JP3517645B2 - Moving body position control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling the movement and stop of a moving body to a target position, and a drive device for driving a moving motor based on a control command transmitted from this control device. The present invention relates to a position control device for a moving body.

[0002]

2. Description of the Related Art A position control device for a moving body of this type is used, for example, in a stacker crane. This stacker crane, for example, travels on rails laid between shelves in an automated warehouse to load and unload loads and transport loads to and from the shelves. is there. On the shelf, a large number of accommodating portions that are two-dimensionally arranged in the traveling direction and the vertical direction (elevating direction) are formed. The stacker crane controls the traveling motor and the elevating motor at the same time so that the fork is accurately positioned with respect to a predetermined housing portion, and the fork is moved in and out of the housing portion in the positioning state. .

Since some of the loads carried by the stacker crane require careful handling such as glass bottles, it is necessary to suppress the swing of the stacker crane as much as possible. In addition, in order to increase the loading / unloading operation rate of the load, it is also important to shorten the cycle time of the loading / unloading process including the positioning process with respect to a predetermined storage unit and the loading / unloading process of the load with respect to the storage unit.

A position measuring wheel is rotatably provided at the bottom of the stacker crane while being pressed against the upper surface of an iron rail, and the shaft of the position measuring wheel is detected by an encoder constituting a pulse generator. The shaft is connected. The pulse generator outputs a position signal that accurately indicates the current position of the stacker crane. However, since the friction coefficient between the drive wheel directly connected to the traveling motor and the rail is relatively low, slippage occurs between the drive wheel and the rail. In such a drive system, if the servo system of the traveling motor is configured by using the position signal from the pulse generator as a main feedback signal, the servo system itself becomes unstable and the positioning accuracy is deteriorated. Therefore, in the stacker crane,
In consideration of versatility and cost reduction, for example, a sequencer and an inverter are combined to control the travel motor in an open loop with respect to the position, and the arrival of the target position is detected by the position signal from the pulse generator. Has become.

FIG. 5 is an electrical configuration diagram showing a position control device for a general stacker crane. As mentioned above,
The position control device 1 includes a sequencer 2, an inverter 3 and a pulse generator 4, and the inverter 3 drives a traveling motor 5 (induction motor) according to a speed command signal from the sequencer 2. Here, the sequencer 2 includes a moving distance generating unit 6 that determines the next moving distance based on the target position of the stacker crane, a speed parameter calculating unit 7 that calculates a speed parameter based on this moving distance, and a speed parameter calculating unit based on this speed parameter. A position control unit 8 for generating a speed command signal, an operation command unit 9 for generating a forward rotation operation signal and a reverse rotation operation signal, and an analog interface 10. In addition, the inverter 3 is
It is composed of an analog interface 11 and a motor drive unit 12.

As shown in FIG. 6, the speed command signal includes an acceleration process (AB), a constant velocity process (BC) and a deceleration process (C).
-D). The position control unit 8 monitors that the deceleration process end position D is reached based on the position signal output from the pulse generator 4, and after reaching the point D, it reaches a target position E at a slight speed (creep speed). Move (creep process).

[0007]

In the above configuration, the transmission of the speed command signal from the sequencer 2 to the inverter 3 is in the form of analog transmission. This is because the general-purpose inverter 3 is generally configured to input a speed command signal by an analog signal. But,
In the digital-analog conversion in the analog interface 10 of the sequencer 2 and the analog-digital conversion in the analog interface 11 of the inverter 3, generation of conversion errors such as linearity error, differential linearity error, and offset error is unavoidable. Therefore, the speed command signal received by the motor drive unit 12 has an error with respect to the speed command signal transmitted by the position control unit 8, and the accuracy of the speed control of the stacker crane deteriorates.

Particularly, since the stacker crane moves at high speed, even if a slight error occurs in the speed command signal,
The stacker crane is prone to sway and variations in position. If the positions vary, for example, the deceleration process changes from (C-D) to (C-D ': shown by a broken line) in FIG. 6, and the deceleration process end position shifts from point D to point D'. For this reason, in the position control device 1 having the above-described conventional configuration, it is necessary to secure a creep process with a margin in advance, which allows for a deviation due to the error. However, since the creep speed is extremely slow as compared with the speed in the traveling process, if there is a margin in the creep process, the cycle time of loading and unloading becomes long, and a new problem arises that the operating rate sharply deteriorates.

