KR100270271B1 - Position control system for a movable machine - Google Patents

Abstract

PURPOSE: A position control system for a movable machine is provided to be capable of decreasing the error range in position control, detecting the generation of the error as well as correcting the error by substituting two pairs of forward/backward sensors for single plate sensor. CONSTITUTION: A plurality of position displaying plates(11) are mounted in respective working points on a transfer rail(11), and shields the beams from U-shaped photoelectric switches(14,18) to sense the positions of the working points. The photoelectric switches(14,18) are suitably disposed under a stacker crane(13), and the backward sensor(18) and forward sensor(14) are respectively disposed behind and front of the stacker crane(13). Therefore, the movable machine moves along the transfer rail(11), sensors are operated in respective positions, and so an ECU verifies the current position of the movable machine on the transfer rail.

Description

Position Control System of Mobile Machinery

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for stopping a moving mechanism precisely at a target exact position when a machine moving left and right or up and down has a plurality of stop positions. The present invention relates to an exact position control system of a mobile machine and a control method thereof capable of compensating an error so as to obtain an exact exact position at a target position by providing a plate sensor.

In general, in a transport system such as a rail or a conveyor system, a moving machine such as a moving truck or a stacker crane moves left and right to stop at a target position, or a system having a plurality of fixed positions while moving up and down like an elevator. It is very important to position it exactly at the point. Therefore, in the related art, the in-situ control of the mobile machinery is achieved by installing an upright plate at a predetermined position on a rail or a conveyor system of the transportation system and attaching a horseshoe type photoelectric switch to the mobile machinery of the transportation system.

An example of a conventional position control system of a mobile machine is shown in FIGS. 1 and 2 of the accompanying drawings, which will be described in detail with reference to the accompanying drawings. Here, FIG. 1 shows a schematic configuration of a position control system of a conventional mobile machine, and FIG. 2 shows a plate and a plate sensing sensor applied to FIG.

First, as shown in FIG. 1, on the rail 1 to which the moving mechanism 3 moves, the several plate 2 is installed in the correct position of a transportation system. Here, the plate 2 has a shape as shown in Figure 2, the upright upper plate of the plate is made of an opaque material that does not transmit light. Further, a horseshoe type photoelectric switch 4 is provided at a predetermined position of the lower part of the moving mechanism 3, and the photoelectric switch 4 has a light transmitting portion 5 and a light receiving portion 6 as shown in FIG. When the moving mechanism 3 reaches the plate 2 installed at the proper position as the moving system moves, the plate is sensed by blocking the transmission of light by the plate.

The exact position correcting operation of the exact position control system having the above-described configuration is described as follows. In order to more easily understand this, the flowchart of FIG. 3 is used. When the direction, target position, and delay time of the mobile mechanism are input to the setting unit of the electronic control unit (ECU) embedded in the mobile machine 3, the electronic control unit (ECU) is based on the set direction and target position. By driving the drive motor to move the mobile mechanism.

If the set direction is the forward direction and the target position is N, the moving mechanism starts from the starting point and moves toward the target position N. At this time, when passing through the position display plate 2 set at each correct position, the photoelectric switch (4) is activated to transmit the detection signal to the detection unit of the electronic control unit (ECU). The signal sensed by the sensing unit is counted by the position counter and then transferred to the calculating unit of the electronic control unit (ECU). The calculating unit compares the counter value with the set target position and sets the speed when the set value is larger. The motor is driven through the unit to continuously move the moving mechanism in the forward direction.

Repeating this process of sensing, comparing, and setting speed, when the moving mechanism reaches the previous stage (N-1) of the target exact position (N) and the photoelectric switch is operated by the N-1th plate, the position counter becomes N- It counters 1 and the electronic control unit decelerates the moving mechanism by reducing the speed of the motor through the speed setting unit. When the moving mechanism that moves at low speed finally reaches the target position (N) and the Nth detection sensor is operated, the detection unit of the electronic control unit detects it to start the timer and the timer operation time matches the set delay time. When the brake is turned on, the moving mechanism stops at the desired target position.

Since the conventional position control system described above uses only one plate sensor to detect the position, all of the plates are recognized as the stationary position within the width L section of the plate, so the range of error is large.

In addition, performing the position control so that the sensor stops after a certain delay time after detecting the plate of the target position as in the prior art is slippery due to the inertia or slip phenomenon caused by the load in the bogie in which the load of the moving mechanism changes. An error has occurred and the correct position cannot be obtained. In addition, the prior art has a problem that can not be recognized even if the error of the position control as described above can not be recognized and cause damage to the mechanism as well as can not correct the error.

Therefore, the present invention was devised to solve the problems of the prior art as described above, and an object of the present invention is to reduce the error range of the position control by replacing a single plate sensor with two sets of forward and reverse sensors. The present invention provides an in-situ control system of a mobile machine that can not only detect the occurrence of an error but also correct the generated error.

In addition, another object of the present invention is an exact position control method of a mobile machine which can simply recognize the error generated after the mobile machine reaches the target position and correct the correct position based on the recognized error. In providing.

Figure 1 shows a schematic configuration of a position control system of a conventional mobile machine.

FIG. 2 illustrates a plate and a plate sensing sensor applied to FIG. 1.

3 shows a flow chart of the operation of the system of FIG.

Figure 4 shows a schematic configuration of an exact position control system of a mobile machine according to the present invention.

FIG. 5 illustrates a plate and a plate sensing sensor applied to FIG. 4.

FIG. 6 shows a block diagram of an electronic control unit (ECU) incorporated in the mobile machine apparatus shown in FIG.

7 is a flowchart illustrating a method for controlling the position of the mobile machine according to the present invention.

<Description of Symbols for Major Parts of Drawings>

12: Plate for position display 14: Forward direction sensor

18: Reverse direction sensor 20: Electronic control unit (ECU)

21: setting unit 22: calculating unit

23: speed setting unit 24: forward, reverse detection unit

25; Position sensor

The control system of the present invention for achieving the above object is to install a plate of the upright type at each stop position of the transport system having a plurality of stop positions, two sets of plates at a predetermined position of the mobile machine moving in the transport system By attaching a sensor and connecting it to the electronic control unit (ECU) of the mobile device, the exact position is controlled by correcting the position by moving the mobile device in the forward or reverse direction according to the detection signal of the two sets of plate sensors. Can be achieved.

Here, the upright plate is an impermeable plate made of a material that does not transmit light. In addition, the pair of plate detection sensor is made by attaching the reverse direction sensor and the forward direction sensor sequentially along the path that the moving mechanism moves, the interval has the same length as the plate width.

Here, the forward and reverse sensor is a horseshoe-shaped gap photoelectric switch having a light transmitting portion and a light receiving portion.

In addition, in order to achieve the above object, the position control method of the mobile machine to the operator setting the target position and the direction to the setting unit of the electronic control unit (ECU) of the mobile machine, and the direction set by the setting unit When the moving mechanism moves along the transportation system, the reverse and forward detection sensors attached to the moving mechanism sequentially follow the moving path to detect the plates installed at each stop position, and the detection signal of the electronic control unit Increasing the position counter one by one, and when the position counter indicates the previous position (N-1) just before the target position (N), the speed setting unit of the electronic control unit decelerates the moving mechanism at low speed, and at low speed. When the moving mechanism moves closer to the target position (N), the position detection part of the electronic control unit operates the two sets of plate detection sensors. Checking whether the electronic control unit finely stops the forward and reverse directions based on the operation state of the forward and reverse detection sensors checked above, and the forward and reverse detection sensors at the target position (N). When all of the state is on, the operation unit of the electronic control unit is to operate the brake to stop the moving mechanism.

Here, when the operation state of the two sets of plate detection sensor checked at the target position (N) is the reverse detection sensor is ON and the forward detection sensor is OFF, the mobile device is moved in the forward direction to correct the correct position. On the contrary, if the reverse direction sensor is OFF and the forward direction sensor is ON, the mobile device is moved in the reverse direction to correct the correct position.

When described in detail with reference to Figures 4 to 6 the preferred embodiment according to the position control system of the present invention having the configuration as described above as follows.

4 shows a schematic configuration of an exact position control system of a mobile machine according to the present invention, FIG. 5 shows a plate and a plate sensing sensor applied to FIG. 4, and FIG. 6 is applied to FIG. A block diagram of an electronic control unit (ECU) embedded in a mobile machine is shown.

As shown in FIG. 4, the stacker crane 13 stops at the work point while moving on the transport rail 11 to perform work such as unloading. At this time, on the transport rail 11, a plurality of position display plates 12 are installed at the correct positions of the respective working points. Here, the position display plate 12 is composed of an upper plate vertically upright with a width L and a lower plate supporting the upper plate as shown in FIG. 5, wherein the upper plate is an opaque thin plate through which light is not transmitted. It serves to hinder the transmission of light, and the lower plate serves to attach the plate on the transport rail by supporting the upper plate.

Such a plate 12 is installed at each working point on the transport rail 11 as shown in FIG. 4 to transfer the horseshoe type photoelectric switches 14 and 18 to be described below without being disturbed by the movement of the stacker crane 13. Position display plate that blocks the light to detect the position of the working point. The width of the plate 12 is not uniformly determined and is appropriately selected according to the type and working environment of the mobile machine, and is not necessarily limited to the above. In addition, the two sets of plate detection sensors 14 and 18 shown in FIG. 4 are properly disposed at the bottom of the stacker crane 13 so that the reverse detection sensor 18 is forwarded based on the traveling direction of the stacker crane 13. Install the forward direction sensor 14 in the rear.

Here, the installation interval of the reverse and forward sensors are to be equal to or slightly smaller than the width of the plate. As shown in FIG. 5, the reverse and forward sensors 18 and 14 are horseshoe-shaped photoelectric switches, and are provided with a light emitting portion 15 for projecting light and a light receiving portion 16 for receiving light at both ends thereof. Attached to the upper end of the horseshoe type sensor 18, 14 is a connection conductor 17 for connecting the electronic control unit (ECU) of the mobile machine and the sensor is attached to the electronic signal shown in Figure 6 It is transmitted to the sensing units 26 and 27 of the control unit ECU. The sensor is normally transmitted light from the light transmitting unit 15 to the light receiving unit 16 smoothly, but when the mobile machine reaches the correct position, the position display plate 12 to block the transmission light of the sensor. And it works.

Therefore, when the moving mechanism moves along the transport rail 11, the sensing sensor is operated at each correct position, and accordingly, the electronic control unit (ECU) knows which point on the current transport rail 11 has been reached. Will be.

The above description assumes the case of the stacker crane 13 in which the mobile machine moves left and right, and the present invention is not necessarily limited thereto, and the present invention can be applied not only to a moving cart but also to an elevator moving up and down.

The operation and action of the position control system of the present invention having the above configuration will be described with reference to FIGS. 6 and 7 of the accompanying drawings.

Before the stacker crane 13 starts the starting point on the transport rail 11, the setting unit 21 of the electronic control unit (ECU) 20 of the stacker crane 13 is operated by an operator or by a remote control device. The set target position and movement direction are input. It is assumed here that the set target position and the moving direction are N and forward directions, respectively. When the target position N and the positive direction are input to the setting unit 21, the driving motor 28 is driven in accordance with the set movement direction so that the stacker crane 13 moves on the transport rail 11. When the stacker crane 13 moves, two sets of plate detection sensors 18 and 14 attached to the lower portion of the stacker crane detect the position display plate 12 installed at each position.

At this time, the two sets of plate detection sensors are composed of the reverse direction and the forward direction detection sensors 18 and 14, when the two sets of detection sensors are both turned on (ON), the detection signal is the forward and reverse direction of the electronic control unit 20 The position counter (not shown in the figure) is countered by input to the sensor detection units 27 and 26 and then to the calculation unit 22 via the normal and reverse detection unit 24.

As described above, the above process is repeated every time the display plate 12 passes, so that the counter value of the position counter is increased and the stacker crane 13 is set at the previous stage point N-1. ) When the (N-1) th position display plate 12 installed at the correct position is detected by two sets of plate detection sensors 18 and 14 and transmitted to the calculation unit 22 of the electronic control unit, the position counter Will counter C = N-1. At this time, the calculating part 22 of the electronic control unit reduces the speed of the stacker crane 13 by setting the low speed through the speed setting part 23 to decelerate the driving motor 28. When the stacker crane 13 moving at a low speed reaches the target position, the signals detected by the two sets of sensors 18 and 14 are not transmitted to the forward and reverse detection unit 24 of the electronic control unit. 25) to perform the exact position correction control operation.

That is, when the reverse direction sensor 18 is turned on and the forward direction sensor 14 is turned off, the stacker crane 13 enters the correct position of the target point, and thus, the operation unit of the electronic control unit ( 22 moves the stacker crane in the forward direction by controlling the drive motor 28 in the forward direction through the speed setting unit 23. On the other hand, if the reverse sensor 18 is in the ON state and the forward sensor 14 is in the OFF state, the stacker crane 13 is past the correct position, so that the calculating unit 22 of the electronic control unit is speeded up. The stacker crane 13 is moved in the reverse direction by controlling the driving motor 28 in the reverse direction through the setting unit. Therefore, if the reverse and the forward detection sensors 18, 14 are both in the ON state in the same process as described above, this indicates that the stacker crane 13 has reached the correct position accurately, The calculation unit 22 operates the brake 29 to block driving of the driving motor 28 to stop the stacker crane 13 to complete the position control.

The above-described embodiments are disclosed to aid the understanding of the present invention, and the present invention is not limited thereto, and the present invention is provided by those skilled in the art to which the present invention pertains. Various modifications and variations are possible, of course, within the scope of equivalents of the claims to be described.

The exact position control system of the mobile machine according to the present invention having the above-described configuration and action can not only minimize the error range but also recognize the occurrence of the error by simply detecting the exact position through two sets of plate sensors. By correcting, it is possible to prevent the breakage of mobile machinery due to errors.

Claims (1)

(Correction) an upright plate made of a material which does not transmit light at each stop position of a transport system having a plurality of stop positions; Two sets of plate sensing sensors having a light transmitting portion and a light receiving portion are attached to a predetermined position of the mobile machinery moving in the transportation system, and the two sets of plate sensing sensors sequentially move the reverse sensing sensor and the forward direction along the path of the moving machinery. Made by attaching a sensing sensor, the gap having a length equal to the plate width; By connecting the two sets of plate detection sensors to the electronic control unit (ECU) embedded in the mobile machine, the two sets of plate detection sensors are turned on on the plate in position at the target point of the electronic control unit (ECU). An exact position control system of a mobile machine, characterized by finding the exact exact position by moving the moving mechanism forward or backward until the state.

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