阅读说明：本技术 一种机器人关节的电机速度环振荡抑制优化方法及装置 (Method and device for optimizing motor speed ring oscillation suppression of robot joint ) 是由 潘月斗 熊展博 于 2021-02-09 设计创作，主要内容包括：本发明提供一种机器人关节的电机速度环振荡抑制优化方法及装置,包括：建立机器人关节对应的永磁同步电机的数据模型；根据所述永磁同步电机的数学模型,建立速度环PI控制器；根据所述速度环PI控制器进行数据采集,获取速度反馈数据,判断所述机器人关节的运行状态,所述运行状态包括发生振荡或不发生振荡；当所述运行状态为发生振荡时,将所述速度反馈数据反馈至所述速度环PI控制器,通过预设的速度环的PI参数优化算法,对所述速度环PI控制器的参数进行优化,以消除所述机器人关节的振荡状态。本发明能够提高机器人关节的控制性能。(The invention provides a method and a device for inhibiting and optimizing motor speed ring oscillation of a robot joint, wherein the method comprises the following steps: establishing a data model of a permanent magnet synchronous motor corresponding to a robot joint; establishing a speed loop PI controller according to the mathematical model of the permanent magnet synchronous motor; acquiring data according to the speed loop PI controller, acquiring speed feedback data, and judging the running state of the robot joint, wherein the running state comprises oscillation or no oscillation; and when the running state is oscillation, feeding the speed feedback data back to the speed loop PI controller, and optimizing the parameters of the speed loop PI controller through a preset PI parameter optimization algorithm of the speed loop to eliminate the oscillation state of the robot joint. The invention can improve the control performance of the robot joint.)

1. A method for suppressing and optimizing the oscillation of a motor speed ring of a robot joint is characterized by comprising the following steps:

establishing a data model of a permanent magnet synchronous motor corresponding to a robot joint;

establishing a speed loop PI controller according to the mathematical model of the permanent magnet synchronous motor;

acquiring data according to the speed loop PI controller, acquiring speed feedback data, and judging the running state of the robot joint, wherein the running state comprises oscillation or no oscillation;

and when the running state is oscillation, feeding the speed feedback data back to the speed loop PI controller, and optimizing the parameters of the speed loop PI controller through a preset PI parameter optimization algorithm of the speed loop to eliminate the oscillation state of the robot joint.

2. The method for optimizing the suppression of the oscillation of the motor speed ring of the robot joint according to claim 1, wherein the data model of the permanent magnet synchronous motor comprises:

the mathematical model of the permanent magnet synchronous motor is expressed as follows:

wherein, ω is_r、i_d、i_qRespectively representing the angular velocity, d-axis current, q-axis current, u_dIs d-axis voltage, u_qIs the q-axis voltage, p_nIs the magnetic pole pair number, L is the direct axis and quadrature axis inductance, #_fIs the rotor total flux linkage vector, J is the moment of inertia, R_sIs stator resistance, T_LThe load torque is, and B is the friction coefficient.

3. The method for optimizing the oscillation suppression of the motor speed ring of the robot joint according to claim 1, wherein the data acquisition according to the speed ring PI controller comprises:

according to the setting of the current loop period, speed loop data are calculated once every 5 current loop periods, 2000 pieces of speed loop data are used as the value range of data acquisition, and 2000 pieces of data are calculated in total.

4. The method for optimizing the suppression of the oscillation of the motor speed ring of the robot joint according to claim 1, wherein the step of acquiring speed feedback data and determining the operation state of the robot joint, the operation state including the occurrence of oscillation or the absence of oscillation, comprises the steps of:

and fitting a speed feedback curve according to the speed feedback data, and if the speed feedback curve is found to generate overshoot oscillation, namely the times that the upper and lower wave peak values of the curve fitted through the data exceed the error band are more than five times, determining that the running state of the robot joint is oscillation, otherwise, determining that the robot joint does not generate oscillation.

5. The method for optimizing the oscillation suppression of the motor speed ring of the robot joint according to claim 1, wherein the optimizing the parameters of the speed ring PI controller by a preset speed ring PI parameter optimization algorithm comprises:

while reducing the proportionality coefficient P of the speed loop PI controller_wAnd integral coefficient I_wEach time by 1%, i.e. P_w＝P_w*99％、I_w＝I_w99% until the operational state of the robot joint is such that no oscillation occurs.

6. A robot joint motor speed ring oscillation suppression optimization device is characterized by comprising:

the establishing unit is used for establishing a data model of the permanent magnet synchronous motor corresponding to the robot joint;

the establishing unit is used for establishing a speed loop PI controller according to a mathematical model of the permanent magnet synchronous motor;

the judging unit is used for acquiring data according to the speed loop PI controller, acquiring speed feedback data and judging the running state of the robot joint, wherein the running state comprises oscillation or no oscillation;

and the optimization unit is used for feeding back the speed feedback data to the speed loop PI controller when the running state is oscillation, and optimizing the parameters of the speed loop PI controller through a preset PI parameter optimization algorithm of the speed loop so as to eliminate the oscillation state of the robot joint.

7. The apparatus for optimizing motor speed ring oscillation suppression for a robot joint according to claim 6, wherein the data model of the permanent magnet synchronous motor comprises:

the mathematical model of the permanent magnet synchronous motor is expressed as follows:

wherein, ω is_r、i_d、i_qRespectively representing the angular velocity, d-axis current, q-axis current, u_dIs d-axis voltage, u_qIs the q-axis voltage, p_nIs the magnetic pole pair number, L is the direct axis and quadrature axis inductance, #_fIs the rotor total flux linkage vector, J is the moment of inertia, R_sIs stator resistance, T_LThe load torque is, and B is the friction coefficient.

8. The apparatus for optimizing motor speed ring oscillation suppression for a robot joint according to claim 6, wherein the determination unit is configured to:

according to the setting of the current loop period, speed loop data are calculated once every 5 current loop periods, 2000 pieces of speed loop data are used as the value range of data acquisition, and 2000 pieces of data are calculated in total.

9. The apparatus for optimizing motor speed ring oscillation suppression for a robot joint according to claim 6, wherein the determination unit is configured to:

and fitting a speed feedback curve according to the speed feedback data, and if the speed feedback curve is found to generate overshoot oscillation, namely the times that the upper and lower wave peak values of the curve fitted through the data exceed the error band are more than five times, determining that the running state of the robot joint is oscillation, otherwise, determining that the robot joint does not generate oscillation.

10. The device for optimizing the suppression of oscillation of a motor speed ring of a robot joint according to claim 6, wherein the optimization unit is configured to:

while reducing the proportionality coefficient P of the speed loop PI controller_wAnd integral coefficient I_wEach time by 1%, i.e. P_w＝P_w*99％、I_w＝I_w99% until the operational state of the robot joint is such that no oscillation occurs.

Technical Field

The invention relates to the technical field of robot control, in particular to a method and a device for inhibiting and optimizing motor speed ring oscillation of a robot joint.

Background

An articulated robot, also called an articulated arm robot or an articulated robot arm, is one of the most common forms of industrial robots in the industrial field today, and is suitable for mechanical automation operations in many industrial fields. For example, the joint robot is driven by a motor and realizes high-precision control of the robot joint by using a high-precision permanent magnet synchronous motor vector control system during the work of automatic assembly, paint spraying, carrying, welding and the like.

A Permanent Magnet Synchronous Motor (PMSM) has the advantages of small size, small inertia, high response speed, high efficiency and the like. The high-precision robot joint mostly adopts a method of controlling a permanent magnet synchronous motor and a vector (including motor voltage, current and the like), however, when the working environment of a permanent magnet synchronous motor vector control system changes and various interferences exist, the performance of the vector control system is reduced, in some working occasions needing high-precision control, the oscillation of the robot joint seriously influences the working performance of the robot joint, and field personnel are required to repeatedly debug the parameters of the joint motor so as to meet the control requirement.

Disclosure of Invention

The invention aims to provide a method and a device for inhibiting and optimizing motor speed loop oscillation of a robot joint.

To solve the above technical problem, an embodiment of the present invention provides the following technical solutions:

in one aspect, a method for optimizing motor speed ring oscillation suppression of a robot joint is provided, which includes the following steps:

establishing a data model of a permanent magnet synchronous motor corresponding to a robot joint;

establishing a speed loop PI controller according to the mathematical model of the permanent magnet synchronous motor;

acquiring data according to the speed loop PI controller, acquiring speed feedback data, and judging the running state of the robot joint, wherein the running state comprises oscillation or no oscillation;

and when the running state is oscillation, feeding the speed feedback data back to the speed loop PI controller, and optimizing the parameters of the speed loop PI controller through a preset PI parameter optimization algorithm of the speed loop to eliminate the oscillation state of the robot joint.

Preferably, the data model of the permanent magnet synchronous motor includes:

the mathematical model of the permanent magnet synchronous motor is expressed as follows:

wherein, ω is_r、i_d、i_qRespectively representing the angular velocity, d-axis current, q-axis current, u_dIs d-axis voltage, u_qIs the q-axis voltage, p_nIs the magnetic pole pair number, L is the direct axis and quadrature axis inductance, #_fIs the rotor total flux linkage vector, J is the moment of inertia, R_sIs stator resistance, T_LThe load torque is, and B is the friction coefficient.

Preferably, the data acquisition according to the speed loop PI controller includes:

according to the setting of the current loop period, speed loop data are calculated once every 5 current loop periods, 2000 pieces of speed loop data are used as the value range of data acquisition, and 2000 pieces of data are calculated in total.

Preferably, acquiring speed feedback data, and determining an operation state of the robot joint, where the operation state includes occurrence of oscillation or non-occurrence of oscillation, includes:

and fitting a speed feedback curve according to the speed feedback data, and if the speed feedback curve is found to generate overshoot oscillation, namely the times that the upper and lower wave peak values of the curve fitted through the data exceed the error band are more than five times, determining that the running state of the robot joint is oscillation, otherwise, determining that the robot joint does not generate oscillation.

Preferably, the optimizing the parameters of the speed loop PI controller by the preset PI parameter optimization algorithm of the speed loop includes:

while reducing the proportionality coefficient P of the speed loop PI controller_wAnd integral coefficient I_wEach time by 1%, i.e. P_w＝P_w*99％、I_w＝I_w99% until the operational state of the robot joint is such that no oscillation occurs.

In another aspect, there is provided a motor speed ring oscillation suppression optimizing apparatus for a robot joint, including:

the establishing unit is used for establishing a data model of the permanent magnet synchronous motor corresponding to the robot joint;

the establishing unit is used for establishing a speed loop PI controller according to a mathematical model of the permanent magnet synchronous motor;

the judging unit is used for acquiring data according to the speed loop PI controller, acquiring speed feedback data and judging the running state of the robot joint, wherein the running state comprises oscillation or no oscillation;

and the optimization unit is used for feeding back the speed feedback data to the speed loop PI controller when the running state is oscillation, and optimizing the parameters of the speed loop PI controller through a preset PI parameter optimization algorithm of the speed loop so as to eliminate the oscillation state of the robot joint.

Preferably, the data model of the permanent magnet synchronous motor includes:

the mathematical model of the permanent magnet synchronous motor is expressed as follows:

wherein, ω is_r、i_d、i_qRespectively representing the angular velocity, d-axis current, q-axis current, u_dIs d-axis voltage, u_qIs the q-axis voltage, p_nIs the magnetic pole pair number, L is the direct axis and quadrature axis inductance, #_fIs the rotor total flux linkage vector, J is the moment of inertia, R_sIs stator resistance, T_LThe load torque is, and B is the friction coefficient.

Preferably, the judging unit is configured to:

according to the setting of the current loop period, speed loop data are calculated once every 5 current loop periods, 2000 pieces of speed loop data are used as the value range of data acquisition, and 2000 pieces of data are calculated in total.

Preferably, the judging unit is configured to:

and fitting a speed feedback curve according to the speed feedback data, and if the speed feedback curve is found to generate overshoot oscillation, namely the times that the upper and lower wave peak values of the curve fitted through the data exceed the error band are more than five times, determining that the running state of the robot joint is oscillation, otherwise, determining that the robot joint does not generate oscillation.

Preferably, the optimization unit is configured to:

while reducing the proportionality coefficient P of the speed loop PI controller_wAnd integral coefficient I_wEach time by 1%, i.e. P_w＝P_w*99％、I_w＝I_w99% until the operational state of the robot joint is such that no oscillation occurs.

The technical scheme of the invention has the following beneficial effects:

in the embodiment of the invention, the data-drive-based method is applied to the PI parameter optimization of the speed loop of the permanent magnet synchronous motor vector control system, the control performance of the vector control system can be improved, the problem of oscillation of the robot joint in some high-precision control working occasions is solved, and the control performance of the robot joint is obviously improved.

Drawings

Fig. 1 is a flowchart of a method for optimizing oscillation suppression of a motor speed ring of a robot joint according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a process for establishing a speed loop PI controller according to a mathematical model of a PMSM according to an embodiment of the present invention;

FIG. 3 is a simplified schematic diagram of a speed loop PI controller of a PMSM vector control system according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an outer loop double closed loop control process using current inner loop rotation speed according to an embodiment of the present invention;

fig. 5 is a schematic flow chart of a data acquisition algorithm in an embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.

The embodiment of the invention firstly provides a method for inhibiting and optimizing the oscillation of a motor speed ring of a robot joint, which comprises the following steps as shown in figure 1:

establishing a data model of a permanent magnet synchronous motor corresponding to a robot joint;

establishing a speed loop PI controller according to the mathematical model of the permanent magnet synchronous motor;

acquiring data according to the speed loop PI controller, acquiring speed feedback data, and judging the running state of the robot joint, wherein the running state comprises oscillation or no oscillation;

and when the running state is oscillation, feeding the speed feedback data back to the speed loop PI controller, and optimizing the parameters of the speed loop PI controller through a preset PI parameter optimization algorithm of the speed loop to eliminate the oscillation state of the robot joint.

In the embodiment of the invention, the data-drive-based method is applied to the PI parameter optimization of the speed loop of the permanent magnet synchronous motor vector control system, the control performance of the vector control system can be improved, the problem of oscillation of the robot joint in some high-precision control working occasions is solved, and the control performance of the robot joint is obviously improved.

Further, the data model of the permanent magnet synchronous motor includes:

the mathematical model of the permanent magnet synchronous motor is expressed as follows:

wherein, ω is_r、i_d、i_qRespectively representing the angular velocity, d-axis current, q-axis current, u_dIs d-axis voltage, u_qIs the q-axis voltage, p_nIs the magnetic pole pair number, L is the direct axis and quadrature axis inductance, #_fIs the rotor total flux linkage vector, J is the moment of inertia, R_sIs stator resistance, T_LThe load torque is, and B is the friction coefficient.

Further, the process of establishing a speed loop PI controller according to the mathematical model of the permanent magnet synchronous motor is shown in fig. 2, wherein w_refFor given values of speed, T_oiIs a filter time constant, ASR is a rotation speed regulator, T is an inertia link comprehensive time constant, K_L,K_tTo increase the coefficient, J_mMoment of inertia, R_sStator resistance, B is coefficient of friction, J_LFor the moment of inertia of the load, s denotes the Laplace transform, K_sFor the current detection method coefficient, T_iIs the velocity loop filter time constant, w_rFor rotor angular velocity, s represents the Laplace transform.

Further, a simplified speed loop PI controller of the vector control system of the permanent magnet synchronous motor is shown in fig. 3. Wherein, w_refThe given value of speed, ASR is a speed regulator, T is an inertia link comprehensive time constant, K_L,K_tTo increase the coefficient, J_mElectronic rotor moment of inertia, R_sStator resistance, B is coefficient of friction, J_LTo load moment of inertia, K_sFor the current detection method coefficient, T_iIs the velocity loop filter time constant, w_rFor rotor angular velocity, s represents the Laplace transform.

Further, the data acquisition according to the speed loop PI controller includes:

designing a dynamic data acquisition window, wherein the window value range is selected as follows: according to the setting of the current loop period, speed loop data are calculated once every 5 current loop periods, 2000 pieces of speed loop data are used as the value range of data acquisition, and 2000 pieces of data are calculated in total.

Further, the acquiring speed feedback data and judging the operation state of the robot joint, wherein the operation state includes oscillation or no oscillation, and the method includes:

and fitting a speed feedback curve according to the speed feedback data, and if the speed feedback curve is found to generate overshoot oscillation, namely the times that the upper and lower wave peak values of the curve fitted through the data exceed the error band are more than five times, determining that the running state of the robot joint is oscillation, otherwise, determining that the robot joint does not generate oscillation.

Further, the optimizing the parameters of the speed loop PI controller by the preset PI parameter optimization algorithm of the speed loop includes:

while reducing the proportionality coefficient P of the speed loop PI controller_wAnd integral coefficient I_wEach time by 1%, i.e. P_w＝P_w*99％、I_w＝I_w99% until the operational state of the robot joint is such that no oscillation occurs.

In an embodiment of the foregoing method for optimizing oscillation suppression of a motor speed ring of a robot joint, the method further includes:

and comparing the current index parameters of the system with the given index parameters of the system, and optimizing the parameters through a rule based on a data-driven algorithm according to the comparison result of the parameters.

As a specific embodiment of the present invention, as shown in fig. 4, a double closed-loop control process using a current inner loop and a rotation speed outer loop includes: reference value omega of the rotation speed^*With the angular speed omega of the motor detected by the rotation speed detector_rObtaining a difference value by making a difference, and outputting a q-axis current reference value I after the difference value is subjected to parameter optimization through a speed controller_qAnd q-axis current I_qDifferential, d-axis current referenceExamination value I_d ^*And d-axis current I_dObtaining a control voltage d-axis voltage u through a PI current controller based on data drive_dAnd q-axis voltage u_q，u_dAnd u_qAfter the conversion from the two-phase rotating coordinate system to the two-phase static coordinate system, the control voltage value u under the two-phase static alpha beta coordinate system is output_αAnd u_β，u_αAnd u_βInputting the output three-phase voltage control signals into an inverter through Space Vector Pulse Width Modulation (SVPWM) so as to control the permanent magnet synchronous motor; a, B, C three-phase current values ia, ib and ic output by the inverter are converted by 3s/2s (the three-phase stationary coordinate system is converted into the two-phase stationary coordinate system) to output current i under the two-phase stationary alpha beta coordinate system_α,i_β，i_α,i_βD-axis and q-axis currents I are output after 2s/2r (the two-phase stationary coordinate system is converted into the two-phase rotating coordinate system)_d,I_qFed back to the comparator and the current reference valueI_d ^*The comparison forms a closed control loop.

As a specific embodiment of the present invention, as shown in fig. 5, the data acquisition window algorithm flow is as follows: compare the instruction outputs at this timeAnd instruction givenIf the instruction difference valueLess than a given value Δ₁，Considering that the system enters a steady state, acquiring speed feedback data under the condition that the system enters the steady state, and continuously exceeding an error band delta for five times through the upper and lower wave peak values of a curve fitted by the data₂The above is regarded as oscillation, i.e. peak e_∞＞Δ₂When the system is considered to oscillate, the parameter adjustment is performed for 5 times after the speed feedback fitting curve exceeds the counter1 and the counter is increased by 1, the proportional coefficient P is reduced by one percent, and the integral coefficient I is reduced by one percent. If the given speed change is found, the counter1 is cleared, data is collected again, 2000 speed ring data are collected in total, and one parameter setting is completed.

In addition, an embodiment of the present invention further provides a motor speed ring oscillation suppression optimization apparatus for a robot joint, including:

the establishing unit is used for establishing a data model of the permanent magnet synchronous motor corresponding to the robot joint;

the establishing unit is used for establishing a speed loop PI controller according to a mathematical model of the permanent magnet synchronous motor;

the judging unit is used for acquiring data according to the speed loop PI controller, acquiring speed feedback data and judging the running state of the robot joint, wherein the running state comprises oscillation or no oscillation;

and the optimization unit is used for feeding back the speed feedback data to the speed loop PI controller when the running state is oscillation, and optimizing the parameters of the speed loop PI controller through a preset PI parameter optimization algorithm of the speed loop so as to eliminate the oscillation state of the robot joint.

Further, the data model of the permanent magnet synchronous motor includes:

the mathematical model of the permanent magnet synchronous motor is expressed as follows:

wherein, ω is_r、i_d、i_qRespectively representing the angular velocity, d-axis current, q-axis current, u_dIs d-axis voltage, u_qIs the q-axis voltage, p_nIs the magnetic pole pair number, L is the direct axis and quadrature axis inductance, #_fIs the rotor total flux linkage vector, J is the moment of inertia, R_sIs stator resistance, T_LThe load torque is, and B is the friction coefficient.

Further, the determining unit is configured to:

according to the setting of the current loop period, speed loop data are calculated once every 5 current loop periods, 2000 pieces of speed loop data are used as the value range of data acquisition, and 2000 pieces of data are calculated in total.

Further, the determining unit is configured to:

and fitting a speed feedback curve according to the speed feedback data, and if the speed feedback curve is found to generate overshoot oscillation, namely the times that the upper and lower wave peak values of the curve fitted through the data exceed the error band are more than five times, determining that the running state of the robot joint is oscillation, otherwise, determining that the robot joint does not generate oscillation.

Further, the optimization unit is configured to:

while reducing the proportionality coefficient P of the speed loop PI controller_wAnd integral coefficient I_wEach time by 1%, i.e. P_w＝P_w*99％、I_w＝I_w99% until the operational state of the robot joint is such that no oscillation occurs.

In summary, the method and the device for optimizing the motor speed ring oscillation suppression of the robot joint based on data driving provided by the invention do not need additional hardware equipment, are designed on a mathematical model of a permanent magnet synchronous motor vector control system directly, compare the current index parameter of the system with the given index parameter of the system, judge the motion state of the robot joint according to the comparison result of the parameters, and optimize the parameters based on the rule of data driving, so that the problem of robot shutdown oscillation in a high-precision control occasion can be solved, and the control performance of the system can be improved.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, where the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.