JPH11296234A - Method and device for weighted control for position control of motor or the like - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain highly reliable method and device capable of executing highly accurate weighted control reflecting a measurement of weighted characteristics. SOLUTION: Command torque Te corresponding to a target weighting value L is selected from a calibration table CT. Various command torque Te measured with a motor 1 or the like and a position control load 1b to be used for weighted control are applied to a working target 14 by the command torque Te at the time of controlling a position on which the load 1b is abutted upon the target 14, corresponding to the result of a weighted characteristics L obtained at the time of driving the load 1b by the torque Te. The motor 1 or the like is driven by the selected command torque Te for weighted control and the measured weighted characteristics is reflected to the control so as to attain the purpose.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position control load for driving various motors such as a servomotor with a command torque to move a position control load to a target position and abut on a work object. The present invention relates to a weight control method for motors for controlling weight applied to a work target from a position control load.

[0002]

2. Description of the Related Art The above-described position control and weight control are used in a technical field which requires high position accuracy and workability, for example, handling electronic components.

Such position control involves controlling the position of a suction nozzle for handling electronic components when mounting or mounting a bare IC chip on a circuit board. There is a corresponding mounting height control, a position control of a bonding tool when forming a metal bump on an electrode portion of a bare IC chip, and particularly a control of a pressing height of a metal wire to a bonding position.

[0004] The weight control is performed by mounting a deformed part such as a connector or an electronic part having a different allowable load range on a circuit board, or by applying a metal wire to an electrode portion of an IC chip by ultrasonic vibration or the like. After melting and welding, when a metal wire is torn off from the welded portion to form a bump on the electrode portion, a component handling tool or a bonding tool for performing these operations is used as a circuit board or a work target. There is a control for pressing an electronic component or a metal wire against an IC chip or the like.

Conventionally, such position control and weighting control are performed by moving a component handling tool, a bonding tool, or an operating member such as a screw shaft connected thereto to a position control target as shown in FIG. The driving is performed using a motor 1a such as an AC servomotor or a voice coil motor as a driving source. The motor 1a performs drive control by giving a command torque Te for performing movement, stop, contact, and weight at the time of the necessary direction and speed to the driver 6a as a current control unit.

The position control is performed by a control function of a positioning control section 7a shown in FIG. In the case of the additional value control, a command position b for moving the control load 1a1 to the target position
A command speed d is generated by the position control unit 4a from the difference between the command speed d and the current position c detected by the position detection unit 2a.
The speed control unit 5a generates a command torque Te required to reach the command position b from the difference between the current speed e and the current speed e detected by the speed detection unit 3a. The command torque Te is given to the driver 6a via the control ON / OFF switch 10a, and the driver 6a drives the motor 1a with an output current corresponding to the received command torque Te to control the load 1a.
1 is continuously controlled to reach a target position, such as a circuit board on which electronic components are mounted, or a position such as a bare IC for forming metal bumps, which comes into contact with the work object 14a as shown in FIG.

When the command torque Te output from the speed control unit 5a increases in response to the current speed becoming 0 when the control load 1a1 comes into contact with the work object 11a, the hit detection unit 8a The contact is detected. Upon detecting the contact, the hit detection unit 8a stops the control of the positioning control unit 7a and activates the weight control unit 9a. The weight control section 9a inputs a predetermined command torque Te 'corresponding to the target weight value to the driver 6a, and the motor 1a further obtains a driving force, and further presses the control load 1a1 in contact with the work object 14a to a predetermined value. Let the weight be achieved.

[0008]

However, while the precision of the position control and the weighting control is desired to be further improved with the help of miniaturization of electronic parts, the above-described conventional control is particularly insufficient in the weighting control. And sufficient reliability cannot be obtained.

In this connection, the present inventors have conducted various experiments and studies and found that the factors affecting the lack of accuracy are the motor A and the motor A, which can be seen in the relationship between the driving current and the weight in FIG.
The variation of the thrust for each of B and C, the variation of the output current of the current control unit for the command torque, ie, the driver 6a,
There are variations in the friction load of the movable part such as the control load 1a1. When the metal bump is formed, as shown in FIG. 9, the command torque Te is gradually increased in the process of contacting the metal wire with the electrode in the predetermined load state by the position control load 1a1 to apply the load. When the weighted contact portion of the metal wire is melted in a predetermined weight state, the command torque Te
Is gradually reduced and finally released, control is performed. When the command torque is increased in this manner,
There is a hysteresis characteristic as shown in FIG. 10 in the change of the weighting characteristic when decreasing, and the difference between the change characteristic Te1n when increasing the command torque Te and the change characteristic Te2n when decreasing the command torque Te. Also affects the lack of accuracy. The above conventional control cannot cope with these.

