JP4840987B2 - Positioning control device for equipment related to electronic component mounting - Google Patents

Description

  The present invention relates to a positioning control device for an electronic component mounting related device that performs positioning control of a moving body in an electronic component mounting related device such as an electronic component mounting machine, an adhesive coating device, and a flux coating device.

  One of the core technologies in surface mount line equipment is high-precision and high-speed positioning technology, and the positioning control device (motion controller) to realize it is a specialized control law (position command / compensator). Etc.) may be implemented. Specialized control laws are those that bring out the maximum performance in high-speed, high-accuracy positioning operations on a point-to-point basis. The control law for realizing another control target such as the above does not necessarily match. For example, in point-to-point operation, the final target position of the position command only needs to be accurate, so a compensator with an arbitrary target value tracking characteristic (trajectory tracking characteristic) in consideration of vibration suppression etc. May provide.

  However, actual operations are not limited to point-to-point operations. For example, in adhesive application, there is a demand for dot application and line application. At this time, the operation of the XY robot may be a point-to-point operation between application coordinates in the case of point application, but the line application needs to be operated by linear interpolation or curve interpolation. Therefore, if a control law that only supports point-to-point operation is implemented in the control device, the control target for these operations may not be reached. -In the two-point operation, the optimal control law could not be implemented and the cycle time could not be shortened to the limit.

  In addition, even when limited to point-to-point operation, it is not easy to design a single compensator that can realize the shortest positioning time under all driving conditions.

For example, in Patent Document 1 (Japanese Patent Laid-Open No. 9-130099), residual vibration is reduced and positioning time is shortened by changing the speed loop gain in servo motor control according to the moving distance of the head unit. It is described that it is planned.
Japanese Patent Laid-Open No. 9-13003 (pages 1 to 3 etc.)

  However, the technique of Patent Document 1 described above is a change in the control parameter (speed loop gain), and the compensator structure itself is not changed. Depending on the control target, the optimal solution cannot be obtained unless the compensator structure itself is changed, and there is a possibility that reduction of residual vibration and reduction of positioning time cannot be realized.

  The present invention has been made in consideration of such circumstances. Therefore, the object of the present invention is to reduce the residual vibration and shorten the positioning time (shortening the cycle time), which has been difficult to realize by changing the conventional control parameters. An object of the present invention is to provide an electronic component mounting related apparatus positioning control apparatus that can be realized.

In order to achieve the above object, the invention according to claim 1 is an electronic component mounting related apparatus that performs positioning control of a moving body in an electronic component mounting related apparatus such as an electronic component mounting machine, an adhesive application device, and a flux application device. In the positioning control device, the compensator circuit is switched by the compensator switching means according to the information relating to the movement of the moving body, and the compensator circuit further includes two or more types of suppressing vibrations in different vibration modes. The compensator switching means switches between the two or more types of compensators . In this configuration, the compensator structure itself can be changed in accordance with the information related to the movement of the moving body. (Shortening) can be realized. In addition, the compensator circuit has two or more types of compensators that suppress vibrations of different vibration modes, and the compensator switching means switches between the two or more types of compensators. It is possible to switch to a more appropriate compensator according to information (movement distance, etc.) relating to the movement of the body, and the vibration suppressing effect can be enhanced.

  In this case, as in claim 2, the compensator switching means may switch the circuit of the compensator according to the moving distance of the moving body. In this way, the circuit of the compensator can be appropriately switched in response to the vibration mode changing according to the moving distance of the moving body.

According to a third aspect of the present invention, when the target position is changed during the movement of the moving body, the compensator circuit switches according to the relative distance between the target position before the change and the target position after the change. The compensator switching means may switch the correction circuit according to the relative distance when the target position is changed during the movement of the moving body. In this way, even when the target position is changed during the movement of the moving body, it is possible to reduce residual vibration and shorten positioning time (cycle time).

  Hereinafter, three Examples 1 to 3 in which the best mode for carrying out the present invention is applied to an electronic component mounter will be described.

