JPH0560122B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a guidance device for guiding an unmanned vehicle such as an unmanned guided vehicle along a guide member provided on the side of the unmanned vehicle. The present invention relates to a guiding device that guides a provided sensor by bringing it into contact with a lateral guide member.

(Prior art) In a system that guides an unmanned vehicle by bringing a sensor installed in the unmanned vehicle into contact with a side guide member, the guide members may not be provided continuously due to ground equipment, etc. be. In such a case, a movable guide member is provided at the place where the guide member is discontinuous, and the movable guide member is moved to the operating position only when the unmanned vehicle passes there. It is conceivable to arrange that the fixed guide member and the fixed guide member form a continuous surface, or to switch to another guiding device such as an electromagnetic induction device for guidance where the guide member becomes discontinuous.

(Problems to be Solved by the Invention) However, in the case of using a movable guide member, the movable guide member must be provided in addition to the normal fixed guide member, and the movable guide member If the movable guide member is moved manually, the problem arises that human work will be involved in the unmanned guidance device and the effectiveness of unmanned vehicle guidance will be drastically reduced.If the movable guide member is moved automatically, A separate drive mechanism and a control device for controlling the timing of movement are required, which raises the problem of increased equipment costs.

In addition, if the guide member is discontinuous and the guide is switched to another guide device for guidance, an on-vehicle control device including a pick-up coil etc. is installed separately from the contact type guide device, and a guide wire etc. Since the guide body must be provided separately from the fixed guide member for normal running, and means for switching between these two types of guide devices must also be provided, problems arise in that the mechanism is complicated and the cost is high.

(Means for solving the problems) In order to solve these problems, the present invention has the following features:
In an unmanned vehicle guidance device equipped with a contact type sensor that detects the relative position of the unmanned vehicle with respect to the guide member by contacting the guide member provided on the side of the running path of the unmanned vehicle, (a) the contact type sensor is attached to the guide member. Discontinuous point detection that detects type 1 discontinuous points that transition from a contactable state to a non-contactable state, and conversely, type 2 discontinuous points that transition from a non-contactable state to a contactable state and (b) when the discontinuity detection device detects a type 1 discontinuity, the contact sensor is retracted to a non-operating position away from the guide member, and the discontinuity detection device detects a type 2 discontinuity. (c) A sensor moving device that returns the contact type sensor to the operating position where it contacts the guide member when a continuous point is detected; The running direction of the unmanned vehicle is controlled based on the output signal, and after detecting the first type discontinuity point, the running direction of the unmanned vehicle is controlled without being based on the output signal of the contact sensor, and the second type discontinuity point is detected. After the contact type sensor is returned to the operating position upon detection of the contact type sensor, a control device is provided which again controls the running direction based on the output signal of the contact type sensor.

Note that in one of the preferred embodiments of the present invention, a plurality of contact sensors are provided at a certain distance in the traveling direction of the unmanned vehicle, and a discontinuity point detection device is provided corresponding to each of the contact sensors. and, in a state where a part of the plurality of contact sensors is between the first type discontinuity point and the first type discontinuity point, the control device is configured to control the control device based on the output signals of the remaining contact sensors. In one embodiment, the direction of travel is controlled, and in another embodiment, the control device is used to control the position of the unmanned vehicle in a state where the contact sensor is between the first type discontinuity point and the second type discontinuity point. There is a mode in which the running direction is controlled according to a predetermined program without obtaining information regarding the vehicle.

(Function) The unmanned vehicle guidance system according to the present invention configured as described above measures the distance between the sensor and the guide member by bringing the contact type sensor into contact with the guide member where the guide members are continuous; Based on the distance and traveling direction of the unmanned vehicle relative to the guide member obtained thereby, the steering system is controlled to control the traveling direction of the unmanned vehicle.

When the discontinuity point detection device detects the first type discontinuity point of the guide member, the sensor moving device moves the sensor to a non-operating position, and if there are multiple sensors, the remaining sensors are used. and provide guidance. However, if the above sensor is composed of two contact sensors, only one contact sensor is in the operating position at this time, and although it can measure the distance to the guide member, it cannot measure the direction. In this case, the unmanned vehicle is guided so that the distance to the guide member is always constant.

In addition, if multiple contact sensors are not installed, or even if multiple sensors are installed but all of them become uncontactable, unattended operation can be performed without using contact sensors and by controlling according to a predetermined program. All you have to do is guide the vehicle. For example, if the traveling path in the part where the guide member is not continuous is straight, the steering is fixed to the direction in which the unmanned vehicle is traveling when it reaches the first type discontinuity point, and the unmanned vehicle is guided in a straight line. If the travel path is curved in a portion where the guide member is not continuous, the unmanned vehicle is guided based on pre-stored information about the curve.

