| With the development of science and technology, every kind of suitable for human torobot has appeared in people’s life and work, the ability of some robot even beyond people’simagination. To control the robot in free space has achieved good results, in this environmentthe robot does not contact with the external object only need to consider the problem of pathplanning. But between objects in industrial production and real life contact is inevitable, therobot also need to contact with the outside world to perform the specified function. Thecontrol algorithm of this research are put forward to solve this kind of powerful contactproblem.Firstly, the impedance control algorithm research foundation, using impedance control tofit into a dynamic framework of motion and force control. To avoid the need for the two setsof position and force control strategy, reduce the control task, and the change of environmentand disturbance has a strong ability to adapt. Through the impedance relationship it is difficultto control the position and force control, it becomes simple. Inertial coefficient, impedanceequation of damping coefficient, stiffness coefficient and other parameters directly affect thedynamic performance of the system. Firstly, through a large number of experiments to obtain3important resistance coefficient, the coefficient of inertia, damping coefficient, stiffnesscoefficient obtained more ideal value. Enter a different function in free space to validate theimpedance control algorithm, can be seen through the controller output curve rapidly andaccurately tracking the input curve. Tracking in stress space is mainly to verify the force,experimental results show the impedance control can force control in a certain range, which isvery useful in practical work.Then, using the critical test method to adjust the impedance parameters, the dampingcoefficient and stiffness coefficient value as small as possible as large as possible, so that thetwo coefficient on the system to minimize the impact, to highlight the inertia coefficient of thesystem of regulation. Gets the critical inertial coefficient and critical period after thedevelopment of empirical formula table, get the ideal impedance parameters. This method ofoff-line adjustment coefficient achieved good results. To avoid a tedious work of a coefficienttest, we can quickly get the numerical optimal system.Then, the study of adaptive impedance control algorithm, and based impedance control algorithm, the biggest advantage is that it can trace the exact expected force in unknownenvironment. Adaptive impedance control algorithm can force information in the environmentof the unknown, the use of the last moment control cycle to compensate for the uncertaintiesin the impedance equation. This algorithm is no longer as the foundation impedance algorithmthat requires accurate models, only through iteration using the last sampling period of torqueand angular velocity. Further study on the coefficient of variation of the control effect, andcompared with the foundation impedance control algorithm.Finally, to adjust the impedance parameters on-line fuzzy theory, in the actual operationof continuous detection, difference between the desired position and the actual position and itsrate of change. The fuzzy inference of fuzzy rules activation of good, and then fuzzy solution,the output control. In order to realize the inertia parameters of damping parameters M, B,adjust the stiffness parameters of the K online, which directly in the simulation platform isideal for impedance parameters, control of position and force of the desired, and accuratelycomplete the control task. |
