Theory And Experiment On Active Compliance Control Of Rigid-Flexible Arm Under An Uncertain Environment

Centered on the special topic of theory and experiment on active compliance control of rigid -flexible arm under an uncertain environment, rigid-flexible arm involving environmental characteristic is fully and systematically studied from the aspects of dynamics modeling, dynamics characteristic analysis, controller design and simulating, obtaining some valuable outcomes of theoretical and practical significance.Based on Kane's equation, dynamics model of flexible body of arbitrary shape is established, and then the general dynamics analysis method for flexible body is extended and applied to general flexible multibody system with no constrains on its topology. Together with Huston low-body array which is used to describe the topology of multibody system, kinematics analysis is carried out, and based on Kane's equation, dynamical equations are set up for general flexible multibody system. For general flexible multibody system in consideration of environment characteristic, environmental characteristic can be seen as external constrains to flexible multibody system, and dynamical equations are set up for constrained general flexible multibody system.As for rigid-flexible arm involving environmental characteristic, nonlinear dynamics model is set up based on Kane's equation, environment restriction is incorporated into nonlinear dynamics equations as external constrains. The effects of the nonlinear terms in the nonlinear dynamics model of flexible arm on accuracy of the system model is analyzed and a method that making linear compensation for the linearization model is presented to improve the precision of the linearization model. And the impact on dynamics performance of flexible arm of modality truncation and different geometric and physical parameters is discussed. Joint characteristic of flexible arm under control condition is studied, and the distinct effects of collocated and noncollocated control on boundary conditions of flexible arm are derived. Active compliance moving process of rigid-flexible arm working in uncertain environment including three processes: movements of quickly positioning, of slowly approachingthe object, and of the active compliance tracking. The system is controlled by vision feedback during the preceding two processes and by force feedback when active compliance tracking the uncertain environment. Considering the three different moving processes, complete mathematic model of controlled system that includes velocity loop of alternating current servomotor, is established.To validate the modeling and the control strategy, the experiment on active compliance control of rigid-flexible arm is studied. In the control process of active compliance movements of the rigid-flexible arm, the quasi-variable structure control strategy is adopted with the fashion of fuse of multi-sensors to realized the control process of whole movements: quick position, slow approach, contacting object, active compliance tracking. The experiment is studied in the full field of view and the part of the field of view respectively. In the process of flexible arm active compliance tracking uncertain environment, the thesis present the method of making online predictive compensation for tracking movement, in order to improve tracking precision.