Therefore, the inventors of the present application studied digital transmission of the speed command signal between the sequencer 2 and the inverter 3. However, in order to accurately and reliably transmit the speed command that changes momentarily in the acceleration process and the deceleration process, the communication speed (RS-485, for example) that can be realized at a relatively low cost cannot be adopted because the communication speed is insufficient. It became clear. Further, it is possible to adopt a communication means capable of high-speed transmission, but there arises a problem that the cost of the position control device 1 becomes extremely high, the configuration becomes complicated, and versatility and expandability are lost.

The present invention has been made in view of the above circumstances, and an object thereof is to realize a high positioning accuracy and a high operating rate by highly accurate speed control, and at the same time, the structure is inexpensive and general-purpose. The object of the present invention is to provide a movable body position control device.

[0011]

In order to achieve the above-mentioned object, a position control device for a moving body according to claim 1 detects a position of the moving body, and the moving body using the detected position. And a drive device that drives a motor for moving the moving body based on a control command from the control device, and the control device and the drive device. In the position control device for a mobile body configured to communicate the control command between the control device and the drive device, the control device includes communication means for performing digital communication with the drive device, and a moving distance of the mobile body. A moving distance generating means for obtaining the calculated distance as a moving distance command to the drive device through the communication means, and the detection position.
Device and the drive received from the drive via the communication means.
A deceleration finger that generates a deceleration start command based on the speed start position
Commanding means, and the drive device provides communication means for performing digital communication with the control device, the travel distance command received via the communication means, and the control device.
And calculating a speed command including an acceleration process, a constant speed process, and a deceleration process based on the deceleration start command.
To start deceleration of the moving body based on the moving distance command
The position is calculated and the position is calculated via the communication means.
And a driving means for driving the motor based on the speed command.

According to this structure, the moving distance generating means of the control device obtains the moving distance to be moved next by the digital object by digital processing, and transmits it as a digital signal to the driving device. The calculating means calculates a speed command by digital processing based on the moving distance of the received digital signal. The moving distance transmitted here has a very small amount of data as compared with the speed command which changes every moment. In addition, the moving distance is transmitted prior to the start of moving the moving body. Therefore, the transmission of the moving distance does not require a high communication speed as compared with the transmission of the speed command, and it is possible to adopt a simple and inexpensive communication means instead of a low communication speed. it can. This makes it possible to configure an inexpensive and versatile device without complicating the configuration of the position control device as a whole.

Further, according to the above configuration, unlike the conventional configuration, no analog signal is present, and a conversion error between a digital signal and an analog signal does not occur. As a result, high-accuracy speed control and high-accuracy positioning control are possible. Further, since the variation in the end position of the deceleration process decreases as the positioning accuracy improves, the fine speed process from the end position of the deceleration process to the target position can be shortened in advance. As a result, the time during which the moving body moves at a low speed is shortened, the cycle time when repeating a predetermined movement is shortened, and a high operating rate is obtained.

[0014]

[0015] system by providing a deceleration command means in the control device, distributed processing is achieved between the control unit and the drive unit. Also, the deceleration start position has a very small amount of data,
Moreover, since it is sufficient to transmit to the control device before the moving body reaches the deceleration start position, digital communication can be performed via the communication means, and an error in the deceleration start position related to the communication can be prevented.

Further, the calculating means shifts the speed command to the deceleration process in accordance with the deceleration start command generated based on the detected position of the moving body and the deceleration start position. The error is once cleared at the start of the deceleration process. Thereby, even when the open loop control is performed on the position, the accumulated error of the position can be reduced and the positioning accuracy can be further improved.

Further, by correcting the deceleration start position toward the front side with respect to the target position by the distance traveled by the moving body during the delay time generated by control, the positioning accuracy is maintained high regardless of the existence of the delay time. It is possible (claim 2 ).

Further, when the deceleration start command is not given within the preset moving distance or the preset time during the movement of the moving body, the speed command is shifted from the constant velocity process to the deceleration process. With this configuration, even in an emergency such as when the position detecting means has a failure, the moving body can be stopped in accordance with a normal deceleration process without giving an impact (such as an emergency brake) to the moving body (claim 3 ).

