JPH01123307A - Constant position stopping control method - Google Patents

Abstract

PURPOSE:To change a stopping position at any time by obtaining a distance up to a brake control starting position due to a pattern from the position of the unmanned carrier at the time of detecting the front edge passage of a cargo based on the information of a cargo width inputted beforehand. CONSTITUTION:When a distance from the position of an unmanned carrier 1 at the time of passing through the front edge of a cargo 14 up to a brake control starting position is operated and obtained based on cargo width information and the arithmetic value and the measurement traveling distance of the unmanned carrier 1 are coincident, a brake control due to the pattern specified beforehand is started, and for that reason, the prescribed position of the cargo comes to a reference stopping position, the unmanned carrier 1 is stopped. Thus, when the cargo is mounted on the pallet of the unmanned carrier with a certain extent of a freedom degree, the prescribed position comes to the stopping position with the prescribed position of the cargo as a reference, the unmanned carrier can be stopped.

Description

[Detailed Description of the Invention] Purpose of the Invention [Field of Industrial Application] The present invention is an unmanned vehicle that carries a load and travels along a predetermined route, decelerates and stops at a fixed position by brake control according to a predetermined pattern. The present invention relates to a fixed position stop control method for a transport vehicle.

[Prior Art] In recent years, automatic guided vehicles have been increasingly adopted in factories and safes from the perspective of streamlining cargo transportation. There is a known method for decelerating and stopping an automatic guided vehicle based on a predetermined deceleration pattern from the time when a photoelectric switch or a proximity switch installed at a predetermined location detects a ground element installed in front of the stopping point. It is being In this method, in order to load and unload cargo, the cargo to be loaded onto the automatic guided vehicle needs to be accurately loaded at a predetermined position on the automatic guided vehicle.

[Problems to be Solved by the Invention] However, in the above-described fixed position stop control method, in order to stop a desired part of the automatic guided vehicle at a reference stop position, a photoelectric switch, a proximity switch, and a ground wire must be operated. It is necessary to relocate or change the deceleration pattern each time. Furthermore, if the load loaded on the automatic guided vehicle is shifted from a predetermined position, the load will shift either forward or backward from the reference stop position. In this case, unloading may be inconvenient. Furthermore, it is difficult to accurately load heavy objects, particularly large-diameter steel pipes, steel plate coils, etc., into predetermined positions on the automatic guided vehicle, and the loading process also takes time.

The present invention has been made in view of the above-mentioned problems, and it is possible to load a load onto the platform of an automatic guided vehicle with a certain degree of freedom, and when the predetermined position of the load reaches a stop position based on the predetermined position of the load, the vehicle is unmanned. This invention provides a fixed position stop control method that can stop a conveyance vehicle.

Means for Solving Problem F] That is, the gist of the present invention is, as illustrated in the basic configuration diagram of FIG. In a fixed-position stop control method for an automatic guided vehicle that decelerates using a brake control tube according to a pattern and stops at a reference stop position, passage of the front end of the load is detected by a light detection device installed a predetermined distance before the reference stop position (Pl). At the same time, measurement of the travel distance of the automatic guided vehicle is started. Based on the load width information entered in advance, the distance from the automatic guided vehicle position when the front end of the load is detected to the brake control start position according to the pattern is calculated. The fixed position stop control method is characterized in that the distance is calculated and determined (P3), and when the measured distance value matches the calculated value, brake control is started according to the pattern and stopped (P4).

[Operation] Based on the load width information, calculate and find the distance from the position of the automatic guided vehicle when the front end of the load passes to the brake control start position, and use this calculated value and the measured travel distance of the automatic guided vehicle from the above position. When they match, brake control is started according to a predetermined pattern, so when the predetermined position of the load reaches the reference stop position, the automatic guided vehicle stops.

[Example] An embodiment of the present invention will be described based on the drawings.

