JP4061845B2 - Servo system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to vibration suppression of a servo system.
[0002]
[Prior art]
Conventionally, a servo system feeds back position information from an encoder attached to a servo motor to a servo driver, and controls the current of the servo motor by a current command.
[0003]
And in order to avoid vibration of the equipment to which the servo motor is attached, the resonance point and vibration status are measured by actual machine operation to set the gain, and after the gain setting, the servo motor is operated within the range where the resonance point does not occur .
[0004]
[Problems to be solved by the invention]
However, recent equipment has been required to increase speed and accuracy, and the conventional servo system can achieve high responsiveness in terms of system performance, but the rigidity of the equipment is weak. The response could not be improved due to the influence of the inherent resonance point, and high responsiveness of the device operation could not be realized.
[0005]
The present invention solves such a conventional problem, and an object of the present invention is to provide a servo system capable of suppressing the vibration of the device with a simple configuration and realizing the high-speed and high-precision operation of the device. .
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention outputs a torque command from position command / speed command calculation, determines an output current amount by current gain, generates an output current by PWM output, and controls the output torque of the servo motor. A servo driver, a device equipped with a servo motor, and an accelerometer that measures vibration, the accelerometer is installed in the device, and a vibration information input connector for inputting the output of the accelerometer to the servo motor is provided, The output of the accelerometer is transmitted to the servo driver as serial data together with the encoder information for detecting the motor position information , the feedback of the current command by the motor current detection sensor installed in the servo driver, the feedback of the vibration by the accelerometer, controls the output torque of the motor using a double feedback loop, preparative said servo motor Intended to suppress the vibration of the attached equipment, it is not necessary to the gain setting of the servo driver by measuring the resonance point by advance actual operation, real time can suppress the vibration of the equipment, can realize high-speed device operation.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The invention of claim 1, wherein in order to solve the aforementioned problem, and outputs a torque command from the position command and speed command calculation determines the output current amounts in the current gain, the servo motor generates the output current by the PWM output Vibration information comprising a servo driver for controlling the output torque of the motor, a device equipped with a servo motor, and an accelerometer for measuring vibration, wherein the accelerometer is installed in the device and the output of the accelerometer is input to the servo motor An input connector is provided, and the output of the accelerometer is transmitted to the servo driver as serial data together with encoder information for detecting the motor position information. Feedback of a current command by a motor current detection sensor installed in the servo driver, and the acceleration It controls the output torque of the motor using a double feedback loop with feedback of the vibration due to total Previously measuring a resonance point due to actual operation, it is not necessary to the gain setting of the servo driver, real time can suppress the vibration of the equipment, the interconnection between devices and servo driver fitted with servo motor by utilizing encoder cable It can be reduced and a simple installation environment can be provided.
[0008]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0009]
( Reference Example 1)
In FIG. 1, a servo driver 101 feeds back position information of an encoder 109 in a servo motor 102 attached to a mechanism system 103 that is a device, thereby controlling the position and speed of the servo motor 102 and driving the mechanism system 103. .
[0010]
The servo driver 101 outputs a torque command from the position command / speed command calculation 110, determines an output current amount by the current gain 105, generates a current to be output to the motor 108 by the PWM output 106, and generates a current to be output to the motor 108 through the motor connector 112. To supply. The current output to the motor 108 is detected by the current sensor 107 that detects the motor current, and the torque transmitted from the servo motor 102 to the mechanism system 103 is controlled by feeding back the torque command and controlling the current. ing.
[0011]
Conventionally, the responsiveness is limited in advance so that the servo driver 101 does not issue a command higher than the resonance frequency of the mechanical system 103, but in the present invention, the information sensed by the accelerometer 104 installed in the mechanical system 103 is Feedback is made to the servo driver 101 from the newly installed vibration information input port 111, and only the vibration information is extracted from the information of the accelerometer 104 by the filter 114, and is taken into the torque command output from the position command and speed command calculation 110, and current feedback and vibration This double feedback allows the current output to the motor 108 to be changed in real time to control the torque of the servo motor 102 and reduce the vibration of the mechanism system 103.
