Analysis And Design Of Bilateral Teleoperation System With Non-passive Ports

Bilateral teleoperation system involves many technologies such as robotics,neurol-ogy,control theory and mechanics.It has high development potential in the fields of machine medicine,space exploration and operation in dangerous environment.Passive control theory is one of the most commonly used control algorithms for bilateral teleop-eration.It takes the energy flow in the whole system as the design basis,and explains the control behavior from the physical point of view.Passive control can optimize the dynamic performance of the system,which is the most significant advantage of it.The traditional passive control theory assumes that the operator port is passive and does not affect the energy exchange of the system.For this reason,it does not consider the state of the operator port when designing the control algorithm.However,as a matter of fact,when the manipulator is operated by human hand to perform specific tasks,its motion state is random,which may become a non-passive port and lead to a negative impact on its control performance.In order to solve the above problems,the following work is carried out in this the-sis.Firstly,it analyzes the passivity of operator port under different motion states,and designs two sets of control algorithms for bilateral teleoperation system with non-passive operator port.Finally,all theoretical analysis and algorithm designs are tested on the Matlab/Simulink platform,which proves the correctness of the passivity analysis method and the practicability of the designed algorithms.The main work is as follows:1.Based on the passive theory,the operator is regarded as a separate port to qualita-tively study its non-passivity under different motion states,and the analysis method based on the integration of operator port's input and output signals is adopted.This method op-timizes the port's modeling mode,the main end velocity v_mand displacement x_mare taken as the inducements for the operator to feel resistance throughout the task.Through sim-ulation's verification,it is finally concluded that the operator port is non-passive in some specific motion modes,which reveals the limitations of the traditional passivity theory hy-pothesis.This optimized method also avoids the randomness of the original human hand impedance modeling method,and has high authenticity.2.Combined with the time-domain passive theory,a set of bilateral teleoperation con-trol algorithm with non-passive port is designed in this thesis.The algorithm uses the pas-sive observer PO to monitor the port's instantaneous power p to judge its passivity in real time,and uses the passive controller PC to dissipate the additional energy in the system.This optimized algorithm avoids the integration error and force mutation of the original energy-based control algorithm,and smoothes the compensation force f_pc.Moreover,the amplitude of tremor and tracking error are reduced in this algorithm.Besides,it has cer-tain universality and can be extended to multiple ports in the system to adjust the impact of their passivity on the overall performance.3.The algorithm is further optimized,and a set of optimized 2-layer control algorithm combined with energy tank is designed in the thesis.In this algorithm,the direct-force-feedback control(DFF)is used as the transparent layer to ensure the transparency of our system.The passive layer uses the energy tank to monitor the additional energy injected into the system through the non-passive behavior of the operator port,and uses the variable damping device B to dissipate it at the slave end to maintain the stability of the system.The simulation test shows that the optimized system has less contact chattering,good position tracking performance,higher stability and stronger tele-presence.This algorithm improves the structure of the original control algorithm with energy tank and extends its function,and it is the first time to use the energy tank to adjust the negative impact of the non-passive operator port on the system,and it develops a new usage of energy tank,which is innovative and practical.