JPS6247713A - Guiding equipment for unmanned carrier - Google Patents

Abstract

PURPOSE:To reduce the cost and to increase the guidance accuracy by shunting a contact type sensor to an inactive position and activating other sensors to guide an unmanned truck in case the first type discontinuous point of a guide member is detected. CONSTITUTION:The lateral displacement sensors 32 and 34 are attached to the side of the body 2 of a forklift 28 to detect the distance and the driving posture of the forklift 28 with a contact secured between a guide wall 30 and a guide wall surface 46. These sensors 32 and 34 contain the input and output members put into a box and are always energized toward the wall surface 46. At the same time, both sensors 32 and 34 are movable. An optical sensor detects the presence or absence of the surface 46. Then a discontinuous point is detected where the sensors 32 and 34 are shifted to a contact unable state with the surface 46 from a contact enable state with the surface 46. In such a case, both sensors 32 and 34 are shifted to the inactive positions distant away from the surface 46. While the sensors 32 and 34 are reset to the active positions when a discontinuous point to the contact enable state from the contact unable state is detected. Thus, an unmanned carrier is controlled according to the outputs of the sensors 32 and 34.

Description

Detailed Description of the Invention (Industrial Application Field) 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, and in particular to an 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 that the guide member and the fixed guide member form a continuous surface, or that where the guide member becomes discontinuous, the guide member may be switched to a magnetic induction device such as an electromagnetic induction device for guidance.

(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 When manually moving a movable or type guide member, there is a problem that human work is involved in the unmanned guidance device and the effectiveness of unmanned vehicle guidance is drastically reduced. A problem arises in that a drive mechanism and a control device for controlling the timing of movement are separately required, which increases the equipment cost.

In addition, when switching to another guidance device for guidance at a place where the guide member becomes discontinuous, an on-vehicle control device including a pickup coil, etc. is provided separately from the contact-type guidance 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 makes contact with a guide member provided on the side of the running path of the unmanned vehicle to determine the relative position of the unmanned vehicle with respect to the guide member. In an unmanned vehicle guidance system equipped with a contact type sensor for detecting, (a) a type 1 discontinuity point where the contact type sensor transitions from a state in which it can contact the guide member to a state in which it cannot contact it; (b) when the discontinuous point detection device detects a type 1 discontinuous point, a contact type discontinuous point is detected; a sensor moving device that retracts the sensor to a non-operating position away from the guide member and returns the contact type sensor to an operating position in contact with the guide member when the discontinuity point detection device detects a second type discontinuity point; (c) The running direction of the unmanned vehicle is controlled based on the output signal of the contact type sensor until the discontinuity point detection device detects the first type discontinuity point, and after the first type discontinuity point is detected, the contact type sensor The running direction of the unmanned vehicle is controlled without being based on the output signal of the sensor, and after the second type discontinuity point is detected and the contact sensor is returned to the operating position, the output signal of the contact sensor is used again. The system is equipped with a control device that controls the running direction based on the following.

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. , Gah, the above control device is configured to control the output signals of the remaining contact sensors when some of the contact sensors are between the first type discontinuity point and the second type discontinuity point. In one embodiment, the running direction is controlled based on the contact sensor, and in another embodiment, the control device is unmanned when the contact sensor is between the first type discontinuity point and the second type discontinuity point. There is a mode in which the driving direction is controlled according to a predetermined program without obtaining information regarding the position of 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 is moved to a non-operating position by the sensor moving device, and if there are multiple sensors, the remaining sensors guide the discontinuity point. I do. 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 from the guide member is always constant.

In addition, if multiple contact sensors are not installed, or if multiple contact sensors are installed but all of them become uncontactable, unmanned vehicles may be controlled according to a predetermined program without using contact sensors. Just guide it. For example, if the running path is straight where the guide member is not continuous, the steering wheel is fixed in the direction in which the unmanned vehicle is traveling when it reaches the first type discontinuity point to guide the unmanned vehicle 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 discontinuity point detection device detects the second type discontinuity 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 is low.

Furthermore, according to the device recited in claim 2 of the present invention, guidance can be performed using a direct guidance method using a contact sensor even in discontinuous portions of the guide member, so guidance accuracy is high and reliable guidance is possible. A unique effect can be obtained.