FIG. 2 shows one embodiment of the present invention, and is a schematic configuration diagram showing an automatic guided vehicle and its peripheral equipment to which the fixed position stop control method of the present invention is adopted. The various devices will be explained below. A distance measurement rack 3 is placed along the travel path 2 of the automatic guided vehicle 1.
(hereinafter simply referred to as rack 3) are continuously laid. An optical sensor 6 is installed at a load front end detection position 5 located at a predetermined distance before the reference stop position 4 of the automatic guided vehicle 1 at the height of the load, and the optical sensor 6 is installed on the ground. is connected to a transmitter 7. Furthermore, the automatic guided vehicle 1 is equipped with a receiver 8 that receives a signal transmitted from a transmitter 7 on the ground side, a proximity switch 9 that detects the rack 3, a vehicle speed sensor 10 shown in FIG. 3, and a keyboard 11. , are each connected to a control device 12 provided in the automatic guided vehicle 1 that controls travel. The control device 12 will be described in detail below. FIG. 3 is a block diagram of the control device 12. The control device 12 is a well-known CPU 20° ROM 2.
1. RAM22. Timer 23. Input/output port 24. Input boat 25. Output boat 26. It is composed of a counter 27. The counter 27 is connected to the receiver 8 and the proximity switch 9, the input port 25 is connected to the vehicle speed sensor 10 and the keyboard 11, and the output port 26
is connected to the drive device 13 of the automatic guided vehicle 1. Moreover, various control programs for driving the automatic guided vehicle 1 safely and accurately are written in the ROM 21.

Next, various signals and their processing in the above devices will be explained. When the front end of the load 14 loaded on the automatic guided vehicle 1 passes the load front end detection position 5, the optical sensor 6 outputs a detection signal of the front end. This detection signal is transmitted from the transmitter 7 on the ground to the receiver 8 on the automatic guided vehicle 1 and input to the counter 27. Counter 27 starts its operation in response to the input signal. Further, the rack 3 detection signal is transmitted from the proximity switch 9 to the counter 27, and when the automatic guided vehicle 1 stops at the reference stop position 4, the CPL
A reset signal from J20 is transmitted to counter 27. In addition, the vehicle speed sensor 10 detects the vehicle speed of the automatic guided vehicle 1 and outputs it to the control device 12, and the keyboard 11 inputs the value of the width of the load 14 or the desired distance from the front end of the load 14, which will be described later. This is input to the control device 12.

Next, a fixed position stop control method will be explained.

FIG. 4 is an explanatory diagram of the fixed position stop control method.

Hereinafter, a method for stopping the center position of the load 14 loaded on the automatic guided vehicle 1 at the reference stop position will be explained based on FIG. 4.

As shown in FIG. 4(B), when the front end 14a of the load 14 loaded on the automatic guided vehicle 1 passes the load front end detection position 5, the optical sensor 6 detects the front end 14a of the load and outputs a detection signal. Then, the counter 27 in the control device 12 starts counting. Then, the counter 27 detects the rack 3 in response to the rack 3 detection signals input one after another from the proximity switch 9.
Continue counting the number of teeth. Next, the optical sensor 6 detects the cargo 14
When the rear end 14b is detected and a detection signal is output, the CPtJ20 in the control device 12 reads the measured value NW of the counter 27 up to the time when the signal was input, calculates the distance to the center of the cargo 14, and calculates the distance to the center of the cargo 14. demand. That is, the product of the pitch length R of the rack 3 and the measurement value NW is the length W of the cargo 14,
The value W/2 obtained by dividing this by 2 is the distance from the front end 14a of the cargo 14 to the center. At the same time, the constant speed traveling distance L1 from the load front end detection position 5 to the first braking start position 30a is calculated and determined. That is, as shown in FIG. 4 (A>), when there is no cargo 14, the known constant speed traveling distance L (known) from the cargo front end detection position 5 to the first braking start position 30 is The sum of the distance W/2 to the center of the cargo 14 described above is the value L1=L+W/
It is 2. Therefore, as shown in FIGS. 4(A) and 4(B), regardless of the presence or absence of the cargo 14, the transition from the first braking starting position 30, 308 to the second braking starting position 31, 31 is possible.
distance L2 to the second braking start position 31°31a
The distance L3 from to the reference stop position 4 is - constant. Therefore, when the cargo 14 is loaded, the distance from the cargo front end detection position 5 to the second braking start position 31a is L1
+12, and the distance from the front end detection position 5 of the load to the reference stop position 4 is calculated as L1+12+L3. Next, each time the counter 27 counts, the CPU 20 calculates the number of measurements N and the pitch length R of the rack 3.
The product, that is, the distance N-R from the load front edge detection position 5 to the current position of the center of the load 14, is the distance NR from the load front edge detection position 5 to the first braking start position, the second braking start position, and the reference stop position 4. Each distance [1°L1+L2. L1+12
+13 is reached, and a predetermined process is executed. That is, as shown in the flowchart of FIG.
U20 performs processing. First, when the front end 14a detection signal of the cargo 14 of the optical sensor 6 is input, the counter 27 starts (step 100). Next, the CPU 20 moves the cargo 1 from the cargo front end detection position 5 based on the distance calculation described above.
4 is equal to or exceeds the distance L1 to the first braking start position 30a (step 110), and if the determination is negative, then , waits for the counter 27 to count (step 120), and returns to step 110. If the determination is affirmative, the CPU 20 immediately sends a braking start signal to the drive device 13 based on the first time vs. speed on-vehicle pattern shown in FIG.
(step 130) and performs the next processing (step 1).
Proceed to step 40). In step 140, the distance N from the load front end detection position 5 to the current position of the center of the load 14 is determined.
2.R is the distance L1+ to the second braking start position 31a
If the determination is negative, the process waits for the counter 27 to count (step 150) and returns to step 140. If the judgment is affirmative, the drive device 1 immediately sends a braking start signal based on the second time-speed on-vehicle pattern shown in FIG.
3, step 160>, and proceed to the next process (step 170). In step 170, the distance N3·R from the front end detection position 5 of the load to the current position of the center of the load 14 is equal to the distance L1+L2+L to the reference stop position 4.
It is judged whether it is equal to or exceeds 3 (step 170), and if the judgment is negative, wait for the counter 27 to count (step 180), and step 17
Return to 0. If the determination is affirmative, the CPU 20 immediately outputs a clear signal to the counter 27 (step 190).
Then, the process ends.

