Permanent magnet servo motor automatic calibration method

Abstract

The application discloses a kind of permanent magnet servo motor automatic calibration method, comprising the following steps: according to motor nameplate data input basic motor parameters;Motor parameter identification, and the resistance and inductance obtained are input into controller;Motor rotation direction debugging, encoder line number identification and pole pair number identification;Incremental encoder direction and bias automatic calibration; HALL Position sensor direction and bias automatic calibration.The application only needs motor rated current and user-defined positive rotation direction, and automatically calibrates motor resistance and inductance parameters, motor pole pair number, encoder line number, encoder direction, encoder angle bias, HALL sensor direction and HALL sensor angle bias, so that three-phase lines of the motor, AB signal lines of the encoder and UVW signal lines of the HALL can be randomly exchanged and connected, solving the problems of long time consumption, complicated steps and easy mistakes in the early stage of controller adaptation to the motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of motor control, in particular to an automatic calibration method of a permanent magnet servo motor. BACKGROUND

[0002] In the vector control of a permanent magnet synchronous motor (PMSM), a driver often needs to be adapted to multiple motors to meet various application requirements of users. When the driver is adapted to the motor, a lot of time is often spent on referring to a motor manual to input motor parameters into the driver. However, the motor parameters are often unknown or the motor manual is lost.

[0003] At present, motor parameters are generally obtained by referring to a motor manual to obtain parameters such as phase resistance, phase inductance, pole pair number and motor rated current. This method is greatly affected by external factors. Many times, there is no detailed motor manual, and there is also a certain difference between actual motor parameters and manual data. The position calibration of an incremental encoder often involves phase locking after finding a z signal, and the position signal calibration of a HALL signal is directly obtained according to the installation angle of a HALL sensor. The traditional method for calibrating a permanent magnet servo motor takes a long time, has low efficiency and is not accurate enough. SUMMARY

[0004] To solve the above technical problems, the present application provides an automatic calibration method of a permanent magnet servo motor, which is efficient, accurate and easy to operate.

[0005] The technical scheme for solving the above problems is as follows: an automatic calibration method of a permanent magnet servo motor, comprising the following steps:

[0006] 1) input basic motor parameters, i.e. rated current, according to motor nameplate data;

[0007] 2) identify motor parameters and input obtained resistance and inductance into a controller;

[0008] 3) debug motor rotation direction, identify encoder line number and identify pole pair number;

[0009] 4) automatically calibrate direction and bias of an incremental encoder;

[0010] 5) automatically calibrate direction and bias of a HALL position sensor.

[0011] In the step 2), the identification method of resistance and inductance is as follows: keep q-axis voltage u q = 0, increase u d from 0, when the current reaches i d1 , id1 Set to half of the rated current, keep u d t seconds until the current is stable, collect the steady-state voltage u d1 and steady-state current i d1 , then continue to increase u d , when the current reaches i d2 , i d2 is set to the rated current, keep u d t seconds until the current is stable, collect the steady-state voltage u d2 and steady-state current i d2 , then u d is stepped from u d2 to u d1 , the current decreases from I d2 to i d2 +(i d1 -i d2 )*63.2%, the time experienced is the time constant τ, finally u d is set to 0, the resistance R and inductance L can be calculated; the calculation formula is:

[0012]

[0013] L=τ*R.

[0014] The automatic calibration method of the permanent magnet servo motor, the specific process of step 3) is: u d =u d2 , u q =0 and setting the open-loop frequency, so that the motor rotates according to the ABC phase sequence open loop, the user judges whether the rotation direction of the motor is the same as the required positive direction, if not, adjust the duty ratio and current sampling of any two phases, so that the positive direction of the motor rotation meets the user-defined positive direction, and save the state value to the flash, so as to automatically load after power on; while open-loop rotating, collect the count value between two z signals of the incremental encoder, get the number of encoder lines; at the same time, record the time of one cycle of open-loop rotation, get the number of pole pairs of the motor by multiplying the time of one cycle of open-loop rotation by the open-loop rotation frequency.

[0015] The automatic calibration method of the permanent magnet servo motor, the specific process of step 4) is: the motor rotates open loop, the system determines the direction of the encoder according to the slope of the encoder angle, finds the z signal, clears the position of the encoder, and then locks the d axis, the obtained encoder reading is the angle offset of the encoder.

[0016] The automatic calibration method of the permanent magnet servo motor, the specific process of the step 5) is: after the direction and position of the incremental encoder are calibrated, the direction of the HALL signal is judged and calibrated, the motor is opened and rotated, the system detects the direction of the HALL signal according to the slope of the HALL angle, and the angle offset of the HALL position signal is obtained according to the average deviation of the encoder angle and the HALL position signal.

[0017] The application has the advantages that: the application can automatically calibrate the motor resistance inductance parameters, motor pole pairs, encoder line numbers, encoder direction, encoder angle offset, HALL sensor direction, HALL sensor angle offset and other parameters under the condition that only the motor rated current and the user-defined positive rotation direction are required, so that the three-phase lines of the motor can be randomly exchanged, the AB signal lines of the encoder can be randomly exchanged, and the UVW signal lines of the HALL can be randomly exchanged, the problems of long time consumption, complicated steps and easy mistakes in the early controller adaptation motor are solved, the accuracy of the set parameters and the working efficiency of the motor adaptation process are greatly improved, and the technology is proved to be feasible through the experiment process. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The whole flowchart of the application.

[0019] Figure 2 The parameter identification flowchart.