When the discontinuous point detection device detects the second type discontinuous point of the guide member, the contact type sensor is returned to the operating position by the sensor moving device to return to steady guidance.

(Effects of the Invention) As described above, according to the unmanned vehicle guidance device of the present invention, the unmanned vehicle can be guided even in areas where the side guide members are discontinuous, and the contact type sensor that detects the guide members can be used to guide the unmanned vehicle. Since there is no need to install any other control mechanism in addition to the one type of guidance device, the configuration is simple, the operation is easy, and the cost can be reduced.

Furthermore, according to the device according to claim 2 of the present invention, even discontinuous portions of the guide member can be guided by the contact sensor directly, so that the precision of the guidance is high and the guidance is reliable. A unique effect can be obtained.

Further, in the case of the device according to claim 3 of the present invention, the number of contact sensors may be one,
This has the effect of making it possible to guide unmanned vehicles at extremely low cost.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIGS. 1 and 2 show a counterbalanced forklift, which is an example of the guided object of the present invention. In the figure, reference numeral 2 denotes a vehicle body, with the front wheels serving as driving wheels 4 and the rear wheels serving as steering wheels 6.
The vehicle body 2 has a balance weight 8 behind it.
A head guard 10 is also provided above.
At the front of the vehicle body 2, as is well known, cargo handling devices including a fork 12, an outer mast 14, and an inner mast 16 are provided.
The inner mast 16 is guided vertically by the outer mast 14 via rollers, and this inner mast 16 is further guided by a lift bracket 18.
It is now designed to guide you. A finger bar 20 is attached to the lift bracket 18 via a side shift attachment 19, and a pair of forks 12 are attached to the finger bar 20. When the inner mast 16 is raised by the operation of the lift cylinder 22, the lift bracket 18, finger bar 20, and fork 12 are raised integrally by a chain (not shown). The lower end of the outer mast 14 is connected to the vehicle body 2.
The load handling device including the outer mast 14 is tilted forward or backward by the operation of the tilt cylinder 24. Further, by the operation of the side shift cylinder 26, the finger bar 20 and the fork 12 are side-shifted relative to the lift bracket 18 in the left-right direction of the vehicle body 2.

This forklift 28 can be operated manned by a driver, but it can also be operated unmanned by direct guidance using a guide wall 30 as shown in FIG. The guide wall 30 serves as a guide member.

Lateral displacement sensors 32 and 34 are attached to the sides of the vehicle body 2 to detect the distance and traveling attitude of the vehicle body 2 with respect to the guide wall 30 by contacting the guide wall 30. The lateral displacement sensor 32 includes a box 36 fixed to the vehicle body 2, as shown in FIG. 3, and an entry/exit member 38 is provided within the box 36. The entrance/exit member 38 is a longitudinal body portion 4
0, and a cross bar 4 fixed at right angles to one end and the upper surface of the intermediate portion of the main body 40, respectively.
2 and 43, and a slider 44 fixed to the middle lower surface of the main body 40, and the slider 44 is connected to the wall surface 46 of the guide wall 30 (hereinafter referred to as the guide wall surface 46) by a guide rail 45 fixed to the box 36. ) is movably supported in a direction perpendicular to This entry/exit member 38 has a spring 47 at one end of the cross bar 42 parallel to the main body 40.
One end is connected, and the other end is connected to the inner peripheral surface of the box 36 on the side far from the vehicle body.
It is constantly biased towards the 6 side. This entrance/exit member 38
The amount of movement in and out of the box 36 is detected by a linear potentiometer 48.

On the other hand, a rack 50 is fixed between the other end of the cross bar 42 and the cross bar 43 in parallel to the main body part 40. A pinion 56 fixed to the rotation shaft of a lateral displacement sensor motor 54 attached to the bottom surface of the box 36 is engaged with the rack 50, and as the motor 54 rotates in both positive and negative directions, the in/out member 38 is moved against the guide wall surface 46. It is now possible to advance and retreat against the enemy. Furthermore, this motor 5
4 is provided with an electromagnetic brake 58 so as to be able to maintain the retractable member 38 at an arbitrary position against the force of the spring 47. When both the electromagnetic brake 58 and the motor 54 are off, the retractable member 38 is constantly pressed against the guide wall surface 46 by the elastic force of the spring 47, as described above.