In each of the above structures, it is preferable to provide the following means in order to prevent malfunction. That is, after the calculation of the speed command is completed, the speed command can be output from the calculation means to the motor drive means, so that the intermediate result of the calculation is erroneously used as the speed command. Can be prevented (Claim 4 ).

Further, after the calculation of the speed command is completed, the calculation means transmits a calculation end signal to the operation command means, and when the operation start means gives the operation start command, the speed command is shifted to the acceleration process. However, by configuring the operation command means to give the operation start command to the operation means on the condition that the operation end signal is received, the operation start command is not input during the operation of the operation means It is possible to prevent the occurrence of the situation where the operation is started in the middle of the step (claims 5 and 6).

Further, only when the moving direction of the moving body to the target position coincides with the driving direction of the driving start command, the moving means is constituted by outputting the speed command to the motor driving means. It is possible to prevent the vehicle from traveling in the direction opposite to the target position (claim 7).

Furthermore, the speed command is calculated so that the acceleration process, the constant velocity process, and the deceleration process fall within the range of the predetermined acceleration limit value or the predetermined maximum speed limit value. It is possible to perform a movement suitable for the property of the object to be carried, the motor driving means, the capacity of the motor, and the like (claim 8).

In each of the above cases, the motor drive means is configured to selectively execute either the automatic operation according to the speed command calculated by the calculation means or the manual operation according to another speed command. As a result, the manual operation becomes possible in the initial operation at the start of work and the recovery operation at the time of power recovery from a power failure, and workability is improved (claim 9).

Further, by providing the motor drive means with drive parameters for each of the plurality of motors to be driven and a selection means for selecting drive parameters for the motor to be actually driven from the drive parameter group, It is possible to drive a plurality of motors by one motor drive means, and thus the cost of the position control device can be reduced (claim 10).

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a stacker crane of an automatic warehouse will be described below with reference to FIGS. 1 to 4. FIG. 2 is a front view of the stacker crane viewed from the lateral direction with respect to the traveling direction. In FIG. 2, a rail 22 is laid on the floor surface of an automated warehouse in which a stacker crane 21 (corresponding to a moving body) is installed, and a guide 23 is laid parallel to the rail 22 on the ceiling surface thereof. . A stopper 24 is provided at the end of the rail 22.
Is provided.

The main body 25 of the stacker crane 21 is constructed as a frame body, and the lower side portion 26 thereof is pressed by two drive wheels 27 rolling on the rail 22 and slipping-free. Position measurement wheels 28 that roll on the rail 22 in this state are attached. Lower part 2
6 is provided with a traveling motor 29 (corresponding to a moving motor) formed of an induction motor, and the shaft of the traveling motor 29 is connected to the shaft of the drive wheel 27. A pulse generator 30 (see FIG. 1) is attached to the axis of the position measuring wheel 28.
The detection axes of a rotary encoder (not shown) that constitutes the above are connected.

A guide roller 32, which is guided along the guide 23, is attached to the upper side portion 31 of the main body 25. Then, when the drive wheels 27 are rotationally driven in the forward rotation direction or the reverse rotation direction by the traveling motor 29, the stacker crane 21 moves along the rails 22 and the guides 23 in the X direction in the figure or in the opposite direction (hereinafter referred to as the traveling direction). It is supposed to run.

A lifting motor 33, which is an induction motor, is mounted near the center of the main body 25. The lifting chain 34 that extends upward from the lifting motor 33 is
A chain guide 35 arranged on the upper part of the No. 5 extends further downward, and an elevating table 36 is supported in a suspended state at its tip. When the lifting motor 33 is rotationally driven in the normal rotation direction or the reverse rotation direction, the lifting platform 36 moves up and down along the main body 25 in the Y direction in the drawing or in the reverse direction (hereinafter, referred to as vertical direction). .

A fork 37 that can move in and out in the horizontal direction (the direction orthogonal to the paper surface of FIG. 2: Z direction) is installed on the upper and lower parts of the lift table 36. The fork 37 is attached to the lower part of the lift table 36 by an induction motor. Is driven by a fork operating motor 38. A position control device 39 (see FIG. 1) described later is provided on the lower side portion 26 of the main body 25.
A control panel 40 in which is stored is provided.

