JPH0130437B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic steering system for a moving object, and more particularly to a system for automatically steering an automobile or an unmanned mobile conveyance system in a factory.

BACKGROUND ART Conventionally, as a method for automatically steering a moving object such as a car or an unmanned transport device in a factory, there has been a method of attaching a track rail to the road surface on which the moving object runs, and having the moving object run on the track rail. This method has the drawback of requiring very large-scale facilities and being expensive.

Therefore, the main object of the present invention is to provide an automatic steering system for a moving body that can move the moving body along a predetermined trajectory with a simple and inexpensive configuration.

In summary, this invention arranges a plurality of light reflecting means for reflecting light in the direction of incident light along a predetermined locus, generates a light beam having a predetermined spread from a moving body, and generates a light beam having a predetermined spread from a moving object. Rotating and scanning the beam in the direction in which the light reflecting means is provided, and detecting the rotational angle of the light beam scanning means at that time by receiving the reflected light reflected from the light reflecting means with a moving body, The steering direction of the moving object is controlled based on the detected rotation angle.

The above objects and other objects and features of the present invention will become more apparent from the following detailed description with reference to the drawings.

1 and 2 are diagrams for explaining the principle of an embodiment of the present invention. In particular, FIG. 1 is a side view of the moving body V, and FIG. 2 is a diagram showing the moving body V. It is a figure seen from the front. In the figure, corner cubes CC, which are an example of light reflecting means, are arranged on the ceiling or wall above the road surface on which the moving body V runs. The corner cubes CC are arranged along a predetermined trajectory along which the moving body V is to be moved. Note that the corner cubes CC may be arranged on a straight line, or may be arranged on a curved locus as shown in FIG. Here, corner cube
The CC is constructed by, for example, combining a plurality of tetrahedral prisms. The corner cube CC has an optical property of reflecting the incident light in the direction of the incident light.

On the other hand, a beam scanner is mounted on the top surface of the moving body V.
BS will be provided. And this beam scanner
A light beam PB with a spread angle φ is emitted from the BS. As shown in FIG. 2, the light beam PB is rotated and scanned by a beam scanner BS, for example, in an angular range of θ1. Note that the spread angle φ of the light beam PB is selected to a value such that light hits at least two corner cubes CCa and CCb in one rotational scan of the light beam PB.

Here, the beam scanner BS scans the light beam every moment.
It has, for example, a rotary encoder for detecting the rotational scanning angle of the PB. The reference angle of this rotary encoder is, for example, a beam scanner.
Selected right above BS. In addition, beam scanner
The BS is provided with light receiving means for detecting reflected light from the corner cube CC. For example, when light emitted from the beam scanner BS hits the corner cube CCa, the corner cube CCa reflects the light beam PB in the direction of the incident light, that is, in the direction of the beam scanner BS. Accordingly, the light receiving means provided in the beam scanner BS receives the reflected light from the corner cube CCa. If you read the output angle of the rotary encoder at this time, you can find the opening angle θa of the corner cube CCa with respect to the reference angle of the rotary encoder.
can be found. Similarly, the opening angle θb of the corner cube CCb with respect to the reference angle of the rotary encoder is determined.

As mentioned above, when the opening angles θa and θb are determined, the traveling direction of the moving body V is the corner cube.
Line segment connecting CCa and CCb (predetermined trajectory)
This is when there is a deviation from the If the moving object V
If the traveling direction of the corner cubes CCa and CCb coincide with the line segment connecting them, the opening angles θa and θb will both be 0. Therefore, if the steering direction of the moving body V is controlled so that the opening angles θa and θb obtained as described above are both 0, the moving body V can be made to travel along the trajectory in which the corner cubes CC are arranged. be able to.

FIG. 4 is an external view of a beam scanner BS used in an embodiment of the present invention. In the figure, a slit 2 is formed in a cylinder 1, and a light beam PB is emitted from this slit 2. Further, at both ends of the slit 2, light receiving sections 3 and 4 are provided for receiving the reflected light from the corner cube CC described above. These light receiving sections 3 and 4 are as follows:
Various photoelectric conversion elements are used. A rotary encoder EC1 and a motor M1 are connected to the cylinder 1. The rotation of motor M1 is transmitted to cylinder 1,
This cylinder 1 is rotated. That is, motor M1
is the light beam PB by rotating the cylinder 1
Rotate and scan. Also, rotary encoder
EC1 detects the rotation angle of motor M1 and therefore of light beam PB.