A first embodiment of the present invention will be described with reference to FIGS.
The positioning control device 11 mainly includes a position command generation unit 12, a position control unit 13, and a switching process determination unit 14 (compensator switching means). The control object integrated with the machine base 15 (see FIG. 3) is a rigid system or a resonance vibration system having a spring characteristic between the electric motor 17 and the movable part 18 (moving body). If the elastic deformation is caused by the load torque generated during the acceleration / deceleration operation of the movable part 18 and further the reaction of the load torque cannot be absorbed, it vibrates at a frequency that depends on the natural frequency of the machine base 15 and is positioned. In some cases, the time is increased and the positioning accuracy is deteriorated. Further, the vibration of the machine base 15 may adversely affect the environment around the machine.

  In the first embodiment, in order to suppress the vibration of the machine base 15, the positioning control device 11 is configured as follows.

  The position command generation unit 12 is equipped with various position command generation algorithms, and the position command trajectory is determined based on the moving distance, moving speed, acceleration, deceleration, and the like.

  The position controller 13 to which the position command generated by the position command generator 12 is input includes a compensator structure switching circuit 20 that switches the compensator structure, compensators 24 and 25 for feedforward, and feedback. And a compensator 26. The compensator structure switching circuit 20 includes a circuit a that passes a position command through the notch filter K1 (s) and a switch unit 21 that switches between a circuit b that bypasses the notch filter K1 (s). The switch means 21 is switched by the switching process determination unit 14 according to the moving distance of the movable unit 18. The notch filter K <b> 1 (s) is a filter for suppressing vibration of the machine base 15.

  D (s) / Na (s) of the compensator 24 is an inverse characteristic of the approximate transmission characteristic from the motor current command to the position of the movable part 18, and Nm (s) / Na (s) of the compensator 25 is This is the inverse characteristic of the approximate transmission characteristic from the position of the electric motor 17 to the position of the movable part 18.

  K2 (s) is a filter that uses D (s) / Na (s) and Nm (s) / Na (s) as proper.

  When the compensator structure switching circuit 20 is switched to the circuit a using the notch filter K1 (s) by the switch means 21, assuming that K1 (s) · K2 (s) = K (s), FIG. This is equivalent to the compensator structure of the comparative example shown in FIG.

  In short, when the notch filter K1 (s) is used, the compensator structure of the position control unit 13 is switched to the compensator structure shown in FIG. 2 as K (s) = K1 (s) · K2 (s). When the filter K1 (s) is not used, the compensator structure is switched to K (s) = K2 (s) in FIG.

  In FIG. 2, K (s) is a filter that uses D (s) / Na (s) and Nm (s) / Na (s) as proper and suppresses vibration of the machine base 15.

  In FIG. 1, a compensator 26 [Cpos (s)] is a PID compensator + torque filter. Here, s represents a Laplace transform operator. In the actual positioning control device 11, the compensator shown in the s region is mounted by being converted into a digital filter by various discretization methods.

  By the way, the thrust (torque) is transmitted from the electric motor 17 to the movable part 18. If the thrust applied to the movable part 18 at this time includes a lot of energy corresponding to the natural frequency of the machine base 15, the movable part. It is considered that 18 resonates with the machine base 15 and the vibration of the machine base 15 increases.

  In the comparative example of FIG. 2, K (s) reduces the energy near the natural frequency of the machine base 15, but the drive condition does not have an excitation force enough to shake the machine base 15, for example, in a narrow adjacent mounting. In the minute movement operation to be used, K (s) may be an overcompensation term, which causes a delay in positioning time.

  Therefore, in the first embodiment, the optimum compensator structure can be switched according to the moving distance of the movable portion 18. First, K (s) in FIG. 2 is separated as follows and configured as shown in FIG.

K (s) = K1 (s) · K2 (s)
K1 (s) is a notch filter that suppresses vibration of the machine base 15.
K2 (s) is a filter that makes D (s) / Na (s) and Nm (s) / Na (s) proper.

  The switching process determination unit 14 executes the compensator structure switching process program of FIG. 4 and switches the switch means 21 of the compensator structure switching circuit 20, so that the compensator structure switching circuit 20 according to the moving distance of the movable part 18. Are switched between the circuit a using the notch filter K1 (s) and the circuit b not using the notch filter K1 (s) to reduce the residual vibration and shorten the positioning time (cycle time).

