JP2003339182A - Method for controlling speed of magnet movable type linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling the speed of a magnet movable type linear motor, which can simply constitute a conveying line including a branch, a join by enabling the speed control of a movable unit even when the unit invades a straight side or a branch side. <P>SOLUTION: The movable unit 2 starting from a working station 32a is accelerated to a target speed in a running control section Lxa to an idling section Ly. If a switching point 35 is not switched, the unit straightly advances to a running control section Lxb and is stopped at a working station 32b by a predetermined speed control. When the point 35 is switched; the unit advances to the branch conveying line 31b to a running control section Lxc, and stops at a working station 32c by the speed control similar to above. Since a control unit 21 and each control unit 11 of the same constitution are connected in series, the softwares of the speed control of the respective running control sections can be used commonly, and a conveying line 31a, having a branch conveying line 31b, can be constituted simply. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a speed control method for a magnet movable linear motor. 2. Description of the Related Art A movable magnet linear motor is used as a drive source for a transport line or the like in which a transport vehicle circulates through a plurality of work stations. At each work station, the carriage is stopped to perform a predetermined work. For this reason, the stator is arranged on the transport line over the entire area of the work station, and the traveling of the mover is controlled. If the accelerated mover can move to the next work station by elliptical movement, it is not necessary to dispose the stator on the entire transport line. A running section is provided to reduce equipment costs. [0003] However, in a transfer line using the above-mentioned magnet movable linear motor,
Due to the problem of the traveling control of the mover, the transport line including the branch and the merge cannot be easily constructed. The present invention has been made in view of the above points, and facilitates formation of a branch orbit,
Provided is a speed control method of a movable magnet linear motor that enables speed control of the mover regardless of the direction of movement of the mover on the straight side and the branch side, and that can easily configure a transfer line including branching and merging. The purpose is. According to a first aspect of the present invention, there is provided a speed control method for a movable magnet type linear motor, comprising: a movable element comprising a plurality of permanent magnets; A stator formed by connecting a plurality of coil units along a traveling trajectory, a sensor disposed on each of the coil units, and detecting a relative position between the mover permanent magnet and the stator coil; and Energization switching means for switching the energization to the stator coil in accordance with the detection signal, position / speed detection means for detecting the position and speed of the mover in accordance with the detection signal of the sensor, and a target speed in which the mover is set. A speed control means for controlling the speed of the movable magnet linear motor having an elliptical section in which the stator is not arranged in the middle of the traveling path of the mover. A branch track that branches from the running section is provided, and a stator having the same configuration as the stator of the running control section located next to the elliptical section is arranged on the branch track, and each stator is connected with a serial signal line and The speed is controlled by connecting to a power supply line. According to the speed control method for a movable magnet type linear motor according to the first aspect, a branch orbit branching from the elliptical section is provided, and the branch orbit is provided in the elliptical section. Next, a stator having the same configuration as the stator in the next travel control section is arranged, and each stator is connected to a serial signal line and a power supply line to control the speed. By branching from the elliptical section where the stator is not arranged, it is easy to form a branch track, and it is possible to control the mover regardless of which direction the mover enters on the straight side or the branch side. Therefore, the branch,
The transport line including the junction can be easily configured, and accurate speed control can be performed. Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a movable magnet linear motor 1 according to the first embodiment. Mover 2
In the figure, a plurality of mover permanent magnets 3 having the same shape are arranged and fixed on a yoke (not shown) so as to be able to travel along a traveling path L. Each mover permanent magnet 3 is magnetized in the thickness direction, and adjacent poles have different polarities. The stator 4 has a plurality of coil units 11 arranged along a traveling trajectory L. The coil unit 11 includes a coil body 12, a pair of sensor units 13, and a switch circuit 14. The coil body 12 includes six stator coils 12a, 12b, 12c and 12a ', 12b',
12c 'is integrated by resin sealing or the like, and the stator coils 12a, 12a', 12b, 12b '
c and 12c 'are connected in series, respectively, to form a three-phase star connection. The sensor unit 13 includes the mover permanent magnet 3
For detecting the relative positions of the magnetic coils 13a, 13b, and 13c.
Are formed as one set, and are disposed at both ends of the coil body 12. As each of the magneto-sensitive elements 13a, 13b, 13c, for example, a Hall element is used. This magneto-sensitive element 1
The interval between 3a, 13b and 13c is set to 1/3 of the magnetic pole pitch of the mover permanent magnet 3, whereby a signal is output at a pitch of 1/3 of the magnetic pole pitch. Each magneto-sensitive element 13a, 13b, 13c is connected to an OR circuit 15 and a sensor bus line 16. The switch circuit 14 is turned on by a signal output from the sensor unit 13 and turns on the coil body 12.
