JPH0337043Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a device for controlling the steering of a guided vehicle such as an unmanned forklift when the vehicle enters a container.

BACKGROUND TECHNOLOGY In general, in transportation work using a transport vehicle such as an unmanned forklift, a cargo M is carried into a container C mounted on a truck T, or a cargo is carried out from a container C, as shown in Fig. 4. There are cases where
Steering control of the guided vehicle during such work is carried out on the platform by using a guide wire L buried under the floor (see Figure 5) and by detecting high-frequency current with a pair of pick-up coils attached to the guided vehicle. This can be done, but since there are no guide lines inside the container, it must be done in a different way.

Therefore, in order to control the steering of an unmanned guided vehicle, such as a forklift, in a conventional container, ultrasonic or infrared rays are installed on the sides of the claws 1A and 1B of the forklift F, respectively, as shown in FIG. Distance detectors 2A and 2B were provided to detect the distance to the inner walls 3A and 3B of the container C, and the servo motor was controlled so that the left and right distances D _L and D _R were equal.

Problems to be solved by the invention In the above-mentioned steering control, when the inner walls 3A and 3B of the container C are flat, D _L
If the servo motor is controlled so that =D _R , the unmanned forklift F will be running in the center of the container C, and the cargo will not collide with the inner walls 3A and 3B. However, the inner walls 3A and 3B of the container C are not normally flat, but are often provided with irregularities as shown in FIG. In this case, if the peaks and valleys of the left and right walls 3A and 3B are detected in exactly the same phase, the forklift F will run in a straight line in the center of the container C, but if the unevenness is out of phase, the forklift F will move in a straight line. Even though the lift F is traveling approximately in the center, for example, the distance detector 2A on the right side detects a valley and the distance detector 2B on the left side detects a mountain, so it feels like it is close to the left wall 3B at that point. It will now be steered to the right. As the car progresses, this relationship reverses, and the car is now steered to the left, making the car run unstable and causing the problem that the load will eventually hit one of the walls 3A and 3B.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide a steering control device for a guided vehicle that allows an unmanned guided vehicle to run stably inside a container.

Means for Solving the Problems The present invention provides a first distance detecting means for detecting the distance to the inner wall of the container on the left side in the direction of travel, and a second distance detecting means for detecting the distance to the inner wall of the container on the right side in the traveling direction.
Each of the distance detecting means is constituted by a plurality of distance detecting meters arranged in a line in the front-rear direction, and the longitudinal interval of each of the distance detecting meters arranged in the line is determined by at least one of the distance detecting meters of the first distance detecting means. and at least one of the distance detectors of the second distance detecting means are aligned to always detect only one of the concave part or the convex part of the inner wall of the container as the first detection distance and the second detection distance, respectively. Further, a first output section and a second output section are provided between the first distance detection means and the second distance detection means and the steering control section, respectively.

Effect: The distance detectors of the first distance detecting means output signals corresponding to the respective detected distances, but at least one of the signals always corresponds to the distance to, for example, the convex part of the inner wall of the container on the left side. This is a corresponding signal (a signal corresponding to the first detected distance), and only this signal is input to the steering control section via the first output section. On the other hand, signals corresponding to the respective detected distances are output from the distance detecting meters related to the second distance detecting means, and at least one of the signals always corresponds to the distance to, for example, a convex part on the inner wall of the container on the right side. (corresponding to the second detected distance), and only this signal is input to the steering control section via the second output section. Therefore, in this case, even if the inner wall of the container is uneven, steering control is always performed based on the signal corresponding to the shortest distance from each distance detection means to the inner wall of the container.

Embodiments of the present invention will be described below with reference to the drawings.

In the embodiment shown in FIG. 1, a first distance detection means 4 and a second distance detection means 5 are provided on the sides of the left and right claws 1A and 1B of the forklift, respectively. are three distance detectors 41 to 43, 51 to each lined up in a row in the front and back direction.
53. Regarding the longitudinal spacing between the distance detecting meters 41 to 43 related to the first distance detecting means 4 and the longitudinal spacing between the distance detecting meters 51 to 53 related to the second distance detecting means 5, at least one of the distance detecting meters 41 to 43 1 and at least one of the distance detectors 51 to 53 are set to always detect, for example, only a convex portion of the inner wall of the container as a first detection distance and a second detection distance, respectively. .

FIG. 2 is an explanatory diagram showing a container inner wall 3A on the left side in the direction of travel and an example of setting the front and rear intervals of the distance detectors 41 to 43 corresponding thereto. Container inner wall 3A
Assuming that the pitch of the unevenness is, for example, 10 in length as shown in the figure, the distance between the distance detectors 41 to 43 is set so that at least one of them always detects only the protrusion 30 on the inner wall of the container. Since it is sufficient that at least one of them always faces the convex portion 30, the length may be, for example, 2.5 to 4.5 (in the example of FIG. 2, the length is 4.5). In this case, the distance detectors 51 to 53 associated with the second distance detector 2 are also arranged at similar intervals at symmetrical positions relative to the distance detectors 51 to 53, respectively, about the center of the forklift. At least one of them is a convex portion 30 on the inner wall of the right container.
will always be detected. In this example, the first detection distance and the second detection distance both correspond to the shortest distance to the inner wall of the container. In addition, if an ultrasonic type distance detector is used, for example, if the ultrasonic waves emitted from one distance detector are received by another distance detector, a distance detection error may occur. , In this embodiment, three distance detectors 41 to 4 are used to prevent mutual interference.
3, the timing of oscillation of 51 to 53 is slightly changed.