The cylinder 1 and motor M1 described above are held by a holding member 5. In particular, the cylinder 1 is rotatably held by the holding member 5, and the motor M1 is held fixedly. A rotary encoder EC2 and a motor M2 are connected to this holding member 5.
The motor M2 rotates the holding member 5, which causes the cylinder 1, rotary encoder EC1, and motor M1 to rotate on a plane perpendicular to the plane of rotation by the motor M1. Also, rotary encoder
EC2 detects the rotation angle of motor M2.

FIG. 5 is a sectional view taken along the line - in FIG. 4. In the figure, a semiconductor laser 11 is provided on the inner peripheral wall of a cylinder 1. This semiconductor laser 1
The laser beam emitted from the laser beam 1 is diffused by a lens 13, and further converted into parallel light by a lens 14. This parallel light is diffused by a lens 15 provided near the slit 2. This diffusion direction is the longitudinal direction of the slit 2, as shown in FIG. In this way, the light beam PB spread in the longitudinal direction of the slit 2 is emitted from the slit 2 to the outside. Note that the light receiving sections 3 and 4 are for receiving the light reflected from the corner cube CC, but instead of receiving the light reflected from the corner cube CC, the light receiving sections 3 and 4 are for receiving the light reflected from the corner cube CC by the beam splitter 16 and the beam splitter 16. A light receiving section 17 that receives light may be provided.

In the above configuration, the reference angle of the rotary encoder EC1 is selected to be directly above the moving body V.
The reference angle of rotary encoder EC2 is the moving object V.
is selected in the straight direction. Furthermore, the motor M1 is rotated sufficiently faster than the motor M2.

FIG. 6 is a preferred block diagram of one embodiment of the present invention. In the figure, the OR gate 60 includes
Light receiving outputs from light receiving sections 3 and 4 are given.
The output of this OR gate 60 is given to one input of each of AND gates 61 and 62.
The other input of the AND gate 61 is given the angle output from the rotary encoder EC1. Therefore, θa or θb explained in FIG. 2 is output from the AND gate 61. The output of this AND gate 61 (hereinafter referred to as θα) is given to the CPU 63. On the other hand, the other input of the AND gate 62 has
The angle output from rotary encoder EC2 is given. Therefore, from AND gate 62,
The rotation angle of the rotary encoder EC2 when the light receiving output is received from the light receiving section 3 or 4 is output. The output of this AND gate 62 (hereinafter θβ
) is given to the CPU 63. moreover,
The CPU 63 includes M for driving the motor M1.
A rotation direction switching signal for the motor M1 is applied from the M1 drive circuit 64. This rotational direction switching signal is, for example, a signal that is at a high level when rotating the motor M1 in the forward direction, and is at a low level when rotating the motor M1 in the reverse direction. Similarly, the CPU 63 has a motor M
A rotation direction switching signal for the motor M2 is applied from an M2 drive circuit 65 for driving the motor M2.

Furthermore, a timer 66, a steering motor 67, a ROM 68, and a RAM 69 are connected to the CPU 63. As will be described later, in this embodiment, the steering control of the moving body V is performed alternately based on two factors, and the timer 66 is used to regulate the steering time in the steering control based on one of the factors. used for. The steering motor 67 is a motor for controlling the steering direction of the moving body V. The ROM 68 stores operating programs for the CPU 63 as shown in FIGS. 9 to 11, for example. The RAM 69 stores various processing data, but the storage areas of particular interest in this embodiment include the counter 69a and the θx register 69.
b, a θy register 69c, and a _θF register 69d.

FIG. 7 and FIG. 8 are illustrative diagrams for explaining the steering control mode of an embodiment of the present invention. Furthermore, FIGS. 9 to 11 are flowcharts for explaining the operation of the CPU 63, and in particular, FIGS.
The figure shows the main flow, and Figures 10 and 11
The figure shows the subroutine in FIG.

