An Analysis, Design And Simulation Study Of An Underactuated Finger Mechanism

Dexterous hand is an important part of robot.The number of actuators of underactuated mechanism is less than the degrees of freedom.Compared to the fully actuated finger mechanism,the underactuated finger mechanism has many advantages like simple control,small volume,light weight,low cost,but also can grasp objects self-adaptively,which make the finger mechanism grasp objects of different shape adaptively without using special control system or special sensors.Therefore underactuated mechanism is an important research direction in the robotics field.Generally,in order to achieve large grasping force,the linkage mechanism must be used to design the underactuated finger mechanism.Linkage underactuated finger mechanism has large grasping force,compact structure and simple control system.It is very necessary to use linkage underactuated mechanism to design and manufacture the robot finger.But at present,the design of linkage underactuated mechanism is carried out by intuition,bionics or adjusting the design according to the simulation results.In this paper,the analysis,design and simulation of a new type of fully rotational joint linkage underactuated finger mechanism are presented.Specific research contents are as follows:1.To deduce the equivalent mechanisms of underactuated finger mechanism according to the minimum damping principle,and apply them to a fully rotational joint linkage underactuated finger mechanism(see Figure 2-2)to finish equivalent mechanisms deduction in grasping state.2.According to equivalent mechanism of each stage,to finish the kinematics equation derivation and its solving method.On this basis,the analysis and solution of the reachable space of the mechanism(the largest space of the finger movement determined by the maximum stroke of the finger mechanism)is carried out.3.Based on the equivalent mechanism of each stage,the size design of the underactuated finger mechanism is completed.And given the size of the shape of premise,to complete the size design of the fully rotational joint linkage underactuated finger mechanism that figure 2-2 shows.4.Based on the fully rotational joint linkage underactuated finger mechanism,the grasping movement simulation of objects of different shapes and sizes and contact force simulation of each knuckles is carried out.