Further, in the case of the device according to claim 3 of the present invention, only one contact type sensor is required, and an effect can be obtained that enables an extremely low-cost unmanned vehicle with BP of 4.

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

FIGS. 1 and 2 show a counterbalance forklift truck, 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 is provided with a balance weight 8 at the rear and a hand guard 10 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 by the outer mast 14 in the vertical direction via rollers, and the inner mast 16 further guides the lift bracket 18. A finger bar 20 is attached to the lift bracket 18 via a side shift cylinder 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 I.18. The finger bar 20 and the fork 12 are raised together.

The lower end of the outer mast 14 is attached to the vehicle body 2 so as to be rotatable about one axis, and the operation of the tilt cylinder 24 causes the cargo handling equipment including the outer mast 14 to be tilted forward or backward. 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. 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 entry/exit member 38 includes a longitudinal main body 40, crossbars 42 and 43 fixed at right angles to one end and the upper surface of the intermediate portion of the main body 40, respectively, and a slider fixed to the lower surface of the intermediate portion of the main body 40. 44, and the slider 44 is supported movably in a direction perpendicular to a wall surface 46 (hereinafter referred to as guide wall surface 46) of the guide wall 30 by a guide rail 45 fixed to the box 36. This entry/exit member 38 includes a spring 4 parallel to the main body 40 at one end of the cross spar 42.
7 is connected to one end, and the other end is connected to the inner peripheral surface of the box 36 on the side far from the vehicle body, and the in/out member 38 is always urged toward the guide wall surface 46 by this spring 47. The amount of movement of the moving member 38 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 spar 42 and the cross spar 43 in parallel to the main body 40. In this rack 50, a fixed pinion 56 is engaged with the rotating shaft of a lateral displacement sensor motor 54 attached to the bottom surface of the box 36, and the rotation of the motor 54 in both positive and negative directions moves the in/out member 38 relative to the guide wall surface 46. It is now possible to advance or retreat. Furthermore, this motor 5
4 is provided with an electromagnetic brake 58, which allows the retractable member 38 to be maintained 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 shaft 72 at an intermediate portion. This contact plate 70 has two symmetrically arranged
It is normally held in a neutral position perpendicular to the main body 40 by two springs 74, as shown in FIG.
A roller 76 is rotatably attached to a position slightly exposed to the outside from the notch at both ends, and when an obstacle such as a protrusion exists on the guide wall surface 46, the contact plate 70 moves around the axis of the shaft 72. It is designed to rotate and easily overcome it. Note that it is possible to wrap a circumferential band (orbital belt) made of a flexible material around both rollers 76 so that the track rotates in contact with the guide wall surface 46, or to rotatably arrange a large number of balls and rollers on the contact plate 70. If provided, friction with the guide wall surface 46 is avoided, and the followability and durability of the lateral displacement sensors 32 and 34 are improved. 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,
The presence or absence of the guide wall surface 46 is detected.

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

Further, the forklift 28 is equipped with a microprocessor and various control circuits and mechanisms described below. That is, as shown in FIG. 5, an I10 interface 124 is connected to the microprocessor 120 together with a memory 122, and the I10 interface
24 is a travel control circuit 140. Steering control circuit 1
42° 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. Further, an electromagnetic brake 152 that brakes the motor shaft of the drive motor 148 is connected to the brake control circuit 144, and an electromagnetic valve 156 that controls the oil pressure to the hydraulic brake 154 that brakes each drive wheel 4.
is connected. The cargo handling control circuit 146 includes the lift cylinder 22. An electromagnetic valve 15 that controls the supply of hydraulic pressure to the tilt cylinder 24°, side shift cylinder 26, etc.
8 is connected, and by controlling the operation of the electromagnetic valve 158, the operation of the cargo handling device 160 including the fork 12 and the lift bracket 18 is controlled. A lateral displacement sensor motor 54 and an electromagnetic brake 58 for braking the rotation of this motor 54 are connected to the lateral displacement sensor control circuit 147 .

The microprocessor 120 also controls the linear potentiometers 48 provided on the lateral displacement sensors 32 and 34.
The operating signals of various sensors and switches including the optical sensors 78a and 78b are processed according to the program stored in the memory 122 in advance to control the steering, acceleration, deceleration, stop, and special operations of the forklift 28. Automatically controls waiting, cargo handling, etc.