The operation of an embodiment of the present invention will be described below with reference to FIGS. 1 to 11.

First, the steps in Figure 9 (abbreviated as S in the illustration)
1, θx is detected. As shown in FIG. 7, θx is the angle that the straight direction of the moving body V makes with the line segment connecting the corner cubes CCa and CCb. Details of the subroutine in step 1 are shown in FIG.

In FIG. 10, in step 101, it is determined whether or not the output θα is received from the AND gate 61. If there is an output θα, then in step 102 the output θβ from the AND gate 62 is read;
It is stored in RAM69. Next, in step 103, the counter 69a is incremented by one. and,
Proceed to step 104. In this step 104, M1
Based on the rotation direction switching signal from the drive circuit 64, it is determined whether the rotation direction of the motor M1 has been switched. If it is not determined in step 104 that the rotational direction of the motor M1 should be changed, the operations from step 101 onward are repeated again. That is, in steps 101 to 104, during one scan of the light beam PB by the motor M1, the corner cube CC is
It detects how many times the reflected light is received. On the other hand, if it is determined in step 104 that the direction of rotation of the motor M1 should be changed, the process proceeds to step 105.
In step 105, it is determined whether the count value of the counter 69a is 1 or not. Now, assume that the straight direction of the moving body V is not parallel to the line segment connecting the corner cubes CCa and CCb. In this case, since the timing of receiving the reflected light from the corner cube CCa and the timing of receiving the reflected light from the corner cube CCb are different, the motor M1
The number of received light outputs obtained during one scan of the light beam PB is two. On the other hand, if the straight direction of the moving body V is parallel to the line segment connecting the corner cubes CCa and CCb, the timing of receiving the reflected light from the corner cube CCa and the corner cube CCb
The timing is almost the same as the timing at which the reflected light is received. Therefore, in this case, the number of received light outputs obtained while the motor M1 scans the light beam PB once is one. That is, in step 105, by determining whether the count value of the counter 69a is 1, it is determined whether the straight direction of the moving body V is parallel to the line segment connecting the corner cubes CCa and CCb. Detected. When it is determined in step 105 that the count value of the counter 69a is not 1,
In step 106, counter 69a is cleared. Thereafter, the operations starting from step 101 are repeated again. By repeating the operations in steps 101 to 106, when the count value of the counter 69a becomes 1, in step 107, θβ is changed to θx register 69a.
9b. Note that here, θx register 6
θβ stored in 9b is the angular output of the rotary encoder EC2 when the spreading direction of the light beam PB becomes parallel to the line segment connecting the corner cubes CCa and CCb.

Referring again to FIG. 9, after the operation in step 1, it is determined in step 2 whether θx is 0 or not. If θx is not 0, proceed to step 3. In step 3, the moving body V is steered by the steering motor 67 based on θx. In the steering in step 3, the steering motor 67 is rotated forward or reverse depending on, for example, whether θx is positive or negative. Further, the rotation angle of the steering motor 67 is controlled according to the magnitude of θx. Next, in step 4, the θx register 69b is cleared. Thereafter, the operations from step 1 onwards are repeated.

As a result of the steering in step 3, when the straight direction of the moving body V becomes parallel to the line segment connecting the corner cubes CCa and CCb, θx becomes 0. This is determined in step 2, a timer 66 is started in step 5, and then, in step 6, θy is detected. This θy is the opening angle of the reflected light from the corner cube CCa (or CCb) with respect to the reference angle of the rotary encoder EC1. In addition, when proceeding to the operation of step 6, since the straight direction of the moving body V has already been made parallel to the line segment connecting the corner cubes CCa and CCb in the operations of steps 1 to 5, the difference in the reflected light of the corner cube CCa is The angle and the opening angle of the reflected light from the corner cube CCb are equal. Here, details of the subroutine of step 6 are shown in FIG.

Next, referring to FIG. 11, in step 111, θα is read. Then, proceed to step 112.
In this step 112, from θα to _θF register 69d
A preset angle θ _F is subtracted from . continue,
At step 113, the result of the subtraction at step 112 is stored in the θy register 69c.