  In the compensator structure switching processing program of FIG. 4, first, in step 101, the moving distance of the movable portion 18 is determined, and in the next step 102, the moving distance is compared with a determination threshold value and the notch filter K <b> 1 (s). Determine whether it is in use. At this time, if the moving distance is equal to or larger than the determination threshold, it is determined that the notch filter K1 (s) is used, and if the moving distance is less than the determination threshold, the notch filter K1 (s) is not used. judge.

  Thereafter, the process proceeds to step 103, and the switch means 21 of the compensator structure switching circuit 20 is switched based on the determination result of step 102, so that the compensator structure switching circuit 20 is changed according to the moving distance of the movable part 18 to the notch filter K1. Switching between the circuit a using (s) and the circuit b not using the notch filter K1 (s). Thereafter, the process proceeds to step 104, where a process for delivering the position command from the position command generating unit 12 to the compensator structure switching circuit 20 is started.

  The effect of the first embodiment is shown by numerical examples and waveforms. For example, a position command is generated with a quintic curve for a controlled object having a machine vibration (attenuation ratio of 0.08) of fHz (refer to page 95 of “Cam Mechanism Handbook” edited by the Japan Cam Industry Association). Further, the notch filter K1 (s) of the compensator structure switching circuit 20 is set as follows.

  FIG. 5 shows the waveforms of the position command, the position command first-order differentiation, and the position command second-order differentiation when the notch filter K1 (s) is used during movement of 7000th-order curve command 7000 pulses that require 192 control cycles for position command delivery.

  FIG. 6 shows the case where the notch filter K1 (s) is used when moving 1000 pulses of the quintic curve command that requires 172 control cycles to issue the position command and the notch filter K1 (s) when moving 1000 pulses of the quintic curve command that requires 200 control cycles. This is a waveform of position command, position command first-order differentiation, and position command second-order differentiation when not. The horizontal axis of the waveform is converted assuming that one control cycle is one.

  From FIG. 6, the position command payout completion time when the notch filter K1 (s) is used during the 1000 pulse movement is 240 control cycles, and the position command payout completion time when the notch filter K1 (s) is not used is 200 control cycles. Yes, the command time for 40 control cycles is shortened.

  FIG. 7 shows the result of comparing the power spectra of the position command second-order derivative. Assuming that reduction of the energy level in the vicinity of the fHz band indicated by the movement of 7000 pulses is necessary for suppressing the positioning machine base vibration, the power spectrum in the vicinity of the fHz band at the time of 1000 pulse movement is expressed by the notch filter K1. Regardless of whether or not (s) is used, the energy level is below this level. This indicates that the vibration suppression term by the compensator is not necessarily required depending on the energy distribution characteristics of the position command defined by the travel distance and travel time. Indicates that the switch is valid. Further, as a disadvantage when the notch filter K1 (s) is used for a command having a short moving distance (moving time), the filter output signal is distorted in an impulse shape, so that high-frequency energy is amplified and vibration in a higher-order mode. May be triggered. As a result, the settling time may be extended.

  When the notch filter is used for K1 (s) as in the first embodiment, the notch filter K1 (s) is used only for the moving distance that does not induce the vibration of the higher order mode. By applying a switching rule that does not use the notch filter K1 (s) for the movement distance that induces vibration of the motor, it is possible to reduce residual vibration and shorten the movement time (shortening the cycle time). it can.

  In the first embodiment, the compensator structure switching circuit 20 is switched between the circuit a using the notch filter K1 (s) and the circuit b not using the notch filter K1 (s) according to the moving distance of the movable part 18. However, the compensator structure switching circuit may be provided with two or more types of compensators (vibration suppression terms) that suppress vibrations in different vibration modes, and the compensator structure switching circuit may be switched to three or more types of compensator structures. good. A second embodiment of the present invention that embodies this will be described below with reference to FIGS.

  In the second embodiment, the primary mode frequency of the machine base vibration is fHz (attenuation ratio 0.08), and the secondary mode (attenuation ratio 0.05) is present in a band 1.5 times that frequency. As an example, the compensator structure switching circuit 30 is provided with the following two types of compensators K11 (s) and K12 (s).

  In this case, K12 (s) is configured as a compensator that simultaneously suppresses the machine vibration primary mode and the secondary mode, and includes K11 (s).