Below, the parts of the above program that are closely related to the present invention are explained in the flowchart shown in FIG. 6 and in FIGS.
The explanation will be made according to a transition diagram of the guidance state of the forklift 28 shown in FIG.

The microprocessor 120 constantly monitors the distance and direction of the forklift 28 with respect to the guide wall surface 46, and performs a guidance routine shown in FIG. 6, which is part of the program, at regular intervals in order to control the steering motor 150. Execute.

That is, the forklift 28 normally moves along a continuous portion of the guide wall surface 46 as shown in FIG. The same applies to steps 312 and below), the optical sensor 78a provided in the lateral displacement sensor 32 detects the side guide wall surface 46 and is in the ON state, so it is determined YES and steps 312 and below are executed. However, since flag A indicating the immediately previous operating state of the lateral displacement sensor 32 is also turned ON indicating that the lateral displacement sensor 32 is in the operating position, it is determined No in S12 and 322 is executed. linear potentiometer 4
The movement 1txl of the lateral displacement sensor 32 is read from 8a. This variable X1 will be changed to forklift 2 in a later step.
This is one variable of the function F that determines the direction in which the 8.

Next, S40 is executed, but since the optical sensor 78b provided in the lateral displacement sensor 34 also detects the side guide wall surface 46 and is in the ON state, all (3)
42 to 350 are executed linear potentiometer 48
The in/out 1lx2 of the lateral displacement sensor 34 is read from b. Using the variables xi and x2 read in this way, the amount of change F (xi, x2) in the steering to be changed is calculated in S52, and F (xi, x2) is output to the steering control circuit 142 in S56. The steering motor 150 is rotated, and a necessary steering operation is performed. In addition, the lateral displacement sensor 32.3
4 are in the non-operating position and xl = n and x2 = m, F (xi, x2)' = L in S52, but now F (xl, x2)≠ Therefore, 354 is determined as NO. Here, sufficiently large values are adopted for n, m, and L, and values other than normal values are expressed.

Next, when the forklift 28 reaches the discontinuous part of the guide wall surface 46 and the optical sensor 78a of the lateral displacement sensor 32 detects the first type discontinuous point, it turns OFF, so S10
If the answer is NO in step 830, steps 830 and subsequent steps 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 330 is determined as YES, steps S32 to 336 are executed, and the lateral displacement sensor 32 is in the operating position of the motor 54. The lateral displacement sensor 3 is pulled toward the vehicle body 2 by rotation, and then the electromagnetic brake 58 is turned on to maintain that position.
2 is locked, flag A is reset to OFF, and 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 78b is ON, so when this guidance routine is executed, SIO, S30, and 338 are executed, and the process reaches S40. 338, xl is taken as a constant n, so S
In calculating the steering change iF at 52, F (xi,
x2)=F (n.

x2), and in the steps from S40 to S56, the steering motor 15 is controlled using only the in/out amount x2 of the in/out member 38 based on the output signal of the linear potentiometer 48b of the lateral displacement sensor 34 in the operating position as a variable.
0 will be controlled and the forklift 28 will be guided.

In this state, the forklift 28 moves forward, and the optical sensor 78
When a detects the second type discontinuity point, YES is determined in both S10 and S12, steps from S14 to 322 are executed, and the lateral displacement sensor 32 is unlocked, as shown in FIG. , the lateral displacement sensor 32 is moved to the operating position, flag A is set to ON again, and the lateral displacement sensor 32 is moved in and out from the linear potentiometer 48a (itxl is read and S50
The amount of movement x2 of the lateral displacement sensor 34 read in
In addition, in S52, the steering change amount F (xi, x
2) is calculated, and the steering system is controlled in S56.