[0012]
( Reference Example 2)
In FIG. 2, information sensed by the accelerometer 104 installed in the mechanism system 103 is fed back to the servo driver 101 from the vibration information input port 111, and only the vibration information is extracted from the information of the accelerometer 104 by the filter 114. In response, the value of the variable current gain 201 is dynamically changed to change the value for amplifying the torque command. When vibration occurs, the torque output from the servo motor 102 is changed in real time by controlling with a gain obtained by changing the current output to the motor 108 via the PWM output 106, and the vibration of the mechanism system 103 is suppressed. be able to.
[0013]
(Example 1 )
In FIG. 3, transmission of position information from the encoder 109 in the servo motor 102 is fed back to the servo driver 101 from the encoder connector 113 by serial communication. At this time, data from the accelerometer 104 installed in the mechanism system 103 is input to a vibration information input connector 301 newly installed in the servo motor 102, and is converted into serial communication data together with position data output by the encoder 109 in a transmission data processing 302. The position / vibration information is transmitted to the encoder connector 113 of the servo driver 101.
[0014]
That is, the vibration information input port of the servo driver 101 is not required, and instead, the vibration information input connector 301 provided in the servo motor 102 is an input port for vibration information, and wiring between the accelerometer 104 and the servo driver 101 can be omitted.
[0015]
The servo driver 101 uses the position information and vibration information for each control process to control the servo motor 102 and operate the mechanism system 103.
[0016]
( Reference Example 3 )
In FIG. 4, the servo motor 102 is mechanically fastened with the mechanism system 103, and the vibration generated in the mechanism system 103 is also transmitted to the servo motor 102. Therefore, the accelerometer 401 is installed inside the servo motor 102 and the servo motor 102 detects the vibration generated in the mechanism system 103.
[0017]
Therefore, the wiring from the accelerometer installed in the device to the servo motor can be omitted as compared with the first embodiment.
[0018]
In the transmission data processing 302, the position information of the servo motor 102 detected by the encoder 109 and the vibration information of the accelerometer 401 are converted into serial communication data and transmitted to the encoder connector 113 as position / vibration information.
[0019]
The servo driver 101 uses the position information / vibration information for each control process to control the servo motor 102 and operate the mechanism system 103.
[0020]
【The invention's effect】
As apparent from the above examples, according to the invention of claim 1 Symbol placement, provided vibration information input connector for inputting the output of the accelerometer to the servo motor, the servo and position information of the vibration information and the encoder serial data By transmitting to the driver, the accelerometer and the servo driver do not need to be directly wired, and can be easily installed.
[0021]
In this way, it is possible to provide a servo system that can suppress the vibration of the device with a simple configuration and can realize a high-speed and high-precision operation of the device.
[Brief description of the drawings]
FIG. 1 is a block diagram of current command correction of a servo system in Reference Embodiment 1 of the present invention. FIG. 2 is a block diagram of variable current gain of a servo system in Reference Embodiment 2 of the present invention. Configuration diagram of servo system in example 1 [Fig. 4] Configuration diagram of servo system in reference embodiment 3 of the present invention [Explanation of symbols]
101 Servo Driver 102 Servo Motor 103 Mechanism (Equipment)
104, 401 Accelerometer 105 Current gain 107 Current sensor (motor current detection sensor)
110 Position command / speed command calculation 111 Vibration information input port 114 Filter 201 Variable current gain 301 Vibration information input connector

Claims (1)

Servo driver that outputs torque command from position command / speed command calculation, determines output current amount by current gain, generates output current by PWM output and controls output torque of servo motor, and device with servo motor attached An accelerometer that measures vibration, the accelerometer is installed in a device, a vibration information input connector for inputting the output of the accelerometer to the servo motor is provided, and the output of the accelerometer is used for detecting motor position information. Serial data is transmitted to the servo driver together with the encoder information, and a motor feedback detection is performed using a double feedback loop of a current command feedback by a motor current detection sensor installed in the servo driver and a vibration feedback by the accelerometer . Servo that controls output torque and suppresses vibration of equipment with servo motor Stem.

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