Research On Active And Passive Compliance Control Of Oscillatory Base Manipulator

With the continuous progress of science and technology,a variety of robots that satisfy human needs have appeared in industrial and life.The position control of robots in free space has acquired good effect at present,but with the continuous expansion of the field of robot applications and the increasing requirements for robot intelligence,the traditional control schemes based on position control cannot meet the certain requirements of Application requirements for complex environments.In industrial production and daily life,most of the robotic arms are unavoidably subject to external interference during operation,especially the vibrations base manipulator.When it is disturbed,the tracking accuracy will be affected.The problem of safety and the reliability of operation is more prominent.At the same time,the robot arm usually needs to complete the task of contact with the environment,and it will also encounter uncertainties in the dynamic model of the manipulator and environmental uncertainty.To prevent accidents caused by hard contact between the manipulator and the environment,the manipulator needs to be compliant.Aiming at this problem,this paper studies the compliance control of the oscillatory base manipulator.In this paper,the basic vibration manipulator is taken as the research object.First,the position control of the passive and compliant basic vibration manipulator is studied.In order to make the manipulator play a buffering role in the event of a collision,a compliant actuator is introduced into the rigid manipulator,so that it has a certain compliance.But the compliant actuator will cause vibration and be coupled with the basic vibration,which affects tracking accuracy.Aiming at the trajectory tracking of the manipulator under the influence of flexible vibration caused by the compliance characteristics and the basic vibration,the oscillatory base manipulator is first modeled.And then the singular perturbation theory is used.Dual time scales are introduced to decouple the complex systems from reduced order.It is decomposed into independent fast-changing subsystem and slow subsystem,and the controller is designed to control.For the slow-changing subsystem,the basic vibration is converted into uncertain interference terms.The robust control of the neural network is adopted to track the robotic arm.For the fast subsystem,the velocity difference feedback controller is used to suppresses flexible vibration.The simulation results verify the robustness of the proposed control algorithm and its ability to suppress flexible vibration.Secondly,the active compliance control of the basic vibration manipulator is studied.The traditional torque-based impedance control can quickly and accurately track the desired trajectory and achieve a smooth transition from free space to contact space,but the force tracking effect in the contact space is poor,and it is unable to accurately control the contact force.Aiming at the deficiency of traditional impedance control,an adaptive impedance control algorithm is studied.The adaptive impedance control algorithm uses an iterative idea to use the torque and angular velocity in previous sampling period to compensate for the uncertainty in the impedance equation.Compared with the traditional impedance control,adaptive impedance control has the benefit that it does not need to know the mechanical arm dynamic model and the environment position accurately.It can accurately track the expected force,and it has certain robustness to the basic vibration.Simulink simulation models of traditional impedance control and adaptive impedance control are established,and the effectiveness and feasibility of the proposed control algorithm are verified by simulation.Finally,the basic vibration manipulator experimental platform was built,and the position control algorithm of the basic vibration manipulator was programmed and debugged in Lab VIEW.The hardware and software communication was realized,and the position control experiment of the basic vibration manipulator was completed.By analyzing the experimental results,it is verified that when the manipulator is disturbed by the basic vibration,the neural network robust control algorithm can still achieve better trajectory tracking effect,and the accuracy is higher than that of the traditional PD control.It is proved that the proposed control algorithm achieves the expected control effect.