On both sides of the rail 22, shelves 41 are provided upright along the traveling direction of the stacker crane 21. Shelf 4
1 is formed with a large number of accommodating portions 42, 42, ... Which are arranged two-dimensionally in the traveling direction and the vertical direction, and the load is accommodated therein.

FIG. 1 is a block diagram showing the electrical construction of a position control device 39 for controlling the stacker crane 21. In FIG. 1, the position control device 39 includes a pulse generator 30 (corresponding to position detecting means), a sequencer 4
3 (corresponding to a control device), an inverter device 44 (corresponding to a driving device), and a relay 45. The reason why the sequencer 43 and the inverter device 44 are combined in this manner is to ensure versatility and reduce costs. Further, as described in [Prior Art], slippage occurs between the drive wheel 27 and the rail 22, and therefore the position control device 39 is configured to control the traveling motor 29 with respect to the position in an open loop. ing. Note that, in FIG. 1, the configurations of the lifting motor 33 and the inverter device that drives the lifting motor 33 are omitted.

The pulse generator 30 is configured to output a position signal Sa indicating the current position of the stacker crane 21 based on the pulse output from the rotary encoder as the position measuring wheel 28 rotates.
As described above, when the stacker crane 21 travels on the rail 22, the position measurement wheels 28 roll on the rail 22 without slipping, so the position signal Sa accurately indicates the current position of the stacker crane 21. Becomes

The sequencer 43 has a moving distance generating section 46.
(Equivalent to moving distance generating means), deceleration command section 47 (corresponding to deceleration command means), operation command section 48 (corresponding to operation command means) and communication interface 49 (corresponding to communication means). These are all designed to be processed by digital signals.

The moving distance generating unit 46, based on the target position of the stacker crane 21 determined from the loading / unloading command of the load,
The moving distance to be moved next is determined, and the moving distance signal Sb is transmitted to the inverter device 44 via the communication interface 49. The communication interface 49 employs a communication standard, such as RS-485, which has a simple structure of a communication driver / receiver, is highly expandable, and has high reliability.

The deceleration command section 47 compares the deceleration start position signal Sc (details will be described later) received from the inverter device 44 via the communication interface 49 with the position signal Sa from the pulse generator 30 to determine the position signal Sa. The deceleration start signal Sd is transmitted to the inverter device 44 when the current position of the stacker crane 21 shown in the drawing coincides with the deceleration start position shown by the deceleration start position signal Sc. In addition, the deceleration command unit 47 uses the stacker crane 2
When 1 reaches the target position, the stop signal Se is output to the operation command unit 48.

The operation command section 48 commands the start / stop of operation and the operation direction of the traveling motor 29, the lifting motor 33, and the fork operation motor 38. The operation command unit 48 receives the calculation end signal Sf from the inverter device 44.
When (after-mentioned) is received, it becomes a state in which the forward rotation operation signal Sg or the reverse rotation operation signal Sh can be output to the inverter device 44. In addition, the deceleration command unit 4 is operated while the traveling motor 29 is operating.
When the stop signal Se is input from 7, the traveling motor 29 is immediately stopped. Here, Sg is at the H level and Sh is at the L level when the forward rotation operation command is issued, Sg is at the L level and Sh is at the H level when the reverse rotation operation command is issued, and both Sg and Sh are at the L level when the stop command is issued. Further, the operation command unit 48 instructs the inverter device 44 to drive the traveling motor 29 and the fork operating motor 3.
The motor switching signal Si for switching between the driving of No. 8 and the driving of No. 8 is output.

On the other hand, the inverter device 44 includes a communication interface 50 (corresponding to communication means), a speed parameter calculation unit 51, a speed command calculation unit 52 and a motor drive unit 53.
(Corresponding to motor driving means). Here, the speed parameter calculation unit 51 and the speed command calculation unit 52 correspond to the calculation means in the present invention. The communication interface 50 is the communication interface 4 described above.
9 has the same configuration.

The speed parameter calculator 51 calculates the speed parameter required for generating the speed command based on the moving distance signal Sb received from the sequencer 43 via the communication interface 50, and uses it as the speed parameter signal Sj. It is adapted to output to the speed command calculation unit 52. The speed command calculated by the speed command calculation unit 52 is shown in FIG.
As shown in, the acceleration process (AB), the constant velocity process (B-
C) and the deceleration process (C-D), and the speed parameter indicates the acceleration in each of these processes.