Is switched to a state in which power can be supplied. Therefore, the switch circuit 14 is connected to each sensor unit 13 via the OR circuit 15. Since the connection mode of the coil body 12 is a three-phase star connection, the stator coil 12
The switch circuit 14 is constituted by two switches 14a and 14b interposed in a three-phase circuit connecting the terminals a and 12b. The switches 14a and 14b and the stator coil 12c are connected to the power bus line 17, respectively. The control unit 21 comprises an operation direction indicating circuit 22, a control circuit 23 connected to the sensor bus line 16, and a transistor circuit 24 connected to the power bus line 17. The operation direction instruction circuit 22 instructs the control circuit 23 on the operation direction of the mover 2. The control circuit 23 includes a mover position detection circuit 23
a, a mover speed detection circuit 23b, a mover speed control circuit 23c, and the like. The mover position detecting circuit 23a detects the mover permanent magnet 3 and the stator coil 1 based on signals output from the magnetic sensing elements 13a, 13b and 13c of the sensor unit 13.
The relative position with respect to 2a to 12c 'is detected. The mover speed detection circuit 23b similarly detects the speed of the mover 2 from the time interval of the signal output from the sensor unit 13. In addition, the mover speed control circuit 23c detects the mover 2 to be detected.
Is converted to a PWM output value. The control circuit 23 controls the stator coils 12a to 12c 'based on the operation direction instruction signal and the relative position signal.
And outputs a speed control signal to the transistor circuit 24 based on the PWM output value. The transistor circuit 24 uses the speed control signal to generate six transistors Tra, Tra ', Trb, Trb' and Tr.
c, Trc 'is turned on / off and the stator coils 12a-1
2c 'is excited to control the speed of the mover 2. As a result, a thrust based on Fleming's left hand rule is generated in the excited stator coils 12a to 12c 'and the mover permanent magnet 3, and the mover 2 moves in the direction indicated by the operation direction instruction signal. FIG. 2 is a schematic plan view of a transfer line 31 incorporating the movable magnet linear motor 1 having the above-described configuration.
The transfer line 31 includes a transfer line 31a and the transfer line 31.
a branch transport line 3 branched from the middle of the elliptical section Ly of a
1b. The transfer line 31a is such that the mover 2 starts from the work station 32a, passes through an elliptical section Ly provided on the way, and stops at the next work station 32b. Further, the branch transfer line 31b switches the mover 2 started from the work station 32a by switching the branch point 35 provided in the middle of the elliptical section Ly.
2c. A coil unit 11 having the same configuration as the coil unit 11 arranged corresponding to the work station 32b is arranged at a work station 32c provided at the end of the branch transfer line 31b. It is connected by a series wiring 18 composed of a bus line 16 and a power bus line 17. The mover 2 is divided into two parts, front and rear, and connected by a coupler J so that the mover 2 can pass through the curved track of the switching point 35. The transport carriage 33 reciprocates between the work stations 32a and 32b by the transport line 31a, and the transport carriage 33 reciprocates between the work stations 32a and 32c by the transport line 31b. Travel trajectories LA and LB of the mover 2 for driving the transport carriage 33 are laid along the transport lines 31a and 31b. At each of the work stations 32a to 32c,
The predetermined work and the loading / unloading of the work W are performed on the work W to be transported. Therefore, each work station 32
a coil unit 11 is disposed over the entire area of a to 32c, and a travel control section Lx that enables travel control of the mover 2
a, Lxb and Lxc are formed. When the mover 2 for driving the transport carriage 33 is accelerated and can move to the next work station by elliptical movement, it is not necessary to dispose the coil unit 11 on the entire transport line 31. The running tracks LA and LB between 32a and 32b and 32a and 32c have coil units 1
Elliptical sections Ly of the mover 2 where no 1 is arranged are formed. The mover 2 having started the work station 32a is accelerated to the target speed in the travel control section Lxa and enters the elliptical section Ly. If the switching point 35 is not switched, the mover 2 goes straight to the travel control section Lxb. The operation is stopped at the work station 32b by the speed control described later. If the switching point 35 has been switched, the vehicle enters the branch transport line 31b, enters the travel control section Lxc, and stops at the work station 32c under the same speed control as described above. In this case, since the control unit 21 and each coil unit 11 are connected by the serial wiring 18 and each coil unit 11 has the same configuration, the speed control of each traveling control section Lxa, Lxb, Lxc is performed. Software can be shared. Therefore, the transport line 31a having the branch transport line 31b can be easily configured. The specific speed control of the mover 2 in the transfer line 31 will be described with reference to FIG. FIG.