An object of the present invention is to provide a highly reliable weight control method at the time of position control of motors capable of performing high-precision weight control by reflecting actually measured weight characteristics in control based on the above new knowledge. And to provide the device.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, a weight control method for controlling the position of motors according to the present invention comprises: Is moved to the target position and is brought into contact with the work target.When controlling the weight applied from the position control load to the work target by the command torque during the position control in which the command torque is used, actual measurement is performed using the motors and the position control load used. A command torque corresponding to a target weight value is selected from a calibration table in which various command torques obtained and the results of the weighting characteristics at the time of driving are obtained, and motors are driven by the selected command torque to perform weighting. Performing control is one feature.

As described above, after the position control load is brought into contact with the work object by the position control of the motors, the command torque for the load control is used to perform the weight control after the load is applied. From the calibration table in which various command torques and the results of the weighting characteristics at the time of driving obtained by actual measurement are selected, the one corresponding to the target weight value is selected and applied. , A weight value as a target can be obtained with high accuracy based on actual data including all variations that can be recognized or cannot be recognized.

In the calibration table, a first change corresponding to the weighting characteristic when increasing the command torque and a second change corresponding to the weighting characteristic when decreasing the command torque are stored. When the weighting control when the command torque is increased is performed by the data of the first change, and when the command torque is decreased, the weighting control is performed by the data of the second change. Even if there is a hysteresis characteristic in the load characteristics when increasing and decreasing the torque, such a load control that increases the command torque and a load control that decreases the command torque are such. It is possible to achieve more accurate weight control in consideration of the influence of the hysteresis characteristic.

The weight control apparatus for controlling the position of motors according to the present invention is a position control for driving a motor such as a servomotor by a command torque to move a position control load to a target position and abut on a work object. In addition to the means, the motors are driven by the command torque, weight control means for controlling the weight applied from the position control load to the work object with which it is in contact, and weight value setting means for setting a target weight value of the weight control. The command torque corresponding to the set target weight value from the calibration table that correlates the various command torques obtained by actually measuring with the motors and position control loads to be used and the results of the weighting characteristics during driving. Command torque setting means for selecting the position control load and the load control means, contact detection means for detecting contact of the position control load with the work object, and contact detection means. Switching means for switching the control of the motor from the position control by the position control means to the weight control by the weight control means when the contact is detected by the weight control means. Can be achieved.

A storage means for storing a calibration table is provided. The command torque setting means reads a command torque corresponding to the set target weight value from the calibration table stored in the storage means and sets the command torque. In this way, once the calibration table obtained by actually measuring the device is stored in the storage means, the necessary weight value is set only at that time until the data needs to be changed due to any change. Can respond automatically.

Further, a load characteristic detecting means for contacting the position control load of the driven motors and detecting a weight characteristic corresponding to the command torque for performing the driving from the pressure state at that time, While driving the position control load with the weighting characteristic detecting means each time while driving with various command torques, the weighting characteristic output from the weighting characteristic detecting means at each time is compared with the corresponding command torque. If it is provided with a table creating means for creating a calibration table, the calibration table is automatically stored in accordance with the operation function of the working machine itself using the calibration data. It is convenient because there is no need to manually test and collect data and set data. That. In addition, when there is a certain change or by periodically re-creating the calibration table, it is possible to automatically cope with the occasional change.

Further features of the present invention will become apparent from the following detailed description and drawings.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a weight control method and apparatus for position control of motors according to the present invention. FIG.

