JP2005210762A - Servo system origin adjustment method - Google Patents

Abstract

An origin adjustment method that eliminates the need for electrical alignment between an origin position of a position detector and a magnetic pole position of a servo motor is provided.
A first step of attaching a position detector 108 at an arbitrary angular position with respect to a rotor magnetic pole position of a servo motor 107; and driving the servo motor 107 at a constant rotational speed by speed control; The detected position data is fetched into the servo amplifier, the second step of sweeping the fetched position data by the calculation means 113, and the current of the servo motor 107 is detected by sweeping the phase with reference to the origin signal of the position data, and the motor A third step of storing the deviation between the position of the origin signal and the original position when the current is minimized in the memory 114 of the servo amplifier as a correction value, and a step of using this correction value as offset data of the position detector 108. 4 steps.
[Selection] Figure 1

Description

  The present invention relates to an origin adjustment method for a servo system provided with a position detector that detects position data as an absolute value.

  As a method for adjusting the origin of the synchronous AC servo motor and position detector, the origin signal of the position detector is output in a state where the rotor is excited and fixed by applying a DC voltage between the U and W windings. In general, the angle position of the magnetic pole position is fixed by adjustment.

  On the other hand, the storage means is mounted on the absolute encoder, and the phase and position of the induced voltage of the motor are offset by giving an offset to one rotation data while applying a DC voltage between the U and W windings to excite and fix the rotor. A method of performing alignment with the origin of the detector is known (see, for example, Patent Document 1).

  The servo system is composed of a servo motor and a servo amplifier equipped with a position detector. As shown in FIG. 6, a position command unit 601 that processes a position command from the outside, a position gain is adjusted, and a speed command is sent. A position controller 602 that emits, a speed command 603 that adjusts the speed gain and issues a current command, a current controller 604 that adjusts the current gain, a power converter 606 that converts DC power of the power source 605 into AC power, and a servo motor 607. An interface 609 that receives position data from a position detector 608 attached to the rotary shaft, a speed converter 610 that converts position data from the position detector 608 into speed data, and an interface 612 that receives current data from the current sensor 611 are configured. Has been.

However, when the position detector fails while attached to the user's equipment, it is not allowed to apply a DC voltage to the servo motor to excite and fix the rotor, so the position detector cannot be replaced. Further, in the case of a resolver in which the detector itself cannot have storage means, an offset cannot be used for alignment of the origin position and the magnetic pole position.
JP-A-4-304613

  The problem to be solved is that the adjustment work for setting the positional relationship between the origin position of the position detector and the rotor magnetic pole position of the servo motor takes a lot of man-hours. In addition, when the position detector fails for some reason, the position detector cannot be easily replaced with the servo motor attached to the device.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the conventional problems and to provide an origin adjustment method that can eliminate the need for electrical alignment between the origin position of a position detector and the magnetic pole position of a servo motor.

In order to solve the above problems, the present invention provides a position detector that is attached to a rotating shaft and detects rotor position data as an absolute value, a servo motor to which this position detector is attached, and a servo amplifier that controls this servo motor. A first step of attaching a position detector at an arbitrary angular position with respect to the rotor magnetic pole position of the servo motor, and the servo motor is driven at a constant rotational speed by speed control, and the position detector detects The second step of fetching the position data into the servo amplifier and sweeping the fetched position data by the calculation means, and the current of the servo motor is detected by sweeping the phase based on the origin signal of the position data, and the motor current is minimized The difference between the position of the origin signal and the original position is stored in the storage means of the servo amplifier as a correction value. 3 steps and a fourth step using this correction value as offset data of the position detector.

  Also, a first step of attaching a position detector at an arbitrary angular position with respect to the rotor magnetic pole position of the servo motor, and driving the servo motor at a constant rotational speed by speed control, position data detected by the position detector is obtained. When the motor current is minimized when the servo motor current is detected by sweeping the phase with reference to the origin position of the position data, and the second step of sweeping the position data that has been taken into the servo amplifier by the calculation means A third step of storing the deviation between the position of the origin signal and the original position in the storage means in the position detector as a correction value, and a fourth step of using the correction value as offset data of the position detector. Is.

  According to the servo system origin adjustment method of the present invention, it is possible to eliminate the need for electrical alignment between the origin position of the position detector that detects position data as an absolute value and the rotor magnetic pole position of the servo motor. The mounting man-hour can be reduced. Even if the position detector fails, the position detector can be replaced with the servo motor attached to the device.

  A position detector that is attached to the rotary shaft and detects the position data of the rotor as an absolute value, a servo motor to which the position detector is attached, and a servo amplifier that controls the servo motor are provided at the rotor magnetic pole position of the servo motor. In contrast, the first step of attaching a position detector at an arbitrary angular position, and this servo motor is driven at a constant rotational speed by speed control, the position data detected by the position detector is taken into the servo amplifier, and the acquired position data The second step of sweeping the signal by the calculation means and the position of the origin signal and the original position when the motor current is minimized by sweeping the phase based on the origin signal of the position data and detecting the current of the servo motor A third step for storing the deviation from the servo amplifier as a correction value in the storage means of the servo amplifier, and the correction value as a position detector And a fourth step used as offset data.

  The servo system according to the first embodiment includes a servo motor and a servo amplifier equipped with a position detector, and stores a correction value in storage means provided in the servo amplifier and uses it as offset data for the position detector.

  In FIG. 1, a servo amplifier includes a position command device 101 for processing a position command from the outside, a position controller 102 for adjusting a position gain and issuing a speed command, a speed command device 103 for adjusting a speed gain and issuing a current command, and a current. A current controller 104 for adjusting the gain, a power converter 106 for converting DC power of the power source 105 into AC power, an interface 109 for receiving position data from a position detector 108 attached to the rotating shaft of the servo motor 107, and a position detector A speed converter 110 that converts the position data from 108 into speed data, a current sensor 111, an interface 112 that receives current data from the current sensor 111, a calculator 113 that sweeps the position data of the position detector 108, a memory 114, The peak detector 115 detects the peak value of the motor current. There.

First, the position detector 108 is attached to the rotation shaft of the servo motor 107. At this time, it is not necessary to align the rotor magnetic pole position and the origin position as in the prior art, and the position detector 108 is attached at an arbitrary angular position of the rotation shaft of the servo motor 107 (first step).

  Next, an origin adjustment method after the servo motor 107 and the position detector 108 are connected to the servo amplifier will be described with reference to FIG.

  After the servo amplifier power supply 105 is turned on, the position data from the position detector 108 is read. Then, the position data is swept by the calculator 113 and the servo is turned on (second step).

  After executing the servo ON, a constant speed command is input to drive the servo motor 107, the motor current is detected by the current sensor 111, and held by the peak detector 115. After the motor current is detected, the speed command is stopped and the servo is turned off. The above operation is repeated, and if the current value detected by the current sensor 111 is equal to or less than a preset value, the operation is stopped, and the position data of the origin signal at that time is used as new origin position data, that is, a correction value. The data is stored and held in the memory 114 of the servo amplifier (third step).

  Thereafter, the origin adjustment of the servo system is completed by using the correction value held in the memory 114 as the offset data of the position detector (fourth step).

  FIG. 3 shows the relationship between the positional deviation of the origin signal of the position detector and the motor current value. The origin position of the position detector 108 attached at an arbitrary angular position with respect to the rotor magnetic pole position is set as a temporary origin position. The point where the motor current value becomes equal to or smaller than the preset value by sweeping by the calculator 113 from the temporary origin position is regarded as the minimum motor current and is set as the adjusted origin position.

  The reason why the motor current is considered to be the minimum value below the set value is that the motor current changes due to the phase difference of the current flowing through each phase winding with respect to the rotor magnetic pole position, but the current change is small and stable near the minimum motor current. It is to do.

  The origin position data after adjustment is stored and held in the memory 114 by sweeping, but this operation may be performed once after the position detector is first attached or replaced, and is corrected in the storage means of the servo amplifier. Since the value is stored, the present invention can be implemented even when a storage means is not provided unlike a resolver.

  In the second embodiment, the correction value is stored in the storage means in the optical absolute encoder as the position detector.

  In FIG. 4, a servo amplifier includes a position command device 401 that processes a position command from the outside, a position controller 402 that adjusts the position gain and issues a speed command, a speed command device 403 that adjusts the speed gain and issues a current command, An interface for receiving position data from a current controller 404 for adjusting gain, a power converter 406 for converting power from a DC power source 405 to AC power, and a position detector 408 attached to a rotating shaft of a servo motor 407 driven by the converted power. 409, a speed converter 410 that converts position data from the position detector 408 into speed data, an interface 412 that receives current data from the current sensor 411, and a peak detector 413 that detects the peak value of the motor current. . On the other hand, the position detector 408 includes an interface 414, a signal processing block 415, a memory 416, and a position signal detection unit 417.

As in the first embodiment, when the position detector 408 is attached to the rotating shaft of the servo motor 407, it is not necessary to align the rotor magnetic pole position and the origin position, and the position is positioned at an arbitrary angular position of the rotating shaft of the servo motor 407. A detector 408 is attached (first step).

  Next, the origin adjustment method after attaching the position detector will be described with reference to FIG. After the servo amplifier power supply 405 is turned on, position data from the position detector 408 is generated. A command for sweeping the position data from the servo amplifier is transmitted to the position detector 408, and the position detector 408 sweeps the position data in accordance with the command and executes the servo ON (second step).

  After the servo is turned on, a constant speed command is input, the servo motor 407 is driven, the current sensor 411 detects the motor current, and the peak detector 413 holds it. After the current is detected, the speed command is stopped and the servo is turned off. The above operation is repeated, and if the current value detected by the current sensor 411 is equal to or lower than a preset value, the operation is stopped, and the position data of the origin signal after the adjustment by sweep is replaced with new origin position data, that is, a correction value. And stored in the memory 416 of the position detector 408 (third step).

  Thereafter, the correction value stored in the memory 416 is used as offset data for the position detector, thereby completing the origin adjustment of the servo system (fourth step).

  By simply changing the storage location of the correction value from the servo amplifier to the storage means in the position detector, the position data is swept to detect the position where the motor current value is less than the set value, and new origin position data is corrected. The point that the value is stored in the storage means is the same as in the first embodiment.

  As is clear from the above two embodiments, the position data with the position detector attached at an arbitrary position is swept, the minimum position of the motor current is detected, and the origin position data after the sweep adjustment is used as a correction value for the servo amplifier or position. Since the servo system origin adjustment work is completed by memorizing it in the storage means of the detector and then using this correction value as offset data, attach the position detector at an arbitrary angular position with respect to the rotation axis of the servo motor. Can do.

  The servo system origin adjustment method of the present invention is optimal for a servo system in which an optical absolute encoder is mounted on a position detector, and is also useful for a servo system in which a resolver with high environmental resistance is mounted.

The block diagram of the servo system in Example 1 of this invention The flowchart of the origin adjustment method in Example 1 of this invention The figure explaining the relationship between the temporary origin position and motor current in the present invention The block diagram of the servo system in Example 2 of this invention The flowchart of the origin adjustment method in Example 2 of this invention Block diagram of a conventional servo system

Explanation of symbols

101, 401 Position commander 102, 402 Position controller 103, 403 Speed controller 104, 404 Current controller 105, 405 Power source 106, 406 Power converter 107, 407 Servo motor 108, 408 Position detector 109, 409 Interface 110 , 410 Speed converter 111, 411 Current sensor 112, 412 Interface 113 Calculator 114, 416 Memory 115, 413 Peak detector 414 Interface 415 Signal processing 417 Position signal detector

Claims (4)

A position detector that is attached to the rotary shaft and detects the position data of the rotor as an absolute value, a servo motor to which the position detector is attached, and a servo amplifier that controls the servo motor are provided at the rotor magnetic pole position of the servo motor. In contrast, the first step of attaching a position detector at an arbitrary angular position, and this servo motor is driven at a constant rotational speed by speed control, the position data detected by the position detector is taken into the servo amplifier, and the acquired position data The second step of sweeping the signal by the calculation means and the position of the origin signal and the original position when the motor current is minimized by sweeping the phase based on the origin signal of the position data and detecting the current of the servo motor A third step for storing the deviation from the servo amplifier as a correction value in the storage means of the servo amplifier, and the correction value as a position detector And a fourth step used as offset data for the servo system. A position detector that is attached to the rotary shaft and detects the position data of the rotor as an absolute value, a servo motor to which the position detector is attached, and a servo amplifier that controls the servo motor are provided at the rotor magnetic pole position of the servo motor. In contrast, the first step of attaching a position detector at an arbitrary angular position, and this servo motor is driven at a constant rotational speed by speed control, the position data detected by the position detector is taken into the servo amplifier, and the acquired position data The second step of sweeping by the calculation means, the position of the origin signal and the original position when the motor current is minimized by detecting the current of the servomotor by sweeping the phase based on the origin position of the position data A third step of storing the deviation from the position as a correction value in the storage means in the position detector, and this correction value as the position detector And a fourth step used as offset data for the servo system. 2. The servo system origin adjustment method according to claim 1, wherein the position detector is a resolver or an absolute encoder. 3. The servo system origin adjustment method according to claim 2, wherein the position detector is an absolute encoder.

Images