Robot vibration suppression method based on intelligent slave station and kinetic model

Abstract

The invention provides a robot vibration suppression method based on an intelligent slave station and a kinetic model, and belongs to the field of robot vibration suppression, and the method comprises the steps: taking a robot controller as a master station, enabling the intelligent slave station to carry a LINUX system, and enabling the master station to be in bidirectional connection with the intelligent slave station; the intelligent slave station obtains the position, the speed and the acceleration of each joint shaft of the robot through the robot controller; a dynamics algorithm model is established at the computer end, the intelligent slave station transmits the position, speed and acceleration of each joint shaft to the computer end and serves as input of the dynamics algorithm model, and the torque feed-forward value of each joint shaft is obtained; the intelligent slave station transmits the received data to the robot controller; and the robot controller sends the torque feed-forward value of each joint shaft to a servo driver of the corresponding joint shaft in each interpolation period, so that vibration suppression is realized. The method is high in transmission efficiency and high in real-time performance, the vibration suppression effect is improved, and then the position control precision of the robot is improved.

Description

Technical Field

[0001] The invention belongs to the field of robot vibration suppression, and in particular relates to a robot vibration suppression method based on an intelligent slave station and a dynamic model. Background Art

[0002] Considering the cost and applicability, robot controllers are generally only applicable to robot motion control and cannot handle complex algorithm calculations. Robot vibration suppression technology generally uses a complex dynamic model of a multi-joint robot to calculate the corresponding torque feedforward value to compensate the servo drive. However, the existing methods are all in the form of upper and lower computers, with the upper computer being an industrial computer and the lower computer being a robot controller. TCP / IP communication is used, which has low communication transmission efficiency, poor real-time performance, and poor vibration suppression effect. Summary of the invention

[0003] The purpose of the present invention is to propose a robot vibration suppression method based on an intelligent slave station and a dynamic model, which uses a computer to calculate the torque feedforward value and transmits it to the robot controller via the intelligent slave station. The transmission efficiency is high and the real-time performance is strong, which improves the vibration suppression effect and thus improves the position control accuracy of the robot.

[0004] The present invention is achieved through the following technical solutions: The robot vibration suppression method based on intelligent slave station and dynamic model, each joint axis of the robot is provided with a servo driver to drive its movement, including the following steps: Step S1, the robot controller is used as the master station, the intelligent slave station is equipped with the LINUX system, the master station and the intelligent slave station are bidirectionally connected, the Beremiz software is installed in the LINUX system, and the Beremiz software is bidirectionally connected to the computer; Step S2: The intelligent slave station obtains the position, velocity and acceleration of each joint axis of the robot through the robot controller; Step S3, establishing a dynamic algorithm model on the computer side, the intelligent slave station transmits the position, velocity and acceleration of each joint axis to the computer side as input of the dynamic algorithm model, and obtains the torque feedforward value of each joint axis; Step S4, the computer feeds back the torque feedforward value of each joint axis to the intelligent slave station, and the intelligent slave station transmits the received data to the robot controller; Step S5: The robot controller sends the torque feedforward value of each joint axis to the servo driver of the corresponding joint axis in each interpolation cycle to achieve vibration suppression.

[0005] Furthermore, the master station communicates with the intelligent slave station via EtherCAT, and the intelligent slave station utilizes OPC UA communication based on Beremiz software to communicate with the computer.

[0006] Furthermore, the intelligent slave station includes an FPGA, a main control chip, and a link layer. The link layer is located in the FPGA. The main control chip accesses the link layer through a PCIe parallel bus. The link layer has a bidirectional data connection with the robot controller.

[0007] Furthermore, in step S3, the dynamic algorithm model is established based on the Newton-Euler dynamic modeling method, and according to the position, velocity and acceleration of each joint axis, the velocity and acceleration of each joint axis are calculated by kinematic extrapolation from the first joint axis to the nth joint axis, and the force and torque of the interaction between the joint axes are calculated by kinematic internalization from the nth joint axis to the first joint axis, thereby obtaining the driving torque of each joint axis, and transmitting the driving torque to the robot controller as the torque feedforward value.

[0008] Furthermore, the intelligent slave station has no application layer protocol, nor a distributed clock function and an SDO function.

[0009] Furthermore, the intelligent slave station is equipped with LINUX system and runs LINUX+Xenomai environment. Beremiz software provides a soft PLC secondary development programming platform compatible with IEC61131 standard.

[0010] Furthermore, the computer uses Matlab software to establish a dynamic algorithm model.

[0011] The present invention has the following beneficial effects: 1. The present invention uses the robot controller as the master station, and carries the LINUX system on the intelligent slave station. The intelligent slave station is bidirectionally connected to the computer side. The intelligent slave station obtains the position, speed and acceleration of each joint axis through the robot controller, and uses these data as the input of the dynamics algorithm model to obtain the torque feedforward value of each joint axis. The dynamics algorithm model is obtained by the computer side, and after the torque feedforward value is obtained, it is transmitted to the robot controller via the intelligent slave station, and then each joint axis is controlled, thereby achieving vibration suppression. In this process, data transmission is performed through the intelligent slave station, which can realize real-time calculation of the feedforward value of each joint axis, and the transmission efficiency is higher, thereby quickly suppressing the vibration of each scanning cycle of the robot, thereby improving the position control accuracy of the robot.

[0012] 2. The intelligent slave station of the present invention has the soft PLC programmable function in accordance with IEC61131-3, supports generating PLCopenXML files from Simulink models, and then importing them into the soft PLC project as function blocks. This fast model-to-code conversion method speeds up development efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention is further described in detail below with reference to the accompanying drawings.

[0014] Figure 1 It is a flow chart of the present invention.

[0015] Figure 2 It is a principle block diagram of the communication between the master station and the intelligent slave station of the present invention.

[0016] Figure 3 It is a functional principle diagram of the intelligent slave station of the present invention.

[0017] Figure 4 It is a schematic diagram of the vibration suppression of the present invention. DETAILED DESCRIPTION

[0018] In this embodiment, the robot has six joint axes, each of which is provided with a servo driver for driving its movement. Figure 1 As shown, the robot vibration suppression method based on the intelligent slave station and the dynamic model includes the following steps: Step S1, the robot controller is used as the master station, the intelligent slave station is equipped with the LINUX system, the master station and the intelligent slave station are bidirectionally connected, the Beremiz software is installed in the LINUX system, and the Beremiz software is bidirectionally connected to the computer; Specifically, Figure 2 As shown, the master station communicates with the intelligent slave station via EtherCAT, and the servo drivers of the six joint axes (the six joint axes are numbered from the robot base to the robot end as the first joint axis J1 to the sixth joint axis J6) are connected to the intelligent slave station via a series bus, and the servo drivers of two adjacent joint axes are connected in series.

[0019] like Figure 3 As shown, the intelligent slave station includes FPGA, main control chip, and link layer. The link layer is located in the FPGA. The main control chip accesses the link layer through the PCIe parallel bus. The link layer has a bidirectional data connection with the robot controller. The EtherCAT communication transmission cycle is 1ms. The intelligent slave station has no application layer protocol, nor does it have distributed clock function and SDO function. It can only be used as an ordinary ECATIO device; The intelligent slave station is equipped with LINUX system and runs LINUX+Xenomai environment. Beremiz software provides a soft PLC secondary development programming platform compatible with IEC61131 standard. Based on Beremiz software, the intelligent slave station realizes communication connection with the computer terminal through OPC UA communication.

[0020] Step S2: The intelligent slave obtains the position of each joint axis of the robot through the robot controller q ,speed and acceleration ; Step S3: Establish a dynamic algorithm model on the computer side. The intelligent slave transmits the position, velocity and acceleration of each joint axis to the computer side as the input of the dynamic algorithm model to obtain the torque feedforward value of each joint axis. T 1 , T 2 , …, T 6 ; Specifically, the computer uses Matlab software to establish a dynamic algorithm model, which is established based on the Newton-Euler dynamic modeling method. Matlab software is connected to the Beremiz software of the intelligent slave through OPCUA communication. Beremiz software transmits the position, velocity and acceleration of each joint axis to the dynamic algorithm model. Matlab software is based on the dynamic algorithm model. According to the position, velocity and acceleration of each joint axis, it is calculated from the first joint axis J1 to the sixth joint axis J6 through kinematic extrapolation. The velocity and acceleration of each joint axis are calculated, and the kinematic internal push from the sixth joint axis J6 to the first joint axis J1 is calculated. The force and torque of the interaction between the joint axes are calculated, and the driving torque of each joint axis is obtained, and the driving torque is transmitted to the robot controller as the torque feedforward value. Among them, the process of obtaining the driving torque of each joint axis according to the force and torque of the interaction between the joint axes is a prior art.