FIG. 1 shows a weight control method according to this embodiment.
Weight control device 21 for performing position control and weight control shown in FIG.
When the position is controlled by driving various motors 1 such as an AC servomotor with a command torque Te to move to a target position and bring a position control load 1b into contact with a work object 14, the command torque Te is used. The motor 1 and the position control load 1 used to control the weight applied from the position control load 1b to the work object 14 to which the position control load 1b abuts.
From the calibration table CT (FIG. 1) corresponding to the weighting characteristic results L1 to Ln at the time of driving with the various command torques Te1 to Ten as shown in Table 1 obtained by actually measuring b and the like, The command torque Te corresponding to L is selected, and the weight control is performed by driving the motor 1 with the selected command torque Te. The position control of the motor 1 may be performed by the position control means 22 shown in FIG. However, another method may be used.

[0020]

[Table 1]

In the position control by the position control means 22 shown in FIG. 2 and the like, the command torque Te for the load control is used as described above to perform the load control after the load 1b comes into contact with the work object 14. Various command torques Te1 obtained by actually measuring the motor 1 and the position control load 1b, etc.
To Ten and the weighting characteristic results L1 to Ln at the time of driving thereby
Is selected from the calibration table CT corresponding to the target weight L and applied.
The target weight value L is achieved with high accuracy based on the actual data including all the recognizable and unrecognizable variations from the motor 1 to the position control load 1b.

On the other hand, the calibration table CT
As shown in Table 2, the command torque Te is changed from Te11 to T
e1n, the first change corresponding to the weighting characteristics L1 to Ln and the command torque Te21 to Te21.
In addition to the second variation corresponding to the weighting characteristics L1 to Ln at the time of decreasing to 2n, the weighting control when the command torque increases is performed by the data Te11 to Te1n of the first variation.
Weighting control when the command torque decreases
Weighting control is performed by the data Te21 to Te2n corresponding to the change of

Thus, even if there is a hysteresis characteristic as described in the weighting characteristics when increasing and decreasing the command torque, the weighting control for increasing the command torque and the command torque It is possible to achieve more accurate weight control with the influence of the hysteresis characteristic and to reduce the weight control, which is suitable for weight control at the time of position control when forming the above-described metal bump. It is.

[0024]

[Table 2]

It is preferable that both of the calibration tables CT shown in Table 1 and Table 2 are provided and selectively used. However, the present invention is not limited to this, and it is effective to use only one of them.

The weight control device 21 for controlling the position of the motors shown in FIG.
Is driven by the command torque Te to move the position control load 1b to the target position and contact the work object, and the motor 1 is driven by the command torque Te. Weight control unit 9 as weight control means for controlling the weight applied to the contacted work object 14, and weight value setting means for automatically inputting and setting a target weight value in the weight control according to a manual input or an operation control program. 23, various command torques Te obtained by actually measuring with the motor 1 and the position control load 1b used as described above, or further measuring the hysteresis characteristics, and the results of the weighting characteristics at the time of driving by using them. A command torque Te corresponding to the set target weight value is selected from the calibration table CT, and is controlled by weighting. Command torque setting means give to the 9 24
And a hit detection unit 8 which is a contact detection means for detecting the contact of the position control load 1b with the work object 14, and a position control for controlling the motor 1 when the contact detection by the hit detection unit 8 is detected. From the position control by the means 22 to the weight control means 21
And switching means 25 for switching to the weighting control by the above-mentioned method, and the above-described method can be automatically achieved.

The position control means 22 is the same as the conventional example described above, and the position control for bringing the position control load 1b into contact with the work object 14 is performed by the control function of the positioning control section 7. The control is additional value control. The weight value setting means 23 is a setting input means for the weight control unit 9, but is set by an operation program stored in a storage device inside or outside the control device such as the operation panel or the weight control unit 9. There may be. The command torque setting unit 24 may use the internal function of the weight control unit 9 or may use an external device. The switching unit 25 may use the internal function of the hit detection unit 8 or may use an external device.
Further, each device shown in FIG. 2 can be replaced by an internal function of a microcomputer for controlling the operation of the work machine, or can be each an independent device or a partial device configured in various combinations. The point is that the necessary functions are achieved.

The weight control means 21 shown in FIGS. 1 and 2 further includes a calibration data table storage unit 1 as storage means for storing the calibration table CT.
The command torque setting means 24 reads the command torque Te corresponding to the set target weight from the calibration table CT stored in the calibration data table storage unit 12 and sets the command torque Te. Thus, once the calibration table CT obtained by actually measuring the apparatus is once stored in the calibration data table storage unit 12, the weight value required at each time is necessary until the data needs to be changed due to some change. It is possible to respond automatically just by setting.