  In the second embodiment, the switching process determination unit 14 executes the compensator structure switching process program of FIG. 9 to switch the switch unit 31 of the compensator structure switching circuit 30, thereby depending on the moving distance of the movable unit 18. The compensator structure switching circuit 30 includes a circuit a using the first compensator K11 (s), a circuit b using the second compensator K12 (s), and compensators K11 (s) and K12 ( By switching to the circuit c that does not use s), the positioning time is shortened.

  In the compensator structure switching processing program of FIG. 9, first, in step 201, the moving distance of the movable portion 18 is determined, and in the next step 202, a compensator to be used is selected based on the moving distance. Thereafter, the process proceeds to step 203, and the switch means 31 of the compensator structure switching circuit 30 is switched based on the selection result of the above step 202, so that the compensator structure switching circuit 30 is changed according to the moving distance of the movable part 18. The circuit a uses the compensator K11 (s), the circuit b uses the second compensator K12 (s), and the circuit c does not use the compensators K11 (s) and K12 (s). Thereafter, the process proceeds to step 204, where a process for delivering the position command from the position command generation unit 12 to the compensator structure switching circuit 30 is started.

  As in the second embodiment, when the number of machine vibration modes to be suppressed changes with respect to the movement distance by two or more, the positioning time can be shortened by increasing the number of circuits to be switched.

  In the second embodiment, two compensators K11 (s) and K12 (s) are arranged in parallel and switched by a single switch means 31, but two or more compensators are connected in series. It is good also as a structure which arranged in order and provided the switching circuit in each.

  In the second embodiment, K12 (s) is configured as a compensator that simultaneously suppresses the machine vibration primary mode and the secondary mode, and includes K11 (s). Therefore, K12 (s) is limited to the second-order mode suppression term, arranged in series with K11 (s), and a switching circuit is provided for each compensator K11 (s), K12 (s). good.

  Embodiment 3 in which the present invention is applied when performing an operation of changing the final target position during operation in an electronic component mounting machine will be described. As a method of generating a position command when an instruction to change the final target position is received during the operation, there are roughly two methods.

  The first is a method of recalculating the trajectory up to the final target position using the position, velocity, and acceleration immediately before the trajectory change as initial values.

  The second method is to obtain a relative distance (hereinafter referred to as “correction distance”) between the initial target position and the final target position, generate a position command for the correction distance, and add the position command to the initial target position. FIG. 11 shows a positioning control device that realizes the latter method. The position command generator 12 outputs trajectory data for the initial target position as a first position command, and outputs trajectory data for the correction distance as a second position command.

  The compensator structure switching circuit 40 is provided with a first switching circuit 43 including a notch filter K1 (s) similar to that of the first embodiment and the first switch means 41 in response to the first position command. For the position command, a second switching circuit 44 (correction circuit) comprising a similar notch filter K1 (s) and second switch means 42 is provided, and according to the combination of the first position command and the second position command. Thus, the compensator structure switching circuit 40 is switched to four compensator structures.

  In the third embodiment, the switching process determination unit 14 executes the compensator structure switching process program of FIG. 12 to switch the two switch means 41 and 42 of the compensator structure switching circuit 40, thereby moving the movable unit 18. The compensator structure switching circuit 40 is switched to four compensator structures according to the distance and the correction distance.

  In the compensator structure switching processing program of FIG. 12, first, in step 301, the moving distance of the movable part 18 is determined, and in the next step 302, the moving distance is compared with a determination threshold value, and the first switching circuit 43 Whether or not the first notch filter K1 (s) is used is determined.

  Thereafter, the process proceeds to step 303, and the first switch circuit 43 is switched according to the moving distance of the movable portion 18 by switching the first switch means 41 of the compensator structure switching circuit 40 based on the determination result of the above step 302. The circuit is switched between a circuit a that uses the first notch filter K1 (s) and a circuit b that does not use the first notch filter K1 (s). Thereafter, the process proceeds to step 304, where a process of paying out the first position command from the position command generating unit 12 to the first switching circuit 43 is started.

  Thereafter, the process proceeds to step 305, where it is determined whether an instruction to change the target position has been issued. If no instruction to change the target position has been issued, the program is terminated as it is.

  On the other hand, if an instruction to change the target position is issued, the process proceeds to step 306 to determine the relative distance (correction distance) between the initial target position and the final target position, and in the next step 307, the correction distance is determined. Whether or not the second notch filter K1 (s) of the second switching circuit 44 is used is compared with the value.