A contact plate 70 having a U-shaped cross section is attached to the distal end of the main body 40 of the entry/exit member 38 so as to be rotatable around a vertical axis 72 at an intermediate portion. This contact plate 7
0 is two symmetrically arranged springs 74
The rollers 76 are normally held in a neutral position perpendicular to the main body 40, and as shown in FIG. I was being treated,
When an obstacle such as a convex portion exists on the guide wall surface 46, the contact plate 70 rotates around the axis of the shaft 72 to easily overcome the obstacle. Note that a crawler belt (circling belt) made of a flexible material is wound around both rollers 76, and the crawler belt is attached to the guide wall surface 4.
If a large number of balls or rollers are rotatably arranged on the contact plate 70, friction with the guide wall surface 46 can be avoided and the followability of the lateral displacement sensors 32 and 34 can be improved. and improved durability. Furthermore, an optical sensor 78 is fixed to the upper surface of the contact plate 70 at a position close to the shaft 72 via a support 79. The optical sensor 78 is fixed in a direction parallel to the moving direction of the in/out member 38 and away from the vehicle body 2, and detects the presence or absence of the guide wall surface 46.

The other lateral displacement sensor 34 also has a similar configuration,
The distance between the vehicle body 2 and the guide wall surface 46 is detected by the output signals of the linear potentiometers 48 of both lateral displacement sensors 32 and 34. Further, the inclination (running posture) of the vehicle body 2 about a vertical line with respect to the guide wall surface 46 is detected based on the difference in output between both linear potentiometers 48 . In addition, below, the optical sensor 78 provided in the lateral displacement sensor 32 is represented by the reference numeral 78a, the linear potentiometer 48 is also indicated by the reference numeral 48a, and the optical sensor 78 provided in the lateral displacement sensor 34 is indicated by the reference numeral 78b, which is also the linear potentiometer. The yometer 48 will be represented by the reference numeral 48b.

Further, the forklift 28 is provided with a microprocessor and various control circuits and mechanisms described below. That is, as shown in FIG.
An I/O interface 124 is connected to 22, and the I/O interface 124 includes a travel control circuit 140, a steering control circuit 142,
A brake control circuit 144, a cargo handling control circuit 146, and a lateral displacement sensor control circuit 147 are connected. A drive motor 148 for driving the drive wheels 4 is connected to the travel control circuit 140, and a steering motor 150 for steering the steering wheel 6 is connected to the steering control circuit 142. Also,
The brake control circuit 144 includes a drive motor 1
An electromagnetic brake 152 that brakes the 48 motor shafts is connected to the electromagnetic valve 1 that controls oil pressure to a hydraulic brake 154 that brakes each drive wheel 4.
56 are connected. The cargo handling control circuit 146 includes the lift cylinder 22 and the tilt cylinder 2.
4. A solenoid valve 158 is connected to control the supply of hydraulic pressure to the side shift cylinder 26, etc.
By controlling the operation of the electromagnetic valve 158, the fork 12 and the lift bracket 18
The operations of the cargo handling device 160 including the following will be controlled. The lateral displacement sensor control circuit 147 includes:
Lateral displacement sensor motor 54 and this motor 54
An electromagnetic brake 58 is connected to brake the rotation.

The microprocessor 120 also operates linear potentiometers 48a, 48b provided on the lateral displacement sensors 32, 34, and optical sensors 78a, 78.
8b and other sensors and switches according to a program stored in advance in the memory 122, and automatically controls the steering, acceleration/deceleration, stop, temporary standby, cargo handling work, etc. of the forklift 28. .

Parts of the above program that are closely related to the present invention will be explained below with reference to the flowchart shown in FIG. 6 and the transition diagrams of the guidance states of the forklift 28 shown in FIGS. 7 to 10.

The microprocessor 120 constantly monitors the distance and direction of the forklift 28 with respect to the guide wall 46 and controls the steering motor 150 at regular intervals as shown in FIG. 6, which is part of the program. Run the induction routine.

That is, the forklift 28 normally advances along a continuous portion of the guide wall surface 46 as shown in FIG. 7, and in this state, step S10 (hereinafter simply referred to as S10) in FIG. The same applies to other steps.) Since the optical sensor 78a provided in the lateral displacement sensor 32 detects the side guide wall surface 46 and is in the ON state, it is determined to be YES and the steps from S12 onwards are executed. is executed, but since flag A indicating the immediately previous operating state of the lateral displacement sensor 32 is also set to ON indicating that the lateral displacement sensor 32 is in the operating position, S12 is determined to be NO and S22 is executed. , the amount of input and output of the lateral displacement sensor 32 from the linear potentiometer 48a x1
is loaded. This variable x1 will be used as one variable of a function F that determines the direction in which the forklift 28 should travel in a later step.