Referring again to FIG. 9, in step 7, θy
The steering motor 67 is controlled based on the angle θy stored in the register 69c. That is, in step 7, the steering motor 67 is controlled in the direction in which θy becomes zero. Therefore, when θ _F is set to 0, the moving body V
It is controlled to run directly under the line segment connecting the CCs.
On the other hand, when θ _F is set to either a positive or negative value, the moving body V is controlled to run on the lower right or lower left of the line segment connecting each corner cube CC. Next, in step 8, it is determined whether the timer 66 has timed up. If the timer 66 has not timed up, the operation of step 7 is repeated. After the operation in step 7 has been performed several times, it is determined in step 8 that the timer 66 has timed up, and in step 9 the angle θy stored in the θy register 69c is cleared. In the steering control of steps 5 to 9, the moving body V is brought closer to a predetermined trajectory.

As described above, in this embodiment, the moving body V is first controlled so as to be parallel to a predetermined trajectory, and then in the next step, the moving body V is controlled so as to approach the predetermined trajectory. When such alternating control is performed, the travel trajectory of the moving body V approaches a predetermined trajectory while drawing a zigzag as shown by the dashed line T in FIG. 3, and then follows the predetermined trajectory.

FIG. 12 is an illustrative view showing another embodiment of the invention. In this embodiment, the corner cubes CC are grouped into groups, and each group is separated by a fairly long distance. Now, mobile V is the first
Assuming that the moving body V is passing under the corner cube CC of the first group, the moving body V is steered based on the reflected light from the corner cube CC of the first group. However, if the moving body V passes through the first group of corner cubes CC, the steering control of the moving body V cannot be performed by the first group of corner cubes CC. Therefore, in this embodiment, the beam scanner BS' is tilted in the traveling direction of the moving body V to project the light beam PB onto the corner cube CC of the second group to perform steering control.

13 and 14 are external views of the beam scanner BS' shown in FIG. 12, especially FIG. 13 is a view seen from the side of the moving body V, and FIG. 14 is a view seen from the front of the moving body V. This is a diagram. In the figure, this beam scanner BS' detects a cylinder 1 housing a semiconductor laser and an optical system, a motor M1 for directly rotating this cylinder 1, and the rotation angle of the motor M1, as in Fig. 4. It also includes a rotary encoder EC1. The cylinder 1 and the motor M1 are held by a holding member 50. A central portion of the bottom side of the holding member 50 is connected to a motor M3 and a rotary encoder EC3. The motor M3 rotates the holding member 50 to tilt the light beam PB as shown in FIG. Rotary encoder EC3 detects the rotation angle of motor M3. Motor M3 and rotary encoder EC3 are held by holding member 51. A rotary encoder EC2 and a motor M2 are connected to the bottom surface of this holding member 51. Similarly to the motor M2 shown in FIG. 4, the motor M2 rotates the holding member 51 on a plane parallel to the plane of movement of the moving body V. Rotary encoder EC2
detects the rotation angle of motor M2.

With the configuration as described above, if the reflected light from the corner cube CC of the first group is no longer obtained, the motor M3 is rotated to project the light beam PB onto the corner cube CC of the second group. Other operations are almost the same as those in the embodiment shown in FIG. 4, and detailed explanation thereof will be omitted.

According to the other embodiment of the present invention described above, the number of corner cube CCs installed can be reduced, and equipment costs can be reduced. Incidentally, such an embodiment would be particularly effective for controlling the steering of an automobile in a tunnel, for example.

Note that although the above explanation has been about steering control of one moving body V, the corner cube CC can be shared by a plurality of moving bodies V at the same time. For example, on a road with multiple lanes, only one row of corner cubes may be arranged at the top of any lane. In that case, θ _F set for the moving object V running in each lane may be set differently to suit each lane. Further, in the above explanation, the case where the present invention is used for steering control of a moving body has been explained, but the present invention can also be applied to a course deviation detection device that warns or displays that a moving body has deviated from a predetermined trajectory. can do.