In this case, the stacker crane 21 and the load are limited in terms of acceleration and speed, rated values of the traveling motor 29 and the fork operation motor 38, and the motor drive section 53.
The acceleration limit value and the maximum speed limit value are determined in advance based on the rated value and the like. Speed parameter calculator 5
1 determines the speed parameter within this limit value. Then, the speed parameter calculation unit 51
Outputs a calculation end signal Sf to the sequencer 43 and the speed command calculator 52 when the calculation of the speed parameter according to the moving distance is completed.

Further, the speed parameter calculation unit 51 calculates the speed parameter and obtains the deceleration start position,
The deceleration start position signal Sc is transmitted to the sequencer 43 via the communication interface 50. The deceleration start position is the position of the stacker crane 21 when the traveling motor 29 shifts from the constant speed process to the deceleration process (corresponding to point C in FIG. 3).

The speed command calculation unit 52 calculates a speed command (see FIG. 3) based on the speed parameter, and when the calculation end signal Sf is input from the speed parameter calculation unit 51, the calculated speed command is changed to the speed command. The signal Sk can be output to the motor drive unit 53. When the forward rotation operation signal Sg or the reverse rotation operation signal Sh is received in this output enable state, the speed command calculation unit 52 determines whether or not the commanded driving direction matches the direction in which the target position should travel. In the case of the traveling motor 29, the forward or reverse speed command signal Sk is actually output to the motor drive unit 53 only when it is determined that they match.

The speed command calculator 52 outputs an acceleration process and a constant velocity process according to the calculated speed command.
The transition from the constant speed process to the deceleration process is performed in synchronization with the deceleration start signal Sd sent from the sequencer 43. Then, the speed command calculation unit 52 causes the deceleration start signal S to be generated within the preset moving distance or within the preset time.
When d is not input, the speed command is shifted from the constant speed process to the deceleration process.

The motor drive section 53 is mainly composed of a converter circuit and an inverter main circuit (not shown). The motor drive unit 53 operates in accordance with a mode switching signal Sl from the outside, an automatic driving mode in which the motor driving unit 53 operates according to the speed command signal Sk, and a manual driving mode in which the motor driving unit 53 operates according to a speed command signal (not shown) input from the outside. It is configured to be switchable. Further, the motor drive unit 53 selects a drive parameter of the traveling motor 29 or a drive parameter of the fork operation motor 38 according to the motor switching signal Si, and uses the selected drive parameter to drive the travel motor 29 or the fork operation motor. 38 is driven. Note that the relay 45 uses the motor switching signal S
Depending on i, the output terminal of the motor drive section 53 is switched to the input terminal of the traveling motor 29 or the input terminal of the fork operation motor 38.

According to the configuration described above, the following actions and effects can be obtained. The moving distance generating unit 46 of the sequencer 43 calculates the address of the accommodating unit 42, obtains the moving distance to which the stacker crane 21 should move next by digital processing, and transmits it to the inverter device 44 as a digital signal. Then, the inverter device 44
The speed parameter calculation unit 51 calculates the speed parameter based on the moving distance of the received digital signal,
The speed command calculator 52 calculates a speed command based on the speed parameter.

The operation command section 48 of the sequencer 43, after switching the motor switching signal Si to drive the traveling motor 29, supplies the speed command calculation section 52 with the forward rotation operation signal Sg or the reverse rotation operation signal Sh. As a result, the speed command calculator 52 accelerates the speed command (A-
B), the process proceeds to the constant velocity process (BC), and the deceleration command unit 4
At the same time as receiving the deceleration start signal Sd from 7, the deceleration process (C-D) is started. Then, after reaching the deceleration process end position D in the deceleration process, it is moved to the target position E at a very low speed (creep speed) (creep process). When the target position E is reached, the forward rotation operation signal Sg and the reverse rotation operation signal Sh
And L both become L level, and the brake device (not shown) is activated accordingly.

Simultaneously with the driving of the traveling motor 29, the elevator motor 33 is also driven by an inverter device (not shown) so that the stacker crane 21 is moved to the target position and the fork 37 is positioned in the target accommodating portion at the same time.