Next, the optical sensor 78b provided in the lateral displacement sensor 34 where S40 is executed is also connected to the side guide wall surface 46.
is detected and is in the ON state, so S42 to S50 are executed in exactly the same manner as above, and the amount x2 of movement in and out of the lateral displacement sensor 34 is read from the linear potentiometer 48b. Using the variables x1 and x2 read in this way, the amount of change F(x1, x2) in the steering to be changed is calculated in S52, and F(x1, x2) is output to the steering control circuit 142 in S56. Steering motor 1
50 is rotated and the necessary steering operations are performed. Note that when both the lateral displacement sensors 32 and 34 are in the non-operating position and x1 = n and x2 = m, F(x1, x2) = L in S52, but now F(x1, x2)≠L, so S54
It is judged as NO. Here, sufficiently large values are adopted for n, m, and L, and values other than normal values are expressed.

Next, the forklift 28 moves to the guide wall surface 46.
When the optical sensor 78a of the lateral displacement sensor 32 detects the first type discontinuous point, the OFF
Therefore, the determination in S10 is NO, and the steps from S30 onwards are executed. At this time, immediately before this, the lateral displacement sensor 32 is in the operating position and the flag A is ON, so it is judged as YES in S30, the steps from S32 to S36 are executed, and the lateral displacement sensor 32 is activated by the motor 54. Due to the rotation of the car body 2
Then, to hold that position, the electromagnetic brake 58 is turned ON, the lateral displacement sensor 32 is locked, and the flag A is turned OFF.
8, and the lateral displacement sensor 32 is placed in the non-operating position as shown in FIG. In this state, the optical sensor 78a is always OFF, and the optical sensor 78a is always OFF.
Since 8b is ON, when this guidance routine is executed, S10, S30 and S38 are executed and S40 is
leading to. Since x1 is set as a constant n in S38, the steering change amount F is calculated as F(x1, x2) in S52.
= F(n, x2), and in the steps from S40 to S56, the lateral displacement sensor 34 in the operating position
The steering motor 150 is controlled using only the amount x2 of the movement in and out of the movement member 38 based on the output signal of the linear potentiometer 48b as a variable, and the forklift 28 is guided.

When the forklift 28 moves in this state and the optical sensor 78a detects the second type discontinuity point,
It was judged as YES in both S10 and S12, and S14
The steps from S22 to S22 are executed to unlock the lateral displacement sensor 32, and as shown in FIG. 9, the lateral displacement sensor 32 is moved to the operating position, and the flag A is set to ON again. The in/out amount x1 of the lateral displacement sensor 32 is read from the linear potentiometer 48a, and the in/out amount x2 of the lateral displacement sensor 34 is read in S50.
In addition, the steering change amount F (x1, x2) in S52
is calculated, and the steering system is controlled in S56.

As the forklift 28 further advances, the optical sensor 78b detects the first type discontinuity point, and similarly to the case where the optical sensor 78a detects the first type discontinuity point, it is determined NO in S40, and , flag B indicating the immediately previous operating state of the lateral displacement sensor 34 is set to ON, so it is judged as YES in S60 and the process starts from S62.
The steps up to S66 are executed, and the lateral displacement sensor 34 is brought to the non-operating position as shown in FIG.
Since x2 is set as a constant m in S68, the steering change amount is set as F(x1, x2) = F(x1, m) in S52, and is based only on the variable x1 obtained from the lateral displacement sensor 32 in the operating position. Steering motor 15
0 will be controlled.

In this state, the forklift 28 is further guided, and when the lateral displacement sensor 34 reaches the continuous part of the guide wall surface and the optical sensor 78b detects the second type discontinuous point, the optical sensor 78a detects the second type discontinuous point. As in the case described above, from S44 to S48, the lateral displacement sensor 34 is moved to the operating position as shown in FIG. 7, and normal control by the two lateral displacement sensors 32 and 34 is performed again.

In this way, the movement of the forklift 28 between the first type discontinuity point and the second type discontinuity point can be guided by at least one of the lateral displacement sensor 32 or the lateral displacement sensor 34. .

However, if both the lateral displacement sensors 32 and 34 are in the non-operating position and x1 = n and x2 = m, F(n, m) = L is calculated in S52, so S54
If the answer is YES, a predetermined exception handling routine such as derailment handling is executed.

Although the above embodiment is an example in which there are two contact sensors, the unmanned vehicle guidance device according to the present invention can be realized by guiding the unmanned vehicle using the same control even in the case where there are three or more contact sensors. .

