The Theory To Controll Machining Trajectory Based On Physics Motion Law

At present, the problem of the relation between geometric function and machining locus motion has not been resolved satisfactorily in theoretical studies. The idea cutting motion which satisfy requirements of locus geometric, machine tool motion and driving force can not be found. With developing of super speed machining, nanometer machining and CIMS, the more and more demand for manufacturing technique is presented. The problem need to be resolved is to pick up the synthetic control ability of machining locus motion. Such as trajectory geometric precision, smooth motion, control timely, etc. Trajectory control is the way to realize prescriptive geometric curve with motion. The key problem is the relationship between geometric characteristic and locus motion characteristic.Assume that the machining locus motion completely suit the requirement which including geometric, dynamic and manufacturing process requirement, the physics model is built, such as position control model, motion model, dynamics model, energy model, relative space model etc. The relationship between geometric function and machining locus motion is studied by means of theories, such as the norm functional multidimensional space theory, kinematics, dynamics, energy method. It is shown by studying result, that there are inherent correspond relation among the parameters, in other words, there is internality regularity of machining locus motion. According this law, to control the simple parameter can realize the complex one. It makes the control process simply. The transient motion parameter of every coordinate axes can be calculated to monitor the locus motion. The numbers of position point are infinity, the regularity, however, is only one. The control method with motion regularity is a short-cut and all-sided method. To control locus motion by control motion regularity is most short-cut and all-sided method. It equals to control motion regularity and geometric law. This thesis describes a new way to control trajectory with motion regularity instead position and give up interpolation. It is proved by experiment and simulation that it is a good way to control geometry and motion comprehensively, to reduce computation times and to increase the capacity of environmental adaptation for path planning.The physics model of machine tool locus motion is built to study internality regularity of machining locus motion theoretically. A good way to control geometry and motion comprehensively is presented, when it is used in practice again and again, new problem is found and studied. Some creative work has been down:a.) to build the physics model of idea motion stateThe speciality of locus motion of CNC machine tool is studied to refine main factors and build-up the physics model. Assume that there is idea machining locus motion and taking the requirement of CNC machining as constraint condition, the motive regularity of locus motion in the idea condition is derived. Motion model is built separately with the follow theory: kinematics, dynamics, energy method. It is studied how the geometric parameter, manufacturing process and motion planning parameter works in this model. The correspond law between geometry factor and motion factor is set up.b.) A new strategy to control locus based on motive regularityThe trajectory geometric character is worked out by motion and the motive regularity correspond to geometric character accurately. The problem of trivially calculation for infinity points can not be solved by traditional position control way. But as far as a motion, there only one motive law, it is shown that some motive parameter is constant or simple equation. To control it can work out locus equally. This way is very good in many characters, such as less calculation, high precision, simple motion control, comprehensive control, etc.c.) Locus motion planning and control method with reference timeThe relation between geometric parameter and reference time is relative relation set up artificially. The tempo of geometric parameter change is measured by reference time as metric, the relatively rate of change is decided by manufacturing process, it is usually a content. Its physics signification is that geometric parameter varies with reference time proportionately. For example, the machining motion velocity of electro-corrosion line cutting is proportional to the voltage between the electrodes, It is a simple way to plan with reference time and to readjust the plan by actual rate of reference time change. It is good way for simple calculation, accurate planning according geometric quality, satisfaction of updated requirements and environment change requirements.d.) Programming software for microcontroller and computer simulationbased on motion lawIt is proved by experiment and simulation that it is a good way to control geometry and motion comprehensively, to reduce computation times and to increase the ability of environmental adaptation for path planning. It is the evolution direction of locus control technology.