[0020] Figure 3 The voltage and current change chart in the resistance and inductance identification process.

[0021] Figure 4 The position signal chart of the encoder and the HALL element. DETAILED DESCRIPTION

[0022] The application will be further described below in combination with the drawings and examples.

[0023] As shown in the drawings, Figure 1 An automatic calibration method of a permanent magnet servo motor comprises the following steps:

[0024] 1) Basic motor parameters, i.e. rated current, are input according to motor nameplate data.

[0025] 2) Motor parameter identification, and the obtained resistance and inductance are input into the controller.

[0026] As shown in the drawings, Figure 2 and Figure 3 The identification method of the resistance and inductance is: u q = 0 is kept, u d is slowly increased from 0, and when the current reaches i d1( can be set to half of the rated current), keep u d 0.5 seconds until the current is stable, 3τ < t < 10τ, collect the steady-state voltage u d1 and the steady-state current i d1 , then continue to increase u d , when the current reaches i d2 ( can be set to rated current), keep u d 0.5 seconds, collect the steady-state voltage u d2 and the steady-state current i d2 , then u d from u d2 step to u d1 , the current from I d2 down to I d2 + (I d1 -I d2 ) * 63.2% experienced time is the time constant τ, finally u d set to 0, that is, the resistance R and inductance L can be calculated. The calculation formula is:

[0027]

[0028] L = τ * R.

[0029] 3) Motor rotation direction debugging, encoder line number recognition and pole pair number recognition.

[0030] The specific process of step 3) is: u d = u d2 , u q = 0 and set the open-loop frequency, so that the motor rotates according to the ABC phase sequence open loop, and the user judges whether the rotation direction of the motor is the same as the required positive direction, if not, adjust the duty ratio and current sampling of any two phases, so that the positive direction of the motor rotation meets the user-defined positive direction, and save the state value to flash, so as to automatically load after power on; At the same time of open loop rotation, collect the count value between two z signals of incremental encoder, get the line number of encoder; At the same time, record the time of one cycle of open loop rotation, get the pole pair number of motor by multiplying the time of one cycle of open loop rotation by the open loop rotation frequency.

[0031] 4) Automatic calibration of incremental encoder direction and bias.

[0032] The motor rotates in open loop, and the system determines the direction of the encoder according to the slope of the encoder angle. After finding the z signal, the encoder position is cleared, and then the d axis is locked, and the obtained encoder reading is the angle bias of the encoder.

[0033] 5) Automatic calibration of HALL position sensor direction and bias.

[0034] After the direction and position of the incremental encoder are calibrated, the direction of the HALL signal is judged and calibrated, and the motor is open-loop rotated. The system detects the direction of the HALL signal according to the slope of the HALL angle, and the angle offset of the HALL position signal is obtained according to the average deviation of the encoder angle and the HALL position signal, as shown in Figure 4 .

Claims

1. An automatic calibration method for a permanent magnet servo motor, characterized in that, Includes the following steps: 1) Input the basic motor parameters, i.e., the rated current, according to the data on the motor nameplate; 2) Identify motor parameters and input the obtained resistance and inductance values ​​into the controller; In step 2), the method for identifying resistance and inductance is as follows: maintain the q-axis voltage. =0, incrementing from 0. When the current reaches hour, Set to half of the rated current and maintain. The steady-state voltage is obtained after t seconds until the current stabilizes. and steady-state current Then continue to increase When the current reaches hour, Set to rated current, maintain The steady-state voltage is obtained after t seconds until the current stabilizes. and steady-state current , and then from Step to The current flows from Descending to The time elapsed is the time constant τ, and finally... Setting it to 0 allows you to calculate the resistance R and inductance L; the calculation formula is: ； ； 3) Motor rotation direction adjustment, encoder line count identification, and pole pair count identification; The specific process of step 3) is as follows: Let , =0 and set the open-loop frequency to make the motor rotate in open loop according to the ABC phase sequence. The user judges whether the rotation direction of the motor is the same as the required positive direction. If they are different, the duty cycle and current sampling of any two phases are adjusted to make the positive direction of the motor rotation match the user-defined positive direction, and the status value is saved to flash for automatic loading upon power-up. While rotating in open loop, the count value between two z signals of the incremental encoder is collected to obtain the encoder line count. At the same time, the time for one rotation of the open loop is recorded. The number of pole pairs of the motor is obtained by multiplying the time for one rotation of the open loop by the electrical frequency of the open loop rotation. 4) Automatic calibration of incremental encoder orientation and bias; The specific process of step 4) is as follows: the motor rotates in open loop, the system determines the encoder direction according to the slope of the encoder angle, after finding the z signal, the encoder position is cleared to zero, and then the d axis is locked. The obtained encoder reading is the encoder angle offset. 5) Automatic calibration of HALL position sensor orientation and offset; The specific process of step 5) is as follows: After calibrating the direction and position of the incremental encoder, the direction of the HALL signal is judged and the position is calibrated. The motor is rotated in open loop. The system detects the direction of the HALL signal according to the slope of the HALL angle. The angle offset of the HALL position signal is obtained according to the average deviation between the encoder angle and the HALL position signal. Under the condition that only the rated current of the motor and the user-defined positive direction of rotation are required, the motor resistance and inductance parameters, the number of motor pole pairs, the number of encoder lines, the encoder direction, the encoder angle offset, the direction of the HALL sensor, and the angle offset of the HALL sensor are automatically calibrated, so that the three-phase wires of the motor, the AB signal lines of the encoder, and the UVW signal lines of the HALL can be freely interchanged.

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