Note that the CPU 20 selects the first braking start position 30.30a.
, or from when the second braking start position 31, 31a passes, the vehicle speed data is read from the vehicle speed sensor 10 in synchronization with the predetermined periodic signal of the timer 23 output, and the first or second time pair stored in the ROM 21 is read. Check the speed pattern on the vehicle and decelerate according to each pattern.
A braking force adjustment signal is output to the drive device 13. In addition, in the case of an empty load, a detection rod (not shown) for recognizing an empty load is placed upright at the front end of the automatic guided vehicle 1, and while the optical sensor 6 detects the front and rear ends of the width of the rod, Proximity switch 9 is connected to rack 3
If no pitch is detected, the cargo is considered empty.

There are various methods for decelerating and stopping using the time-velocity on-vehicle pattern in the present invention, and there are no particular limitations on the method based on the fixed-position stopping control method described in Patent Publication No. 51-45842. is in good condition. That is,
As shown in FIG. 6, when the speed V of the automatic guided vehicle 1 exceeds the upper limit a1 of the first time-velocity pattern P1, a strong brake is applied and the speed of the automatic guided vehicle 1 rapidly decreases.

When the brake force falls below the lower limit b1 of the pattern P1, the braking force weakens and becomes a weak brake, and when it again exceeds the upper limit a1 of the pattern P1, a strong brake is applied again. Hereinafter, when the speed of the automatic guided vehicle 1 reaches the preset second predetermined speed 2, the brake force is released and the second braking start position 31, 31 is reached.
8, the vehicle travels at a constant speed at the second predetermined speed v2, and the distance error up to that point is corrected. and second braking start position 31°3
18, the speed of the automatic guided vehicle 1 is decelerated based on the second time-velocity on-vehicle pattern P2, and the vehicle speed of the automatic guided vehicle 1 is controlled so that the vehicle speed does not exceed the upper limit a2 of the pattern P2.
The vehicle decelerates and stops while switching between strong and weak brakes so as not to fall below the lower limit b2.

Note that FIG. 7 is a re-plot of FIG. 6 as a relationship between distance and speed. Note that Vl in FIGS. 6 and 7 is a predetermined first predetermined speed.

