JPH03175505A - Guidance method for unattended carriage - Google Patents

Abstract

PURPOSE:To improve the guidance precision of a carriage by setting a virtual straight line in a place where it is difficult to lay a guide line or zone and controlling the carriage so that the extent of deviation at a carriage body representative point calculated by the extent of movement is zero. CONSTITUTION:A running controller 11 of the carriage main body is provided with the arithmetic function and the storage function; and when the carriage reaches a prescribed point, the extent of movement of the carriage is detected by movement detecting means 6 and 7 provided on wheels or the like, and the position and the attitude angle of the carriage body representative point are calculated by this extent of movement, and steering is controlled based on these position and attitude angle so that the carriage body representative point is run along the virtual straight line by the distance stored in the running controller. Thus, steering wheels are controlled to run the carriage through the carriage is run in a place where it is difficult to lay the guide line or the carriage is hardly guided by disturbance, and the guidance precision is improved.

Description

[Detailed description of the invention] [Industrial application field] Akira Kito, regarding the method of guiding automatic guided vehicles.

[Prior Art] Conventionally, in the continuous guidance method of a transport vehicle for people using electromagnetic induction, etc., when there are some places where it is difficult to install guide wires or where it is difficult to guide due to disturbance, the transport vehicle is The vehicle was traveling with the steering angle of the steering wheels fixed, that is, without control.

[Problem 1 to be solved by Departure J] However, in the above-mentioned guidance method, since the steered wheels of the guided vehicle are run in an uncontrolled state, there is a problem in that the guiding accuracy of the guided vehicle is poor.

The present invention solves the above-mentioned problems. Even when a guided vehicle travels in a place where it is difficult to install a guide line or where guidance is difficult due to external disturbances, the vehicle can be guided by driving with the steering wheels at i and IJmL. The purpose of the present invention is to provide a method for guiding an automatic guided vehicle that can improve accuracy.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an automatic guided vehicle that travels by controlling the steering using a guide line or a guide belt installed on the ground. ! This travel control device has an L function and a memory function, and when the guided vehicle reaches a predetermined point, it detects the amount of movement of the guided vehicle using movement detection means provided on the wheels, etc., and determines the representative point of the vehicle body from this amount of movement. The position and attitude angle of the vehicle are calculated, and based on the position and attitude angle, steering control is performed so that the representative point of the vehicle travels along a virtual straight line by a distance stored in the travel control device.

[Operation] According to the above configuration, when the guided vehicle reaches a predetermined point, the travel control device determines the position and attitude angle of the representative point of the vehicle body based on the amount of movement of the guided vehicle detected by the amount of movement detection means provided on the wheels, etc. is calculated, and based on the calculated position and attitude angle, steering control is performed so that the vehicle body representative point travels along the virtual straight line by the stored predetermined distance.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 2 shows the configuration of the wheel portion for traveling of the automatic guided vehicle according to this embodiment. An encoder 6°7 for detecting (distance) is attached to each. The tread spacing of the fixed wheel 4.5 is W. Also,
The transport vehicle 3 is provided with steering/driving wheels 8 . In addition,
Front part of transport vehicle 3! On the right side of E, there is a detection coil for guided travel that detects the magnetic field from a guide wire laid on the ground, but it is not shown here.

FIG. 1 is a diagram for explaining the guidance method.

Electromagnetic induction wire! The terminal end of electromagnetic guiding wire 2 and the starting end of electromagnetic guiding wire 2 are separated by a distance on a - straight line, and there is no guiding wire between them, and in the present invention, steering control is performed using this interval as a pre-stored virtual straight line. ing. That is, when the guided vehicle 3 reaches the end of the electromagnetic guide line 1, that is, the point (calculation starting point) A at which the calculation by the guidance method of the present invention starts, the travel control device (described later) is installed immediately before or in the vicinity of the calculation starting point A. When a signal from a signal generator (not shown) is detected, a steering speed command is output to the steering system so that the vehicle moves straight along a pre-stored virtual straight line, and at the same time, the vehicle body representative point B of the guided vehicle 3 is The coordinates are determined, and from this, the lateral displacement, which is the deviation from the target, is calculated as 1. and attitude angle ψ, are calculated as follows.

