JPS62160008A - Travel controller for unmanned conveying vehicle - Google Patents

Abstract

PURPOSE:To hold an unmanned conveying vehicle to stably travel by selecting a deviation gain constant suited for each traveling speed deceleration. CONSTITUTION:A travel control deviation calculating means 56 calculates a travel control deviation (e) on the basis of a deviation (epsilon) from a traveling route of an unmanned conveying vehicle output from a deviation detecting means 52 and a deviation gain constant K, and applies it to a travel control means 57. A traveling speed comparing means 54 compares the traveling speed V of the vehicle with a preset speed when the vehicle is decelerated. Deviation gain constant selecting means 55 selects the constant K in response to the output of the means 54. Thus, the stable traveling of the vehicle can be maintained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a travel control device for an automatic guided vehicle that moves along a travel route, and in particular, the present invention relates to a travel control device for an automatic guided vehicle that moves along a travel route, and particularly for deceleration travel in which the automatic guided vehicle transitions from high-speed travel to low-speed travel. Or regarding the travel control device of an automatic guided vehicle during low-speed travel.
A guided vehicle (also referred to as a guided vehicle) is an unmanned, self-propelled transportation means that does not have a track such as a rail in its travel route, and meets the recent demands for labor saving and unmanned production in manufacturing plants. For example, a workpiece may be placed on an automated guided vehicle and transported to a predetermined location within a factory, or an industrial robot may be integrally attached to an automated guided vehicle and moved between workstations within a factory. It is used as a mobile industrial robot that performs specific tasks.

[Conventional technology]

Conventional AGVs move while being guided by guide wires that are buried, for example, directly below the travel route. In other words, the magnetic field generated from the guide wire through which current is passed is
This is detected using a pickup coil installed inside the vehicle to determine whether or not the vehicle is traveling correctly. If the AGV deviates from the travel route, the rotation of the left and right drive wheels is controlled to cancel the deviation.

By the way, the normal running speed at which the AGV moves between each stage is as high as, for example, 60 m/min, so it cannot suddenly stop from normal high-speed running. Therefore, the traveling speed of the AGV is at stage 1 where it stops.
The vehicle must be decelerated from a high speed for movement in the vicinity of the vehicle to a low speed for immediate stopping. This A
The deceleration of the GV is performed by detecting a deceleration command mark provided on the travel route with a deceleration position detection unit of the AGV.

The deceleration command sign is, for example, a plurality of permanent magnets embedded in the road surface, and the arrangement of the permanent magnets indicates the address of the immediately next workstation. Then, the AGV detects the address of this deceleration command mark with a deceleration position detection section, and if this address matches the address of a predetermined stage where the vehicle is to be stopped, it immediately starts decelerating. This deceleration control causes the AGV to shift from high-speed to low-speed driving.
The AGV travels near the stopping position of the station at a low speed, confirms the fixed position by optical means, etc., and immediately stops.

Here, the installation position of the deceleration command sign is the optimum distance for the AGV to decelerate from high speed to low speed and stop at the work station, that is, the distance that takes into account the AGV's total weight and braking characteristics, etc. separated from.

[Problem that the invention seeks to solve]

As mentioned above, when the AGV stops at work stage 1, it is decelerated from high-speed travel to low-speed travel by the deceleration command sign, continues to travel at low speed near the stop position of the station, and returns to the fixed position. Immediately after confirming the
It also stops reliably. However, during deceleration driving or low-speed driving that transitions from high-speed driving to low-speed driving, when the AGV deviates from the driving route, corrections are made in the same way as when driving at high speed, so the driving of the AGV becomes unstable. There was a problem.

This is because the travel control required when the AGV is traveling at normal high speeds is not suitable for medium to low speed AGVs when the AGV is decelerating or traveling at low speeds. That is, travel control when the AGv is traveling at high speed must respond sharply or sensitively to even a small deviation from the travel route and correct the deviation.

Otherwise, the AGV could deviate significantly from the travel route and come into contact with stations and auxiliary equipment on both sides of the travel route.

However, when the AGV is decelerating or running at a low speed, the travel control is such that the speed gradually decreases and the vehicle travels at medium to low speeds, so even if the AGV deviates from the travel route to some extent, if the AGV is traveling at high speed, The vehicle will not suddenly deviate significantly from the driving route.

If the same driving control as in high-speed driving is performed during such deceleration driving, the response to deviations in the driving route is too sensitive compared to the driving speed of the AGV, making it impossible to maintain stable driving.

An object of the present invention is to provide a travel control device for an automatic guided vehicle that can maintain stable travel even when such an automatic guided vehicle decelerates or travels at low speed.

