The Technology Of Control Based On Tendon-driven Fingers

The simple gripper is commonly used as end effector of robot,without fine operation of load.As the end effectors,fingers can greatly improve the intelligence of robot.Tendon-driven fingers are driven by tendons remotely,which can reduce size and weigth of the dexterous hands.So the tendon-driven hands have received great attention with much research results.But the friction between tendons and mechanical structures affects design of the laws for controlling the tendon-driven fingers,as well as uncertainty of external environment.For improving the flexibility control and real-time control of control system,the paper designs the control algorithm of a single finger of robot hand,which aims at the above problems.The research contents are as follows:1.Decouling of the joint space controller is verified by the simulations with MATLAB.The tendon tension/position control is designed.When in the free space motion,the joint torques would be obtained with the desired position of the end effector.When in the working motion,the joint torque is controlled by the contact force through the Jacobian matrix.The simulation results show that the tendon position control can achieve joint decoupling.2.For the problem that the parameters of controller can not be adjusted in real time,the adaptive torque control which based on the neural network system is designed.The neural network can work with the traditional controller.So the new controller can adjust itself in real time as the simulations in the end of the paper.The simulation results show that new control system can work better than the traditional system when the finger is in uncertain environment.3.For dealing with the problem that the controllers can not achieve the compliant operation,a hybrid control system of force/position based on fuzzy control is desigened in this paper.The new system is based on the impedance control for compliant operation.In this paper,the structure of the control system is described in detail.At the same time,the overall design and simulation are made in detail.The simulation results show that the fuzzy control system has faster adjustment speed and less delay time comparing with the conventional controller.