As described above, the first braking start position 30 and the second braking start position 31 are moved in the traveling direction of the automatic guided vehicle 1 by the distance W/2 from the front end 14a to the center of the load 14 as shown in FIG.
Move as shown in A) and (B) (30→30a, 31→
31a) After that, the automatic guided vehicle 1 is decelerated based on the first time-velocity pattern from the time it passes the first braking start position 30a. Next, when the vehicle speed reaches a second predetermined speed, the automatic guided vehicle is caused to travel at a constant speed until the second braking start position 31a to correct the distance error, and from the time when the vehicle passes the second braking start position 31a, the automatic guided vehicle 1 is decelerated and stopped based on the second time vs. speed on-vehicle pattern.
The center of the cargo 14 is stopped at the reference stop position 4.

In addition, in order to stop the cargo 14 at an arbitrary distance F from the front end 14a at the reference stop position 4, the arbitrary distance F must be input into the control device 12 from the keyboard 11 or the transmitter 7 in advance. , by setting F as a numerical value instead of W/2. In addition, in order to stop the automatic guided vehicle 1 at a position at an arbitrary distance from the front end of the vehicle body instead of the cargo 14, all that is required is to arrange the optical sensor 6 so that the optical sensor 6 can detect the front end. can be stopped in a similar way.

As explained above in 1, in the fixed position stop control method of this embodiment, the automatic guided vehicle 1 is stopped so that the center or desired position of the load 14 on which it is loaded comes to the reference stop position 4. be able to.

Therefore, even if the cargo 14 is loaded at a position shifted from the predetermined position, the center or desired position of the cargo 14 can be stopped at the reference stop position 4. especially,
When loading large-diameter steel pipes, steel plate coils, etc., it is not necessary to load them precisely in a predetermined position, so the loading work can be carried out efficiently, and even if the load shifts during transportation, the load will still be 14. Since the center of the container stops at the reference stop position 4, there is no problem in unloading. Furthermore, if an automatic loading/unloading machine or the like is placed at the standard stop position 4, it is necessary for the predetermined position of the cargo 14 to always stop at the standard stop position @4. The effect is remarkable.

In addition, it is also possible to stop a part of the automatic guided vehicle 1 at a desired distance from the front end so that it comes to the standard stopping position @4. The door can be stopped at the standard stop position.

[Effects] As explained above, in the present invention, it is possible to stop the automatic guided vehicle so that a desired part of the automatic guided vehicle or a desired part of the load comes to the reference stop position. Therefore, there is no need to relocate photoelectric switches, ground switches, etc.
Alternatively, the stopping location can be changed at any time without changing the deceleration pattern.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram illustrating the present invention, and FIG. 2 is a
FIG. 3 is a schematic configuration diagram showing an automatic guided vehicle and its peripheral equipment in which a fixed position stop control method according to an embodiment of the present invention is adopted; FIG. 3 is a block diagram of a control device for the automatic guided vehicle;
5 is an explanatory diagram of the fixed position stop control method according to the above embodiment, FIG. 5 is a flowchart showing the control process executed in the control device, and FIG. 6 is a diagram showing the first and second time-versus-velocity vehicles. An explanatory diagram of the upper pattern, FIG. 7, is an explanatory diagram in which the time-versus-speed on-vehicle pattern of FIG. 6 is re-plotted into a distance-versus-velocity relationship. 1...Automated guided vehicle 3...Distance measurement rack 4...Reference stop position 5...Load front end detection position 6...Optical sensor 9...Proximity switch 12...Control device] 4 ...Load 30.308...First braking start position 31.318.
...Second braking start position P1...First time-versus-speed on-vehicle pattern P2...Second time-versus-speed on-vehicle pattern Agent Patent attorney Tsutomu Sadatsu ct? w1%) Figure 1 Figure 2 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] A fixed position stop control method for an automated guided vehicle in which, after traveling on a predetermined travel route with a load loaded, the vehicle is decelerated by brake control according to a predetermined pattern and stopped at a reference stop position, comprising: A light detection device installed a predetermined distance before the stop position detects the passage of the front end of the load, and at the same time starts measuring the travel distance of the automatic guided vehicle, and detects the passage of the front end of the load based on the information on the width of the load entered in advance. calculating and determining the distance from the position of the automatic guided vehicle at the time to the brake control start position according to the pattern, and when the distance measurement value matches the calculated value, starting the brake control according to the pattern and stopping the vehicle; A fixed position stop control method characterized by the following.