On the other hand, when a single contact type sensor is used, a rotary potentiometer for detecting the rotation of the contact plate 70 is provided in addition to a linear potentiometer for the lateral displacement sensor, so that the direction as well as the distance relative to the guide wall can be detected. Then, in the part where the guide wall surface is continuous, normal control is performed with this single lateral displacement sensor, and when the unmanned vehicle reaches the discontinuous part of the guide member, the lateral displacement sensor moves from the first kind of discontinuity point of the guide member to the second one. In the state between the seed discontinuity point, the steering motor 1
The unmanned vehicle may be guided by a program control method that controls 50. That is, if the course of the discontinuous portion of the guide wall surface is a straight line, the above-mentioned traveling direction guidance data string is made up of all 0s, and if it is a curved line, it is made up of a data string corresponding to the curve. That's what I do. In the latter case, the discontinuous portion of the guide member is actually operated by a man,
Another method is to store the guidance data string regarding the direction of travel obtained at that time and use that data string when driving unmanned. Of course, the program control method described above can be applied even when there is more than one contact type sensor.

Alternatively, if a rotary potentiometer is mounted on each of the plurality of contact sensors so that the linear potentiometer can detect the distance and the direction in which the unmanned vehicle is traveling, it is possible to detect the discontinuity of the guide member. The vehicle can be more reliably guided in this area.

Further, in the above embodiment, the sensor moving device includes a lateral displacement sensor motor 54, a pinion 56, a rack 50, and an electromagnetic brake 58, but this can be constructed using an actuator such as an electromagnetic brake or a hydraulic cylinder. You can also.

Although no other examples are given, the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a forklift, which is an unmanned vehicle, equipped with a guidance device according to an embodiment of the present invention, and FIG. 2 is a front view thereof. FIG. 3 is a plan view of a contact type sensor that is part of a guidance device according to an embodiment of the present invention, and FIG. 4 is a front view thereof. FIG. 5 is a control block diagram of the guidance device, and FIG. 6 is a flowchart showing a portion of the control program closely related to the present invention. Moreover, FIGS. 7 to 10 are transition diagrams of the guidance state of the unmanned vehicle. 28...forklift, 30...guide wall,
32, 34... Lateral displacement sensor, 38... In/out member, 46... Wall surface (guide wall surface), 48... Linear potentiometer, 50... Rack, 54...
(For lateral displacement sensor) Motor, 56...pinion,
58... Electromagnetic brake, 70... Contact plate,
78... Optical sensor, 120... Microprocessor, 142... Steering control circuit, 147...
...Lateral displacement sensor control circuit, 150...Steering motor.

Claims (1)

[Scope of Claims] 1. An unmanned vehicle guidance device comprising a contact type sensor that detects the relative position of the unmanned vehicle with respect to the guide member by contacting a guide member provided on the side of the running path of the unmanned vehicle, comprising: A first type discontinuity point where the sensor transitions from a state where it can contact the guide member to a state where it cannot contact the guide member, and a second type discontinuity point where the sensor transitions from a state where it cannot contact the guide member to a state where it can contact it. a discontinuity point detection device for detecting the discontinuity point; and when the discontinuity point detection device detects the first type discontinuity point, the contact type sensor is evacuated to a non-operating position away from the guide member, and the discontinuity inspection is performed. a sensor moving device that returns the contact type sensor to an operating position where it contacts the guide member when the output device detects the second type discontinuity point; Until the point is detected, the running direction of the unmanned vehicle is controlled based on the output signal of the contact sensor, and after the first type discontinuity point is detected, the direction of travel of the unmanned vehicle is controlled based on the output signal of the contact sensor. The running direction is controlled, and after the second type discontinuity point is detected and the contact sensor is returned to the operating position, the running direction is again controlled based on the output signal of the contact sensor. An unmanned vehicle guidance device characterized by comprising a control device. 2. A plurality of the contact type sensors are provided at a certain distance in the traveling direction of the unmanned vehicle, and the discontinuity point detection device is provided corresponding to each of the contact type sensors, and the control device However, in a state where some of the plurality of contact sensors are between the first type discontinuity point and the second type discontinuity point, the direction of travel is determined based on the output signals of the remaining contact sensors. An unmanned vehicle guidance system according to claim 1, which performs control. 3. The control device operates according to a predetermined program without obtaining information regarding the position of the unmanned vehicle in a state where the contact sensor is between the first type discontinuity point and the second type discontinuity point. The unmanned vehicle guidance system according to claim 1, wherein the unmanned vehicle guidance system controls the traveling direction.