In this case, the communication interfaces 49, 5
The data amount of the moving distance signal Sb transmitted via 0 is
Very small compared to the ever-changing speed command data volume. In addition, the moving distance generation unit 46 uses the stacker crane 2
Prior to the start of move 1 (eg during the previous move period)
The moving distance signal Sb is transmitted. For this reason, the transmission of the moving distance does not require high speed as compared with the transmission of the speed command, and the communication interfaces 49 and 50 have a simple and inexpensive structure instead of a low communication speed (here, RS-48).
5) can be adopted. As a result, an inexpensive and versatile device can be obtained without complicating the configuration of the position control device 39 as a whole.

Further, in the present embodiment, unlike the conventional configuration, no analog signal is present, and a conversion error between a digital signal and an analog signal does not occur. As a result, high-accuracy speed control and high-accuracy positioning control are possible. Since the variation in the deceleration process end position D decreases as the positioning accuracy improves, the creep process (DE) can be made almost zero as shown by the solid line in FIG. As a result, the time required for the stacker crane 21 to move at the creep speed can be shortened as much as possible, the loading / unloading cycle time of the load can be shortened, and a high operating rate can be obtained.

In this embodiment, a speed parameter calculation unit 51 and a speed command calculation unit 52 are provided in the inverter device 44. Therefore, in order to reduce the processing load on the inverter device 44 and to disperse the processing between the sequencer 43 and the inverter device 44, the deceleration command unit 47 is provided in the sequencer 43. In this case, communication of the deceleration start position signal Sc is required between the sequencer 43 and the inverter device 44, but the deceleration start position signal Sc has a very small amount of data, and the stacker crane 21 reaches the deceleration start position. Since it is sufficient to complete the transmission until (due to the delay in communication and processing, etc., slightly before the arrival), it is possible to perform sufficient communication even with the low-speed communication interfaces 49 and 50. .

Further, the speed command calculation unit 52 shifts the speed command from the constant speed process to the deceleration process in accordance with the deceleration start signal Sd commanded when the stacker crane 21 actually reaches the deceleration start position. The position error caused by the slip of the drive wheels 27 in the process and the constant velocity process is once cleared at the start of the deceleration process. As a result, the position control device 39 can reduce the cumulative error of the position and improve the positioning accuracy, although the position control device 39 performs the open loop control regarding the position.

In this case, the deceleration start signal Sd is transmitted as a contact signal, for example. Since the stacker crane 21 is moving at a high speed in the constant speed process, the transition point from the constant speed process to the deceleration process is delayed by the delay time due to the contact operation as shown by the broken line in FIG. 4 (point C → point C1). Accordingly, the deceleration process end position also deviates from point D to point D1. As a result, when the target position E is reached, the creep speed is not yet reduced, and the brake is applied in that state, resulting in a state in which sudden braking is applied. Therefore, the speed parameter calculation unit 51 corrects the deceleration start position toward the front by the distance traveled by the stacker crane 21 during the transmission delay time of the deceleration start signal Sd (C →
C2 point). This makes it possible to control the deceleration process end position so that it is always at the point D (= point E), and it is possible to prevent the positioning accuracy from decreasing.

Further, the speed command calculation unit 52 shifts the speed command from the constant speed process to the deceleration process when the deceleration start signal Sd is not input within the preset moving distance or within the preset time. For example, even in an emergency such as a failure of the pulse generator 30, the stacker crane 21 can be stopped according to a normal deceleration process without giving an impact such as an emergency brake to the stacker crane 21.

The speed parameter calculation unit 51 outputs a calculation end signal Sf when the calculation of the speed parameter is completed, and the operation command unit 48 receives the calculation end signal Sf as a condition, and the forward rotation operation signal Sg or the reverse rotation operation signal Sh is set. Can be output. Further, the speed command calculation unit 52 uses the calculation end signal S
The speed command signal Sk is output under the condition that f is input. Therefore, it is possible to prevent the occurrence of malfunction such that the intermediate result of the speed calculation is used as the speed command.

Since the speed command calculation unit 52 outputs the speed command signal Sk only when the operation command direction matches the direction to travel with respect to the target position, the stacker crane 21 travels in the direction opposite to the target position E. This can be prevented in advance.

The speed parameter calculation unit 51 calculates the speed parameter so that the acceleration process, the constant speed process and the deceleration process of the speed command are within the ranges of the predetermined acceleration limit value and the predetermined maximum speed limit value. Acceleration and speed that the crane 21 and the load to carry can withstand, a traveling motor 29,
The fork movement motor 38 and the motor drive unit 53 can be moved in an electrical state suitable for the motor.