Now, assume that the conveyance vehicle 3 is at the position and direction (attitude angle) shown in the figure with respect to the virtual straight line connecting the electromagnetic induction line 1 and the electromagnetic induction line 2. At this time, the conveyance vehicle 3 is at Y
It is located at the coordinate position B (x,,y,), and the position and direction of the transport vehicle 3 are determined by the following equation.

1, -1,000ΔX.

y・−yl−1+Δy.

1 θ = θ, +Δθ.

i l-11 Here, ΔX = Δj, Xcos (θ + Δθl/i
l 1-1 2) Δy, = Δj, xsin(θ, 1 Δθ, /1
1 1-1 12) ΔJIR, -ΔJIL.

1 1 Δθ　,= ΔjR1 ΔJIL.

1 1 Δ1 In the above equation, : y indicating the multi-value for each calculation cycle, : @ Position of vehicle transport: Direction angle of transport vehicle, Δy, : Movement of the XY coordinates of the representative point of the vehicle body between calculation cycles! I
! 1Jjt: Amount of change in the direction of the guided vehicle between calculation cycles: Amount of movement of the representative point of the vehicle body during the calculation cycle Δ'L: Amount of rolling of the fixed wheels (right) (left) during the calculation cycle: Length between the treads of the fixed wheels Δθ.

Δ1.

ΔjlR,.

Lateral displacement1. and attitude angle ψ, are 1.

therefore, 1・-y・ 1 ψ, = θ.

1 It can be found by

The steering speed command output E is calculated from the lateral displacement 1 and attitude angle ψ of the guided vehicle 3 thus obtained, and the steering angle φ of the steered wheel l detected by the sensor using the following equation.

E−e i G p x J t +G ψXψs
+ G φXφ1) Here, e is the target value and is O when traveling on a virtual straight line. Further, G, Gψ, and Gφ are constants.

When the steering speed command output E is set to 0, the guided vehicle 3 travels while being fixed at the steering angle φ, which is ζJ. Now, lateral displacement 1
．． If the steering angle φ1 is 0, E=O, and the conveyance vehicle 3 will travel straight. Therefore, the lateral displacement 11 and attitude angle ψ
If controlled so that , becomes 0, the conveyance vehicle 3 can travel straight.

FIG. 3 shows the peripheral configuration of the travel control device. The travel control device 11 is composed of a microcomputer with calculation and storage functions, etc., and includes a pickup (detection) coil 12 for guided travel, a travel speed encoder 13, encoders 6.7 for the left and right fixed wheels, and a steering angle. Receives detection signals from various sensors such as the detection potentiometer 14, performs the above-mentioned predetermined calculations to obtain a command signal, outputs this to the steering motor M2 to perform steering control, and outputs the command signal to the steering motor M2.
outputs a speed signal set according to the driving course,
Controls the traveling of the transport vehicle 3.

FIG. 4 does not show the configuration of the microcomputer in the travel control device 11 and its surroundings, but the microcomputer 2.
1 includes a central processing unit 22 having an arithmetic circuit 23, a storage circuit (memory) 24, and the like. Left and right pickup coils 12. a, 12b and the output of the steering angle detection potentiometer 14 are connected to the switching circuit 25 and the A/D converter 2.
6 to the arithmetic circuit 23 via the data bus 27. Similarly, the outputs of the encoders 6.7 of the left and right fixed wheels are inputted to the data bus 27 via the counter circuit 28, and the output of the signal generator 29 is inputted via the I10 device 30, respectively. In addition, the detection signals from these various sensors are
The virtual straight line data stored in the memory circuit 24 is compared and calculated by the calculation circuit 23, and the result is used as a command signal.
PWM from the D/A converter 31 via the data bus 27
The steering motor M2 passes through the circuit 32 and the drive circuit 33.
The control signal is output to the steering/drive 91a8.