Shows a mode in which the mover 2 starts from the work station 32a and stops at the next work station 32b after passing through an elliptical section Ly provided on the way. In the travel control sections Lxa, Lxb provided corresponding to the work stations 32a, 32b, the travel of the mover 2 is controlled by one control unit 21. The mover 2 that has started the work station 32a is accelerated to the target speed at the set acceleration, and moves in the travel control section Lxa at the target speed. Then, the vehicle enters the elliptical section Ly and performs the elliptical movement, gradually reduces the speed, and enters the next traveling control section Lxb. FIG. 4 shows the speed control when the mover 2 enters the travel control section Lxb by elliptical movement as described above.
This will be described with reference to the flowchart of FIG. Here, the signal output from the sensor unit 13 is referred to as an encoder signal. First, in step S10, the mover permanent magnet 3
Element 13a of the sensor unit 13 in response to the magnetic pole of
It is determined whether there is an interruption of the encoder signal from .about.13c. If there is an interrupt, it is determined in step S15 whether the number of interrupts is the second. If it is the second time, in step S20, the current speed V of the mover 2 is calculated based on the time interval between the first and second encoder signals (1 pitch = 4 mm). Then, the process proceeds to step S25, where the virtual start position S is set to a set acceleration a, and the calculation formula S = V ²
/ 2a. Then, in step S30, the target speed Va at the current position calculated based on the number of interruptions of the encoder signal is calculated assuming that the start is from the virtual start position S. In step S35, a deviation between the target speed Va and the current speed V is calculated, and the speed deviation is calculated as P
Convert to WM output value. Then, in step S40, the P
Speed control is performed on the mover 2 based on the WM output value. Subsequently, in step S45, it is determined whether or not there is an interruption of the encoder signal. If it is determined that the encoder signal is interrupted, the speed control by the PWM method in steps S30 to S40 is continued, and the mover 2 is controlled to the set maximum speed Vmax. And
When approaching the stop position, the mover 2 stops at the stop position by the deceleration control performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of a movable magnet linear motor according to the present invention. FIG. 2 is a schematic plan view of a transfer line incorporating a movable magnet type linear motor. FIG. 3 is an explanatory diagram showing an outline of speed control. FIG. 4 is a flowchart showing an outline of speed control. [Description of Signs] 1 ... Magnet movable linear motor 2 ... Mover 3 ... Mover permanent magnet 4 ... Stator 11 ... Coil unit 12 ... Coil bodies 12a to 12c. ..Stator coil 13 ... Sensor units 13a to 13c ... Magnetic sensing element 21 ... Control unit 23 ... Control circuit 23a ... Mover position detection circuit 23b ... Mover speed detection circuit 23c mover speed control circuit 31, 31a transfer line 31b branch transfer line LA, LB travel trajectory Lxa, Lxb, Lxc travel control section Ly ... elliptical section

   ────────────────────────────────────────────────── ─── Continuation of front page    F term (reference) 5H113 BB06 CC04 CD02 CD16 DC03                       DC15 FF07 FF10 GG02 GG13                       GG16                 5H540 AA01 BA03 BA05 BB01 BB06                       BB09 DD02 DD07 EE06 EE11                       FA03 FA13 FA23 FB02

Claims (1)

Claims: 1. A mover comprising a plurality of permanent magnets, a stator comprising a plurality of coil units connected along a traveling path of the mover, and a plurality of coil units arranged on each of the coil units. A sensor for detecting a relative position between the mover permanent magnet and the stator coil; an energization switching means for switching energization to the stator coil based on a detection signal from the sensor; A position / speed detecting means for detecting the position and speed of the armature; and speed control means for controlling the mover to a set target speed, wherein the stator is not disposed in the course of the moving path of the mover. A speed control method for a movable magnet linear motor provided with a running section, comprising: providing a branch track that branches from the elliptical section, wherein the branch track is fixed to a running control section located next to the elliptical section. With placing stator child the same structure, the magnet movable type linear motor speed control method characterized by speed control by connecting the respective stators in series of signal lines and power lines.