Calibration method for disassembly and assembly motor reconstruction-free table based on semi-closed-loop pitching position ring

Abstract

The invention discloses a calibration method for a reconstruction-free table of a dismounting motor based on a semi-closed-loop pitching position ring, and relates to the technical field of servo control. The method comprises the specific steps that S1, before a motor is disassembled or replaced, the angle Ax of a load end absolute value encoder and the code value ax of a motor end absolute value encoder in a corresponding table are obtained, and the position of a position ring of a servo driver is fed back as the code value of the motor end absolute value encoder, namely PosFb = ax; s2, after the motor is reassembled or replaced, the code value ay of the absolute value encoder at the motor end is obtained, and the position feedback of the position loop of the servo driver is PosFb = ay; s3, the servo driver calculates the difference value ENC of the code values of the absolute value encoder at the motor end before and after the motor is replaced and stores the difference value ENC; and S4, the position feedback PosFb of the position loop of the servo driver is re-calibrated as ax. According to the method, the feedback code value of the motor can correspond to the data in the table by only needing the driver to control and execute one-time calibration, so that the advantages are obvious, and the method is accurate and efficient.

Description

Technical Field

[0001] The invention relates to the technical field of servo control, and in particular to a calibration method for a disassembled motor rebuild-free table based on a semi-closed pitch position loop. Background Art

[0002] The semi-closed-loop system feeds back the output on the motor shaft and does not care about the mechanical transmission error. Unlike the closed-loop system, the system will not be unstable due to the mechanical transmission chain error. The accuracy and stability of the semi-closed-loop system are between the open-loop system and the closed-loop system. Therefore, the semi-closed-loop system has the characteristics of high accuracy, simple structure, and easy debugging. It is widely used in modern CNC machine tools and automatic control.

[0003] The semi-closed loop system uses the motor-end encoder as a feedback element and does not detect the output of the end position of the transmission chain. When a multi-turn absolute encoder is used at the motor end for pitch position loop control, because the load is doing pitch (high and low) motion, there is no linear correspondence between the load-end absolute encoder angle and the motor rotation position. The usual practice is to build a table to match the load-end absolute encoder angle with the motor-end absolute encoder position. For example, the load-end absolute encoder angle corresponds to a motor-end absolute encoder code value every 0.01 degrees. When you want the load to rotate to a given angle, just send the corresponding motor-end absolute encoder code value to the drive device as the target position, and the load can be rotated to the given angle. When the load rotates to the given angle and stops, the current motor-end absolute encoder code value is the motor-end absolute encoder code value corresponding to the load angle in the table.

[0004] However, when the motor needs to be disassembled for maintenance and rotated or replaced with another motor, after the motor is installed, the current encoder code value of the motor does not correspond to the value in the table, and normal control cannot be restored. There are generally two solutions: one is to rotate the motor to the encoder code value corresponding to the current load angle before installing it. During the installation process, the motor may rotate slightly, which will cause a slight error in the subsequent position loop control. This method is time-consuming and labor-intensive; the second is to rebuild the table, but it is time-consuming and labor-intensive. Summary of the invention

[0005] The purpose of the present invention is to provide a method for recalibrating a disassembled motor without rebuilding the table. After the table is built, when the motor is disassembled or replaced, after the motor is reinstalled, only one calibration is required by the driver control to make the motor feedback code value correspond to the data in the table. The advantages are obvious, that is, accuracy and efficiency.

[0006] The technical scheme for achieving the above purpose is: a calibration method for a disassembled motor reconstruction-free table based on a semi-closed pitch position loop, which is used to automatically calibrate the position of the assembled or replaced motor, wherein the output end of the motor is connected to a load, and the load end is provided with a load end absolute value encoder, the motor is correspondingly connected to a servo drive and a motor end absolute value encoder, the servo drive is provided with a power-off memory, and is respectively connected to the load end absolute value encoder and the motor end absolute value encoder, and the servo drive is also connected to a host computer for communication; The servo driver stores a table of the correspondence between the angle of the absolute encoder at the load end and the code value of the absolute encoder at the motor end. The angle of the absolute encoder at the load end is the load pitching angle. The angle of the absolute encoder at the load end is expressed by A1, A2, A3, ... n Indicates that the starting angle is A1 and the ending angle is A n ; The absolute encoder code value at the motor end is a1, a2, a3...a n Indicates that the starting code value is a1 and the ending code value is a n , the angle of the absolute encoder at the load end and the code value of the absolute encoder at the motor end correspond to each other in sequence, and the position feedback of the position loop of the servo drive is Pos_Fb; It is characterized in that when the motor is disassembled or replaced, the host computer sends a Pos_Fb recalibration instruction to the servo driver. The specific steps are: S1. Before disassembling or replacing the motor, the servo driver obtains the load-end absolute encoder angle A in the corresponding table. x , the code value of the absolute encoder at the motor end is a x , the position feedback of the servo drive position loop is the code value of the absolute encoder at the motor end, that is, Pos_Fb = a x ; S2. After the motor is reassembled or replaced, the servo driver obtains the code value of the absolute encoder at the motor end as a y , x ≠ y, the position feedback of the servo drive position loop is Pos_Fb = a y ; S3. The MCU in the servo drive calculates the code value of the absolute encoder at the motor end before the motor is disassembled or replaced. x After the motor is assembled or replaced, the code value of the absolute encoder at the motor end is a y The difference between ENC And save, ENC = a x – a y ; S4. After the motor is assembled or replaced, recalibrate the position feedback Pos_Fb of the servo drive's position loop to: the absolute encoder code value at the motor end + △ ENC= a y + △ ENC = a y + a x – a y = a x , that is, the recalibrated Pos_Fb is restored to a x .

