enters. The voltage output from BPF is the current circuit 57, 58, 59, 60 and LPF (low-pass filter) 61, 62, 6 respectively.
The required electrical processing is performed at 3,64 and the voltage values V _Ha , V _Hb , V _La , V
_Lb is obtained.

FIG. 6 is a schematic explanatory view of a concrete example of the present invention at a civil engineering work site. In the figure, 71 and 72 are both construction vehicles during civil engineering work, and 73 and 74 are both laser light emitting devices described in FIG. 2, which are installed at two points that serve as a reference for position measurement on the ground, and two The leg lengths of the light emitting lasers are adjusted so that the ground heights are the same. 75 and
76 is the omnidirectional transmitter described in FIG.
77 and 78 are both laser receiving devices described in FIG. 3, 79 and 80 are both radios, and receive pulse transmissions from transmitters 75 and 76, and inside the work site management office 81. The vehicle position management device 82 installed in the vehicle and the wireless device 83 connected to the vehicle position management device 82 communicate with each other. In the vehicle management device 82, for example, when the position reading of the construction vehicle 71 is completed, the position reading of the construction vehicle 72 is performed next.

FIG. 7 is a block diagram of a specific example in the case of measuring the position of the construction vehicle 71 in FIG. 6, for example. When the construction vehicle 71 leans due to the slope or unevenness of the road surface, a signal from the inclinometer 91 (two sets for the front-rear direction and the left-right direction of the vehicle) actuates the operating member of the attitude control device 32 via the arithmetic circuit 92. By doing so, the light receiving surface of the laser light receiving portion 31 is always held vertically. The other parts shown in FIG. 7 have already been described or consist of a combination of conventional techniques, and therefore description thereof will be omitted.

(Effects of the Invention) Since the present invention is configured as described above, (a) the track of the vehicle frequently changes, (b) the track surface of the vehicle is uneven, as in a civil engineering work site where a construction vehicle operates. Even under such adverse conditions, it is possible to easily and inexpensively measure the position of multiple traveling vehicles equipped with a laser receiver by simply installing the laser emitters at two reference points. Furthermore, since the information on the height direction of the work vehicle is directly related to the flatness of the ground level in civil engineering work in particular, and the progress status of the work can be grasped, it is expected that the efficiency of the dispatch work will be improved. Furthermore, in one work site management office, it is possible to grasp the positions of a plurality of work vehicles over a wide range, so it is possible to issue appropriate work instructions,
This has the excellent effect that work efficiency can be greatly improved and safety can be ensured, and further unmanned work can be expected.

[Brief description of drawings]

FIG. 1 is an explanatory view of a vehicle position calculating method of the present invention, FIG. 2 is a schematic view of a specific example of a laser emitting device, FIG. 3 is a schematic view of a specific example of a laser receiving device, and FIG. ) And (b)
Is an explanatory view showing the relationship between the reception time and the electrical waveforms of the laser light and the pulse signal in the vehicle whose position is to be measured. FIG. 5 is a specific example of a light receiving laser calculation processing block diagram, FIG. Is a schematic explanatory view of a concrete example of the civil engineering work site of the present invention, FIG. 7 is a block diagram of a concrete example in the case of measuring the position of the construction vehicle 71 in FIG. 6, FIGS. 8 (a) and (b) 13A and 13B are explanatory views of a free path method, an arc method and a hyperbolic method, of the conventional position measuring methods. 20 …… Laser emitting device, 21 …… Laser emitting device, 22 …… Turntable, 25 …… Leg, 26 …… Omnidirectional transmitter, 30 …… Laser receiving device, 31 …… Laser receiving unit, 32… ... Attitude control device.

Claims (1)

[Claims] 1. A laser emitter, two legs and a turntable for rotating the laser beam in a horizontal plane at a constant speed, and an omnidirectional transmitter for transmitting a reference azimuth signal. A laser emitting device comprising: a laser emitting device capable of receiving laser light from the laser emitting device in all directions,
A laser light receiving part in which a laser light receiving plate is attached on a polygonal prism surface,
An in-vehicle laser light receiving device comprising an attitude control device for keeping the laser light receiving part vertical regardless of the attitude of the vehicle, and for keeping the height of the laser light receiving part constant from the ground; Two emission angles and an in-vehicle arithmetic device that calculates a vehicle position from a known distance between reference points; a wireless communication device that transmits vehicle position and height information obtained from the in-vehicle arithmetic device to a ground station A three-dimensional vehicle position measurement system characterized by the following: