JPS63209405A - Controller for carrier driven by linear motor - Google Patents

Abstract

PURPOSE:To enable a device to be positioning-controlled at an arbitrary stop position at high precision, by feeding back positional informations from an absolute position detector, negatively at a carrier station, and by controlling a thrust generated from a pair of primary conductors. CONSTITUTION:When it is detected by a sectional position detector 10 that the central point m of a secondary conductor 2 is admitted into a section I, then a primary conductor 3A is negative-phase-excited by an excitation controller 4A, and a damping force is generated. When it is detected by the sectional position detector 10 that the central point m is admitted into a section 11, then the primary conductor is positivephase-excited by the excitation controller 4A and is negativephase-excited by an excitation controller 4B, and a counterdirectional thrust is generated on the primary conductors 3A, 3B. When the central point m is admitted into the section III of the effective output area of an absolute position detector 11, then the exciting degree of the excitation controllers 4A, 4B is controlled by a control circuit 12 according to a deviation between the output of the absolute position detector 11 and a desired stop position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a device for controlling a traveling conveyor driven by a linear motor, and particularly to a control device for positioning the conveyor at a conveyance station.

[Conventional technology]

6 and 7 are diagrams showing a conventional IJ = amotor-driven conveyor control device disclosed in, for example, Japanese Unexamined Patent Publication No. 61-135303, where FIG. 6 is a block diagram and FIG. 7 is a generated thrust. It is a figure showing the relationship between and crossing rate.

In Figure 6, (1) is a roller provided along a predetermined track, (2) is a secondary motor of an induction type linear motor (hereinafter referred to as rig M) that constitutes a conveyor that runs on a roller. conductor,
(5A) and (5B) are a pair of primary conductors of the L-work M arranged below the above-mentioned track of the transfer station.

(4A), (4B) are primary conductors (5A),
(4B) An excitation controller that is connected to and controls each excitation and adjusts the generated thrust, (5) a position detector tB consisting of a plurality of proximity switches arranged along the above trajectory, (
A sequence circuit that controls the excitation mode of the excitation controllers (4A) and (4B) based on device information composed of 61 position detectors 151, and (7) a workpiece loaded on the secondary conductor (2). etc. are transported items.

The conventional control device for a linear motor-driven conveyor is constructed as described above, and its operation is controlled by the secondary conductor (2) traveling from the left side in FIG. 6 and the primary conductor (5A).

A case will be described in which the vehicle enters (3B) and, after being positioned at 2, reruns toward the right.

First, when the leading end of the secondary conductor (2) in the traveling direction is in section I, the outputs of the excitation controllers (4A) and (4B) are stopped. Next, the tip of the secondary conductor (2) is connected to the section ■
When the position detector (5) detects that the vehicle has entered the

The excitation controller (4A) is activated by the output of the sequence circuit 16).
performs reverse phase excitation, generates a braking force in the primary conductor (3A), and rapidly reduces the speed of the secondary conductor (2).

When the position detector (5) detects that the tip of the secondary conductor (2) has entered the section mark, the excitation controller (4A) performs positive phase excitation according to the output of the sequence circuit (61). Excitation controller (4B) H performs reverse phase magnetization, and the primary conductors (3A) and (5B) generate thrusts in opposite directions.This generated thrust is generated by the primary conductors (3A) and (5B).
(5B) and the intersection rate of the secondary conductor (2) and the primary conductor (5B).
A) It is proportional to the amount of excitation in (5B).

Figure 1 shows the relationship between the thrust generated by the primary conductors (5A) and (5B) and the crossing rate, and Ka and Kb are the crossing rates of the primary conductors (3A) and (5B) and the secondary conductor (2), respectively. ,Fal.

Fa2 is the absolute value of the thrust generated by the primary conductor (3A), Fb1
Fb2 is the absolute value of the thrust generated by the primary conductor (3B) e P
O is the thrust balance point p fle '2 is the absolute value of the generated thrust at each balance point.

Now, the secondary conductor (2) moves from the thrust balance point PQ to ΔP
When the secondary conductor (2) is in the front position by Fal-
The resultant thrust of Pb1 = Δf1 is the thrust balance point p
(.

Move in a direction. In this way, the resultant thrust is reduced and the secondary conductor (2) is moved to the balance point Po of the thrust.
is automatically positioned. In addition, an excitation controller (4A
), (4B), the generated thrust of the primary conductors (5A), (5B) becomes 2, for example, Fa
Since the combined thrust force as large as 2°Pb2 also increases as shown by Δf2, the stopping holding force at the thrust balance point PO also increases.

Next, if you want to restart the secondary conductor (2) in the right direction,
Both excitation controllers (4A) and (4B) are excited in positive phase.

