Research On Electromechanical-coupling Dynamic And Vibration Control Of The Translational Flexible Manipulator System

Because of the simple movement mode and programmable controllability,the Cartesian coordinate robot is widely used in industrial fields such as pickup,spray painting,welding and so on.The Cartesian coordinate robot is this kind device whose actuators are mainly assembled by mechanical manipulator.Owing to the fact that the mechanical manipulator is in direct contact with the operating objects,the structural and dynamic characteristics of the mechanical manipulator have a very important influence on the operation precision of the whole machine.Currently,the rigid structure is often adopted to the manipulator of the traditional Cartesian coordinate robot,and the overall structure is heavy as well as the structural buffeting is inevitable,which has a great influence on the working efficiency and positioning accuracy of the whole machine.In order to improve the overall performance of the Cartesian coordinate robot,the system structure should be improved to achieve the purpose of light-weight,which is also the basis for high-speed and integration.The flexible manipulator has many advantages,such as light-weight,high-load and low-energy consumption,and it is very suitable for the development trend of integration and high-speed for the industrial robot.However,for the flexible manipulator,because of the feeble rigidity,the heavy deflection and the low modal frequency,it is easy to produce elastic vibration during the process of motion and generate residual vibration when the positioning position is reached.Furthermore,because the structural damping of the flexible manipulator is small,the vibration will last for a long time which goes against the precision requirements of the IC packaging and such applications.Therefore,it is the basis for the effective utilization of the flexible manipulator in the industrial robot to in-depth study its dynamic characteristics and vibration control technology.On the other hand,the existing high-precision Cartesian coordinate robots are driven by the permanent magnet servo system,which cause that the translational flexible manipulator system(TFMS)is also a typical electromechanical-coupling system.Due to the low modal frequency,the motor electromechanical-coupling effect will have a significant impact on the dynamic characteristics and stability of the flexible manipulator under high-speed and light-weight conditions.Moreover,there are variable load conditions during the actual operation for the Cartesian coordinate robot,which puts forward higher requirements for the elastic vibration controller of the TFMS.Therefore,when analyzing the dynamic characteristics and vibration control of the TFMS,we should give full consideration to the influence of system electromechanical-coupling effect and load variation.The research work of this article mainly includes:(1)The global electromechanical-coupling dynamic models for the TFMS are established and the construction of the experiment object is completed.Based on the mechanical and electric analytical dynamics,the global electromechanical-coupling analysis of the TFMS is completed to get the main coupling form inside the system;Then,on the basis of the subsystem division and local coupling analysis of the TFMS,the motion mechanism of each subsystem is discussed to clarify the coupling factors between the subsystems and determine the coupling intermediate quantity.Finally,the global electromechanical-coupling dynamic models of the TFMS are constructed.On the other hand,the experiment platform of the space TFMS is set up.Furthermore,the virtual simulation platform of the TFMS is also constructed to carry on numerical simulation analysis of the output characteristics of the motor driving end,subsystems dynamic characteristics and system global electromechanical-coupling dynamic characteristics.(2)With the influence of the electromechanical-coupling effect of the motor driving end and load variation considered,the parametrically-excited vibration characteristics and stability of the TFMS are analyzed.The transverse vibration of the flexible manipulator plays a leading role in the positioning accuracy of the whole system.Compared to the transverse motion,the translational motion of the other two directions for the base has no effect on the transverse vibration of the flexible manipulator.Thus,the dynamic characteristics analysis of the whole system is mainly carried out under the transverse motion of the base.Firstly,the exact modal frequency equation and modal shape function,with the effect of terminal load,of the flexible manipulator are deduced to provide a basis for the later analysis.Secondly,based on the direct multiscale method,the influence mechanism of system drive excitation and load variation on the transverse parametrically-excited vibration characteristics of the TFMS is analyzed.Thirdly,the Cartesian coordinate transformation is introduced to explore the influence law of load variation on the system transverse vibration stability.Finally,the above theoretical analysis results are verified by the finite element analysis and numerical simulation calculation.(3)Based on the state estimation and singular perturbation theory,the soft sensing research on the elastic vibration of the TFMS is carried out to avoid the influence of the introduced physical sensors on the stability of the flexible manipulator itself.Firstly,the singular perturbation factor is introduced to realize the dimensionality reduction decomposition of the dynamic models for the TFMS.Secondly,based on the controllability and observability theory,the observability and controllability of the state variables for the two-time scale subsystems are analyzed by using the rank criterion.Thirdly,the two-time scale observer model,of which observation gains are optimized by the linear-quadratic differential games,of the TFMS is constructed.Finally,the numerical calculation and experiment verify the effectivity of the soft measurement scheme,based on the designed two-time scale observer,for the elastic vibration of the TFMS.(4)The design of the master-slave integrated controller for the elastic vibration of the TFMS is carried out.Aiming at the load variation,the master controller,state feedback integral controller,of the transverse vibration for the flexible manipulator is constructed with the two-time scale observer combined.Based on the optimal theory and the input shaper,the slave controller,two mode vibration cascading shaper,of the transverse vibration is designed to suppress the electromechanical-coupling effect of the motor driving end.Then,with the designed master controller and slave controller combined,the design scheme of the master-slave integrated controller for the system transverse vibration is given to achieve the complementary advantages and disadvantages blocking of the designed master controller and slave controller.Finally,through the simulation analysis and experimental test,the effectiveness of the designed master-slave integrated controller for the system elastic vibration is verified.