[0021] Step S4, the computer feeds back the torque feedforward value of each joint axis to the intelligent slave station, and the intelligent slave station transmits the received data to the robot controller; Step S5: The robot controller sends the torque feedforward value of each joint axis to the feedforward module of the servo driver of the corresponding joint axis in each interpolation cycle to achieve vibration suppression. The servo driver is specifically a servo motor.

[0022] The above description is only a preferred embodiment of the present invention, and therefore cannot be used to limit the scope of implementation of the present invention. That is, equivalent changes and modifications made according to the scope of the patent application of the present invention and the contents of the specification should still fall within the scope covered by the patent of the present invention.

Claims

1. A robot vibration suppression method based on an intelligent slave station and a dynamic model, wherein each joint axis of the robot is provided with a servo driver for driving its movement, and the characteristics are: The steps include: Step S1, the robot controller is used as the master station, the intelligent slave station is equipped with the LINUX system, the master station and the intelligent slave station are bidirectionally connected, the Beremiz software is installed in the LINUX system, and the Beremiz software is bidirectionally connected to the computer; Step S2: The intelligent slave station obtains the position, velocity and acceleration of each joint axis of the robot through the robot controller; Step S3, establishing a dynamic algorithm model on the computer side, the intelligent slave station transmits the position, velocity and acceleration of each joint axis to the computer side as input of the dynamic algorithm model, and obtains the torque feedforward value of each joint axis; Step S4, the computer feeds back the torque feedforward value of each joint axis to the intelligent slave station, and the intelligent slave station transmits the received data to the robot controller; Step S5: The robot controller sends the torque feedforward value of each joint axis to the servo driver of the corresponding joint axis in each interpolation cycle to achieve vibration suppression.

2. The robot vibration suppression method based on intelligent slave station and dynamic model according to claim 1 is characterized in that: The master station communicates with the intelligent slave station via EtherCAT, and the intelligent slave station is connected to the computer terminal via OPC UA communication based on Beremiz software.

3. The robot vibration suppression method based on intelligent slave station and dynamic model according to claim 1 is characterized in that: The intelligent slave station includes an FPGA, a main control chip, and a link layer. The link layer is located in the FPGA. The main control chip accesses the link layer through a PCIe parallel bus. The link layer is bidirectionally connected to the robot controller.

4. The robot vibration suppression method based on intelligent slave station and dynamic model according to claim 1, 2 or 3, characterized in that: In the step S3, the dynamic algorithm model is established based on the Newton-Euler dynamic modeling method. According to the position, velocity and acceleration of each joint axis, the velocity and acceleration of each joint axis are calculated by kinematic extrapolation from the first joint axis to the nth joint axis, and the interaction force and torque between the joint axes are calculated by kinematic internalization from the nth joint axis to the first joint axis, so as to obtain the driving torque of each joint axis, and transmit the driving torque to the robot controller as the torque feedforward value.

5. The robot vibration suppression method based on intelligent slave station and dynamic model according to claim 1, 2 or 3, characterized in that: The intelligent slave station has no application layer protocol, nor distributed clock function and SDO function.

6. The robot vibration suppression method based on intelligent slave station and dynamic model according to claim 1, 2 or 3, characterized in that: The intelligent slave station is equipped with LINUX system and runs LINUX+Xenomai environment. Beremiz software provides a soft PLC secondary development programming platform compatible with IEC61131 standard.

7. The robot vibration suppression method based on intelligent slave station and dynamic model according to claim 1, 2 or 3, characterized in that: The computer uses Matlab software to establish a dynamic algorithm model.

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