Design And Implementation Of Joint Torque Sensor For Collaborative Robot

When people and robots work together in the same environment,in order to ensure the safety of human-machine work,robots are required to be able to perceive the environment from all directions.The existing method of adding force sensor at the end of the manipulator can not meet the requirement of omni-directional force sensing.The introduction of a series elastic actuator with integrated lightweight design solves this technical problem well.Different from the traditional design concept of rigidity supremacy for robot joint actuators,series elastic actuators connect elastomers in series between the motor and the output of the actuator to sacrifice certain rigidity.Force control units are added to the actuator and precise force control data are added to the control loop,which improves the controllability,safety and impact resistance of the robot.However,the drive to reduce stiffness needs to resist non-axial bending moments,which brings great difficulties to the design of Eastern District.Therefore,in the structural design of series elastic actuators,elastomer design and anti-interference design are the key and difficult points.In this paper,according to the advantages and characteristics of series elastic actuators,the actuator torque sensor is studied,and a design method of the torque sensor is proposed,and the overall design of the actuator system is carried out.Firstly,the development status of torque sensors with series elastic actuators is analyzed,and the strain sensor with cross roller bearings is selected as the design scheme.Then,the force on the joint of cooperative robot is calculated by static method,and the design index of the torque sensor is put forward.Combined with the dimensions of other parts of the manipulator,three kinds of series elastic actuator structures are proposed.The three-dimensional model of the sensor is established by Solidworks,and the finite element analysis is carried out by ANSYS.A good design scheme of the sensor system is selected,and the parametric design method of the sensor elastomer is put forward according to the space restriction conditions and the mechanical properties of the material,and the key dimension parameters of the sensor are obtained.Finally,the key parts are selected and a design scheme of series elastic actuator is presented.The research results show that the torque sensor structure designed in this paper has good process performance;the output signal has good linearity and high sensitivity;the system structure is reasonable in design and the assembly process performance is good.It has certain reference value for the cooperative robot elastic drive and its torque sensor design.