Research On Robot Joint System And Dynamic Characteristic

With the rapid development of artificial intelligence,more and more robots are integrated into people’s production and life.On the one hand,in industrial production,industrial robots have become the key to the development of modern manufacturing and have achieved unprecedented development.On the other hand,various types of robots such as manipulators and humanoid robots also play an important role in the fields of service,medical treatment,and fire fighting.As the actuator of robot action,robot joints directly affect the performance of robots.At present,robot technology is developing towards standardization and modularization.Therefore,robot joint technology will also tend to be highly integrated and low power consumption.This paper takes low-cost,highly integrated robot joints as the research object,designs a robot joint and a control drive system,and studies the inherent characteristics of the robot joint and the electromechanical coupling dynamics.The specific research content of the thesis is as follows:(1)Designed a two-stage series planetary reduction structure,explained the transmission principle of the planetary gear structure,and designed the main mechanical parts,and the stiffness of the sun gear and the planetary gear,the planetary gear and the ring gear are calculated according to international standards,and the stiffness is measured The fifth-order Fourier expansion lays the foundation for the study of inherent characteristics and electromechanical coupling dynamics.According to the working requirements and characteristics of the robot joints,a brushless motor drive and a CAN bus-based control system circuit were designed,the corresponding circuit printed circuit board was designed and developed,and an experimental platform was built to verify the feasibility of the robot joint design scheme.(2)Introduced the principle of brushless motor PWM speed regulation,CAN bus communication software principle,analyzed the principle of two schemes of brushless motor square wave and field-oriented control from the mathematical point of view,combined C and C# programming language to compile the brushless motor formula Wave control,field-oriented control program and CAN bus communication program,developed a robot joint upper computer control system that can support up to 17 degrees of freedom,and realized the robot joint brushless motor control system from the code point of view.(3)Taking into account the error and the time-varying stiffness of gear meshing,the lumped parameter method is used to establish the dynamic model of the two-stage series planetary gear transmission system,and the inherent characteristics of the robot joint system and the modal energy distribution law are studied in detail.The influence of the quality of each part on the natural frequency of the system is studied,and the vibration mode of the system is analyzed,which provides a theoretical basis for system vibration reduction.(4)Considering the electromagnetic characteristics of the brushless motor and the torsional vibration of the two-stage series planetary system,a two-stage series planetary electromechanical coupling system model driven by the brushless motor is established.The electromechanical coupling system under the impact load is analyzed,and the meshing force of the gears before and after the impact is solved It carries out Fourier transform and time-frequency analysis to study the relationship between natural frequency and motor speed during impact,which provides a theoretical basis for optimizing system parameters and system resonance zone.