Further, the weight control means 2 shown in FIGS.
1 is the calibration data table storage unit 1
2 has a function of creating the calibration table CT to be stored in the storage unit 2 by itself, a calibration control unit 11 as a table creation unit, and a weight characteristic detection including a pressure sensor for detecting an actual weight characteristic of the work machine. Means 13 are also provided. The calibration control unit 11 causes the position control load 1b of the driven motor 1 to abut on the weighting characteristic detecting means 13 and changes the weighting characteristic L corresponding to the command torque Te performing the driving from the pressure state at that time. Are stored in the calibration data table storage unit 12 as calibration data paired with the corresponding command torque Te, and a calibration table CT is created. As a result, the calibration table CT is automatically obtained by the operation function of the working machine itself that uses the calibration table CT, so that it is not necessary for a person to perform a test operation to collect data and set data, which is convenient.
In addition, when there is some change or by periodically re-creating the calibration table CT, it is possible to automatically cope with the occasional change.

The weighting characteristic detecting means 13 is fixedly installed in the vicinity of the position where the work object 14 of the work machine is positioned, and pushes the position control load 1b to the work machine when the calibration table CT is created. You just have to hit it. However, the weighting characteristic detecting means 13 can be moved to a required position when necessary.

To utilize the calibration table CT as described above, first, before the end user starts using the work machine, at the manufacturer or before the end user starts using the work machine, the calibration table CT shown in FIG. It is preferable to perform an operation of creating the option table CT. Automatic judgment signal or artificial input signal based on predetermined judgment data only at the beginning of operation or periodically after operation time of operation machine or start of operation of work machine during operation program of work machine It is preferable that the operation of creating the calibration table CT is performed by the above operation.

The operation of preparing the calibration table CT is performed when the calibration operation for each designated torque is performed a required number of times as shown in FIG. 3 and the motor 1 is actually driven as shown in FIG. Command torque Te
And the load cell output of the weighting characteristic detecting means 13 detected at that time are collected to create a calibration data table. Next, this is stored in the calibration data table storage unit 12.

Thereafter, the use of the working machine is started, and as shown in FIG. 5, first, a positioning operation is performed by the position control means 22, and a search operation is performed to determine whether or not the target position has been reached. Specifically, a command position b for moving the control load 1b to the target position and a current position c detected by the position detection unit 2
A speed command d is generated by the position control unit 4 from the difference between the speed command d and the current speed e detected by the speed detection unit 3. The command torque Te required for the above is generated. Command torque T
e is supplied to a current control unit 6 including a driver via a control on / off switch 10, and the current control unit 6 drives the motor 1 in accordance with the received command torque Te to control the position of the control load 1b, thereby controlling the target position. For example, it is caused to reach a position where it comes into contact with the work object 14 such as a circuit board on which electronic components are mounted or a bare IC for forming metal bumps.

When it is detected that the position control load 1b has come into contact with the work object 14 after reaching the target position, the control is switched to the weight control by the weight control means 21, and the weight operation is performed. More specifically, the change in the command torque Te output from the speed control unit 5 corresponding to the current speed becoming 0 when the control load 1b abuts on the work object 14 causes the hit detection unit 8 detects the contact. When the hit detection unit 8 detects the contact, the control of the positioning control unit 7 is stopped, and the weight control unit 9 is activated.
The weight control section 9 inputs a predetermined command torque Te 'to the current control section 6 based on a signal such as a subsequent command position, so that the motor 1 obtains further driving force and the position control load 1b
Is further pressed against the work object 14 against which it abuts, and a predetermined weighted state is obtained. Upon completion of the weighting operation, a return operation is performed.

[0035]

According to one aspect of the weight control method and apparatus for controlling the position of motors according to the present invention, any variation elements that can be recognized or not, from the motor to the position control load, can be recognized. A weight value as a target is obtained with high accuracy based on the performance data included, and the apparatus can automatically achieve such weight control in particular.

According to another feature, a weighting control for increasing the command torque even if the weighting characteristics for increasing and decreasing the command torque have a hysteresis characteristic. Weighting control for decreasing the command torque and more accurate weighting control that takes into account the influence of such hysteresis characteristics can be achieved.