Since the motor drive section 53 is configured to be capable of switching between the automatic operation mode and the manual operation mode,
Manual operation is possible during the initial operation at the start of work and the recovery operation at the time of power recovery from a power failure, improving workability.

The motor drive unit 53 includes drive parameters for the traveling motor 29 and the fork operation motor 38 that are not used at the same time, and the drive parameters can be selected according to the motor switching signal Si. Therefore, one motor drive unit 5
The drive motor 29 and the fork operation motor 38 can be driven by the method 3 and the cost can be reduced.

The present invention is not limited to the embodiments described above and shown in the drawings, but can be modified or expanded as follows, for example. Mobile unit is stacker crane 2
The number is not limited to 1, and may be, for example, a conveyer such as a conveyor or a constant-size feeder. Further, the control device is not limited to the sequencer 43, and may be, for example, a personal computer or a microcomputer. Further, the motors 29, 33, 38 are not limited to induction motors, and may be DC motors (including brushless motors). When using a brushed DC motor, a variable DC power supply may be used instead of the motor drive unit 53. Further, the communication interfaces 49, 50 can be used even if the communication speed is relatively slow, as long as the communication standard has a simple configuration, expandability, and high reliability.

Although the traveling motor 29 is configured to be controlled in an open loop with respect to the position, it may be configured to perform feedback control when the drive wheels 27 do not slip. In addition, the speed command calculation unit 52 includes the deceleration command unit 47.
The deceleration start signal Sd is received at the same time from the constant speed process to the deceleration process. However, when the drive wheels 27 do not slip, the deceleration start signal Sd is entered regardless of the deceleration start signal Sd. May be. Further, the deceleration command unit 47 may be provided inside the inverter device 44.

[0060]

As is apparent from the above description, the position control device for a moving body according to the present invention is a control device for controlling the movement and stop of the moving body to a target position and a drive device for driving a moving motor. Since the moving distance command is transmitted via this communication means, a conversion error between the digital signal and the analog signal does not occur, and high-accuracy speed control and high-precision Positioning control can be performed. As a result, the variation in the end position of the deceleration process is reduced, so that the time for the moving body to move at a fine speed can be shortened, the cycle time can be shortened, and a high operating rate can be obtained. The moving distance transmitted here has a very small amount of data as compared with the speed command that changes every moment, so a simple and inexpensive structure can be adopted instead of a low communication speed. This makes it possible to configure an inexpensive and versatile device without complicating the configuration of the position control device as a whole.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a position control device according to an embodiment of the present invention.

FIG. 2 is a front view of the stacker crane as seen from the side with respect to the traveling direction.

FIG. 3 is a diagram showing a speed command when the creep process is set to be long.

FIG. 4 is a diagram showing a speed command when the creep process is set to almost 0.

FIG. 5 is a diagram corresponding to FIG. 1 showing a conventional technique.

FIG. 6 is a diagram showing a speed command.

[Explanation of symbols]

21 is a stacker crane (moving body), 29 is a traveling motor (moving motor), 30 is a pulse generator (position detecting means), 38 is a fork operation motor (motor),
39 is a position control device, 43 is a sequencer (control device),
44 is an inverter device (driving device), 46 is a moving distance generating unit (moving distance generating means), 47 is a deceleration commanding unit (deceleration commanding unit), 48 is a driving commanding unit (driving commanding unit), 49,
Reference numeral 50 is a communication interface (communication means), and 53 is a motor drive unit (motor drive means).

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiro Uesugi 1-24-2 Harumi-cho, Fuchu-shi, Tokyo Inside Toshiba IT Control System Co., Ltd. (72) Inventor Hiromichi Nishimura Asahi-cho, Mie-gun, Mie Raw 2121 Toshiba Industrial Equipment Manufacturing Co., Ltd. (72) Inventor Toshiya Tadokoro 6-4 Akashi-cho, Chuo-ku, Tokyo Ishikawajima Transporting Machinery Co., Ltd. (72) In-Ken Shiotani 6 Akashi-cho, Chuo-ku, Tokyo No. 4 Ishikawajima Transport Machinery Co., Ltd. (56) References JP-A-4-303391 (JP, A) JP-A-10-25006 (JP, A) JP-A-8-202446 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65G 1/00-1/20 B66F 9/07 G05D 1/02

