A flexible joint vibration suppression method, system and storage medium

Abstract

The present invention discloses a flexible joint jitter suppression method, system, and storage medium, including the following steps: S1: obtaining the motor end speed as a first speed feedback and a given speed instruction, and the load end speed as a second speed feedback and a given torque feedback; S2: calculating the second speed feedback and the torque feedback through a preset jitter suppression module to obtain a jitter speed; S3: fine-tuning the first speed feedback according to the jitter speed to obtain a jitter speed feedback; S4: the difference between the jitter speed feedback and the speed instruction generates a speed error, which is transmitted to a speed controller, which adjusts the speed error and generates a torque instruction to achieve jitter suppression of the flexible joint. This reduces the fluctuation in the servo motor torque feedback, thereby obtaining a stable speed at the output end of the flexible joint, allowing the robot to accurately and stably position itself during operation.

Description

Technical Field

[0001] The present invention relates to the field of servo control technology, and more particularly to a method, system and storage medium for suppressing jitter of a flexible joint. Background Art

[0002] In production equipment, load actuators made of lightweight or flexible materials have the advantages of light weight, compact structure, and high safety, and are gradually being used in fields such as manufacturing and robotic arms. However, for robotic arms, jitter is prone to occur during operation. On the one hand, the jitter during robot operation is mainly caused by resonance. On the other hand, it is difficult for the drive control loop to adapt to all working conditions with a set of parameters, resulting in a large dynamic range of the load and the position sensor being unable to directly control the load end, resulting in end position deviation and causing jitter. At the same time, due to the presence of flexible links such as reducers, the robot is very prone to jitter oscillation at the end during positioning, which will seriously affect its positioning accuracy and work efficiency.

[0003] The academic paper "Research on Residual Vibration Suppression and Measurement Methods of Flexible Loads in Robots" discloses a zero-vibration first-order differential input shaper (ZVD) for residual vibration suppression, and designs an amplitude detection device based on a laser tracker. Although this method can effectively suppress the residual vibration of the end of an industrial robot, the ZVD shaper only focuses on suppressing the residual vibration of the end of the robot, and is of no help to the vibration problem during operation. It may even cause the running trajectory profile error to increase due to changes in the timing of each joint. Patent publication number CN107942680A discloses a robot jitter suppression method that achieves the purpose of suppressing the jitter of the robot end by optimizing the planned trajectory of the original host computer, but does not involve the suppression of mechanical changes, so its scope of application will be greatly limited. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a method for suppressing flexible joint jitter, comprising the following steps:

[0005] S1: The motor end speed is obtained as the first speed feedback and the given speed command, and the load end speed is obtained as the second speed feedback and the given torque feedback;

[0006] S2: Calculating the second speed feedback and the torque feedback using a preset vibration suppression module to obtain a vibration speed;

[0007] S3: fine-tuning the first speed feedback according to the shaking speed to obtain shaking speed feedback;

[0008] S4: The difference between the vibration speed feedback and the speed command generates a speed error, which is transmitted to the speed controller, and the speed error is adjusted to generate a torque command to achieve vibration suppression of the flexible joint.

[0009] As a preferred technical solution, the rotation speed of the motor end obtained in step S1 is the first speed feedback, which is generated by the first encoder at the motor end obtaining the current speed information of the servo motor through the first encoder speed measurement module.

[0010] As a preferred technical solution, the rotation speed of the load end obtained in step S1 is the second speed feedback, which is generated by the second encoder at the load end obtaining the current speed information of the load end through the second encoder speed measurement module.

[0011] As a preferred technical solution, at least one of the first encoder speed measurement module and the second encoder speed measurement module includes an encoder counting unit and a program execution timing unit; the encoder counting unit is used to count the pulse edges of the encoder output signal; the program execution timing unit is used to time the running of the speed measurement program and the front and back windows of the encoder pulse and the speed measurement program cycle.

[0012] As a preferred technical solution, the program execution timing unit includes a first timing unit and a second timing unit;

[0013] The first timing unit is used to time the running time of the speed measurement program;

[0014] The second timing unit is used to time the encoder pulse and the front and rear windows of the speed measurement program cycle.

[0015] As a preferred technical solution, the jitter suppression module in step S2 includes a filter and a speed observer, and the torque feedback is filtered by a preset filter to obtain the jitter torque; then, the jitter torque and the second speed feedback are calculated by the preset speed observer to obtain an estimated jitter speed, which is further output as the jitter speed after adjusting the gain.

[0016] As a preferred technical solution, the fine adjustment of the first speed feedback by the shaking speed in step S3 is performed by inputting the shaking speed and the first speed feedback into a preset adder for performing an addition operation to obtain the shaking speed feedback.

[0017] As a preferred technical solution, the torque error generated by comparing the torque command in step S4 with the torque feedback output by the motor is transmitted to the torque controller, which adjusts the torque error and generates a current command; the current command is transmitted to the current controller, which adjusts the current command to generate an SPWM signal for driving the switching device, thereby controlling the servo motor current by driving the switching device.

[0018] The present invention also provides a flexible joint jitter suppression system, comprising a memory, a processor, and a flexible joint jitter suppression program stored in the memory and executable on the processor. When the flexible joint jitter suppression is executed by the processor, the steps of the above-mentioned flexible joint jitter suppression method are implemented.

[0019] The present invention also provides a storage medium storing a flexible joint jitter suppression program. When the flexible joint jitter suppression program is executed by a processor, the steps of the flexible joint jitter suppression method described above are implemented.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention collects the second speed feedback information generated by the second encoder installed at the load end of the flexible joint, combines it with the actual torque feedback information of the servo motor to extract the jitter of the joint, decomposes the jitter speed of the output end through the jitter suppression module, adds it to the first speed feedback signal output by the motor end in the form of negative feedback, and fine-tunes the first speed feedback signal output by the servo motor, so that the torque instruction delivered to the motor is stable, the fluctuation of the servo motor torque feedback is reduced, and a stable speed is obtained at the output end of the flexible joint, so that the robot can be positioned accurately and stably during operation;

[0022] (2) The first speed feedback signal output by the servo motor is calculated by a specific first encoder speed measurement module, which improves the motor speed measurement accuracy and is conducive to improving the joint jitter suppression effect;

[0023] (3) By regularly monitoring the speed and torque signals fed back by the servo motor, the vibration of the flexible joint caused by the degradation of mechanical performance due to long-term use can be effectively avoided. There is no need to manually set the servo parameters, which reduces the waste of human resources and is conducive to improving the control efficiency of joint vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 Schematic diagram of a flow chart of a method for suppressing jitter of a flexible joint according to the present invention;

[0026] Figure 2This is a schematic diagram of an application of a flexible joint vibration suppression method of the present invention;

[0027] Figure 3 This is a schematic structural diagram of a first encoder speed measurement module in one embodiment of the present invention;

[0028] Figure 4 This is a test principle diagram of the first encoder speed measurement module in one embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of an application of a jitter suppression module in one embodiment of the present invention;

[0030] Figure 6 Schematic diagram of a flow chart of timing adjustment rules in one embodiment of the present invention;

[0031] Figure 7 This is a comparison diagram of the first velocity feedback waveform and the torque command waveform before and after suppression using the flexible joint vibration suppression method of the present invention in one embodiment of the present invention;

[0032] Figure 8 This is a comparison diagram of the first velocity feedback waveform and the torque command waveform before and after suppression using the flexible joint jitter suppression method of the present invention in another embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention may be more readily understood by referring to the following detailed description of preferred embodiments of the present invention and the included Examples. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention pertains. In the event of a conflict, the definitions in this specification shall prevail.

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] An embodiment of the present invention provides a method for suppressing jitter in a flexible joint. The method can be applied to a servo system of a flexible joint. The servo system includes a servo driver, a servo motor, a reducer, an encoder, and a control terminal. The control terminal can be a computer terminal or server directly connected to the servo system, or a computer terminal or server connected to a device for acquiring relevant data. The servo driver includes a position controller, a speed controller, a torque controller, and a current controller. Figure 1 As shown, the flexible joint vibration suppression method includes the following steps:

[0036] S1: The motor end speed is obtained as the first speed feedback and the given speed command, and the load end speed is obtained as the second speed feedback and the given torque feedback;

[0037] S2: Calculating the second speed feedback and the torque feedback using a preset vibration suppression module to obtain a vibration speed;

[0038] S3: fine-tuning the first speed feedback according to the shaking speed to obtain shaking speed feedback;

[0039] S4: The difference between the vibration speed feedback and the speed command generates a speed error, which is transmitted to the speed controller, and the speed error is adjusted to generate a torque command to achieve vibration suppression of the flexible joint.

[0040] In the above step S1, specifically, Figure 2 As shown, during the servo system's control of motor operation, the motor's rotational speed is obtained as the first speed feedback, generated by the first encoder at the motor end, which obtains the servo motor's current speed information through the first encoder speed measurement module. The load's rotational speed is the second speed feedback, generated by the second encoder at the load end, which obtains the load's current speed information through the second encoder speed measurement module. The servo system's speed command is specifically generated and output by the position controller in the servo system. The servo system's torque feedback is specifically generated and output by the servo driver in the servo system, based on the motor's current feedback.

[0041] It is easy to understand that the motor end is the end of the robot's flexible joint where the servo motor is located. The load end refers to the end of a joint that bears the load, and the motor end and the load end are connected through a reducer. In some embodiments, the servo motor is communicatively connected to a servo driver. The servo motor can receive a control current associated with the torque value fed back by the servo driver and output a torque of corresponding magnitude to drive the motor end and the load end to move. In addition, the servo driver is connected to a control terminal, i.e., a robot controller. The robot controller is provided with a timing clock, and the servo driver can be controlled by a timing adjustment rule.

[0042] Preferably, Figure 3 As shown, at least one of the first encoder speed measurement module and the second encoder speed measurement module includes an encoder counting unit and a program execution timing unit; the encoder counting unit is used to count the pulse edges of the encoder output signal; the program execution timing unit is used to time the running of the speed measurement program and the front and back windows of the encoder pulse and the speed measurement program cycle.

[0043] In an exemplary embodiment, the first encoder speed measurement module includes an encoder counting unit and a program execution timing unit; the encoder counting unit is used to count the pulse edges of the encoder output signal; the program execution timing unit is used to time the running of the speed measurement program and the windows before and after the encoder pulse and the speed measurement program cycle.

[0044] It should be noted that the first encoder is a photoelectric encoder. A photoelectric encoder is a sensor that uses the photoelectric effect to convert physical quantities such as angle, position, and speed into electrical signals. It features high resolution, fast response, simple structure, and long life, and is often used to measure motor speed. Specifically, the detection end of the photoelectric encoder detects the servo motor using an optical signal, converts the optical signal into an electrical signal, and calculates the servo motor's real-time position and speed information based on the electrical signal. As mentioned above, the first speed feedback is calculated by the first encoder's speed measurement module. Photoelectric encoders can be divided into two types based on their encoding method: absolute and incremental. Absolute photoelectric encoders are primarily used to determine the position of the motor rotor, while incremental encoders are primarily used to measure speed. The photoelectric encoder described in the present invention is an incremental encoder. The line count, or resolution, of a photoelectric encoder is expressed as the number of pulses generated per revolution of the encoder shaft, i.e., pulses per revolution (p / r). In practical applications of measuring motor speed, an incremental photoelectric encoder with an appropriate line count can be selected based on specific needs.

[0045] Preferably, the program execution timing unit includes a first timing unit and a second timing unit; the first timing unit is used to time the running time of the speed measurement program; the second timing unit is used to time the encoder pulse and the window before and after the speed measurement program cycle. The output signal of the first encoder is connected to the encoder counting unit and the second timing unit. The core of the first encoder speed measurement module is an STM32 chip, which does not require multiple ICs for data exchange, avoids problems such as bit errors caused by multi-chip communication, and effectively ensures the stability of the first encoder speed measurement module.

[0046] It should be noted that the adjustment of the front and rear windows is achieved by soft resetting the second timing unit after the encoder counting unit receives the edge signal output by the encoder. The soft reset will cause the second timing unit to switch to recording the window time of the speed measurement program cycle and the encoder pulse edge.

[0047] It is easy to understand that the speed measurement program cycle refers to the running time of the speed measurement program software, that is, the execution cycle of the speed measurement algorithm; that is, the time recorded by the first timing unit.

[0048] Preferably, Figure 4 As shown, the first encoder speed measurement module calculates the current speed of the motor using the following formula:

[0049]

[0050] Among them, Ne is the number of encoder lines; M x The number of pulse edges recorded by the encoder counting unit in the xth speed measurement program cycle; T x t is the running time of the speed measurement program recorded by the first timing unit in the xth speed measurement program cycle; x-1 t is the time between the encoder pulse edge recorded by the second timing unit in the xth speed measurement program cycle and the window before the speed measurement program cycle; x It is the time between the encoder pulse edge recorded by the second timing unit in the xth speed measurement program cycle and the window after the speed measurement program cycle.

[0051] Preferably, the encoder counting unit is an encoder pulse counter, which records the number of pulse edges of the first encoder output signal; the first timing unit is a clock pulse counter, which records the number of clock pulses corresponding to the speed measurement program cycle; the second timing unit is a clock pulse counter, which records the number of clock pulses between the encoder pulse edge and the window before and after the speed measurement program cycle.

[0052] Preferably, the first encoder speed measurement module calculates the current speed of the motor using the following formula:

[0053]

[0054] Among them, f clk is the clock pulse frequency; Ne is the number of encoder lines; M1 x M2 is the number of pulse edges of the output signal of the first encoder in the xth speed measurement program cycle; x is the number of clock pulses in the xth speed measurement program cycle; m x-1 m is the number of clock pulses between the encoder pulse edge and the window before the speed measurement program cycle in the xth speed measurement program cycle; x It is the number of clock pulses between the encoder pulse edge and the window after the speed measurement program cycle in the xth speed measurement program cycle.

[0055] It should be noted that the speed measurement program cycle x≥2, that is, the first encoder speed measurement module starts from the second speed measurement program cycle.

[0056] Preferably, the clock pulse frequency f clk ≥80MHz; More preferably, the clock pulse frequency f clkThe clock pulse frequency is selected within a specific range to reduce test errors. The first speed feedback signal output by the servo motor is calculated using a specific first encoder speed measurement module, which improves the accuracy of motor speed measurement and is conducive to improving the joint vibration suppression effect.

[0057] In an exemplary embodiment, the second encoder speed measurement module is an M-method speed measurement module.

[0058] In the above step S2, if Figure 5 As shown, the jitter suppression module operates within the servo drive and includes a filter and a speed observer. Specifically, a preset filter filters the torque feedback to obtain a jitter torque. A preset speed observer then calculates the jitter torque and the second speed feedback to obtain an estimated jitter speed, which is then output as the jitter speed after gain adjustment.

[0059] Preferably, the filter is selected from one or more combinations of a high-pass filter, a low-pass filter, and a band-pass filter; in an exemplary embodiment, the filter is a band-pass filter, which refers to a filter that can pass frequency components within a certain frequency range but attenuates frequency components in other ranges to an extremely low level, and the cutoff frequency parameter of the band-pass filter refers to the difference between the maximum frequency and the minimum frequency allowed to pass by the band-pass filter. Before using the band-pass filter to filter the torque feedback, the cutoff frequency parameter of the band-pass filter can be adjusted according to the actual vibration frequency of the load end, and its cutoff frequency parameter can be set to be within a certain range of the vibration frequency that needs to be suppressed. The torque feedback can be subjected to frequency screening to obtain a jitter torque in a specific frequency range, so that the interference signal in the torque feedback signal passing through the band-pass filter can be filtered out, the interference item is eliminated, and the obtained vibration signal is more accurate.

[0060] Preferably, the speed observer calculates the jitter torque and the second speed feedback to obtain a speed observation compensation amount, which is used to compensate for the second speed feedback output by the load end through the second encoder speed measurement module (specifically, the second speed feedback and the speed observation compensation amount are input into a preset adder for addition operation) to reduce the disturbance component caused by the external load disturbance and obtain the estimated jitter speed. Furthermore, the estimated jitter speed is adjusted and compensated for the amplitude ratio of the formed estimated jitter speed through gain adjustment, and the amplitude ratio of the jitter frequency to be suppressed is ensured to be around 0db to obtain the jitter speed. Preferably, the gain adjustment includes gain compensation and damping gain.

[0061] In the above step S3, if Figure 2As shown, the shaking speed fine-tunes the first speed feedback, specifically by inputting the shaking speed and the first speed feedback into a preset adder for addition operation to obtain the shaking speed feedback.

[0062] In the above step S4, if Figure 2 As shown, the torque error generated by comparing the torque command with the torque feedback output by the motor is transmitted to the torque controller, which adjusts the torque error and generates a current command; further, the current command is transmitted to the current controller, and the current controller adjusts the current command to generate an SPWM signal for driving the switching device, thereby controlling the servo motor current by driving the switching device.

[0063] In specific implementation, for flexible joints that have been running for a period of time, the jitter information is also changing due to changes in mechanical properties or uneven running friction. At this time, the jitter information can be identified by pre-setting the timing adjustment rules running in the robot controller, and the phase of the torque feedback can be adjusted by adjusting the cutoff frequency parameters of the bandpass filter, and the amplitude of the estimated jitter speed can be adjusted by adjusting the gain compensation and damping gain. That is, the cutoff frequency parameters, gain compensation, and damping gain parameters in step S2 can be set by the timing adjustment rules until the joint jitter generated by the servo system during full closed-loop control can be effectively suppressed after compensation adjustment, thereby improving the robustness of the flexible joint.

[0064] like Figure 6 As shown, the timing adjustment rule includes the following steps: the robot controller receives the motor speed and torque information fed back by the servo driver; the controller performs torque spectrum analysis; the jitter frequency and amplitude are calculated in real time during operation; it is determined whether the jitter amplitude is less than or equal to a preset threshold; when the jitter amplitude is greater than the preset threshold, the cutoff frequency parameter, the damping gain parameter and the gain compensation parameter are set and it is determined whether the damping gain parameter and the gain compensation parameter have reached the maximum set value, until the jitter amplitude is less than or equal to the preset threshold or the damping gain parameter and the gain compensation parameter have reached the maximum set value.

[0065] Preferably, when the jitter amplitude is greater than a preset threshold, the cutoff frequency parameter is set to the main frequency in the torque spectrum, the gain compensation parameter and the damping gain parameter are set, the robot continues to run, collects the motor speed and torque information fed back by the servo driver, and continues to calculate in real time. When the controller detects that the jitter amplitude is less than or equal to the preset threshold, the gain compensation parameter and the damping gain parameter are saved; when the gain compensation parameter and the damping gain parameter both reach the maximum set value, the controller prompts an error.

[0066] Preferably, when the jitter amplitude is greater than a preset threshold, the detected jitter frequency is transmitted to the cutoff frequency parameter of the filter in the corresponding joint servo driver via bus communication, the cutoff frequency parameter is set to the main frequency in the torque spectrum, and the damping gain parameter of the corresponding joint servo driver is set according to a certain compensation; the robot controller continues to control the operation of the robot, while collecting the motor speed and torque information fed back by the servo driver via the bus, and continues to perform real-time calculations. When the damping gain parameter of the joint servo driver reaches the maximum set value, if the jitter amplitude is still greater than the preset threshold, the gain compensation parameter of the joint servo driver is continued to be set according to a certain compensation. After setting the gain compensation parameter and damping gain parameter of the joint servo driver, if the controller detects that the jitter amplitude is less than or equal to the preset threshold, the gain compensation parameter and damping gain parameter are saved, and the cutoff frequency parameter, gain compensation parameter, and damping gain parameter are sent to the servo driver via the bus for storage. If, after the gain compensation parameter and damping gain parameter have reached the maximum set value, the jitter amplitude is still greater than the preset threshold, the controller will issue an error prompt and manual intervention will be performed for repair or maintenance.

[0067] It should be noted that the preset threshold is a preset detection value, that is, the acceptable jitter amplitude of the flexible joint; the certain compensation can be compensated according to a certain proportional relationship, and there is no specific limitation on this. Technical personnel in this field can set it according to actual needs.

[0068] Through the timing adjustment rules in this scheme, by regularly monitoring the speed and torque signals fed back by the servo motor, performing online calculations through the controller, and sending the calculated results to the servo system for processing, the jitter of the flexible joint caused by the degradation of mechanical performance due to long-term use can be effectively avoided. There is no need to manually set the servo parameters, which reduces the waste of human resources and is conducive to improving the control efficiency of joint jitter.

[0069] In a specific embodiment, in the first encoder speed measurement module, the clock pulse frequency fclk is 160MHz, the number of encoder lines is 10000 lines, and other conditions remain the same. The first speed feedback waveform and the torque command waveform before and after the flexible joint jitter suppression method of the present invention are suppressed are compared. Figures 7-8 As shown, Figure 7 This is the comparison of the first speed feedback waveform and the torque command waveform before and after suppression when the load end is 12kg. Figure 7 The load at the load end is 6kg, and the comparison between the first speed feedback waveform and the torque command waveform before and after suppression is shown in Figure 2. Figures 7-8It can be seen from the torque command waveform in that after adopting the suppression method provided by the present invention, the output torque command noise is significantly reduced. Furthermore, the first speed feedback is also smoother and quieter, which greatly improves the control, noise and loss of the motor. It can be seen that the flexible joint jitter suppression method provided by the present invention can make the torque command delivered to the motor stable, reduce the fluctuation in the servo motor torque feedback, and then obtain a stable speed at the output end of the flexible joint, that is, the load end, so that the robot can be accurately and stably positioned during operation.

[0070] It should be noted that in Figures 7-8 The waveform line near the torque instruction after being suppressed by the flexible joint jitter suppression method of the present invention is the intermediate variable of the jitter torque in the jitter suppression module, which is used to observe the change of the jitter torque and can be ignored. The focus is on the changes in the first speed feedback waveform and the torque instruction waveform.

[0071] The present invention collects the second speed feedback information generated by the second encoder installed at the load end of the flexible joint, combines it with the actual torque feedback information of the servo motor to extract the jitter of the joint, decomposes the jitter speed of the output end through the jitter suppression module, adds it to the first speed feedback signal output by the motor end in the form of negative feedback, and fine-tunes the first speed feedback signal output by the servo motor, so that the torque instruction delivered to the motor is stable, reducing the fluctuation in the torque feedback of the servo motor, and then obtaining a stable speed at the output end of the flexible joint, so that the robot can accurately and stably position itself during operation. Furthermore, by regularly monitoring the speed and torque signals fed back by the servo motor, the jitter of the flexible joint caused by the decline in mechanical performance due to long-term use can be effectively avoided. The invention has the characteristics of high real-time performance and excellent anti-disturbance ability, and improves the robustness of the flexible joint.

[0072] Correspondingly, an embodiment of the present invention also provides a flexible joint jitter suppression system, comprising a memory, a processor, and a flexible joint jitter suppression program stored on the memory and runnable on the processor. When the flexible joint jitter suppression is executed by the processor, the steps of the flexible joint jitter suppression method in any of the above embodiments are implemented.

[0073] In this embodiment, the method implemented when the motor vibration suppression compensation program running on the processor is executed can refer to the various embodiments of the motor vibration suppression compensation method of the present invention described above, and will not be repeated here.

[0074] Correspondingly, an embodiment of the present invention further provides a storage medium storing a flexible joint jitter suppression program. When the flexible joint jitter suppression program is executed by a processor, the steps of the flexible joint jitter suppression method in any of the above embodiments are implemented.

[0075] In this embodiment, the above-mentioned storage medium may include but is not limited to any type of disk (including floppy disk, hard disk, optical disk, CD-ROM, and magneto-optical disk), ROM (Read-Only Memory), RAM (Random Access Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, magnetic card or optical card and other media that can store program code.

[0076] Obviously, those skilled in the art will appreciate that the various steps of the present invention described above can be implemented using a general-purpose computing device, centralized on a single computing device, or distributed across a network of multiple computing devices. Alternatively, they can be implemented using program code executable by a computing device, which can then be stored in a storage device and executed by the computing device. In some cases, the steps shown or described can be performed in a different order than that shown, or can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0077] It should be noted that other contents of the flexible joint jitter suppression method disclosed in the present invention can be referred to the existing technology (for example, the position controller, speed controller, bandpass filter, gain compensation, damping gain, second encoder, and M-method speed measurement involved in the embodiments of the present invention can all be implemented using mature related technologies in the field, which can be understood by those skilled in the art and will not be repeated here), and will not be repeated here.

[0078] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions are possible for those skilled in the art without departing from the scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for suppressing jitter of a flexible joint, characterized in that: The following steps are involved: S1: Obtain the motor end speed as the first speed feedback, obtain the speed command given by the servo system, obtain the load end speed as the second speed feedback, and obtain the torque feedback given by the servo system; the speed command given by the servo system is generated and output by the position controller in the servo system; the torque feedback given by the servo system is calculated and output by the servo driver in the servo system based on the current information fed back by the motor and outputs the actual motor torque feedback; S2: Calculating the second speed feedback and the torque feedback using a preset vibration suppression module to obtain a vibration speed; S3: fine-tuning the first speed feedback according to the shaking speed to obtain shaking speed feedback; S4: The difference between the vibration speed feedback and the speed command generates a speed error, which is transmitted to the speed controller, which adjusts the speed error and generates a torque command to achieve vibration suppression of the flexible joint; The jitter suppression module in step S2 includes a filter and a speed observer. The jitter torque is obtained by filtering the torque feedback using a preset filter. The jitter torque and the second speed feedback are then calculated using a preset speed observer to obtain an estimated jitter speed, which is then output as the jitter speed after further gain adjustment. The fine adjustment of the first speed feedback by the shaking speed in step S3 is performed by inputting the shaking speed and the first speed feedback into a preset adder for performing an addition operation to obtain the shaking speed feedback; The torque error generated by comparing the torque command in step S4 with the torque feedback output by the motor is transmitted to the torque controller, which adjusts the torque error and generates a current command; the current command is transmitted to the current controller, which adjusts the current command to generate an SPWM signal for driving the switching device, thereby controlling the servo motor current by driving the switching device.

2. The method for suppressing flexible joint vibration according to claim 1, characterized in that: The rotation speed of the motor end obtained in step S1 is the first speed feedback, which is generated by the first encoder at the motor end obtaining the current speed information of the servo motor through the first encoder speed measurement module.

3. The method for suppressing flexible joint vibration according to claim 2, characterized in that: The rotation speed of the load end obtained in step S1 is the second speed feedback, which is generated by the second encoder at the load end obtaining the current speed information of the load end through the second encoder speed measurement module.

4. The method for suppressing flexible joint vibration according to claim 3, characterized in that: At least one of the first encoder speed measurement module and the second encoder speed measurement module includes an encoder counting unit and a program execution timing unit; the encoder counting unit is used to count the pulse edges of the encoder output signal; the program execution timing unit is used to time the running of the speed measurement program and the front and back windows of the encoder pulse and the speed measurement program cycle.

5. The method for suppressing flexible joint vibration according to claim 4, characterized in that: The program execution timing unit includes a first timing unit and a second timing unit; The first timing unit is used to time the running time of the speed measurement program; The second timing unit is used to time the encoder pulse and the front and rear windows of the speed measurement program cycle.

6. A flexible joint vibration suppression system, characterized in that: The method comprises a memory, a processor, and a flexible joint jitter suppression program stored in the memory and executable on the processor. When the flexible joint jitter suppression program is executed by the processor, the steps of the flexible joint jitter suppression method according to any one of claims 1 to 5 are implemented.

7. A storage medium, characterized in that: The storage medium stores a flexible joint shaking suppression program, which, when executed by the processor, implements the steps of the flexible joint shaking suppression method according to any one of claims 1 to 5.

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