The forklift 28 further advances and the optical sensor 78b
detects the first type discontinuous point and the optical sensor 78a detects the first type discontinuous point, the result is NO in S40 and indicates the immediately previous operating state of the lateral displacement sensor 34. Since flag B is ON, YES is determined at 360, steps S62 to S66 are executed, the lateral displacement sensor 34 is set to the non-operating position as shown in FIG. 10, and x2 is set to a constant at S68. m, so S52
The amount of steering change is F (xi, x2) = F (x
i, m), and the steering motor 15 is controlled only by the variable x1 obtained from the lateral displacement sensor 32 in the operating position.
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 discontinuity point, the optical sensor 78a
As shown in FIG.
The two lateral displacement sensors 32 are moved to the working position again.
, 34 is performed.

In this way, it is possible to guide the movement of the forklift 28 from the first type discontinuity point to the second type discontinuity point using only one lateral displacement sensor 32 or 34. .

However, if both the lateral displacement sensors 32 and 34 are in the non-operating position and xl = n and x2 = m, F (n, m) = L is calculated in S52, and YES is determined in 354 at S52. Then, a predetermined exception handling routine such as derailment handling is executed.

Although the above embodiment is an example in which the number of contact sensors is 211i1, the unmanned vehicle guiding device according to the present invention can be realized by guiding the unmanned vehicle using the same control even when there are three or more contact sensors.

On the other hand, when there is a single contact type sensor, the contact plate 70 is used together with the linear potentiometer for the lateral displacement sensor.
A rotary potentiometer is installed to detect the rotation of the guide member, so that it can detect both the distance and the direction to the guide wall surface.In the part where the guide wall surface is continuous, normal control is performed using this single lateral displacement sensor, and the unmanned vehicle can detect the rotation of the guide member. When the lateral displacement sensor reaches the discontinuous part of the guide member and is located between the first type discontinuity point and the second type discontinuity point, the data that fixedly guides the traveling direction stored in the memory in advance is used. The unmanned vehicle may be guided by a program control method that controls the steering motor 150 using a column. 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, there is also a method in which a man actually runs the discontinuous portion of the guide member, stores a guidance data string regarding the traveling direction obtained at that time, and uses that data string when running unmanned. . Of course, the program control method as 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 Guidance can be performed more reliably.

Further, in the above embodiment, the sensor moving device is the lateral displacement sensor motor 54. Binion 56. Although the pump 50 and the electromagnetic brake 58 are included, this can also be constructed using an actuator such as an electromagnetic brake or a hydraulic cylinder.

Although other examples are not provided, 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 Nigite wall 32. 34: Lateral displacement sensor 38: In/out member 46: Wall surface (guide wall surface) 48: Linear potentiometer 50: Rank 54: (For lateral displacement sensor) Motor 56: Binion 58: Electromagnetic brake 70: Contact Plate 78: Optical sensor 120: Microprocessor 142 Steering control circuit 147: Lateral displacement sensor control circuit 150 Steering motor Applicant Toyota Industries Corporation Toyota Motor Corporation Fig. 7 Fig. 8 Fig. 9 Fig. 10

Claims (3)

[Claims] (1) 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 a guide member provided on the side of a running path of the unmanned vehicle, the contact type sensor is configured to contact the guide member. A discontinuity that detects a type 1 discontinuity point where a member transitions from a state in which it can be contacted to a state in which it cannot be contacted, and a type 2 discontinuity point where it transitions from a state in which it cannot be contacted to a state in which it can be contacted. a point detection device; when the discontinuity point detection device detects the first type discontinuity point, the contact type sensor is retracted to a non-operating position away from the guide member; a sensor moving device that returns the contact type sensor to an operating position where it contacts the guide member when a second type discontinuity point is detected; The running direction of the unmanned vehicle is controlled based on the output signal of the contact type sensor, and after the first type discontinuity point is detected, the running direction of the unmanned vehicle is controlled without being based on the output signal of the contact type sensor. and after the second type discontinuity point is detected and the contact sensor is returned to the operating position, a control device that again controls the running direction based on the output signal of the contact sensor. An unmanned vehicle guidance device characterized by: (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 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 control device controls the control device based on the output signals of the remaining contact sensors. The unmanned vehicle guidance system according to claim 1, which controls the direction of travel. (3) In a state where the contact type sensor is between the type 1 discontinuity point and the type 2 discontinuity point, the control device determines the position of the unmanned vehicle in advance without obtaining information regarding the position of the unmanned vehicle. The unmanned vehicle guidance system according to claim 1, wherein the driving direction is controlled according to a program.