  Thereafter, the process proceeds to step 308, where the second switch circuit 44 of the second switch circuit 44 is switched based on the determination result of step 307, so that the second switch circuit 44 is changed to the second notch according to the correction distance. Switching between the circuit c using the filter K1 (s) and the circuit d not using the second notch filter K1 (s). Thereafter, the process proceeds to step 309, where a process for paying out the second position command from the position command generation unit 12 to the second switching circuit 44 is started.

  In this way, for example, the first notch filter K1 (s) is used for the first position command and the second notch filter K1 (s) is not used for the second position command. The effect of shortening the positioning time can be expected when the target position and the final target position are designated. For example, after outputting the trajectory data of the 7000 pulse movement shown in the first embodiment to the first position command, the first notch filter K1 (s) is used, and a correction distance of 1000 pulses is generated during the operation. By not using the second notch filter K1 (s) when designated, the positioning time can be shortened.

  In each of the first to third embodiments described above, the compensator circuit is switched according to the moving distance. However, for example, the compensator circuit is switched according to any of the moving time, moving speed, acceleration, and the like. In short, the circuit of the compensator may be switched in accordance with at least one piece of information regarding the movement of the moving body.

  In addition, the present invention is not limited to an electronic component mounting machine, and can be widely applied to electronic component mounting related devices such as an adhesive coating device and a flux coating device.

It is a block diagram which shows the structural example of the positioning control apparatus of Example 1 of this invention. It is a block diagram which shows the structural example of the positioning control apparatus of a comparative example. 1 is a conceptual diagram of a ball screw system to which the present invention is applied. It is a flowchart which shows the flow of a process of the compensator structure switching process program of Example 1. FIG. FIG. 6 is a waveform of a position command, a position command first-order differential, and a position command second-order differential when the notch filter K1 (s) is used during movement of 7000 pulses of a quintic curve command that requires 192 control cycles to issue a position command according to the first embodiment. When the notch filter K1 (s) is used when moving 1000 pulses of the quintic curve command that requires 172 control cycles to issue the position command in the first embodiment and when the notch filter K1 (s) is moved when moving 1000 pulses of the quintic curve command that requires 200 control cycles. This is a waveform of a position command, a position command first-order derivative, and a position command second-order derivative when not used. It is the result of having compared the power spectrum of the position command second order differential of Example 1. FIG. It is a block diagram which shows the structural example of the positioning control apparatus of Example 2. FIG. It is a flowchart which shows the flow of a process of the compensator structure switching process program of Example 2. It is a block diagram which shows the structural example of the positioning control apparatus of Example 3. FIG. It is a flowchart which shows the flow of a process of the compensator structure switching process program of Example 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Positioning control apparatus, 12 ... Position command production | generation part, 13 ... Position control part, 14 ... Switching process determination part (compensator switching means), 15 ... Machine stand, 17 ... Electric motor, 18 ... Movable part (moving body), DESCRIPTION OF SYMBOLS 20 ... Compensator structure switching circuit, 21 ... Switch means, 30 ... Compensator structure switching circuit, 31 ... Switch means, 40 ... Compensator structure switching circuit, 41 ... First switch means, 42 ... Second switch means, 43 ... first switching circuit, 44 ... second switching circuit (correction circuit)

Claims (3)

In an electronic component mounting related device positioning control device that performs positioning control of a moving body in an electronic component mounting related device such as an electronic component mounting machine, an adhesive coating device, a flux coating device,
Compensator switching means for switching the circuit of the compensator according to information relating to the movement of the moving body ,
The compensator circuit has two or more types of compensators that suppress vibrations in different vibration modes, and the compensator switching means switches between the two or more types of compensators. Device positioning control device.   2. The positioning control device for an electronic component mounting related apparatus according to claim 1, wherein the compensator switching unit switches a circuit of the compensator according to a moving distance of the moving body. The circuit of the compensator has a correction circuit that is switched according to the relative distance between the target position before the change and the target position after the change when the target position is changed during the movement of the movable body,
3. The electronic component mounting-related device according to claim 1, wherein the compensator switching unit switches the correction circuit according to the relative distance when a target position is changed during the movement of the moving body. Device positioning control device.

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