Make the thrust generated by the primary conductors (3A) and (5B) in the positive direction.

The secondary conductor (2) now receives thrust in the positive direction and restarts.

[Problem that the invention seeks to solve]

In the conventional IJ near-motor-driven conveyor control device as described above, positioning was performed at the balance point PQ of the thrust generated by the primary conductor (5A (3B)).

When changing the stopping position, connect the primary conductor (5A), (
5B) There is a problem in that it is not possible to perform multi-point positioning within the transfer station.Also, 1 positioning is performed using only a constant balanced force.9) Highly accurate stopping and holding Therefore, it is necessary to keep exciting the primary conductor (3A) t (5B) during 2nd positioning, which causes problems such as wasting power and generating heat.

This invention was devised to solve the above-mentioned problems, and it is possible to perform multi-point positioning within the transfer station and to
The present invention aims to improve positioning accuracy and reduce power consumption, and to provide a control device for a near motor-driven conveyor.

[Means for solving problems]

A control device for an IJ near motor-driven conveyance body according to the present invention arranges a plurality of absolute position detectors in a conveyance station, and controls an excitation controller based on the deviation between the output of the absolute position detector and a target stop position. A control circuit is provided to control the thrust generated by the pair of primary conductors.

[Effect]

In this invention, in order to control the thrust generated by a pair of primary conductors by negatively feeding back the position information from the absolute position detector at the transfer station, the balance point of the thrust generated by the two primary conductors is changed. be able to.

[Laughter side]

Figures 1 to 3 are diagrams showing one embodiment of the present invention.
The figure is a block diagram, and FIG. 2 is an operation explanatory diagram.

FIG. 3 is a diagram showing the relationship between the generated thrust and the crossing rate in the section INK, and the same parts as in the conventional device are indicated by the same symbols.

In the figure, 18) is the orbit, (9) is the secondary conductor (2) the entire orbit (
8) A roller supported on the track 18), αυ is a section position detector consisting of a plurality of proximity switches arranged along the track 18).

αB is an absolute position detector consisting of a plurality of semiconductor device detection elements arranged at the center position of the transfer station [Po;
α2 is an excitation controller (4a) based on the position information detected by the section position detector unit and the absolute position detector U.

The control circuit that controls the excitation mode (4b) is a host control device that gives operation commands to a plurality of control circuits 112 arranged along the cI3Vi trajectory 18) and unifies the entire system of the conveyance device. In addition, the total length L1 of the primary conductor (5A (5B)
is longer than the total length L2 of the secondary conductor (2).

In the control device for a near-motor-driven conveyor constructed as described above, the secondary conductor (2) runs from the left side of FIG. 2 through the shaft punch, and the primary conductor (5a).

After entering (5B) and being positioned at 7, the process of re-running toward the right will be described.

First, when the center point (m) of the secondary conductor (2) falls in the section O, the control circuit +12 is the excitation controller (4A), (4
The reason for completely stopping the output of B) is that the secondary conductor (2) does not intersect with the primary conductors (5A) and (5B).
This is because thrust cannot be generated.

Next, when the section position detector section detects that the center point (m) has entered section IK, the excitation amount ff1l device (4A
) performs reverse phase excitation, generates a braking force in the primary conductor (5A), and rapidly reduces the speed of the secondary conductor (2).

Then, when the 6-section position detector α1 detects that the center point (Iffl) has entered section ■, the excitation 1!1
1115 (4A) is positive phase excitation i't, excitation BB system 1i
111 device (4B) performs fl reverse phase excitation and connects the primary conductor (5
A) and (5B) generate thrusts in opposite directions. As a result, the transfer station is automatically moved to the center position p, ) where the absolute position detector 11jj aυ is arranged.

When the 1-section position detector α1 detects that the center point (m) has entered the section I within the effective circular range of the absolute position detector αJ), it is the same as in the case of the 1-section ■.

The excitation i1 controller (4A) performs positive phase excitation, and the excitation controller (4A)
B) performs reverse phase excitation, and the primary conductor (5A), (5B
) generate thrusts in opposite directions. At this time,
The control circuit a3 outputs the current position indicated by the output of the absolute position detector αB and the upper control device so that the thrust generated by the primary conductors (5A) and (5B) decreases as the target stop position approaches. Excitation according to the deviation from the target stop position? 1gl + Goki (4A), (4B)
Controls the amount of excitation. These states are shown in a table as follows.

×・・・Stop →・・・Forward thrust ←・・・Reverse thrust−・・
・Forward thrust (variable) 〆...Reverse thrust (variable) In Fig. 3, r F'a3 t 1! bs is the primary conductor (5A
).

