JP2009077591A - Drive controller of xy positioning arrangement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide optimum positioning control while suppressing interference between motor shafts when driving a single load using a plurality of motor shafts. <P>SOLUTION: The XY positioning arrangement drives a single load L using a plurality of motor shafts. It comprises disturbance observers 68L and 68R provided in the control system of each motor shaft, and observer output adjusting parts 70L, 70R, and 70 which are provided at the output part of each disturbance observer, to monitor a positional deviation for controlling the output of the disturbance observer according to the amount of positional deviation. When the amount of positional deviation is large, the output of disturbance observer is returned much for positive compensation, and when the amount of positional deviation is small, the output of disturbance observer is limited. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drive control device for an XY positioning device, and in particular, using a plurality of motor shafts suitable for use in an electronic component mounting device (referred to as a mounter), an adhesive application device (referred to as a dispenser), or the like. The present invention relates to an improvement in a drive control device of an XY positioning device that drives one load.

  In a mounter for adsorbing electronic components from a component supply device and mounting them on a substrate, or a dispenser for applying adhesive for temporarily fixing components onto a substrate, a mounting head or application head (hereinafter simply referred to as a head). A gantry type XY positioning device is used for positioning.

  As shown in FIG. 1, this gantry type XY positioning device has a pair of left and right Y-axis drive units 20 and 30 for movement in the Y direction to position the head 10 in the XY direction, and on that, In general, a configuration is adopted in which the X-axis drive unit 40 is moved in the X direction. In the figure, reference numeral 50 denotes a substrate transfer unit.

  The motor for positioning driving may be cantilever provided only on one side of the shaft. However, when positioning at a higher speed, one motor is provided on each side of the shaft as shown in detail in FIG. In some cases, the motors 22, 32, 42, 44 are provided, and one load (Y axis, X axis) is driven using two motors (22, 32), (42, 44), respectively. For driving the Y-axis and the X-axis, a combination of the rotary motors 22, 32, 42, 44 and the timing belts 24, 34, 46 or the ball screw as illustrated in the figure, a linear motor, or the like is used. In the figure, reference numerals 26 and 36 denote bearing portions.

  Such a gantry-type XY positioning device has a problem that positioning accuracy and settling time are deteriorated when receiving external force or vibration during positioning. In order to eliminate the problem of such disturbance, the applicant proposes the use of a disturbance observer in Patent Document 1.

  That is, by providing the disturbance observer shown in FIG. 3 in the motor control system as shown in FIG. 4, an acceleration control system as shown in FIG. 5 can be configured, and the influence of the disturbance can be removed. .

In FIG. 3, Ia ^ref is a current reference value, Icmp is a compensation current for compensating for disturbance torque and ensuring robustness, Fm is disturbance torque applied to the motor due to parameter variation, Dm is viscous friction torque, Treac is Shaft reaction force, θm is the motor position, Tdism ^* is the estimated disturbance torque, Jm is the motor inertia, Jmn is the nominal value, Gdis is the disturbance observer gain, and Kt is the torque constant.

  In FIG. 4, motor shaft positioning control is performed in accordance with a position command signal output from a position command section (not shown). Specifically, the position deviation is calculated by comparing the position feedback value output from the encoder E attached to the motor end with the position command value. Based on this position deviation, the position deviation control calculation unit 60 calculates a speed command value. Further, a current (torque) command value is calculated by the speed deviation control calculation unit 62 based on a deviation between the speed command value and the speed feedback value calculated by the speed calculation unit 66 from the output value of the encoder E. The calculated current command value is output to the servo current amplifier 64, and a motor current is given to the motor M to drive the shaft.

  When performing the above control, an estimated value of disturbance torque received by the motor shaft is calculated by the disturbance observer 68, and the value is fed back to compensate for suppressing the influence of the disturbance.

  In FIG. 4, L is a load, B is a timing belt, and A is a bearing portion.

  FIG. 4 shows an example of a control system for a one-side motor. FIG. 6 shows an example in which control systems are provided for the left and right motors ML and MR. The control system for the left side is indicated by L, and the control system for the right side is indicated by R.

JP 2007-43884 A

  However, the disturbance observer 68 works to remove all the forces that the motor M itself receives from the outside as disturbances. Therefore, as shown in FIG. 2, when driving one load using two motors, the observer receives the force received from the other motor as a disturbance and removes both. There is a possibility that the motors are pulled and interfere with each other's control.

  Control interference adversely affects positioning accuracy and speed. Further, when the generated torque is large, the shaft portion may be damaged.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to enable optimum positioning control while suppressing interference between motor shafts.

  The present invention provides an XY positioning apparatus that drives a single load using a plurality of motor shafts, a disturbance observer provided in a control system of each motor shaft, and a position deviation provided in an output portion of the disturbance observer. And the observer output adjusting unit that limits the output of the disturbance observer according to the amount of the position deviation, thereby solving the above-mentioned problem.

  Here, the observer output adjustment unit is shared by a plurality of motor shafts, and the output of the disturbance observer with the smaller amount of positional deviation can be strongly limited.