FIG. 5 shows a control system that feeds back signals for performing the above-mentioned straight running.

The amount of displacement, etc. calculated by calculation based on signals from various sensors is fed back to the steering system (steering motor M2).
This allows the steering speed command output E to be sent to the steering system.

FIG. 6 is a flowchart of the operation of the guided vehicle 3 from guided travel, straight forward travel, and then to guided travel again. When the guided vehicle 3 receives the signal from the signal generator from the guided traveling state (step St) and starts traveling on the stored virtual straight line (
YES in S2), the travel control device 11 counts the detection pulses of the distance encoder 6.7 (33), calculates the coordinates of the representative point of the vehicle body <x-, y,) and the direction angle θ1 (S4).
), 1 lateral displacement', and attitude angle ψ, S5), above 1
1 Steering speed command output E- from distortion degree (α1. and attitude angle ψ)
−11, E−−(G xJ, 10G xψ, 10Gφ×φi)
J l ψ is calculated (S6), and while performing steering travel according to this steering speed command, it is checked whether the guided vehicle 3 has traveled a predetermined distance (87), and the predetermined distance is reached. If not, return to S3 and repeat the same operation. When a predetermined distance is reached and the pickup coils 12a and 12b for guided travel on the left and right sides of the transport vehicle 3 detect the electromagnetic induction wire 2, the vehicle switches to electromagnetic guided travel again (S8).

In addition, even if there are places where continuous electromagnetic interfering wires and electromagnetic induction belts have been installed and there are places where the guidance accuracy of the conveyance vehicle is expected to deteriorate due to disturbances, the above guidance method can be used to improve the conveyance. Vehicles can be guided reliably. .

Furthermore, in the above example, the vehicle starts traveling along a virtual straight line after detecting a signal from a signal generator installed at an arbitrary position on the ground. It may also be configured to start from the moment the vehicle starts running.

[Effects of the Invention] As described above, according to the present invention, a virtual straight line is set for a place where it is difficult to install a guide line or a guide belt, and the deviation amount (JKF! displacement 1
．． , attitude angle ψ,) to zero, the attitude angle of the vehicle body representative point of the automatic guided vehicle is guided onto the imaginary line. Therefore, the conveyance vehicle can reliably reach another guide line or guide zone from the current guide line or guide zone via the virtual straight line, and the guidance accuracy of the vehicle can be improved.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining calculation of the lateral displacement and attitude angle of a guided vehicle while traveling straight according to the method of the present invention, and FIG. 2 is a top view of an embodiment of the automatic guided vehicle according to the present invention. 3
Figure 4 is a block diagram of the surroundings of the traveling control device of the guided vehicle, Figure 4 is a block diagram of the microcomputer in the traveling control device of the guided vehicle and its surroundings, and Figure 5 shows the steering speed command, lateral displacement, and attitude angle. and a control system diagram for feeding back the steering angle, and FIG. 6 is a flowchart of the traveling operation related to the method of the present invention. 1.2... Electromagnetic induction wire, 3... Transport vehicle, 4.5...
・Fixed width, 6.7... t/1iAf detection encoder, 8... Steering/drive shaft, 11... Travel control device, 1
4... Steering angle detection potentiometer, 21... Microcomputer, 23... Arithmetic circuit, 24...
Memory circuit, 29...signal generator, Ml...travel motor, M2...steering motor. Higanjin Nippon Yusoki Co., Ltd.

Claims (1)

[Claims] (1) In an unmanned guided vehicle that runs by controlling the steering using a guide line or guide strip laid on the ground, the running control device of the guided vehicle itself has a calculation function and a memory function. When it reaches a predetermined point, the amount of movement of the guided vehicle is detected by the amount of movement detection means provided on the wheels, etc., and the position and attitude angle of the representative point of the vehicle body are calculated from this amount of movement. A method for guiding an automatic guided vehicle, comprising controlling steering so that a representative point of the vehicle body travels along a virtual straight line by a distance stored in a travel control device.