As described above, according to the present invention, it is only necessary to arrange the light reflecting means along a predetermined trajectory instead of the conventional track rail, and it is possible to obtain a very simple and inexpensive automatic steering system for a moving body. is obtained. Further, the light reflecting means can be shared by a plurality of moving bodies at the same time, and equipment costs can further be reduced. Further, according to the present invention, the light beam is rotated in two directions, one in a direction perpendicular to the plane on which the moving body travels and the other in a plane parallel to the plane, and two different rotation angles are set in relation to each of these rotation directions. Since this is detected and used as a parameter for guiding the moving object, the deviation angle of the moving direction of the moving object with respect to the guidance course and the vertical angle of the light reflecting means with respect to the moving object can be determined from these two types of parameters. As a result, the moving object can be guided while maintaining the vertical angle between the moving object and the light reflecting means at a predetermined angle. As a result, if there is an obstacle directly above the guiding course of the moving object, the light reflecting means can be placed to avoid it, and the guiding course of the moving object can be guided without being affected by surrounding obstacles. It also has the effect of being configurable.

[Brief explanation of drawings]

1 and 2 are diagrams for explaining the principle of an embodiment of the present invention, and FIG. 1 shows a moving body V
FIG. 2 is a diagram of the mobile body V viewed from the front. Figure 3 shows the corner cube.
FIG. 3 is a diagram showing an example of the arrangement of CCs and a traveling trajectory of a moving body V. FIG. Figure 4 is an external view of the beam scanner BS. FIG. 5 is a sectional view taken along the line - in FIG. 4. FIG. 6 is a preferred block diagram of one embodiment of the present invention. FIG. 7 and FIG. 8 are illustrative diagrams for explaining the steering control mode of an embodiment of the present invention. Figures 9 to 11 show CPU6
3 is a flowchart for explaining the operation of step 3. FIG. 12 is an illustrative view showing another embodiment of the invention. 13 and 14 are external views of the beam scanner BS' shown in FIG.
FIG. 4 is a diagram of the moving body V seen from the front. In the figure, V is a moving body, BS is a beam scanner, CC is a corner cube, M1 to M3 are motors, EC1 to EC3 are rotary encoders,
4 and 3 are light receiving sections, and 11 is a semiconductor laser.

Claims (1)

[Scope of Claims] 1. An automatic steering device for a movable body that performs steering control of a movable body in order to move the movable body along a predetermined trajectory, comprising: a plurality of light reflecting means for reflecting light in the direction of the incident light; a light beam generating means provided on the movable body for generating a light beam having a predetermined spread; a light beam generating means provided in association with the light beam generating means; a light beam scanning means for rotationally scanning the light beam generated from the light beam generating means in the direction of the light reflecting means; provided in association with the light beam scanning means and receiving reflected light from the light reflecting means; a rotation angle detection means that is provided in association with the light beam scanning means and detects the current rotation angle of the light beam scanning means in response to the light receiving output of the light receiving means; The light beam scanning means includes a steering direction control means for controlling a steering direction of the movable body based on the rotation angle detected by the rotation angle detection means, and the light beam scanning means is configured such that the light beam causes the mobile body to travel. a first light beam scanning device that rotates and scans the light beam in a direction perpendicular to a plane on which the moving object moves; and a second light beam scanning device that rotates the light beam on a plane that is parallel to the plane on which the moving body runs. , the rotation angle detection means includes: an aperture angle detection means for detecting an aperture angle of reflected light from the light reflection means with respect to a predetermined reference rotation angle in the first light beam scanning means; parallel rotation angle detection means for detecting a rotation angle when the rotation angle of the light beam scanning means becomes parallel to the predetermined trajectory, and the steering direction control means includes comprising means for controlling the steering direction of the movable body based on the opening angle detected by the angle detection means and the parallel rotation angle detected by the parallel rotation angle detection means;
Automatic steering device for mobile objects. 2. The light reflecting means has a plurality of groups arranged at relatively short intervals, each group is arranged at relatively long intervals, and the light beam is scanned in the direction of one of the groups. 2. The automatic steering system for a moving body according to claim 1, further comprising means for tilting a scanning direction of the light beam scanning means with respect to a plane on which the moving body runs.