  According to the present invention, when the amount of position deviation is large due to the function of the observer output adjustment unit, the output of the disturbance observer is returned to a large amount and compensation is performed actively, and the amount of position deviation is small and no compensation is required. By limiting the output of the disturbance observer, interference between the motor shafts can be suppressed, and optimal positioning control can be performed.

  In addition, since the motor control device includes a disturbance observer, robust control that compensates for the influence of disturbances such as external force, vibration, and friction is possible.

  Furthermore, since the disturbance observer and the observer output adjustment unit can be realized by software processing for calculation, it is not necessary to add hardware and the cost is not increased. In addition, the disturbance observer and observer output adjuster have a simpler control system and a smaller amount of computation than state feedback control and H∞ control, so there is no need to use an expensive CPU, etc., and design and adjustment are easy. is there.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the first embodiment of the present invention, as shown in FIG. 7, in the same configuration as FIG. 6, in order to suppress the interference between the motor shafts, the observers are respectively provided on the output side of the disturbance observers 68L and 68R of the left and right control systems. Output adjustment units 70L and 70R are provided.

  As shown in FIG. 8, the observer output adjusting units 70L and 70R monitor the amount of position deviation. If the amount of position deviation is larger than a set value (for example, several pulses), the output of the disturbance observer is passed through as it is. To do. On the other hand, when the amount of position deviation is smaller than the set value, the output of the disturbance observer is stopped (0 times) to limit the feedback amount.

  In this way, by adjusting the outputs of the disturbance observers 68L and 68R according to the amount of position deviation, when the amount of position deviation during high-speed movement of the motors ML and MR is large, compensation is performed positively. While the motor ML, MR is performing positioning settling, the compensation between the motor shafts can be suppressed by limiting the compensation when the position deviation amount is small, and the optimum positioning control can be performed. Is possible.

  In the first embodiment, when the deviation amount is smaller than the set value, the output of the disturbance observer is stopped (0 times) and the feedback amount is limited. However, as in the second embodiment shown in FIG. It is also possible to limit the feedback amount by multiplying the output of the disturbance observer by a factor α (α = 0 to 1).

  According to the second embodiment, finer control than in the first embodiment can be performed by adjusting the coefficient α.

  Furthermore, the setting value of the observer output adjustment unit and the coefficient α are not only set to one setting, but are given in a table, so that it can be switched to several stages more finely, and in each case according to positioning accuracy and load conditions, it is optimal. It is also possible to limit the amount of feedback.

  In the first and second embodiments, the disturbance observers for the left motor ML and the right motor MR are limited independently. However, as in the third embodiment shown in FIG. A common observer output adjustment unit 70 that restricts the outputs of the respective disturbance observers 68L and 68R according to both deviations XL and XR of the motor MR is provided so as to strongly restrict the one with a smaller amount of positional deviation. It is also possible.

  The observer output adjustment unit 70 is configured as shown in FIG. 11, for example, so that the disturbance observer with the larger position deviation is left as it is (1 time), and the disturbance observer with the smaller position deviation is stopped (0 times). Has been. Note that a variable gain amplifier and a table similar to those in the second embodiment may be provided in the observer output adjustment unit 70.

  According to the third embodiment, the output can be limited according to the balance between the left and right axes.

  In each of the above embodiments, a rotary motor is used. However, the type of motor is not limited to this, and a linear motor may be used. Also, the number of motors is not limited to two.

The perspective view which shows the whole structure of an example of a gantry type XY positioning device. The top view which shows the detail of an X-axis drive part and a Y-axis drive part similarly The block diagram which shows the structural example of the disturbance observer proposed by patent document 1 A block diagram showing an example of the configuration of a control system using a disturbance observer Block diagram showing the configuration of the acceleration control system Similarly, a block diagram showing a configuration example of a control system when the number of motors is two The block diagram which shows the control system of 1st Embodiment of this invention. Similarly, a block diagram showing the configuration of the observer output adjustment unit The block diagram which shows the structure of the observer output adjustment part in 2nd Embodiment of this invention. Similarly, a block diagram showing a control system of the third embodiment Similarly, a block diagram showing the configuration of the observer output adjustment unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Head 20, 30 ... Y-axis drive part 40 ... X-axis drive part M, ML, MR ... Motor L ... Load E, EL, ER ... Encoder 60L, 60R ... Position deviation control calculating part 62L, 62R ... Speed deviation control Calculation unit 64L, 64R ... Current amplifier 66L, 66R ... Speed calculation unit 68L, 68R ... Disturbance observer 70L, 70R, 70 ... Observer output adjustment unit

Claims (2)

In an XY positioning device that drives one load using a plurality of motor shafts,
Disturbance observer provided in the control system of each motor shaft,
An observer output adjustment unit provided in an output portion of the disturbance observer, which monitors a position deviation and limits the output of the disturbance observer according to the amount of the position deviation;
A drive control device for an XY positioning device, comprising:   2. The XY positioning according to claim 1, wherein the observer output adjusting unit is shared by a plurality of motor shafts, and is configured to strongly limit the output of a disturbance observer having a smaller amount of positional deviation. Device drive control device.

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