Design Of Integrated Drive And Control System For Modular Joints Of Collaborative Robots

With the rise of collaborative robots,highly integrated modular joints continue to develop,and requirements for the integration,safety,and servo efficiency of the joint servo control system are getting higher and higher.The traditional servo controller is arranged outside the joint and separates the drive and control.It occupies a large space,has serious interference,and has low reliability.It not only affects the performance of the joint,but also is not conducive to the integration of modular joints,and it is difficult to meet the needs of collaborative robots.This paper developed a flexible modular joint,and then developed a high-performance integrated drive controller embedded in the modular joint to build a bridge between electromechanical products and software.First,according to the performance and functional requirements of the collaborative robot,a flexible,high-precision,and highly integrated modular joint was designed,including the selection of intra-articular transmission,braking and sensing components and the design of related structural parts.For mechanical assembly of the joint,the entire joint weighs 3.30 kg,has a length of 160 mm and a diameter of 100 mm.Finally,a dynamic model of the joint is established,the transmission principle is explained from the mathematical level,and the theoretical foundation for the control algorithm is laid.Secondly,on the basis of mechanical design,in accordance with the requirements of joints for drive control,servo efficiency and safety,starting from the three directions of drive,control and power,an integrated drive controller embedded in the joint was developed.First,according to the requirements of drive control,braking,high integration and miniaturization,a hardware development plan was drawn up,and the main control chip adopts FPGA;then,the principle circuit design and anti-interference layout and wiring were carried out;finally,the board and hardware Testing and online debugging.The designed integrated drive controller fits reasonably in the joint mechanically,and has complete functions and high efficiency in hardware.Then,on the basis of hardware,according to the requirements of motion accuracy,flexibility and torque ripple,based on the direct drive torque motor drive control theory,the motor main control algorithm,data acquisition algorithm and host computer communication algorithm are designed using Verilog language.And carried out simulation and online debugging to ensure the rationality of the design.In the motor commutating direction,magnetic fieldoriented control is adopted,and model predictive control algorithms are designed to improve servo efficiency.After completing the top-level design of the main control algorithm,a bridge between electromechanical products and software was built.Finally,according to the communication protocol and drive control requirements,the joint adjustment of the whole machine was carried out to verify the performance parameters of the joints.The results showed that the repeated positioning accuracy of the joints was less than 0.016°,the torque reached 19.61 Nm,the hysteresis error was less than 0.021°,and good speed The tracking verifies the functionality and adaptability of the modular joints.