Research On Force Control Of 2-DOF Series Manipulator And Simple Mechanical Gripper

The manipulators are urgently applied to contact tasks in unstructured environments,and mechanical grippers,which are closely related to manipulator,are also required for smart grasping.This article focuses on the problems on the safety?stability and cost of the mechanical gripper's grasping tasks,as well as the softness and security of the manipulator's contact tasks,and researchs the force control of simple grippers based on the virtual force sensor,as well as force tracking impedance control and force estimation collision avoidance control of the 2-DOF series manipulator.First of all,the paper through the analys is of the subject to recognize: the commom characteristic of study objects is that both mechanical gripper and manipulator are link mechanism,as well as their model methods of kinematics and dynamics;the symmetrical part of common simple mechanical gripper is the parallel four-link Institutions,and its actual DOF degenerates into one,so it can be applied a simple control mode;the mechanical grippers based on the force sensor have expensive cost,the force can be indirectly measured by other variables;common mechanical arms' contact tasks need to meet the different directions force control and position control effects.According to the above understanding,the thesis is divided into three parts: kinematics and dynamic model of mechanical gripper and manipulator;the switch PID control of simple mechanical gripper based on the virtual force sensor;force tracking impedance control and force estimation collision avoidance control on 2-DOF series manipulator with different destinations.Secondly,the paper carries out the following specific research contents for the three parts of the subject:The first part includes: the forward kinematics,inverse kinematics and trajectory planning of the 2-DOF series manipulator;the kinematics constraints of the simple mechanical gripper;the duality principle of the motion-static;the dynamic model of the link mechanism.The second part includes:the open chain dynamic model of joint space of simple mechanical gripper;according to the duality principle of motion-statics to build the close chain kinematic model of joint space of smple mechanical gripper;estimating the interference torque of driven joint;estimating the grasping force according to the principle of virtual displacement.The third part includes: the dynamics model of the manipulator;the Inverse dynamic position control;the impedance control with inner loop of postion;the force tracking impedance control on the x-axis direction;the force estimation collision avoidance control on the y-axis direction.Finally,the results of MATLAB-Adams simulation show that the research content of the paper solves the two problems of manipulator and manipulator: one is the force control of simple mechanical gripper based on virtual force sensor,which solves the problem of the safety and stability of the grasping task;The second is the force tracking impedance control and for ce estimation collision control's combination on the different directions,which solves the problems of softness and security of manipulator's contact task systematically.