[Failure to solve the problem]

The present invention has been made in view of the above-mentioned problems and provides a novel travel control device for an automatic guided vehicle.

FIG. 1 is a block diagram showing the configuration of a travel control device according to the present invention.According to the present invention, the device moves along a travel route and decelerates before a predetermined station at which it should stop;
In a travel control device for an automatic guided vehicle that stops at a fixed position of the station, means 51 for detecting the traveling speed of the automatic guided vehicle, means 52 for detecting a deviation from the traveling route of the automatic guided vehicle, and the automatic guided vehicle. Means 53 for determining deceleration running of
, means 54 for comparing the traveling speed V of the automatic guided vehicle with a preset speed when the automatic guided vehicle is traveling at a reduced speed;
, means 55 for selecting a deviation gain constant according to the traveling speed of the automatic guided vehicle, means 56 for calculating a deviation for travel control using the selected deviation gain constant and the detected deviation C, and , means 57 for controlling the travel of the automatic guided vehicle according to the calculated travel control deviation e.

[Effect]

The automatic guided vehicle travel control device of the present invention having the above-described configuration is capable of controlling the automatic guided vehicle at a speed suitable for the current traveling speed when the automatic guided vehicle is decelerating or traveling at low speed in order to stop at a predetermined work station. Stable running is maintained by selecting a deviation gain constant and slowing down the response of the automatic guided vehicle to correct deviations from the running route.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a travel control device for an automatic guided vehicle according to the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram partially schematically showing an automatic guided vehicle using the travel control device according to the present invention, and 1 is an AGV (
2 and 2I are pickup coils, 3 is a differential amplifier, and 4 is a microprocessor.

Aavt is connected to the road surface 12 via a pair of left and right drive wheels 8, 8/.
It moves along a predetermined route. A guide wire 11 is buried directly below the travel path, and the AGV1 travels guided by a magnetic field (concentric dotted lines in FIG. 2) generated from the guide wire. The magnetic field generated from the guide wire 11 is detected by the pickup coils 2 and 21, and the deviation from the correct traveling path can be determined from the output balance of the two pickup coils 2 and 2'. .

That is, the outputs of the pickup filters 2, 2' are supplied to the differential amplifier 3, and the output of the differential amplifier is inputted to the microprocessor 4 as one piece of control information.

The microprocessor 4 inputs the output of the differential amplifier 3 and other information, performs predetermined processing, and controls the acceleration/deceleration control section 5.
, 5'.

The output of the acceleration/deceleration control section 5, 5' is servo amplifier 6゜6.
The rotation of the servo motors 7 and 7/ is controlled by the output of the servo amplifier 6.6I. A pair of left and right drive wheels 8, 8 coupled to a servo motor 7.7I
' rotation is individually controlled, and AGvl travels correctly along the travel path.

By the way, 9.9' is a pulse coder attached to the servo motor 7.7', and the traveling speed of the AGVl and the left and right drive wheels 8.81 are determined from the output of this pulse coder 9,9'.
The microprocessor 4 is configured to be able to calculate the rotational speed difference between the two. In addition, it is possible to directly control A from the speed control command of the microprocessor 4 without using the pulse coder 9, 9/.
Of course, the traveling speed of the GV, etc. may also be calculated.

and,! When the AGVl stops at the work stage 1 30 as shown in FIG. and start decelerating.

Further, the deceleration command mark 32 in FIG. 3 is for the AGV 1 to move in the opposite direction and stop at the work station 30.

The automatic guided vehicle has been briefly described above, but the following K, Figures 4 and 5
The control operation based on the present invention will be explained with reference to the drawings.

Fig. 4 is a diagram showing the relationship between the speed curve of the automatic guided vehicle and the deviation gain constant, and Fig. 5 is a flowchart showing an example of control operation, where V is the traveling speed of the AGV, K is the deviation gain constant, and 6 is the detected deviation (differential amplifier output), e
is the travel control deviation of the AGV.

When the deceleration position detection unit 10 of the AGV detects the deceleration command mark 31 and decelerates from high-speed travel to low-speed travel, first, in step 41, it is determined whether the AGVl is in deceleration travel. In this case, the AGV deceleration position detecting section 10 detects the deceleration command indicator 31, and a speed detector such as the pulse kneader 9, 9' determines whether the AGV 1 is decelerating or not. Of course, it is also possible to directly determine whether the AGVl is decelerating or not because the deceleration position detecting section 10 detects a predetermined deceleration command mark 31 to be stopped.

If it is determined that the AGVl is decelerating, the process proceeds to step 42, where it is determined whether the traveling speed V of the AGVl is less than the preset speed V, and if V is less than Vl, step 43 Proceed to.

