Research On Torque Sensorless External Force Detection Method For Humanoid Robot

With the development of artificial intelligence and robotics,the robot is no longer expected to stay in the factory repetitive replacement of human labor,but to fine robot operation in the field of medical,assembly,family services and so on.Therefore,higher requirements are placed on the performance of the robot.This requirement is reflected in higher positioning accuracy,faster corresponding speed,and more secure safety performance.In order to improve the safety of robots coexisting with people,it is necessary to increase the force perception capability of the robot.In view of the shortcomings of current robot systems,this thesis develops a set of intelligent humanoid robot systems without torque sensors by comprehensively applying mechatronics technology.Aiming at the shortcomings of traditional robots,such as lack of force perception function,high cost of adding six-dimensional force perception and limited application scope,in this paper,aiming at the shortcomings of current robotic systems,the joint force perception methods of humanoid robots without torque sensors are studied in depth by using Mechatronics technology.The main research contents are as follows.1.Design of a highly humanoid and fully functional high power density robot system.Considering the requirements of system function and appearance bionics,the new configuration design method of humanoid robot is studied.The design method of the whole robot system is that the upper body is the humanoid robot and the lower body is the wheeled omni-directional mobile platform.According to the maximum load and speed requirement of the robot,a seven-degree-of-freedom manipulator structure is designed with unbiased aspheric wrist configuration.The designed robot system has the functions of autonomous positioning and navigation,target detection,voice interaction,force interaction and so on.It can be used as a comprehensive robot and artificial intelligence research platform.2.Torque sensor-free robot joint external torque detection: firstly,the differential amplifier circuit is used to collect the joint armature current,so as to calculate the actual output torque of the robot joint;secondly,the theoretical joint torque is calculated according to the motion state of the robot through the dynamic equation of the robot;because a large number of non-linear factors are neglected in the process of robot modeling,the modeling error is introduced in this paper.Neural network method is used to compensate model error.The experimental results show that the method proposed in this paper can achieve low-cost and high-precision external force detection.3.The safety physics human-robot interaction method for robot based on impedance control: The switching method between the collision response strategy and the compliance control strategy is studied.The reflection control strategy is used to realize the collision response strategy of the robot,and the impedance control method based on joint external force detection is used to realize the compliance control strategy.Experiments show that the designed robot collision response strategy can effectively detect the occurrence of robot collision and quickly leave the collision position,while the robot compliance control strategy can effectively detect the operator's force in the process of human-computer interaction,comply with the operator's motion intentions,and achieve human-computer interaction tasks such as direct teaching.