Kinematic Replaning Of A Hybrid-driven Machine Taking Speed Fluctuation Into Account

The two degree-of-freedom hybrid-driven machine is a new type of machinesystem, which is to combine the motion of a general motor (main motor) with a smallcontrollable servomotor via a two-DOF mechanism, where, the general motorprovides main torque and motion requirements, while the servomotor contributes tomodulations on this motion. This kind of machine system not only has advantages ofclassical mechanical system, but also is controllable and has great flexibility. Thesame hybrid-driven machine system is able to provide for different motion output andprogrammable output.Unlike the mostly researchers who use the constant speed motor as the mainmotor, this thesis selects the uncontrollable AC motor as the main motor, whichcan decrease the manufacture cost. In this case, the AC motor is uncontrollable,therefore, after exerting the load, the system will have the velocity fluctuation. Thennot only the system's output will change, but also the ideal phase relations of the twocranks which is obtained by the kinematic optimization will be destroyed along withthe velocity fluctuation. As the first step, this thesis mainly discusses how to maintainthe ideal phase relations of the two cranks.The first process is to connect the two cranks by a pair of imaginary noncirculargears which can force the two cranks maintain the ideal phase relations. By this waythe hybrid-driven machine is changed into one-DOF model. Secondly, the dynamicmodel of two-DOF hybrid-driven machine is constructed, which is based on theprediction-correction control method.The theoretical research of hybrid-driven machine mainly includes: (1) Theone-DOF model is used to simulate the hybrid-driven machine's dynamic response,(2) The prediction model and the feedback-correction method of thehybrid-machine are established. (3) Based on Lagrange's formulation the dynamicmodel of two-DOF hybrid-driven machine which is driven by AC motor isconstructed. Then it is linked to dynamic model of the servomotor controlled withPID, hence, the dynamic model of the whole system;(4) The dynamic equations aretransformed into a system of first order equations. The dynamic simulation is carriedon through solving the equations by the fourth Runge-Kutta approach. (5) The PIDcontroller's proportional gain, differential gain and integral gain are optimized.At the end of the thesis, some suggestions are given for further studies andapplication of the hybrid-driven mechanism.