Claims (10)

(57) [Claims] 1. A position detecting means for detecting a position of a moving body, a control device for controlling movement and stop of the moving body to a target position using the detected position, and a control command from the control device. And a drive device for driving a motor for moving the mobile body, in the position control device of the mobile body configured to communicate the control command between the control device and the drive device, The control device includes a communication unit that performs digital communication with the drive unit, and a moving distance generation unit that obtains a moving distance of the moving body and transmits the moving distance command to the driving unit via the communication unit as a moving distance command. And from the detection position and the drive device through the communication means.
Generates a deceleration start command based on the received deceleration start position
And a deceleration command means for said drive device, said communication means for performing digital communication between the control device, and the moving distance command received via the communication means
A speed command including an acceleration process, a constant speed process, and a deceleration process is calculated based on the deceleration start command given from the control device , and the shift command is calculated based on the movement distance command.
The deceleration start position of the moving body is calculated and is calculated through the communication means.
And a motor driving unit that drives the motor based on the speed command, and a position control device for the moving body. 2. The calculation means is configured to control the delay time.
The deceleration start position by the distance that the moving body moves during
Position is corrected to the front side with respect to the target position.
Position control apparatus for a mobile body according to claim 1, wherein the being. 3. The calculating means is provided while the moving body is moving.
Within a preset travel distance or preset
If the deceleration start command is not given within the time,
The position control device for a moving body according to claim 1 or 2, wherein the speed command is configured to shift from a constant speed process to a deceleration process . 4. The calculation means is configured to end the calculation of the speed command.
After that, the speed command is output to the motor driving means.
The position control device for a moving body according to any one of claims 1 to 3, wherein the position control device is configured to be in a possible state . 5. The controller controls the operation means.
The operation means for giving a rotation start instruction, and the operation means operates the operation after the operation of the speed instruction is completed.
While transmitting the operation end signal to the command means,
Before the operation start command is given from the operation command means
It is configured to shift the speed command to the acceleration process, and the operation command means has received the calculation end signal.
On the condition that the operation start command is given to the calculation means.
Position control apparatus for a mobile body according to any one of claims 1 to 4, characterized in that it is configured to obtain. 6. A position detecting means for detecting the position of a moving body.
And using this detection position, move the moving body to the target position.
From the controller that controls the start and stop
Based on the control command of the
And a drive unit that operates, and includes the control unit and the drive unit.
Is configured to communicate the control command to and from a moving device.
In the position control device for the moving body, the control device communicates digitally with the drive device.
Then, the moving distance of the moving body is calculated and used as the moving distance command.
Distance traveled to the drive via the communication means
The driving device on condition that the generation means and the calculation end signal are received
Commanding means for giving a driving start command to the driving device, and the driving device performs digital communication with the control device.
Based on the movement distance command received via this communication means.
Speed finger consisting of acceleration process, constant velocity process and deceleration process
Calculating a command and transmitting an operation end signal to the operation command means after the operation of the speed command is completed, and an operation of shifting the speed command to an acceleration process when the operation start command is given from the operation command means. And a motor drive that drives the motor based on the speed command.
It characterized by being composed of the motion means moves the position controller of the moving object. 7. The driving command means is configured to give a driving start command designating a driving direction to the computing means, and the computing means is configured such that the moving direction of the moving body to the target position is the driving direction. 7. The position control device for a moving body according to claim 5, wherein the speed command is output to the motor drive means only when the driving command coincides with the driving direction. 8. The calculating means calculates the speed command so that the acceleration process, the constant speed process and the deceleration process fall within a range of a predetermined acceleration limit value or a predetermined maximum speed limit value. The position control device for a moving body according to any one of claims 1 to 7. 9. The motor drive means is configured to selectively execute either an automatic operation according to a speed command calculated by the calculation means or a manual operation according to another speed command. The position control device for a moving body according to any one of claims 1 to 8, characterized in that: 10. The drive unit selects a drive parameter for each of a plurality of motors including a motor for moving the moving body and a drive parameter for an actually driven motor from the drive parameter group. 10. The position control device for a moving body according to claim 1, further comprising means.