In this embodiment, the preset speed is Vl.

V, , V3, Vs < Vt < Vl
However, the number of set speeds can be changed as necessary.

In step 41 or step 42, if the vehicle is not decelerating or if Vl<v, the deviation gain constant is set to K = Ko (step 47), resulting in a sharp response similar to normal high-speed travel.

Next, in step 43, the pulse coder 9.9'
Discrimination is made between the traveling speed V of the AGV detected by the above method and preset speeds V, , V, , V, etc.

That is, if V, < V≦V, then = (step 44); if Va < V≦V, then K = Kt
(Step 45), if V≦V, then K = K3 (
Step 46), AGV (7) traveling speed V is set to set speed v, , v2 . v.

Depending on the range, the value of the deviation gain constant is Kr.
, Kt and Ks are selected.

These set speeds v1. ■2. V3 and the corresponding deviation gain constant +, Kt, KsO values are set in advance by RO.
M (read-only memory) etc., the set speeds V, , V2. V3 is defined as Vl < Vl < between the high speed and low speed of the AGV.
It is set in the relationship of Vs. Furthermore, the deviation gain constants + -Kt and Ks are determined so that as the traveling speed V of the AGV decreases, the response to deviation from the traveling route becomes slower.

By the way, the time during which AGvl is decelerating, that is, the time from the deceleration start point 13 to the deceleration end point 14 in FIG. By the time the AGV1 is detected, it has been running in a sufficiently corrected state, and the running speed is medium to low, so even if the response to deviations from the running route becomes slow, the workstation or There is no contact with other attached equipment.

Then, in step 4, using the deviation gain constant determined in steps 44 to 47 and the detected deviation ε,
In step 8, the travel control deviation e is calculated. The deviation 6 is a differential amplifier 3 whose inputs are the pickup coils 2 and 2'.
This is the output of Moreover, the deviation e for driving control is directly AGV1
It is used for travel control and is given by je = .epsilon. When specifying the travel control deviation e from this relational expression of e=K・ε, the deviation gain constant KH+ Kt *
Ks r and Ko are 0<Ks<Kt<Kl<Ko=
It is sufficient to set it as 1. In other words, as the traveling speed of the AGV decreases, the deviation e of the traveling control vehicle from the actual traveling route of the AGV1 also represents a small deviation. Since the correction for the deviation becomes slow, the running of the AGV 1 becomes stable.

〔Effect of the invention〕

As described above in detail, the automatic guided vehicle travel control device according to the present invention, when the automatic guided vehicle is decelerating or traveling at low speed in order to stop at a work station or the like,
A system that can maintain stable running even when the automatic guided vehicle is decelerating in order to correct deviations from the running route using a deviation gain constant appropriate to the current running speed. It is.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a travel control device according to the present invention, FIG. 2 is a block diagram partially showing an automatic guided vehicle using the travel control device according to the present invention, and FIG. 3 is a block diagram showing the configuration of a travel control device according to the present invention. A schematic diagram of an automatic guided vehicle seen from above as it moves along a route, Figure 4 is a diagram showing the relationship between the speed curve of the automatic guided vehicle and the deviation gain constant, and Figure 5 is a diagram showing the control operation based on the present invention. It is a flowchart which shows an example. 51... Traveling speed detecting means 52... Deviation detecting means 53... Deceleration traveling determining means 54... Traveling speed comparing means 55... Deviation gain constant selecting means 56... Deviation calculating means for traveling control 57... Traveling control means ■... Traveling speed K... Deviation gain constant ε... Deviation e... Deviation for driving control 1... ...Automated guided vehicle 2.2'...Pickup coil 3...Differential amplifier 4...Microprocessor 5.5'...
・Acceleration/deceleration control unit 6.6'...Servo amplifier 7.71...Servo motor 8.8'...Drive wheel 9.9'...Pulse coder 11...Guide wire 12 ...road surface

Claims (1)

[Scope of Claims] 1. A travel control device for an automatic guided vehicle that moves along a travel route, decelerates before a predetermined station to stop, and stops at a predetermined position of the station, comprising: means for detecting the traveling speed of the automatic guided vehicle; means for detecting deviation from the traveling route of the automatic guided vehicle; means for determining whether the automatic guided vehicle is traveling at a deceleration; means for comparing the traveling speed of the automatic guided vehicle with a preset speed; means for selecting a deviation gain constant according to the traveling speed of the automatic guided vehicle; and traveling using the selected deviation gain constant and the detected deviation. A travel control device for an automatic guided vehicle, comprising: means for calculating a control deviation; and means for controlling travel of the automatic guided vehicle according to the calculated travel control deviation.