The absolute value of the generated thrust of (5B), f5F! This is the balancing force at the target stop position FD. At this time, the secondary conductor (
2) receives the combined thrust of Fag pb3=Δf3 in the direction of thrust balance point p, ) and moves. Secondary conductor (2)
As approaches the balance point P, , the primary conductor (
IA).

The generated thrust of (5B) decreases as shown in Fe2 p 1'b4 , and when it stops at the balance point PO, the generated thrust becomes zero.

Also, when the target stop position is set to Pl, 2 points P
The primary conductors C are symmetrical with respect to 1.
It is sufficient to control the thrust generated by IA) and (5B).

Fe2 + Fb5 is the thrust generated when approaching point P1. In order to increase the stopping holding force, either increase the balance force at the target stopping position or increase the gain of the two-position deviation. So the primary conductor (5A).

By controlling the position by negative feedback to the thrust generated in (3B), highly accurate and highly rigid positioning is maintained, and positioning can be performed at any desired position.Next, the secondary conductor (
2) in the right direction in Fig. 2, excite both the excitation controllers (4A) and (4B) in positive phase to make the thrust generated by the primary conductors (5A) and (5B) in the positive direction. do. The secondary conductor (2) now receives thrust in the positive direction and resumes movement. When passing the primary conductors (3A) and (5B), subdivide the section ■ (do-tt+i+i) using the two-section position detector α1 so that only the primary conductor that intersects with the secondary conductor (2) is excited. It's okay.

The host controller α3 manages and instructs the stopping positions and running directions at a plurality of transfer stations installed on the track (8).

4 and 5 are diagrams showing other embodiments of the present invention,
FIG. 4 is a plan view of the primary conductor and secondary conductor portions, and FIG. 5 is a front view of the same.

That is, the embodiment shown in Fig. 1 is an L construction M with a movable secondary conductor and one-side excitation, whereas the embodiment shown in Fig. 4 has a primary conductor (3A
) and (5B) are placed on both sides of the secondary conductor (2). The one in Figure 5 is a primary conductor (5A
) and (5B) are movable, and the secondary conductor (2) is fixed. Either of them can have the same effect as the one in FIG.

Further, although the primary conductors (3M) eC5B) are arranged in the direction along the tri orbit 18), any configuration may be used as long as the thrust forces generated by each other are in opposite directions and positioning can be performed using the combined force.

They may be arranged in a direction transverse to the track (8).

Furthermore, although the absolute position detector (11) K semiconductor device detection element is used, it is obvious that an optical encoder or other position detection device may be used.

〔Effect of the invention〕

As explained above, in this invention, when a plurality of absolute position detectors are arranged in a transfer station and positioning is performed at the transfer station, the thrust generated by the pair of primary conductors is reversed, and the current position from the absolute position detector is Since the thrust force generated by the primary conductor is controlled based on the deviation between the target stop position and the target stop position, highly accurate and highly rigid positioning can be performed without contact, and the stop position can be set arbitrarily. Furthermore, there is no need to keep exciting the primary conductor to maintain the stop position, which has the effect of reducing power consumption.

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams showing one embodiment of a control device for a linear motor-driven transport body according to the present invention, in which Figure 1 is a block diagram, Figure 2 is an explanatory diagram of the operation, and Figure 3 is a diagram showing the generated thrust and Figures 4 and 5 are diagrams showing the relationship between crossing rates, and are diagrams showing other embodiments of the present invention. Figure 4 is a plan view of the primary conductor and secondary conductor portions, and Figure @5 is the same (front view). , 6 and 7 are diagrams showing a control device for a conventional linear motor-driven conveying body, and FIG.
The figure is a block diagram, and FIG. 7 is a diagram showing the relationship between generated thrust and crossing rate. In the figure, (2) is the secondary conductor, (5A), (5B)
is the primary conductor. (4A) and (4B) are excitation controllers, and aυ is an absolute position detector. aZ is a control circuit. Note that the same reference numerals in the two figures indicate the same parts.

Claims (1)

[Claims] A secondary conductor is arranged so that it can run on a predetermined track, a pair of primary conductors that give thrust to the secondary conductor are arranged in the transfer station, and an excitation controller is connected to each of the primary conductors, and the secondary conductor When positioning the conductors at the transfer station, the exciter is controlled so that the thrust forces generated by the pair of primary conductors are directed in opposite directions, and the absolute positions of a plurality of conductors arranged at the transfer station are determined. A detector, and a control circuit that controls the excitation controller based on the deviation between the current position indicated by the output of the absolute position detector and the target stop position to control the thrust generated by the pair of primary conductors. A control device for a linear motor-driven transport body that features: