Research On Joint Force Perception Technology Of Collaborative Robot

Collaboration robot joint force perception refers to the collaborative robot perception of the outside world and force measurement capability information is a collaborative robot to complete the force interaction with the force control foundation.At present,most studies often use modular joint torque sensors to complete the perception of force information.But the use of modular joint torque sensor not only needs to deal with the overall rigidity of the robot,but also needs to deal with the problem of position accuracy caused by the modular joint torque sensor.It is noted that the harmonic reducer,as the core transmission part in the joint of the collaborative robot,is very suitable as a carrier for the realization of the force sensing ability of the collaborative robot.Therefore,this article takes harmonic reducer as the main research object and collaborative robot joint force measurement technology as the main research purpose,and completes the following work:The basic structure and transmission principle of the harmonic reducer are introduced.The flexspline of the harmonic reducer is selected as the elastic body,and a measurement scheme of the robot joint torque based on the flexspline strain detection is proposed.The traditional harmonic reducer which only has the function of torque transmission is improved into a harmonic force reducer with joint torque measurement capability.A proper strain gauge sticking scheme and harmonic drive scheme are designed to solve the winding problem of the internal wiring of the harmonic force reducer.A set of performance test platform for harmonic force reducer was designed.The lever of planetary reducer was used to amplify the small load torque of the magnetic powder brake,which broadened the calibration range of the experimental platform.The electrical controllable output characteristics of the magnetic powder brake were used to achieve the dynamic load of the experimental platform.Based on VS,a set of supporting host computer software was developed to realize the drive communication and data collection of the experimental platform.A set of data processing schemes for harmonic force reducer is designed.The frequency domain characteristics of the flexspline torque signal of the harmonic force reducer are analyzed by Fourier transform.The filtering process of the flexspline torque signal and the standard The smooth processing of the torque sensor establishes the torque measurement model of the harmonic force reducer;the data processing software of the host computer is developed based on MATLAB.The self-developed harmonic force reducer was fitted with calibration and performance test experiments.Experimental results show that the developed harmonic force measuring reducer has high sensitivity,its linearity is about 2%F.S,and a repeatability is about 1%F.S.The relative error of the measurement is less than 4%,and the absolute error is less than 0.5Nm.