Servo drive system torque detection and compensation method, system, device and medium

Abstract

The application provides a servo transmission system torque detection and compensation method, system, device and medium, wherein the method comprises the following steps: collecting torque signals and angle signals of a planetary gear of an industrial precision servo transmission system; gain calibration is performed on the torque signals to obtain torque signal voltage values after gain calibration; multi-stage filtering processing is performed to output torque effective voltage values; it is judged whether a compensation trigger condition is met, torque compensation is performed according to a single planetary gear interference compensation trigger condition or a double planetary gear interference compensation trigger condition, and output torque is obtained. The application has the beneficial effects that: in view of the core problem that periodic magnetic field interference caused by gear transmission in an industrial precision servo transmission system leads to a decrease in torque detection accuracy, an anti-interference technology framework of multi-source signal collection and dynamic compensation is constructed, torque detection error is effectively reduced, torque signal accurate detection under variable working conditions is realized, and the performance of the industrial precision servo transmission system is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of torque control of servo transmission system, and particularly relates to a servo transmission system torque detection and compensation method, system, device and medium. BACKGROUND

[0002] In an industrial precision servo transmission system, a torque signal is a core parameter for judging a load state and realizing closed-loop control. At present, torque detection of an industrial servo transmission system mainly relies on a reluctance torque sensor, which realizes torque signal acquisition by detecting magnetic field changes. Generally, the structure of an industrial precision servo transmission system is "servo motor-reducer-load", a planetary wheel is engaged between a sun gear and an inner ring gear of the reducer, rotates around the sun gear and the inner ring gear, and transmits power to an output shaft of the reducer through a planet carrier. Some industrial precision servo transmission systems are provided with one planetary wheel, and some are provided with two planetary wheels. When the planetary wheel in the reducer rotates, it drives a radially multi-stage magnetized permanent magnet to move synchronously. Since the magnetic field of the permanent magnet presents periodic spatial distribution, when the planetary wheel rotates, the spatial position of the permanent magnet relative to the torque sensor continuously changes, causing the direction and strength of the magnetic field in the detection area of the sensor to periodically fluctuate. When the magnetic field in the detection area of the torque sensor periodically fluctuates due to the movement of the permanent magnet, the voltage signal collected will superimpose periodic interference, causing the signal waveform to be abnormal. In short, gear meshing transmission will cause periodic magnetic field interference, resulting in errors in torque detection.

[0003] In torque detection, in order to avoid the influence of errors, the processing schemes of the existing mainstream technologies mainly include a scheme combining hardware filtering and magnetic shielding and a fixed parameter software compensation scheme. The scheme combining hardware filtering and magnetic shielding is to additionally provide a magnetic shielding cover outside the torque sensor, and connect an RC low-pass filter in series at the output end of the sensor signal, so as to block the magnetic field interference through the hardware structure and filter out the high-frequency interference signal. The fixed parameter software compensation scheme is to directly write a fixed amplitude and fixed phase compensation function in the control system based on a preset interference period, and to statically correct the torque value.

[0004] But the magnetic shield added by the combination scheme of hardware filtering and magnetic shielding cannot completely block the magnetic field interference, especially the dynamic magnetic field of the gear when rotating at high speed, while also increasing the system volume and cost; in addition, the RC low-pass filter has the problem of phase lag, and the lag time is usually 5-10 ms. When the speed of the servo system rises above 3000 rpm, the interference period of the magnetic field is shortened, and the filtering parameters cannot be dynamically adapted, resulting in an increase in torque error, which ultimately leads to compensation failure. The compensation parameters of the fixed parameter software compensation scheme are preset based on the fixed speed. When the speed of the servo transmission system deviates from the rated value, the interference period of the magnetic field does not match the preset compensation period, and the torque error increases instead. In summary, the existing technical solutions still have the difficulty of dynamically tracking the interference period of the magnetic field, which leads to the difficulty of meeting the precision manufacturing requirements of the torque detection accuracy of the industrial precision servo transmission system in the variable speed scene. SUMMARY

[0005] Therefore, the present application aims to overcome the above-mentioned problems in the prior art and proposes a servo transmission system torque detection and compensation method, system, device and medium.

[0006] To achieve the above-mentioned purposes, the technical solution of the present application is as follows:

[0007] The present application provides a servo transmission system torque detection and compensation method in the first aspect, comprising the following steps:

[0008] S1. Collecting the torque signal and the angle signal of the planetary gear of the industrial precision servo transmission system;

[0009] S2. Gain calibration of the torque signal to obtain the gain calibrated torque signal voltage value;

[0010] S3. Multi-stage filtering of the gain calibrated torque signal voltage value to output the torque effective voltage value , wherein k is the sampling time sequence number;

[0011] S4. Determine whether the compensation trigger condition is met. In the case of a single planetary gear, if the single planetary gear interference compensation trigger condition is met, calculate the compensation amplitude , and , wherein is the basic compensation coefficient, is the load correction coefficient,

[0012] Calculate the compensation torque , and , wherein is the angle signal of the planetary gear, is the initial phase of the planetary gear,

[0013] obtain the output torque , and wherein is a limiting function, is a conversion coefficient of effective voltage to torque, is a set capacity reduction coefficient, , are respectively minimum and maximum values of torque output of the industrial precision servo transmission system in a non-interference state;

[0014] In the case of double planetary gears, if the double planetary gear interference compensation triggering condition is met, the interference amplitudes corresponding to the two planetary gears are obtained respectively , ,

[0015] The compensation amplitudes corresponding to the two planetary gears are calculated respectively and wherein , and is a calibration coefficient,

[0016] The compensation torque is calculated , and

[0017] ,

[0018] wherein , are angle signals of the two planetary gears, , are initial phases of the two planetary gears, , is a weight coefficient, and , ,

[0019] The output torque is obtained , and .

[0020] Further, in step S2, the gain calibration is performed by using the ADC signal conversion formula, and the ADC signal conversion formula is as follows:

[0021] ,

[0022] wherein is a torque signal voltage value after gain calibration at the mth sampling time, is a torque signal digital quantity collected by the ADC, is a set digital quantity zero point value, is an ADC reference voltage, is an ADC full-scale digital quantity, is a torque sensor gain calibration coefficient, and , The standard torque source calibrates the voltage.

[0023] Further, the multi-stage filtering process in step S3 includes the following steps:

[0024] S31. Smooth the high-frequency electromagnetic interference through the sliding window mean filtering, and the formula of the sliding window mean filtering is as follows,

[0025] ,

[0026] wherein, is the torque signal voltage value after the sliding window mean filtering at the kth sampling moment, and N is the sliding window width;

[0027] S32. Suppress the pulse noise through the median filtering, and the formula of the median filtering is as follows,

[0028] ,

[0029] wherein, is the torque signal voltage value after the median filtering at the kth sampling moment, and med[·] is the median value of , , 3 mean values;

[0030] S33. Dynamically optimize the smoothness of the torque signal voltage value through the Kalman filtering, and adapt to the interference fluctuation, and the formula of the Kalman filtering is as follows,

[0031] ,

[0032] wherein, is the predicted value of the torque signal voltage value at the kth sampling moment, and , is the Kalman gain.

[0033] Further, the process of determining whether the interference compensation triggering condition is met in step S4 is as follows:

[0034] If the torque effective voltage value fluctuates more than the interference amplitude threshold value within the continuous three interference periods, it is determined that the effective interference is present, and the interference flag function is,

[0035] ,

[0036] wherein, is the average value of the torque effective voltage value collected in the ith interference period, is the average value of the torque effective voltage value collected in the continuous interference periods, is the interference amplitude threshold value;

[0037] theoretical interference period wherein, is the number of planet wheel teeth, is the number of magnet poles, is the planet wheel rotation frequency, and , is the angular increment of the planet wheel rotation in a single sampling period; is the sampling period length;

[0038] In the case of a single planet wheel, when the interference flag function is satisfied in a continuous preset number of sampling periods, and the interference period of the single planet wheel satisfies wherein, is the actual interference period, the single planet wheel interference compensation triggering condition is satisfied;

[0039] In the case of a double planet wheel, when the interference flag function is satisfied in a continuous preset number of sampling periods, the interference periods of the double planet wheels both satisfy , and the double planet wheel interference amplitude ratio , the double planet wheel interference compensation triggering condition is satisfied.

[0040] Further, the process of obtaining the interference amplitudes , corresponding to the two planet wheels is as follows: the two planet wheels are a first planet wheel and a second planet wheel, the interference amplitude of the first planet wheel is denoted as , the interference amplitude of the second planet wheel is denoted as , the theoretical interference period is used to calculate the theoretical interference period corresponding to the first planet wheel and the theoretical interference period corresponding to the second planet wheel, the interference frequency corresponding to the first planet wheel is denoted as , the interference frequency corresponding to the second planet wheel is denoted as , and , The torque effective voltage values in the continuous three interference periods are filtered by a band-pass filter according to , to decompose , , wherein is the voltage component of the first planet wheel interference, is the voltage component of the second planet wheel interference, the interference amplitude of the first planet wheel is , and the interference amplitude of the second planet wheel is The expression is,

[0041] ,

[0042] ,

[0043] wherein, , are the maximum and minimum values of the torque error in the last three consecutive interference periods, , are the maximum and minimum values of the torque error in the last three consecutive interference periods.

[0044] Further, the load correction coefficient , in step S4 is the rated load, and the actual load torque.

[0045] Further, the angle signal of the planet wheel in step S4 is wherein, is the encoder digital quantity, is the encoder zero point; the initial phase of the planet wheel is wherein, is the angle corresponding to the torque trough of the planet wheel, n is an integer, and .

[0046] Further, the condition is satisfied in the last fifty sampling periods, and the compensated torque error is less than the error preset value, wherein is the target torque, then the system switches to the normal state.

[0047] The second aspect of the present application provides a torque detection and compensation system for a servo drive system, comprising:

[0048] a collection module for collecting the torque signal and the angle signal of the planet wheel of the industrial precision servo drive system;

[0049] a first processing module for gain calibration of the torque signal to obtain the torque signal voltage value after gain calibration;

[0050] a second processing module for multi-stage filtering processing of the torque signal voltage value after gain calibration to output the torque effective voltage value ;

[0051] a third processing module for judging whether the compensation trigger condition is met, in the case of a single planet wheel, if the single planet wheel interference compensation trigger condition is met, the compensation amplitude , the compensation torque , and the output torque are calculated, and the output torque is obtained.; in the case of a double planetary gear, if the double planetary gear interference compensation triggering condition is met, the interference amplitudes corresponding to the two planetary gears are calculated respectively and and the compensation amplitudes and , and the compensation torque is calculated, and the output torque is obtained.

[0052] The third aspect of the present application provides a device comprising:

[0053] one or more processors;

[0054] a memory for storing one or more programs,

[0055] when the one or more programs are executed by the one or more processors, the one or more processors implement the servo drive system torque detection and compensation method described above.

[0056] The fourth aspect of the present application provides a computer readable storage medium comprising computer executable instructions for executing the servo drive system torque detection and compensation method described above when executed by a computer processor.

[0057] Compared with the prior art, the present application has the following advantages:

[0058] The servo drive system torque detection and compensation method described in the present application aims at the core problem of the periodic magnetic field interference caused by gear transmission in industrial precision servo drive system, which leads to the decrease of torque detection accuracy. The anti-interference technology architecture of multi-source signal acquisition and dynamic compensation is constructed, the magnetic field interference generated by gear transmission is divided into single planetary gear interference and double planetary gear interference two working condition scenes, different dynamic compensations are carried out for single planetary gear interference and double planetary gear interference scenes, the torque detection error is effectively reduced, the torque signal accurate detection under variable working conditions is realized, and the performance of industrial precision servo drive system is improved. BRIEF DESCRIPTION OF DRAWINGS

[0059] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. The accompanying drawings do not constitute an inappropriate limitation on the present application. In the drawings:

[0060] Figure 1 The servo drive system torque detection and compensation method flowchart of the first embodiment of the present application is described. DETAILED DESCRIPTION

[0061] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0062] In the following detailed description, it is to be understood that all the descriptions are merely exemplary and are not intended to limit the scope of the present application. And for the convenience of explanation, many specific details are set forth in order to provide a thorough understanding of the embodiments of the present application. However, it is apparent that one or more embodiments can be implemented without these specific details. Furthermore, in the following description, the description of well-known structures and techniques is omitted to avoid unnecessarily obscuring the concept of the present application.

[0063] The terms used herein are merely used to describe specific embodiments and are not intended to limit the present application. The terms "include", "comprise" and the like used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0064] All terms used herein, including technical and scientific terms, have meanings commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted in a manner consistent with the context of the specification, and should not be interpreted in an idealized or overly formal manner.

[0065] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0066] Embodiment one

[0067] As shown in the figure, the servo drive system torque detection and compensation method comprises the following steps: Figure 1

[0068] S1. Collect the torque signal and the angle signal of the planet wheel output by the industrial precision servo drive system in each collection period; in this embodiment, the torque signal and the angle signal are collected in the same collection period, and the sampling period is the time interval between adjacent two samplings, and one sampling is performed in each sampling period;

[0069] S2. Gain calibration is performed on the torque signal to obtain the torque signal voltage value after gain calibration;

[0070] S3. Multi-stage filtering is performed on the torque signal voltage value after gain calibration to eliminate noise and output a high signal-to-noise ratio torque effective voltage value , wherein k is the sampling time sequence number (i.e. the time sequence number of collecting the torque signal, and the sampling time sequence number is a discrete sampling sequence number);

[0071] S4. Determine whether the compensation trigger condition is met, and if the single-planet-wheel interference compensation trigger condition is met in the case of a single planet wheel, calculate the compensation amplitude of the industrial precision servo drive system , and , wherein is the basic compensation coefficient, which is a system experimental calibration value,​ is a load correction coefficient,

[0072] calculating compensation torque of industrial precision servo drive system , and wherein is an angle signal of the planetary gear, is an initial phase of the planetary gear,

[0073] obtaining output torque of industrial precision servo drive system , and wherein is a limiting function, avoiding motor overload caused by torque out of range, and the limiting range matches the rated torque of the servo motor, is a conversion coefficient of effective voltage to torque, that is, the torque value corresponding to a unit effective voltage, which is an inherent parameter of the torque sensor and the industrial precision servo drive system, and is obtained through a standard torque source calibration experiment, and in the embodiment, the inherent parameter is 1.25 N·m / V; is a set capacity reduction coefficient, in the embodiment, under magnetic field interference, is 0.7, which meets the fault tolerance performance requirements specified in GB / T 30244-2013 “Industrial Servo System Performance Test Method”, and when there is no magnetic field interference, is 1.0; , are respectively the minimum value and the maximum value of the torque output of the industrial precision servo drive system under an interference-free state;

[0074] In the case of double planetary gears, if the double planetary gear interference compensation triggering condition is met, the interference amplitudes corresponding to the two planetary gears are obtained respectively , ,

[0075] The compensation amplitudes corresponding to the two planetary gears are calculated respectively and wherein , and is a calibration coefficient, which is calibrated according to the gear ratio of the double planetary gears, and in the embodiment, according to the compensation amplitudes of the industrial precision servo drive system in the case of double planetary gears are obtained , and then according to is obtained; in the double planetary gear scenario, ​For the calibration coefficient, its core role is to match the interference intensity difference caused by the tooth number difference of the two planetary gears, and then correct and compensate the amplitude; the interference amplitude of the planetary gear is positively correlated with the coupling times of "tooth-permanent magnet magnetic pole", the more the planetary gear teeth, the more the coupling times of the planetary gear per rotation with the permanent magnet magnetic pole, the greater the amplitude of the magnetic field interference, the greater the corresponding compensation amplitude demand, that is, the compensation amplitude needs to be proportional to the interference amplitude, so for the calibration coefficient should match the interference amplitude ratio of the double planetary gears , that is ;

[0076] Calculate the compensation torque of the industrial precision servo transmission system , and

[0077] ,

[0078] Among them , is the angle signal of the two planetary gears, , is the initial phase of the two planetary gears, , is the weight coefficient, and , In this embodiment, the weight is updated every 200ms; and in this embodiment, since the compensation amplitude and can be determined by the tooth number ratio of the two planetary gears, and then and corresponding to the compensation torque of the expression can be determined respectively, that is corresponds to and , corresponds to , , and finally the angle signal and the initial phase of the corresponding planetary gear are substituted into the corresponding position of the expression of the compensation torque ,

[0079] The output torque of the industrial precision servo transmission system is obtained, and . The servo controller receives the final output torque signal for operation.

[0080] When gain calibration is performed by using the ADC signal conversion (i.e., converting analog signals to digital quantities) formula in step S2, and the ADC signal conversion formula is as follows:

[0081] ,

[0082] Among them V (m) is the torque signal voltage value after gain calibration for the mth sampling moment, V (k) is the torque signal digital quantity collected by ADC (i.e., analog-to-digital converter), 32768 is the set digital quantity zero point value, 5.00 V is the ADC reference voltage, 65535 is the ADC full-scale digital quantity, K is the torque sensor gain calibration coefficient, and , V (k) is the standard torque source calibration voltage (i.e., the reference DC voltage signal output by the standard torque calibration device when calibrating the torque sensor).

[0083] The multi-stage filtering process in step S3 includes the following steps:

[0084] S31. Smooth high-frequency electromagnetic interference through sliding window mean filtering, and the formula for sliding window mean filtering is as follows,

[0085] ,

[0086] wherein, V (k) is the torque signal voltage value after sliding window mean filtering for the kth sampling moment, and N is the sliding window width, V (m) is the torque signal voltage value after gain calibration for the mth sampling moment;

[0087] S32. Suppress pulse noise through median filtering, and the formula for median filtering is as follows,

[0088] ,

[0089] wherein, V (k) is the torque signal voltage value after median filtering for the kth sampling moment, and med[·] is the median value of , , 3 mean values to eliminate pulse interference;

[0090] S33. Dynamically optimize the smoothness of the torque signal voltage value through Kalman filtering, adapt to interference fluctuations, and the formula for Kalman filtering is as follows,

[0091] ,

[0092] wherein, V (k) is the predicted value of the torque signal voltage value for the kth sampling moment, and is a simplified prediction model based on the effective signal of the previous sampling period, is the Kalman gain.

[0093] In the process of interference period quantification calculation, the number of planet wheel teeth, the number of permanent magnet poles and the planet wheel frequency are associated. The magnetic field interference is generated by the rotation of the planet wheel driving the permanent magnet. Since the permanent magnet is charged in a radial multi-pole, the magnetic field generated in the space presents a periodic distribution. With the rotation of the planet wheel, the spatial position of the permanent magnet relative to the torque sensor mounted on the output end of the reducer changes continuously, resulting in periodic fluctuations in the direction and strength of the magnetic field in the detection area of the torque sensor. Therefore, the following interference compensation trigger condition is set. Specifically, the process of determining whether the interference compensation trigger condition is met in step S4 is:

[0094] In the continuous three interference periods, the multi-period comparison is used to avoid misjudgment. If the torque effective voltage value fluctuation exceeds the interference amplitude threshold, it is determined that there is effective interference, and the interference flag function is

[0095] ,

[0096] wherein, is the average value of the torque effective voltage value collected in the ith interference period, is the average value of the torque effective voltage value collected in the continuous interference periods. In the embodiment, the average value of the torque effective voltage value collected in the continuous 10 interference periods is used; is the interference amplitude threshold;

[0097] Theoretical interference period wherein, is the number of planet wheel teeth, is the number of permanent magnet poles, is the planet wheel rotation frequency, and , is the angular increment of the planet wheel rotation in a single sampling period, which is collected by the position detection sensor; is the sampling period length, and in the embodiment, ;

[0098] In the case of a single planet wheel, when the interference flag function is met in the continuous preset number of sampling periods, and the interference period of the single planet wheel meets , wherein is the actual interference period, the single planet wheel interference compensation trigger condition is met. In the embodiment, the actual interference period is measured and calibrated by experiment;

[0099] In the case of a double planet wheel, when the interference flag function is met in the continuous preset number of sampling periods, the interference periods of the double planet wheels meet , and the double planet wheel interference amplitude ratio , the double planetary wheel interference compensation trigger condition is met. In this embodiment, the preset number of sampling periods is thirty sampling periods.

[0100] Since in the double planetary wheel scenario, the output torque effective voltage value is a complex value, which includes a useful torque signal and a voltage component signal generated by each planetary wheel interference, based on two different theoretical interference periods, two independent voltage component signals generated by the planetary wheel interference are decomposed from in the continuous three interference periods. Specifically, the process of obtaining the interference amplitudes , corresponding to the two planetary wheels is as follows: the two planetary wheels are the first planetary wheel and the second planetary wheel, the interference amplitude of the first planetary wheel is denoted as , and the interference amplitude of the second planetary wheel is denoted as . The theoretical interference period corresponding to the first planetary wheel is calculated to obtain the theoretical interference period corresponding to the first planetary wheel, and the theoretical interference period corresponding to the second planetary wheel, the interference frequency corresponding to the first planetary wheel is denoted as , and the interference frequency corresponding to the second planetary wheel is denoted as , and , , the torque effective voltage value in the continuous three interference periods is filtered by a band-pass filter according to , to decompose , , wherein is the voltage component of the first planetary wheel interference, and is the voltage component of the second planetary wheel interference, the interference amplitude of the first planetary wheel is denoted as , and the interference amplitude of the second planetary wheel is denoted as , and the expression is

[0101] ,

[0102] ,

[0103] wherein , are the maximum value and the minimum value of in the continuous three interference periods, , are the maximum value and the minimum value of in the continuous three interference periods. In this embodiment, for the first planetary wheel and the second planetary wheel with two different interference frequencies, the interference amplitudes of the first planetary wheel and the second planetary wheel are calculated according to the number of teeth of the first planetary wheel and the number of teeth of the second planetary wheel, and the corresponding planetary wheel rotation frequency , and the number of permanent magnet poles P, the interference frequency of the first planetary gear , the interference frequency of the second planetary gear , the signal components corresponding to the frequencies can be extracted through two independent band-pass filters, specifically, two independent narrow-band band-pass filters are designed, denoted as the first filter and the second filter, and the bandwidth of the filter is set to 5% of the center frequency. The narrow-band design can avoid signal interference between the two interference frequencies, while being compatible with frequency fluctuations under actual working conditions. That is, the bandwidth of the first filter is 5% of the interference frequency of the first planetary gear, and the bandwidth of the second filter is 5% of the interference frequency of the second planetary gear. In this way, it can be ensured that the first filter only decomposes the signal of the interference frequency of the first planetary gear, and the second filter only decomposes the signal of the interference frequency of the second planetary gear. In the present embodiment, a Butterworth filter is used, and the effective torque voltage values within the same period (e.g., within three consecutive interference periods) are collected ; the effective torque voltage values are input into the first filter, and the output only contains the voltage component of the first planetary gear interference that meets the interference frequency of the first planetary gear ; the effective torque voltage values are input into the second filter, and the output only contains the voltage component of the second planetary gear interference that meets the interference frequency of the second planetary gear .

[0104] The load correction coefficient in step S4 , = 5N·m is the rated load, is the actual load torque, representing the current actual load torque of the industrial precision servo transmission system, and the quadratic term suppresses excessive compensation under heavy load.

[0105] The angle signal of the planetary gear obtained by the encoder in step S4 , where is the digital quantity of the encoder, is the zero point of the encoder; the initial phase of the planetary gear , where is the angle corresponding to the torque trough of the planetary gear, located by bench testing, n is an integer, and .

[0106] The continuous fifty sampling periods all satisfy , and the compensated torque error is less than the error preset value, where is the target torque, i.e., the torque expected to be output by the industrial precision servo transmission system, which is set according to the working condition requirements. Then switch to the normal state, i.e., the interference-free state, without torque compensation.

[0107] In this embodiment, the curves of the effective voltage value of the torque, the compensated torque and the output torque are displayed on the host computer in real time, and the state monitoring is performed.

[0108] In this embodiment, for the core problem that the periodic magnetic field interference generated by the gear transmission in the industrial precision servo transmission system leads to the decrease of torque detection accuracy, a multi-source signal acquisition and dynamic compensation anti-interference technical architecture is constructed, the accurate torque signal detection under variable working conditions is realized, and the system performance is improved.

[0109] The present application realizes interference suppression for three core scenes of normal working condition, single planetary gear interference working condition and double planetary gear composite interference working condition of the industrial precision servo transmission system. A specific example is given as follows:

[0110] System initialization and parameter setting, torque signal acquisition, double differential input circuit is adopted, first planetary gear torque signal (T1, corresponding to Z1=30 tooth planetary gear) and second planetary gear torque signal (T2, corresponding to Z2=28 tooth planetary gear) are synchronously collected, and a programmable gain amplifier (PGA, gain range 1-100 times, adaptive to T1 / T2 sensor sensitivity difference, T1 sensitivity , T2 sensitivity );

[0111] ADC signal conversion, through 16-bit type ADC (sampling frequency 1 kHz), the analog signal is converted into digital quantity, and the digital voltage value obtained after calibration calculation of the digital quantity is , the torque signal voltage value (unit: V, range 0-5V) after gain calibration at the mth sampling moment; the torque signal digital quantity collected by the ADC; the set digital zero point value 32768, the ADC reference voltage 5.00V, the ADC full-scale digital quantity 65535, the standard torque source is loaded, the calibration voltage =4.0V is measured, which is substituted into the gain calibration coefficient formula of the torque sensor to obtain = 1.6;

[0112] Multi-stage filter cascade processing is adopted to suppress random noise and pulse interference, and the effective voltage value of the torque is obtained. Specifically, sliding window mean filtering, median filtering and Kalman filtering are adopted for processing, and the sliding window width N=32 (considering real-time and filtering effect) in the sliding window mean filtering; Kalman gain , =0.01 is the process noise covariance, and R=0.005 is the measurement noise covariance;

[0113] Theoretical disturbance period is calculated for different industrial precision servo drive systems, permanent magnet magnetization pole number P is 16, planetary gear rotation frequency , wherein the angular increment of planetary gear rotation in a single sampling period is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length is obtained by a position detection sensor (an encoder can be used), and the sampling period length, speed range 1000~3000rpm, consistent with the interference conditions); c. Start the industrial precision servo drive system, adjust the load according to the actual working conditions (from 0 to rated load ), through calculation to obtain the load torque under each load, and record; d. Traverse the entire operating speed of the servo system (1000~3000rpm), repeat step a, collect the load torque under different speed-load combinations; e. Statistics of all load torques, obtain the minimum value and maximum value of torque output of the industrial precision servo drive system in the non-interference state, that is, the torque limit. In this embodiment, the torque limit is 、 , where the negative sign indicates the opposite direction.

[0114] The interference processing flow is as follows,

[0115] 30 consecutive sampling periods (30ms) are determined by the corresponding formula to determine the effective interference, and the validity of the non-interference channel signal is verified; when the condition is met, the finite state machine (FSM) switches from the normal state to the corresponding interference state (single planet wheel interference or double planet wheel interference), and simultaneously triggers the compensation parameter loading;

[0116] Compensation calculation and execution: based on the interference type, call the corresponding signal source, calculate the compensation amplitude according to the dynamic compensation formula, and superimpose through the amplitude weight, execute the capacity reduction control, and substitute the final output torque formula to calculate the output torque;

[0117] Dynamic monitoring and adjustment: the host computer displays the curves of the effective voltage value of the torque, the compensation torque and the output torque in real time, and performs state monitoring. In the double planet wheel scenario, the interference amplitude ratio and the weight coefficient are additionally dynamically updated to correct the compensation torque;

[0118] Interference recovery and state regression: when the interference disappears for 50 consecutive sampling periods, and the error after compensation , trigger the recovery condition, switch from the interference state back to the normal state (non-interference state), and reset the compensation amplitude and the capacity reduction coefficient =0, =1.0.

[0119] In this embodiment, the torque detection and compensation method of the servo transmission system is adopted to optimize the torque detection and interference suppression strategy, avoid the problems of unstable operation or shutdown of the industrial precision servo transmission system caused by poor adaptability, insufficient precision, weak anti-interference ability and other problems in the prior art, and maintain the effectiveness of torque detection and the continuity of system operation in the process of industrial equipment operation, no matter facing single planetary gear magnetic field interference, double planetary gear composite interference, or interference changes caused by working condition switching. The specific problems solved and the advantages embodied are as follows: the present application eliminates noise interference through multi-stage filtering, combines with compensation amplitude and phase correction of dynamic adjustment of working condition, significantly improves the torque detection accuracy under interference working condition, solves the problem of low detection accuracy caused by interference; the prior art can only adapt to a single rated working condition, when the industrial precision servo transmission system is in different speed intervals or various load working conditions, the change of interference characteristics is easy to cause compensation failure, and then trigger system shutdown, the present application can realize full working condition adaptation by dynamically calculating the interference period and adding multiple interference compensation on demand, and can output stable torque according to the requirements of industrial related standards when single / double wheel interference occurs, effectively solving the problem of high system shutdown risk under variable working conditions; the prior art often relies on a single threshold to determine interference, the present application verifies the effectiveness of interference through multi-cycle verification, cooperates with torque output amplitude limiting control, greatly reduces the interference misjudgment rate, and reduces unnecessary equipment loss.

[0120] For example, the scheme is applied in the actual control of the machine tool feed shaft servo system. After the system is powered on, the torque signal and the angle signal of the planetary gear of the machine tool feed shaft servo system are collected. When there is no interference, the torque signal is used as the input by default, and multi-stage filtering is used to ensure the detection accuracy. During operation, if single-wheel interference corresponding to the planetary gear is detected within a continuous set period, the normal signal is automatically switched to the input, the adaptive compensation amplitude is loaded, the torque is output according to the requirements, and the accuracy after compensation is continuously monitored. If double-wheel interference corresponding to the planetary gear is detected, the corresponding compensation parameters are calculated, the weights are allocated according to the interference amplitude ratio, the compensation is added, and the parameter correction compensation effect is updated in real time. When the interference disappears within a continuous set period and the accuracy after compensation returns to the normal range, the normal running state is switched back, the control parameters and compensation coefficients are reset, and the interference processing related information is recorded. The whole process does not require manual intervention, ensures that the machine tool feed shaft machining precision significantly improves, and solves various operation problems of the industrial precision servo transmission system caused by periodic magnetic field interference.

[0121] Embodiment two

[0122] The servo transmission system torque detection and compensation system comprises:

[0123] The acquisition module is configured to acquire a torque signal and an angle signal of a planetary gear of an industrial precision servo transmission system.

[0124] The first processing module is configured to perform gain calibration on the torque signal to obtain a torque signal voltage value after gain calibration.

[0125] The second processing module is configured to perform multi-stage filtering on the torque signal voltage value after gain calibration to output a torque effective voltage value .

[0126] The third processing module is configured to determine whether a compensation trigger condition is met. In the case of a single planetary gear, if a single planetary gear interference compensation trigger condition is met, a compensation amplitude , a compensation torque , and an output torque are calculated. In the case of a double planetary gear, if a double planetary gear interference compensation trigger condition is met, two interference amplitudes and corresponding to the two planetary gears and compensation amplitudes and are calculated, and a compensation torque is calculated to obtain an output torque .

[0127] Embodiment Three

[0128] An apparatus comprising:

[0129] one or more processors;

[0130] a memory storing one or more programs,

[0131] which, when executed by the one or more processors, cause the one or more processors to implement the servo drive system torque detection and compensation method described above.

[0132] Embodiment Four

[0133] A computer-readable storage medium containing computer-executable instructions, which, when executed by a computer processor, are configured to perform the servo drive system torque detection and compensation method described above.

[0134] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for torque detection and compensation in a servo drive system, characterized in that, Includes the following steps: S1. Acquire torque signals and planetary gear angle signals from industrial precision servo transmission systems; S2. Perform gain calibration on the torque signal to obtain the gain-calibrated torque signal voltage value; S3. Perform multi-stage filtering on the torque signal voltage value after gain calibration, and output the effective torque voltage value. Where k is the sampling time number; S4. Determine if the compensation trigger condition is met. In the case of a single planetary gear, if the single planetary gear interference compensation trigger condition is met, calculate the compensation amplitude. ,and ,in Basic compensation coefficient, Calculate the compensation torque using the load correction factor. ,and ,in This is the angle signal of the planetary gears. This represents the initial phase of the planetary gears. Obtain output torque ,and ,in For the amplitude limiting function, The conversion factor from effective voltage to torque. The set derating factor, , These are the minimum and maximum torque output values ​​of an industrial precision servo drive system under interference-free conditions, respectively. In the case of a dual planetary gear system, if the dual planetary gear interference compensation trigger condition is met, then the interference amplitude corresponding to each of the two planetary gears is obtained. , , Calculate the compensation amplitude for each of the two planetary gears. and ,in ,and For calibration coefficients, Calculate the compensation torque ,and ， in , These are the angle signals for the two planetary gears. , The initial phase of the two planetary gears, , These are the weighting coefficients, and , , Obtain output torque ,and .

2. The servo drive system torque detection and compensation method according to claim 1, characterized in that, In step S2, when performing gain calibration using the ADC signal conversion formula, the ADC signal conversion formula is as follows: ， in Let be the gain-calibrated torque signal voltage value at the m-th sampling time. The digital quantity of the torque signal acquired by the ADC. The zero point value of the set digital quantity, This is the ADC reference voltage. This represents the full-scale digital value of the ADC. This is the torque sensor gain calibration coefficient, and , This is the calibration voltage for the standard torque source.

3. The servo drive system torque detection and compensation method according to claim 2, characterized in that, The multi-stage filtering process in step S3 includes the following steps: S31. High-frequency electromagnetic interference is smoothed through sliding window mean filtering, and the formula for sliding window mean filtering is as follows: ， in, For the kth sampling time, the torque signal voltage value after sliding window mean filtering is denoted as N, where N is the width of the sliding window. S32. Median filtering suppresses impulse noise, and the formula for median filtering is as follows: ， in, At the k-th sampling time, the torque signal voltage value after median filtering, med[·] represents... , , Take the median of the three mean results; S33. Kalman filtering is used to dynamically optimize the smoothness of the torque signal voltage value, adapting to interference fluctuations. The formula for Kalman filtering is as follows. ， in, Let be the predicted value of the torque signal voltage at the k-th sampling time, and , For Kalman gain.

4. The servo drive system torque detection and compensation method according to claim 1, characterized in that, The process of determining whether the interference compensation triggering condition is met in step S4 is as follows: If the effective torque voltage value fluctuates beyond the interference amplitude threshold within three consecutive interference cycles, it is determined to be valid interference, and the interference flag function... for, ， in, This represents the average value of the effective torque voltage collected during the i-th interference cycle. It is the average value of the effective torque voltage collected over several consecutive interference cycles. This is the threshold for interference amplitude. Theoretical interference period ,in, The number of teeth on the planetary gear. To increase the number of magnetized poles of a permanent magnet, Let be the rotational frequency of the planetary gears, and , It is the angular increment of the planetary gear rotation within a single sampling period; This refers to the sampling period duration; In the case of a single planetary gear, when the interference flag function is satisfied within a preset number of consecutive sampling periods. And the disturbance period of a single planetary gear satisfies At that time, among them If the actual interference period is met, then the single planetary gear interference compensation trigger condition is satisfied. In the case of a dual planetary gear system, when the interference flag function is satisfied within a predetermined number of consecutive sampling periods... The interference cycles of the two planetary gears all meet the requirements. Furthermore, the interference amplitude of the dual planetary gears is greater than that of the dual planetary gears. This satisfies the trigger condition for interference compensation of the dual planetary gears.

5. The servo drive system torque detection and compensation method according to claim 4, characterized in that, Obtain the interference amplitude corresponding to each of the two planetary gears. , The process is as follows: the two planetary gears are the first planetary gear and the second planetary gear, and the interference amplitude of the first planetary gear is denoted as... The interference amplitude of the second planetary gear is Through theoretical interference cycle The theoretical disturbance period corresponding to the first planetary gear was calculated. The theoretical disturbance period corresponding to the second planetary gear. Let the interference frequency corresponding to the first planetary gear be . The interference frequency corresponding to the second planetary gear is ,and , The effective torque voltage value during three consecutive interference cycles is obtained by using a bandpass filter. according to , Perform filtering to decompose , ,in The voltage component of the interference from the first planetary gear. The voltage component of the interference from the second planetary gear, and the amplitude of the interference from the first planetary gear. Interference amplitude of the second planetary gear The expression is, ， ， in, , These are three consecutive interference cycles. The maximum and minimum values, , These are three consecutive interference cycles. The maximum and minimum values.

6. The servo drive system torque detection and compensation method according to claim 1, characterized in that: Load correction factor in step S4 , For rated load, This represents the actual load torque. The angle signal of the planetary gear in step S4 ,in For encoder digital quantities, The encoder zero point; the initial phase of the planetary gears. ,in Let n be the angle corresponding to the trough of the planetary gear torque wave, where n is an integer. .

7. The servo drive system torque detection and compensation method according to claim 4, characterized in that: Satisfying the requirements for fifty consecutive sampling periods And the compensated torque error Less than the preset error value, where If the target torque is reached, switch to normal mode.

8. A servo drive system torque detection and compensation system, used to implement the servo drive system torque detection and compensation method as described in any one of claims 1-7, characterized in that, include: The acquisition module is used to acquire torque signals and planetary gear angle signals from industrial precision servo transmission systems. The first processing module is used to perform gain calibration on the torque signal to obtain the gain-calibrated torque signal voltage value. The second processing module performs multi-stage filtering on the gain-calibrated torque signal voltage value and outputs the effective torque voltage value. ; The third processing module is used to determine whether the compensation triggering condition is met. In the case of a single planetary gear, if the single planetary gear interference compensation triggering condition is met, the compensation amplitude is calculated. Compensating torque and obtain output torque ; In the case of a dual planetary gear system, if the dual planetary gear interference compensation triggering condition is met, then the interference amplitude corresponding to each of the two planetary gears is calculated. and and compensation amplitude and And calculate the compensation torque To obtain output torque .

9. A device, characterized in that, include: One or more processors; Memory, used to store one or more programs. When one or more programs are executed by one or more processors, the one or more processors implement the servo drive system torque detection and compensation method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: It contains computer-executable instructions, which, when executed by a computer processor, are used to perform the torque detection and compensation method for a servo drive system as described in any one of claims 1-7.

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