[0007] Furthermore, in step S3, ENC Save to power-off memory.

[0008] Further, in step S3, when △ ENC After saving to the power-off memory, confirm whether the servo drive is powered on again. If not, directly go to step S4. If yes, the servo drive reads △ from the power-off memory. ENC , then enter step S4.

[0009] Beneficial effects of the present invention: The present invention provides a method for recalibrating a disassembled motor without rebuilding the table. After the table is built, when the motor is disassembled or replaced, after the motor is reinstalled, only one calibration is required by the driver control to make the motor feedback code value correspond to the data in the table. The advantages are obvious, that is, accurate and efficient.

[0010] After the motor is replaced or reassembled, the value in the table remains unchanged and there is no need to rebuild the table. The only thing that needs to be done is that the position feedback of the position loop changes from the "current motor end absolute value encoder value" before the motor is removed to the "current motor end absolute value encoder value + △ ENC ", the host computer only needs to send angle A x The corresponding code value a in the table x As the target position, the motor will rotate to "the current motor end absolute encoder value + △ ENC = a x ", to achieve the correct position. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a principle block diagram of the present invention; Figure 2 It is a flow chart of the calibration method of the present invention. DETAILED DESCRIPTION

[0012] like Figure 1 , 2As shown, the present invention discloses a calibration method for a disassembled motor reconstruction-free table based on a semi-closed pitch position loop, which is used for automatically calibrating the position of an assembled or replaced motor 1, wherein the output end of the motor 1 is connected to a load, and the load end is provided with a load end absolute value encoder 2, the motor 1 is correspondingly connected to a servo driver 3 and a motor end absolute value encoder 4, the servo driver 3 is provided with a power-off memory 5, and is respectively connected to the load end absolute value encoder 2 and the motor end absolute value encoder 4, and the servo driver 3 is also communicatively connected to a host computer 6; The servo driver 3 stores a corresponding table of the angle of the load-end absolute encoder 2 and the code value of the motor-end absolute encoder 4. The angle of the load-end absolute encoder 2 is the load pitching motion angle. The angle of the load-end absolute encoder 2 is expressed by A1, A2, A3, ... n Indicates that the starting angle is A1 and the ending angle is A n ; The 4 code values ​​of the absolute encoder at the motor end are a1, a2, a3...a n Indicates that the starting code value is a1 and the ending code value is a n , the angle of the absolute encoder at the load end in the corresponding table corresponds to the code value of the absolute encoder at the motor end in sequence, and the position feedback of the position loop of the servo drive is Pos_Fb.

[0013] When disassembling or replacing the motor, the host computer sends a Pos_Fb recalibration command to the servo drive. The specific steps are as follows: S1. Before disassembling or replacing the motor, control the servo driver to obtain the load-end absolute encoder angle A in the corresponding table. x , the code value of the absolute encoder at the motor end is a x , the position feedback of the servo drive position loop is the code value of the absolute encoder at the motor end, that is, Pos_Fb = a x ; S2. After the motor is reassembled or replaced, the servo driver is controlled to obtain the code value of the absolute encoder at the motor end, which is a y , x ≠ y, the position feedback of the servo drive position loop is Pos_Fb = a y ; S3, control the MCU in the servo driver to calculate the code value of the absolute encoder at the motor end before the motor is disassembled or replaced. x After the motor is assembled or replaced, the code value of the absolute encoder at the motor end is a y The difference between ENC And save, ENC = a x – a y ; S4. Check whether the servo drive is powered on again. If not, recalibrate the position feedback Pos_Fb of the servo drive’s position loop to: the absolute encoder code value at the motor end + △ ENC = a y + △ ENC = a y + a x – a y = a x , that is, the recalibrated Pos_Fb is restored to a x； If so, the servo drive reads △ from the power-off memory ENC After the motor is assembled or replaced, the position feedback Pos_Fb of the servo drive position loop is recalibrated to: the absolute encoder code value at the motor end + △ ENC = a y + △ ENC = a y + a x – a y = a x , that is, the recalibrated Pos_Fb is restored to a x .

[0014] For example: For example, when the host computer sends a new angle setting An, the driver reads the motor end absolute encoder code value a corresponding to An in the table n As the target position of the position loop, when the load rotates to A n When the absolute encoder code value at the motor end changes to a n - (a y + △ ENC ) = a n - a x , so the current Pos_Fb = a x + a n - a x = a n .

[0015] Specifically, for example, in the constructed table, when the load angle is 15 degrees, the corresponding motor-end encoder code value is 15000; when the load angle is 17 degrees, the corresponding motor-end encoder code value is 17000.

[0016] Before removing the motor at a load of 15 degrees, a x = 15000, Pos_Fb = 15000; After the motor is reloaded at 15 degrees, a y = 20000, △ ENC= 15000 – 20000 = -5000, Pos_Fb =a y + △ ENC = 200000 – 5000 = 15000; when the load rotates to 17 degrees (corresponding to the encoder code value at the motor end is 22000), Pos_Fb = a y + △ ENC = 220000 – 5000 = 17000. In this way, the load angle and the encoder code value at the motor end are restored to the one-to-one correspondence established in the table.

[0017] After the motor is replaced or reassembled, the value in the table remains unchanged and there is no need to rebuild the table. The only thing that needs to be done is that the position feedback of the position loop changes from the "current motor end absolute value encoder value" before the motor is removed to the "current motor end absolute value encoder value + △ ENC ", the host computer only needs to send the table code value a corresponding to the angle Ax x As the target position, the motor will rotate to "the current motor end absolute encoder value + △ ENC = a x ", to achieve the correct position.

[0018] As a further illustration of this embodiment, Figure 2 The lower computer described in the figure is the servo driver described in this embodiment.

Claims

1. A calibration method for a disassembled motor without rebuilding table based on a semi-closed pitch position loop is used to automatically calibrate the position of a disassembled or replaced motor. The output end of the motor is connected to a load, and a load end absolute value encoder is provided at the load end. The motor is correspondingly connected to a servo driver and a motor end absolute value encoder. The servo driver is provided with a power-off memory and is respectively connected to the load end absolute value encoder and the motor end absolute value encoder. The servo driver is also connected to a host computer for communication; The servo driver stores a table of the correspondence between the angle of the absolute encoder at the load end and the code value of the absolute encoder at the motor end. The angle of the absolute encoder at the load end is the load pitching angle. The angle of the absolute encoder at the load end is expressed by A1, A2, A3, ... n Indicates that the starting angle is A1 and the ending angle is A n ; The absolute encoder code value at the motor end is a1, a2, a3...a n Indicates that the starting code value is a1 and the ending code value is a n , the angle of the absolute encoder at the load end and the code value of the absolute encoder at the motor end correspond to each other in sequence, and the position feedback of the position loop of the servo drive is Pos_Fb; It is characterized in that When disassembling or replacing the motor, the host computer sends a Pos_Fb recalibration command to the servo drive. The specific steps are as follows: S1. Before disassembling or replacing the motor, the servo driver obtains the load-end absolute encoder angle A in the corresponding table. x , the code value of the absolute encoder at the motor end is a x , the position feedback of the servo drive position loop is the code value of the absolute encoder at the motor end, that is, Pos_Fb = a x ; S2. After the motor is reassembled or replaced, the servo driver obtains the code value of the absolute encoder at the motor end as a y , x≠y, the position feedback of the servo drive position loop is Pos_Fb = a y ; S3. The MCU in the servo drive calculates the code value of the absolute encoder at the motor end before the motor is disassembled or replaced. x After the motor is assembled or replaced, the code value of the absolute encoder at the motor end is a y The difference between ENC And save, ENC = a x –a y ; S4. After the motor is assembled or replaced, recalibrate the position feedback Pos_Fb of the servo drive's position loop to: the absolute encoder code value at the motor end + △ ENC = a y + △ ENC = a y + a x – a y = a x , that is, the recalibrated Pos_Fb is restored to a x .

2. The calibration method for the motor disassembly and assembly without rebuilding table based on the semi-closed pitch position loop according to claim 1 is characterized in that: In step S3, ENC Save to power-off memory.

3. The calibration method for disassembling and assembling a motor without rebuilding the table based on a semi-closed pitch position loop according to claim 2 is characterized in that: In step S3, when △ ENC After saving to the power-off memory, confirm whether the servo drive is powered on again. If not, directly go to step S4. If yes, the servo drive reads △ from the power-off memory. ENC , then enter step S4.

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