6 is the first output section, and distance detector 4 on the left side
Output signals from 1 to 43 are input, and only the signal corresponding to the first detection distance, that is, the signal corresponding to the distance to the convex portion 30 on the inner wall of the left container in this example, is output to the steering control unit 8. do. Reference numeral 7 designates a second output section, into which the output signals from the distance detectors 51 to 53 on the right side are input, and the signal corresponding to the second detected distance, that is, in this example, the convex portion 30 on the inner wall of the right container. Only the signal corresponding to the distance up to the steering wheel is output to the steering control section 8. Incidentally, this steering control section 8 is constituted by a microcomputer etc. mounted on the forklift main body.

In this embodiment, when the forklift enters the container, the three distance detectors 41 to 43 provided on the left claw 1A detect the distance to the inner wall of the container at slightly different timings. , signals corresponding to each distance are input to the first output section 6. This first output section 6 outputs only the signal corresponding to the shortest distance among the signals from the three distance detectors 41 to 43, but at least one of the three distance detectors 41 to 43 outputs the signal corresponding to the shortest distance. Since the protrusion 30 on the left container inner wall is detected regardless of the position of the forklift, the first output section 6 detects the shortest distance from the first distance detection means 4 to the left container inner wall. A corresponding signal is always input to the steering control section 8. Also, at least one of the three distance detectors 51 to 53 provided on the right claw 1B always detects the right protrusion 30 on the inner wall of the container, and as a result, the second output section 6, a signal corresponding to the shortest distance from the second distance detecting means 5 to the inner wall of the right container is always input to the steering control section 8. In this way, the steering control section 8 performs steering control based on the input signals from the first output section 6 and the second output section 7.

Note that when the inner wall of the container has the shape shown in FIG. In this case, the two distance detectors may both detect a recess, so the shortest distance to the inner wall of the container cannot always be detected.
One input signal may correspond to the distance to the convex part of the inner wall of the container, and the other input signal may correspond to the distance to the recessed part of the inner wall of the container.
Driving becomes unstable.

Here, in the present invention, at least one of the distance detectors on the left side and at least one of the distance detectors on the right side are aligned so that only the recessed part of the inner wall of the container is always detected at the first detection distance and the second detection distance. The distance between the front and rear distance detectors may be set so that each distance is detected as a detection distance, and the same effect can be obtained even in this case. In this case, the first detection distance and the second detection distance each correspond to the longest distance to the inner wall of the container.

Furthermore, distance detectors can be installed not only on the sides of the forklift's claws, but also with the arms 10A and 10B protruding forward from the top of the mast on both sides of the forklift, respectively, as shown in Figure 3. For example, three distance detectors 41 to 43 and 51 to 5 are installed on the arms 10A and 10B, respectively.
3 may be provided.

Effects of the invention As described above, the present invention uses a plurality of distance detectors as means for detecting the distance to the left and right inner walls of a container, and at least one distance detector for left side detection and one distance detector for right side detection. At least one of the distance detectors are arranged together to always detect only one of the recesses and the protrusions on the inner wall of the container. Therefore, regardless of the unevenness of the inner wall of the container, the steering control section always performs steering control based on the signal corresponding to the shortest distance to the left and right inner walls of the container, so even if the vehicle is traveling in the center of the container as in the past. Regardless of the situation, the position of the container is not detected as if it is leaning towards one wall. Therefore, it is possible to move stably inside the container, which eliminates the problem of cargo hitting the inner wall. .

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the positional relationship between the distance detector and the inner wall of the container, and Fig. 3 is a side view showing another embodiment of the invention. Figure 4 is a side view showing the state in which loading work into the container is being carried out by a forklift;
The figure is a plan view showing part of a conventional control device together with a container, and FIG. 6 is an enlarged view showing part of the inner wall of the container. C...Container, F...Forklift, 1
A, 1B...Forklift claw, 3A, 3B
...container inner wall, 4...first distance detection means,
5...Second distance detection means, 41-43, 51-
53... Distance detector, 6... First output section, 7...
...Second output section, 8...Steering control section, 1
0A, 10B...Arm.

Claims (1)

[Scope of Claim for Utility Model Registration] A first distance detecting means and a second detecting means for detecting the distances to the inner wall of the container located on the left side and the inner wall of the container located on the right side of the transport vehicle, respectively; In a steering control device for a guided vehicle that performs steering control by a steering control unit based on a signal, the first distance detection means and the second distance detection means are each arranged in a row in the longitudinal direction of the guided vehicle. The distance detectors are configured by distance detectors, and the distance between the front and back of each of the distance detectors arranged in a row is determined by at least one of the distance detectors of the first distance detector and at least one of the distance detectors of the second distance detector. one of the first distance detecting means is set to always detect only one of the concave portion or the convex portion of the inner wall of the container as the first detection distance and the second detection distance, respectively, and each of the first distance detection means A first sensor receives an output signal from a distance detector and outputs only a signal corresponding to the first detected distance to the steering controller.
and a second output section that receives output signals from each distance detector of the second distance detection means and outputs only the signal corresponding to the second detected distance to the steering control section. A steering control device for a conveyance vehicle, characterized in that it is provided with: