Accelerometer-based robot terminal vibration suppression system and suppression method

Abstract

The present invention relates to the field of industrial robots, and in particular to an accelerometer-based robot terminal jitter suppression system and a suppression method thereof. The system comprises: a synchronous trigger module, a robot terminal acceleration acquisition module, a joint servo system, a data processing module, a data storage module, and a data interpolation module. The specific steps are as follows: S1, running; S2, calculating acceleration; S3, sending data; S5, saving data; S6, compensating data using an interpolation algorithm; and S7, achieving suppression. The system interpolates and subdivides jitter compensation data of original low-rate steps using a cubic spline interpolation method, thereby saving data storage space while ensuring the smoothness of the jitter compensation data. The system generates a jitter suppression compensation signal using the output of a speed observer in the joint servo system, thereby reducing the influence of the delay introduced by motor speed feedback and improving the effectiveness of the jitter suppression compensation signal.

Description

Technical Field

[0001] The present invention relates to the field of industrial robots, and in particular to an accelerometer-based robot terminal jitter suppression system and a suppression method thereof. Background Art

[0002] Industrial robots are widely used in numerous industries, including automotive, chemical, logistics, furniture, and bathroom fixtures. Because they operate through actuators mounted on their endpieces during production, vibration at the endpiece can severely impact operational accuracy. The stability of the endpiece's operation is a key performance indicator. The serial cantilever structure of industrial robots, characterized by high flexibility and strong coupling, is highly susceptible to endpiece vibration under conditions such as multi-axis linkage, rapid starts and stops, and extreme trajectories. Existing methods for mitigating endpiece vibration include those based on position sensors at the joint outputs and those based on iterative learning control using sensors at the endpieces. The former requires encoders at the robot joint outputs, which increases costs and places additional demands on joint design and fabrication. The latter requires multiple iterations of learning the same trajectory using sensors mounted on the endpiece, which is complex and requires the iterative algorithm to converge to achieve optimal control performance, posing numerous limitations. Summary of the Invention

[0003] In order to solve the above problems, the present invention proposes a robot end jitter suppression system and a suppression method based on an accelerometer.

[0004] The robot end jitter suppression system based on accelerometer includes:

[0005] A synchronous trigger module is used to synchronously trigger the accelerometer and the robot controller to collect relevant data using the trigger signal line at the initial moment of the robot's operation;

[0006] The robot end acceleration acquisition module collects the acceleration data of the robot end jitter using a low sampling rate control cycle;

[0007] The joint servo system collects feedback data from the joint motor end at a low sampling rate control cycle and sends the collected data to the next station;

[0008] The data processing module calculates the jitter suppression compensation amount through the built-in algorithm and sends it to the next workstation;

[0009] A data storage module saves the received data to a memory to facilitate repeated use of the jitter compensation data after the device is restarted;

[0010] The data interpolation module reads the low sampling rate compensation data saved from the data storage module, obtains the high sampling rate compensation data required by the servo system through the interpolation algorithm, and sends it to the joint servo system.

[0011] The synchronous trigger module is used to send a trigger signal to the robot terminal acceleration acquisition module and the joint servo system.

[0012] The joint servo system utilizes the subdivided jitter suppression compensation amount output by the data interpolation module to output torque to achieve jitter suppression at the end of the robot.

[0013] The robot end acceleration acquisition module includes a motor end position and torque data that can be obtained in the motor coordinate system, a robot end acceleration data obtained by an accelerometer installed at the end of the robot, a joint coordinate system conversion module for obtaining the motor position in the joint coordinate system, a joint end position calculation module that can calculate the joint end position based on the joint flexibility model and the relevant data in the joint coordinate system, a robot end rotation matrix calculation module for obtaining the joint end position output by the joint end position calculation module, a joint end velocity calculation module obtained according to the joint end position calculation module, and a module for calculating the robot Jacobian matrix J and the derivative of the Jacobian matrix. The Jacobian matrix related calculation module, the robot base coordinate system acceleration calculation module that uses the rotation transformation matrix to convert the robot terminal acceleration data into the robot base coordinate system, and the joint acceleration calculation module that finally calculates the joint accelerations of the first three joints based on the mapping relationship between the robot joint acceleration and the terminal acceleration.

[0014] The joint servo system includes a motor that applies a jitter suppression compensation amount to a robotic arm via a reducer, a position loop output for providing a speed command signal, a jitter suppression module for outputting a subdivided jitter suppression compensation speed as an actual speed command signal, a speed controller that generates a torque command signal based on the modified speed command signal and a motor speed signal output by a speed observer, a torque controller that outputs a corresponding current and applies it to the motor to generate an actual motor torque, and a speed observer that outputs an observed speed based on the torque command and the motor speed for speed closed loop and jitter compensation signal generation.

[0015] The data processing module includes a joint end speed that can be obtained by integrating the joint end acceleration calculated by the robot end acceleration acquisition module, a motor end observation speed that uses the deviation from the joint end speed as a measure of the original jitter signal of the robot end, a bandpass filtering module that obtains a jitter component of a single frequency band by filtering the original jitter signal, an input shaping module for signal conditioning, a gain adjustment module that uses the corresponding proportional gain as the original signal of the jitter compensation amount, and a jitter suppression compensation amount output module for receiving the original signal of the jitter compensation amount.

[0016] The data storage module includes an upper controller, a bus communication interface for sending data, a lower driver for sending the original jitter suppression compensation value through the bus interface, a peripheral driver module for realizing read and write functions, and a data storage device for offline storage of the original jitter compensation value output by the data processing module.

[0017] The data interpolation module includes the original data set and the original low-rate step size, a curve interpolation matrix equation for constructing a curve, a solution matrix equation capable of calculating 4N-4 unknowns of the interpolation curve function, and also includes obtaining the interpolation curve function, subdividing the high-rate step size, and subdividing the compensation data set.

[0018] The specific steps of the robot end vibration suppression system based on the accelerometer are as follows:

[0019] S1, Run: When the robot starts running, the synchronous trigger module sends a trigger signal to the robot end acceleration acquisition module and joint servo system at the same time;

[0020] S2. Calculate acceleration:

[0021] a. The robot end acceleration acquisition module starts to collect acceleration data of the robot end jitter at a low sampling rate control cycle. The end acceleration acquisition module calculates the position of the joint end based on the joint flexibility model and the relevant data in the joint coordinate system. The formula is as follows:

[0022]

[0023] where K i is the joint stiffness, B v is the viscous friction coefficient at the motor end, B c is the Coulomb friction coefficient at the motor end, J mi is the motor end inertia, η i is the joint reduction ratio, θ i is the motor position, is the motor speed, is the motor acceleration, τ mi is the motor torque;

[0024] b. According to the mapping relationship between the robot joint acceleration and the terminal acceleration, the joint acceleration of the first three joints can be calculated, and the Jacobian matrix J and the derivative of the Jacobian matrix Divided into two parts, J and The first three columns of the first three rows are denoted as J1 and J and The last three columns of the first three rows are denoted as J2 and The acceleration data of the robot end can be expressed as a e=[a x ,a y ,a z ] T , the rotation transformation matrix R can be used to transform the robot end acceleration data to the robot base coordinate system a 0 =Ra e Finally, the joint accelerations of the first three joints can be calculated according to the following formula:

[0025]

[0026] S3, sending data: the joint servo system starts to collect joint motor end feedback data in a control cycle with a low sampling speed and sends the collected data to the data processing module;

[0027] S4. Processing jitter compensation data:

[0028] a. The data processing module calculates the jitter suppression compensation amount through the built-in algorithm and sends it to the data storage module;

[0029] b. The joint end acceleration obtained by the robot end acceleration acquisition module is integrated to obtain the joint end speed. The deviation between the joint end acceleration and the observed speed at the motor end is used as the original signal to measure the jitter of the robot end.

[0030] c. Obtain the jitter component of a single frequency band by filtering the original jitter signal and perform signal conditioning on it;

[0031] d. The conditioned signal is multiplied by the proportional gain to obtain the original signal of the jitter compensation amount;

[0032] S5. Save data: The data storage module saves the received data to the memory, so that the jitter compensation data can be repeatedly called after the device is restarted.

[0033] S6. Interpolation algorithm compensation data: The data interpolation module reads the low sampling rate compensation data stored in the data storage module, obtains the high sampling rate compensation data required by the servo system through the interpolation algorithm, and sends it to the joint servo system;

[0034] S7, achieve suppression:

[0035] a. The joint servo system can introduce the jitter compensation data obtained from the data interpolation module into the servo control loop, and the position loop output gives the speed command signal;

[0036] b. Subtract the subdivided vibration suppression compensation speed from the speed command signal as the actual speed command signal. At this time, the motor torque generated by the joint motor already includes the vibration suppression compensation amount. It is applied to the robotic arm through the reducer, ultimately achieving the effect of suppressing the vibration of the robot end.

[0037] The interpolation scheme adopted in step S6 is as follows: the blank data area between the low-rate step lengths 62 is interpolated using a cubic function. This curve function has the advantage of continuous second-order derivatives. Compared with linear interpolation, the generated curve is smoother and avoids the introduction of additional impact signals into the system due to unreasonable interpolation. The interpolation function used is y=a i x 3 +b i x 2 +c i x+d i , where: a i , b i , c i , d i is the interpolation coefficient.

[0038] The beneficial effects of the present invention are as follows: the original low-rate step-size jitter compensation data is interpolated and subdivided using a cubic spline interpolation method, thereby saving data storage space while ensuring the smoothness of the jitter compensation data; the output of a speed observer in a joint servo system is used to generate a jitter suppression compensation signal, thereby reducing the impact of the delay introduced by motor speed feedback and improving the effectiveness of the jitter suppression compensation signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention will be further described below with reference to the accompanying drawings and examples.

[0040] Figure 1 This is a block diagram of the operating principle of the present invention;

[0041] Figure 2 This is a flowchart for obtaining the acceleration of the robot end of the present invention;

[0042] Figure 3 A flowchart of the jitter suppression data generation process of the present invention;

[0043] Figure 4 This is a flow chart of the jitter suppression data storage of the present invention;

[0044] Figure 5 This is a flow chart of the jitter suppression data subdivision and interpolation process of the present invention;

[0045] Figure 6 This is a control block diagram of the joint servo system of the present invention. DETAILED DESCRIPTION

[0046] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below.

[0047] like Figures 1 to 6As shown in FIG, the robot end vibration suppression system based on the accelerometer includes:

[0048] Synchronous trigger module 1, used to synchronously trigger the accelerometer and robot controller to collect relevant data using the trigger signal line at the initial moment of the robot operation;

[0049] The robot end acceleration acquisition module 2 collects the acceleration data of the robot end jitter in a low sampling rate control cycle;

[0050] Joint servo system 3, collects joint motor end feedback data in a control cycle with a low sampling speed and sends the collected data to the next station;

[0051] Data processing module 4 calculates the jitter suppression compensation amount through a built-in algorithm and sends it to the next station;

[0052] The data storage module 5 saves the received data to the memory to facilitate repeated use of the jitter compensation data after the device is restarted;

[0053] The data interpolation module 6 reads the low sampling rate compensation data stored in the data storage module 5 , obtains the high sampling rate compensation data required by the servo system through an interpolation algorithm, and sends it to the joint servo system 3 .

[0054] The synchronous trigger module 1 is used to send a trigger signal to the robot end acceleration acquisition module 2 and the joint servo system 3.

[0055] The data processing module 4 generates a corresponding vibration suppression compensation amount using the joint end acceleration data processed by the robot end acceleration acquisition module 2 and the motor feedback data collected by the joint servo system 3.

[0056] Specifically, the data storage module stores the jitter suppression compensation value generated by the data processing module 4 in the data storage device, so that the jitter suppression compensation value can still be normally called after the acceleration sensor is removed.

[0057] When suppressing the jitter of the robot end, the present invention only needs to install an acceleration sensor at the end during the first trajectory operation, and there is no need to install additional sensors at the robot joint end or load end, which reduces the cost of the jitter suppression solution and improves its usability. According to reasonable assumptions introduced according to the robot model, the acceleration data obtained by the accelerometer installed at the end of the robot is resolved to the joint end, solving the mapping problem of the end jitter signal to the joint end.

[0058] The data interpolation module 6 performs cubic spline interpolation on the acquired original vibration suppression compensation amount according to the control step size of the joint servo system 3 , thereby obtaining a vibration suppression compensation amount with a smaller step size.

[0059] The joint servo system 3 uses the subdivided jitter suppression compensation output by the data interpolation module 6 to output torque to achieve jitter suppression at the end of the robot.

[0060] The robot end acceleration acquisition module 2 includes a motor end position and torque data 21 that can obtain the motor coordinate system, a robot end acceleration data 22 obtained by the accelerometer installed at the end of the robot, a joint coordinate system conversion module 23 for obtaining the motor position in the joint coordinate system, a joint end position calculation module 24 that can calculate the joint end position based on the joint flexibility model and the relevant data in the joint coordinate system, a robot end rotation matrix calculation module 25 for obtaining the joint end position output by the joint end position calculation module 24, a joint end velocity calculation module 26 obtained according to the joint end position calculation module 24, and a module for calculating the robot Jacobian matrix J and the derivative of the Jacobian matrix. Jacobian matrix related calculation module 28, robot base coordinate system acceleration calculation module 27 that can convert robot terminal acceleration data into robot base coordinate system using rotation transformation matrix, joint acceleration calculation module 29 that finally calculates the joint accelerations of the first three joints based on the mapping relationship between robot joint acceleration and terminal acceleration.

[0061] Specifically, such as Figure 2 As shown; the motor position θ in the motor coordinate system can be obtained by using the motor end position and torque data 21 i ′, motor speed Motor acceleration Motor torque τ′ mi ; Joint coordinate system conversion module 23 through the joint reduction ratio η i Get the motor position θ in the joint coordinate system i , motor speed Motor acceleration Motor torque τ mi , the conversion formula is:

[0062]

[0063] The joint end position calculation module 24 can calculate the position of the joint end according to the joint flexibility model and the relevant data in the joint coordinate system. The joint flexibility model is as follows, where K i is the joint stiffness, B v is the viscous friction coefficient at the motor end, B c is the Coulomb friction coefficient at the motor end, J mi is the motor end inertia:

[0064]

[0065] The robot end acceleration data 22 obtained by the accelerometer installed at the end of the robot is represented as a e =[a x ,a y ,a z ] T The robot end rotation matrix calculation module 25 obtains the joint end position q output by the joint end position calculation module 24 i The robot forward kinematics is used to calculate the terminal rotation transformation matrix R. The robot base coordinate system acceleration calculation module 27 uses the rotation transformation matrix to convert the robot terminal acceleration data into the robot base coordinate system:

[0066] a 0 =Ra e (3)

[0067] The Jacobian matrix related calculation module 26 can calculate the robot Jacobian matrix J and the derivative of the Jacobian matrix according to the output of the joint end position calculation module 24 and the joint end velocity calculation module 25. Since the acceleration sensor can only measure the acceleration in three translational directions, and considering that the flexible deformation of joints 4, 5, and 6 is very small, it is assumed that the joint positions, joint velocities, and joint accelerations of joints 4, 5, and 6 are equal to the motor positions, motor velocities, and motor accelerations. Divided into two parts, J and The first three columns of the first three rows are denoted as J1 and J and The last three columns of the first three rows are denoted as J2 and Right now:

[0068]

[0069] The joint acceleration calculation module 29 can finally calculate the joint accelerations of the first three joints according to the mapping relationship between the robot joint accelerations and the terminal accelerations:

[0070]

[0071] The joint servo system 3 includes a motor 36 that applies the jitter suppression compensation amount to the robotic arm 38 through a reducer 37, a position loop output 31 for providing a speed command signal, a jitter suppression module 32 for outputting a subdivided jitter suppression compensation speed as an actual speed command signal, a speed controller 33 that generates a torque command signal based on the modified speed command signal and the motor speed signal output by the speed observer, a torque controller 34 that outputs a corresponding current and applies it to the motor 36 to generate the actual motor torque, and a speed observer 35 that outputs an observed speed based on the torque command and the motor speed for speed closed loop and jitter compensation signal generation.

[0072] Specifically, the joint servo system 3 uses the subdivided vibration suppression compensation amount output by the data interpolation module 6 to output torque to achieve vibration suppression of the robot end.

[0073] Specifically, the cubic spline interpolation method is used to interpolate and subdivide the original low-rate step jitter compensation data, which saves data storage space while ensuring the smoothness of the jitter compensation data; the output of the speed observer in the joint servo system 3 is used to generate a jitter suppression compensation signal, which reduces the impact of the delay introduced by the motor speed feedback and improves the effectiveness of the jitter suppression compensation signal.

[0074] Specifically, in the joint servo system 3, the vibration suppression of the robot end is achieved by applying a vibration suppression compensation amount to the speed instruction, which improves the convenience of vibration suppression and achieves the vibration suppression effect without multiple iterations.

[0075] Specifically, such as Figure 6 As shown; the position loop output 31 gives a speed command signal, which is subtracted from the subdivided jitter suppression compensation speed output by the jitter suppression module 32 as the actual speed command signal; the speed observer 35 outputs the observed speed based on the torque command and the motor speed for speed closed loop and jitter compensation signal generation; the speed controller 33 generates a torque command signal based on the modified speed command signal and the motor speed signal output by the speed observer, and the torque controller 34 outputs the corresponding current and applies it to the motor 36 to generate the actual motor torque; at this time, the motor torque generated by the motor 36 already includes the jitter suppression compensation amount, which is applied to the robot arm 38 through the reducer 37 to achieve the final jitter suppression effect at the end of the robot.

[0076] The data processing module 4 includes a joint end speed 41 that can be obtained by integrating the joint end acceleration calculated by the robot end acceleration acquisition module 2, a motor end observation speed 42 whose deviation from the joint end speed 41 is used as a measure of the original jitter signal of the robot end, a bandpass filtering module 43 that obtains the jitter component of a single frequency band by filtering the original jitter signal, an input shaping module 44 for signal conditioning, a gain adjustment module 45 that uses the corresponding proportional gain as the original signal of the jitter compensation amount, and a jitter suppression compensation amount output module 46 for receiving the original signal of the jitter compensation amount.

[0077] Specifically, the joint end acceleration integral calculated by the robot end acceleration acquisition module 2 can be used to obtain the joint end speed 41, and its deviation from the motor end observation speed 42 is used as a measure of the original jitter signal of the robot end; the bandpass filtering module 43 obtains the jitter component of a single frequency band by filtering the jitter original signal, and gives it to the input shaping module 44 for signal conditioning; the conditioned signal is multiplied by the proportional gain corresponding to the gain adjustment module 45 as the original signal of the jitter compensation amount, and is input into the jitter suppression compensation amount output module 46, which outputs the original jitter suppression compensation amount to the data storage module 5 for data storage processing.

[0078] The data storage module 5 includes an upper controller 51, a bus communication interface 52 for sending data, a lower driver 53 for sending the original jitter suppression compensation value through the bus interface 52, a peripheral driver module 54 for implementing read and write functions, and a data storage device 55 for offline storage of the original jitter compensation value output by the data processing module 4.

[0079] like Figure 4 As shown; the upper controller 51 sends the original jitter suppression compensation amount to the lower driver 53 through the bus interface 52; the lower servo driver realizes the read and write function of the data storage 55 through the peripheral driver module 54, and uses the write function to write the original jitter compensation amount output by the data processing module 4 into the data storage for offline storage, and uses the read function to read the data in the data storage during the power-on initialization task and perform subdivision interpolation for online use.

[0080] The data interpolation module 6 includes an original data set 61 and an original low-rate step size 62, a curve interpolation matrix equation 63 for constructing a curve, a solution matrix equation 64 capable of calculating 4N-4 unknowns of the interpolation curve function, and also includes obtaining an interpolation curve function 65, subdividing the high-rate step size 66, and subdividing the compensation data set 67.

[0081] Specifically, the original data set 61 and the original low-rate step size 62 in the data storage module 5 can be used to construct a curve interpolation matrix equation 63. Preferably, the curve interpolation matrix equation 63 adopts a cubic spline interpolation scheme, which uses a cubic function to interpolate the blank data area between the low-rate step sizes 62. This curve function has the advantage of continuous second-order derivatives. Compared with linear interpolation, the generated curve is smoother and avoids the introduction of additional impact signals into the system due to unreasonable interpolation. The interpolation function used is as follows:

[0082] y=a i x 3 +b i x 2 +c i x+d i (6)

[0083] The original data set 61 is N-point data with an interval of the original low-rate step size 62, the corresponding data segment is N-1 segments, and the corresponding spline curve equation has 4N-4 unknowns; all points in the original data set 61 need to satisfy the interpolation curve equation, and 2N-2 equations can be obtained; the internal points in the original data set 61 need to satisfy the equality of the first-order derivative and the second-order derivative, and 2N-4 equations can be obtained; preferably, the boundary condition of the interpolation scheme selects a natural boundary, that is, the second-order derivative of the two end points of the original data set is 0, and 2 equations can be obtained; the curve interpolation matrix equation 63 can be constructed based on these 4N-4 equations, and the 4N-4 unknowns of the interpolation curve function can be calculated by solving the matrix equation 64; the subdivided high-rate step size 66 is substituted into the interpolation curve function 65 to obtain the subdivided compensation data set 67.

[0084] The specific steps of the robot end vibration suppression system based on the accelerometer are as follows:

[0085] S1, Run: When the robot starts running, the synchronous trigger module 1 sends a trigger signal to the robot end acceleration acquisition module 2 and the joint servo system 3 at the same time;

[0086] S2. Calculate acceleration:

[0087] a. The robot end acceleration acquisition module 2 starts to collect the acceleration data of the robot end jitter at a low sampling rate control cycle. The end acceleration acquisition module 2 calculates the position of the joint end based on the joint flexibility model and the relevant data in the joint coordinate system. The formula is as follows:

[0088]

[0089] where K i is the joint stiffness, B v is the viscous friction coefficient at the motor end, Bc is the Coulomb friction coefficient at the motor end, J mi is the motor end inertia, η i is the joint reduction ratio, θ i is the motor position, is the motor speed, is the motor acceleration, τ mi is the motor torque;

[0090] b. According to the mapping relationship between the robot joint acceleration and the terminal acceleration, the joint acceleration of the first three joints can be calculated, and the Jacobian matrix J and the derivative of the Jacobian matrix Divided into two parts, J and The first three columns of the first three rows are denoted as J1 and J and The last three columns of the first three rows are denoted as J2 and The acceleration data of the robot end can be expressed as a e =[a x ,a y ,a z ] T , the rotation transformation matrix R can be used to transform the robot end acceleration data to the robot base coordinate system a 0 =Ra e Finally, the joint accelerations of the first three joints can be calculated according to the following formula:

[0091]

[0092] S3, sending data: the joint servo system 3 starts to collect joint motor end feedback data in a control cycle with a low sampling speed and sends the collected data to the data processing module 4;

[0093] S4. Processing jitter compensation data:

[0094] a. The data processing module 4 calculates the jitter suppression compensation amount through a built-in algorithm and sends it to the data storage module 5;

[0095] b. The joint end acceleration obtained by the robot end acceleration acquisition module 2 is integrated to obtain the joint end speed, and the deviation between the joint end acceleration and the motor end speed is used as the original signal to measure the jitter of the robot end;

[0096] c. Obtain the jitter component of a single frequency band by filtering the original jitter signal and perform signal conditioning on it;

[0097] d. The conditioned signal is multiplied by the proportional gain to obtain the original signal of the jitter compensation amount;

[0098] S5. Save data: The data storage module 5 saves the received data to the memory, so as to facilitate repeated use of the jitter compensation data after the device is restarted;

[0099] S6, interpolation algorithm compensation data: the data interpolation module 6 reads the low sampling rate compensation data stored in the data storage module 5, obtains the high sampling rate compensation data required by the servo system through the interpolation algorithm, and sends it to the joint servo system 3;

[0100] S7, achieve suppression:

[0101] a. The joint servo system 3 can introduce the jitter compensation data obtained from the data interpolation module 6 into the servo control loop, and the position loop output gives a speed command signal;

[0102] b. Subtract the subdivided vibration suppression compensation speed from the speed command signal as the actual speed command signal. At this time, the motor torque generated by the joint motor already includes the vibration suppression compensation amount. It is applied to the robotic arm through the reducer, ultimately achieving the effect of suppressing the vibration of the robot end.

[0103] The interpolation scheme adopted in step S6 is as follows: the blank data area between the low-rate step lengths 62 is interpolated using a cubic function. This curve function has the advantage of continuous second-order derivatives. Compared with linear interpolation, the generated curve is smoother and avoids the introduction of additional impact signals into the system due to unreasonable interpolation. The interpolation function used is y=a i x 3 +b i x 2 +c i x+d i , where: a i , b i , c i , d i is the interpolation coefficient.

[0104] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and description merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. The robot end-user vibration suppression system based on accelerometer is characterized by: include: A synchronous trigger module (1) is used to synchronously trigger the accelerometer and the robot controller to collect relevant data using a trigger signal line at the initial moment of the robot operation; The robot end acceleration acquisition module (2) collects acceleration data of the robot end jitter in a control cycle with a low sampling rate; The joint servo system (3) collects feedback data from the joint motor end in a control cycle with a low sampling speed and sends the collected data to the next station; The data processing module (4) calculates the jitter suppression compensation amount through a built-in algorithm and sends it to the next station; A data storage module (5) stores the received data in a memory, so as to facilitate repeated use of the jitter compensation data after the device is restarted; A data interpolation module (6) reads the low sampling rate compensation data stored in the data storage module (5), obtains the high sampling rate compensation data required by the servo system through an interpolation algorithm, and sends the data to the joint servo system (3); The robot terminal acceleration acquisition module (2) includes a motor terminal position and torque data (21) capable of obtaining a motor coordinate system, robot terminal acceleration data (22) obtained by an accelerometer installed at the robot terminal, a joint coordinate system conversion module (23) for obtaining the motor position in the joint coordinate system, and a joint acceleration calculation module (29) for finally calculating the joint accelerations of the first three joints based on a mapping relationship between the robot joint accelerations and the terminal accelerations. The data processing module (4) includes a bandpass filtering module (43) for filtering the original jitter signal to obtain a jitter component of a single frequency band, an input shaping module (44) for signal conditioning, a gain adjustment module (45) for using the corresponding proportional gain as the original jitter suppression compensation signal, and a jitter suppression compensation output module (46) for receiving the original jitter suppression compensation signal. The data interpolation module (6) includes an original data set (61) and an original low-rate step size (62), a curve interpolation matrix equation (63) for constructing a curve, and a solution matrix equation (64) capable of calculating 4N-4 unknowns of the interpolation curve function.

2. The accelerometer-based robot end-user vibration suppression system according to claim 1, characterized in that: The synchronous trigger module (1) is used to send a trigger signal to the robot terminal acceleration acquisition module (2) and the joint servo system (3).

3. The accelerometer-based robot end-user vibration suppression system according to claim 1, characterized in that: The joint servo system (3) utilizes the subdivided vibration suppression compensation amount output by the data interpolation module (6) to output torque to achieve vibration suppression at the end of the robot.

4. The accelerometer-based robot end-user vibration suppression system according to claim 1, characterized in that: The robot terminal acceleration acquisition module (2) further includes a joint end position calculation module (24) capable of calculating the joint end position according to the joint flexibility model and the relevant data under the joint coordinate system, a robot terminal rotation matrix calculation module (25) for obtaining the joint end position output by the joint end position calculation module (24), a joint end velocity calculation module (26) obtained according to the joint end position calculation module (24), a robot Jacobian matrix J and a derivative of the Jacobian matrix J calculated by the robot terminal acceleration acquisition module (24), and a robot terminal rotation matrix calculation module (25) for obtaining the joint end position output by the joint end position calculation module (24). The Jacobian matrix related calculation module (28) and the robot base coordinate system acceleration calculation module (27) can convert the robot terminal acceleration data into the robot base coordinate system using the rotation transformation matrix.

5. The robot end-user vibration suppression system based on an accelerometer according to claim 1, characterized in that: The joint servo system (3) includes a motor (36) for applying a jitter suppression compensation amount to a mechanical arm (38) via a speed reducer (37), a position loop output (31) for providing a speed command signal, a jitter suppression module (32) for outputting a subdivided jitter suppression compensation speed as an actual speed command signal, a speed controller (33) for generating a torque command signal based on the modified speed command signal and a motor speed signal output by a speed observer, a torque controller (34) for outputting a corresponding current to be applied to the motor (36) to generate an actual motor torque, and a speed observer (35) for outputting an observed speed based on the torque command and the motor speed for a speed closed loop and jitter compensation signal generation.

6. The accelerometer-based robot end-user vibration suppression system according to claim 1, characterized in that: The data processing module (4) further includes a joint end rotation speed (41) that can be obtained by integrating the joint end acceleration calculated by the robot end acceleration acquisition module (2), and a motor end observation rotation speed (42) that is used as a deviation from the joint end rotation speed (41) to measure the original signal of the jitter of the robot end.

7. The accelerometer-based robot end-user vibration suppression system according to claim 1, characterized in that: The data storage module (5) comprises an upper controller (51), a bus communication interface (52) for sending data, a lower driver (53) for sending the original jitter suppression compensation amount through the bus interface (52), a peripheral driver module (54) for realizing a read and write function, and a data storage device (55) for offline storage of the original jitter suppression compensation amount output by the data processing module (4).

8. The robot end-user vibration suppression system based on an accelerometer according to claim 1, characterized in that: The data interpolation module (6) further includes obtaining an interpolation curve function (65), subdividing the high-speed step (66), and subdividing the compensation data set (67).

9. A method for suppressing vibration of a robot end-user using an accelerometer-based vibration suppression system according to any one of claims 1 to 8, characterized in that: The specific steps are as follows: S1, operation: When the robot starts to operate, a trigger signal is sent to the robot terminal acceleration acquisition module (2) and the joint servo system (3) simultaneously through the synchronous trigger module (1); S2. Calculate acceleration: a. The robot end acceleration acquisition module (2) starts to collect acceleration data of the robot end jitter at a low sampling rate control cycle. The end acceleration acquisition module (2) calculates the position of the joint end based on the joint flexibility model and the relevant data in the joint coordinate system. The formula is as follows: where K i is the joint stiffness, B v is the viscous friction coefficient at the motor end, B c is the Coulomb friction coefficient at the motor end, J mi is the motor end inertia, η i is the joint reduction ratio, θ i is the motor position, is the motor speed, is the motor acceleration, τ mi is the motor torque; b. According to the mapping relationship between the robot joint acceleration and the terminal acceleration, the joint acceleration of the first three joints can be calculated, and the Jacobian matrix J and the derivative of the Jacobian matrix Divided into two parts, J and The first three columns of the first three rows are denoted as J1 and J and The last three columns of the first three rows are denoted as J2 and The acceleration data of the robot end can be expressed as a e =[a x ,a y ,a z ] T , the rotation transformation matrix R can be used to transform the robot end acceleration data to the robot base coordinate system a 0 =Ra e Finally, the joint accelerations of the first three joints can be calculated according to the following formula: S3, sending data: the joint servo system (3) starts to collect joint motor end feedback data at a control cycle with a low sampling speed and sends the collected data to the data processing module (4); S4. Processing jitter compensation data: a. The data processing module (4) calculates the jitter suppression compensation amount through a built-in algorithm and sends it to the data storage module (5); b. The joint end acceleration obtained by the robot end acceleration acquisition module (2) is integrated to obtain the joint end speed, and the deviation between the joint end speed and the motor end speed is used as the original signal to measure the jitter of the robot end; c. Obtain the jitter component of a single frequency band by filtering the original jitter signal and perform signal conditioning on it; d. The conditioned signal is multiplied by the proportional gain to obtain the original signal of the jitter suppression compensation amount; S5. Saving data: The data storage module (5) saves the received data to the memory, so as to facilitate repeated calling of the jitter compensation data after the device is restarted; S6, interpolation algorithm compensation data: the data interpolation module (6) reads the low sampling rate compensation data stored in the data storage module (5), obtains the high sampling rate compensation data required by the servo system through the interpolation algorithm, and sends it to the joint servo system (3); S7, achieve suppression: a. The joint servo system (3) can introduce the jitter compensation data obtained from the data interpolation module (6) into the servo control loop, and the position loop output gives a speed command signal; b. Subtract the subdivided vibration suppression compensation speed from the speed command signal as the actual speed command signal. At this time, the motor torque generated by the joint motor already includes the vibration suppression compensation amount. It is applied to the robotic arm through the reducer, ultimately achieving the effect of suppressing the vibration of the robot end.

10. The method for suppressing vibration of a robot end-user based on an accelerometer according to claim 9, characterized in that: The interpolation scheme adopted in step S6 is specifically as follows: the blank data area between the low-rate step (62) is interpolated using a cubic function. The interpolation curve function has the advantage of continuous second-order derivatives. Compared with linear interpolation, the generated curve is smoother and avoids the introduction of additional impact signals into the system due to unreasonable interpolation. The interpolation function used is y=a i x 3 +b i x 2 +c i x+d i , where: a i , b i , c i , d i is the interpolation coefficient.

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