Research On Modeling And Collision Detection Of Flexible Joint Manipulator

In recent years,physical human-robot interaction and cooperation to complete complex work is becoming more and more popular.Different from the previous industrial robots working in the fence,physical human-robot interaction and cooperation is becoming a tendency of the industrial development,and flexible joint manipulator is an important tool for advanced manufacturing in the future.Its key technology has also become a research hotspot.An important thing is how to ensure the safety during the man-machine interaction.It is an extremely important technical issue.Based on this,this thesis will do some study on the algorithms of flexible joint manipulator collision detection and the estimation method of the robot joint torque.Firstly,this thesis introduces the research status of flexible joint manipulator at home and abroad,and reviews the existing flexible joint manipulators,the common modeling methods of flexible joint manipulators and the current methods of collision detection of flexible joint manipulators.Secondly,through the analysis of flexible joints,we propose the modeling theory of the flexible joint robot.Base on this theory,a 4-dof flexible joint manipulator was modeled for later study.Then,we find a fact that momentum-based collision detection methods have few tunable parameters,so this method can't detect collision quickly and stable.Therefore,we propose an improved collision detection algorithm.According to the model deduced in Chapter 2,a simulation platform is set up to verify the effectiveness of the algorithm.Finally,considering that the observer needs the joint torque and the joint torque is usually obtained by the torque sensor,but its high price hindered the industrial promotion.Therefore,the method of estimating the motor torque for the joint torque is studied.Based on the laboratory flexible single-joint platform,the torque estimation of the motor is completed by the torque constants of the motor and the frictional force of the flexible joint.The joint torque estimation of the motor current is completed,and the joint torque estimation of the torque-less sensor is achieved.