According to another feature of the apparatus, a calibration table CT obtained by actually measuring the apparatus is provided.
Is temporarily stored in the storage means, until the data needs to be changed due to some change thereafter, it is possible to automatically cope with the situation simply by setting the necessary weight value.

Further, as another characteristic, since the calibration table CT is automatically obtained by the operation function of the actual machine using the calibration table CT, it is necessary for a person to perform a test operation to collect data and set data. There is no convenience. Also, when there is any change or periodically, the calibration table CT is re-created,
It can automatically respond to the occasional change.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a weight control method and device during positioning control of motors according to a representative embodiment of the present invention.

FIG. 2 is a block diagram showing a specific configuration of the method and apparatus of FIG. 1;

FIG. 3 is a flowchart illustrating an example of a calibration operation in the method and apparatus of FIG. 1;

FIG. 4 is a graph showing a calibration table obtained in the operation of FIG. 3;

FIG. 5 is a flowchart showing an example of positioning control and subsequent weighting control when a calibration table obtained by the operation of FIG. 3 is used.

FIG. 6 is a schematic diagram showing a conventional weight control method and device during positioning control of motors.

FIG. 7 is a block diagram showing a specific configuration of the method and apparatus of FIG. 6;

FIG. 8 is a graph showing a state in which the thrust and the load characteristics of each motor vary.

FIG. 9 is a graph showing an example of a weight control state for increasing or decreasing a command torque.

FIG. 10 is a graph showing a hysteresis characteristic of a weight characteristic generated in the weight control shown in FIG. 9;

[Explanation of symbols]

 Reference Signs List 1 motor 1b position control load 4 position control unit 5 speed control unit 6 current control unit 7 positioning control unit 8 per unit detection unit 9 weight control unit 11 calibration control unit 12 calibration data table storage unit 13 weight characteristic detection unit 14 work target 21 weight control means 22 position control means 23 weight value setting means 24 command torque setting means 25 switching means Te, Te 'command torque L weighting characteristics

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Takeda 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] When a position control load is moved to a target position by driving motors such as a servomotor with a command torque and brought into contact with a work object, the position control load is moved from the position control load to the work object by the command torque. In the weight control method for the motors that control the applied weight, a calibration table that correlates various command torques obtained by actually measuring the motors and position control load to be used and the results of the weighting characteristics at the time of driving with them is used. A weighting control method for motors, comprising selecting a command torque corresponding to a target weight value, and performing weighting control by driving the motors with the selected command torque. 2. The calibration table according to claim 1, wherein the first change corresponding to the weighting characteristic when increasing the command torque and the second change corresponding to the weighting characteristic when decreasing the command torque. The weight control when the command torque increases is performed by the data of the first change, and the weight control when the command torque decreases is performed by the data of the second change, respectively. 4. A weight control method at the time of position control of motors according to 4. 3. A motor, such as a servomotor, is driven by a command torque to move a position control load to a target position and abut on a work object. Weight control means for controlling the weight given to the work object contacted by the position control load, weight setting means for setting a target weight value of the weight control, motors and position control loads to be actually measured. A command torque corresponding to a set target weight value is selected from a calibration table in which various command torques obtained and a result of a weight characteristic during driving are obtained, and the command torque is given to the weight control means. Setting means, contact detection means for detecting contact of the position control load with the work object, and control of the motor when contact is detected by the contact detection means. Switching means for switching from the position control by the position control means to the weight control by the weight control means. 4. A storage means for storing a calibration table, wherein the command torque setting means reads a command torque corresponding to the set target weight value from the calibration table stored in the storage means, and stores the command torque. 4. The weight control device for motors according to claim 3, wherein the setting is performed. 5. A load characteristic detecting means for contacting a position control load of a driven motor and detecting a load characteristic corresponding to a command torque for performing the driving from a pressure state at that time, and a motor and the like. While driving the position control load with the weighting characteristic detecting means each time while driving with various command torques, the weighting characteristic output from the weighting characteristic detecting means at each time is compared with the corresponding command torque. 5. The weight control device according to claim 4, further comprising: a table creation unit that stores the calibration data obtained in the storage unit in the storage unit and creates a calibration table.