Robot Contact Force Control System Based On Series Elastic Actuators

With the continuous development of robot technology,the application requirements of robots are also constantly improving.When the robot interacts with the environment,due to the uncertainty of the robot and environmental parameters and the model error,a very large contact force is generated between the robot and the environment,especially when the rigidity of the robot and the environment is large,in the interaction process.It is easy to cause harm to the environment and human.This thesis focuses on the dynamic interaction process between robot and environment.By assembling the series elastic actuator(SEA)at the end of the robot,the robot contact force control system is designed to meet the processing needs of industrial robot contact operation and improve the safety of the robot's contact work.The main work and results of this thesis are as follows:1.The SEA model and the friction model are established.The influence of friction on the contact force during the movement of SEA is analyzed.Based on the improved Dahl friction model,the friction feedforward compensation method in SEA is studied and the force tracking simulation experiment is carried out.2.The influence of the SEA-end gravity with the attitude change of the SEA end effector on the contact force is analyzed.The SEA end compensation method based on the end attitude angle of industrial robot is studied.A PD type force controller is designed and the force tracking simulation experiment is carried out.3.The experimental platform of industrial robot contact force control system is set up.The SEA force control system program and the TX90 industrial robot control program are written.The force tracking control experiment is carried out.The contactforce signal is detected by the external force sensor.The contrast experiment is carried out under the condition of gravity compensation and gravity-free compensation.The spectrum of the contact force signal is analyzed.The experimental results are verified the effectiveness of the studied method.