Research On The Non-contact Bearing And Active Guidance Technology Of Superconducting Machine Tool

The machine tool is used to produce all kinds of advanced equipment.Improvement of its performance has a decisive significance to improve the ability and level of manufacturing industry.However,due to some inherent defects,such as mechanical errors,friction and wear,static pressure heating and so on,it is difficult to effectively improve the machining precision and cutting feedrate of machine tools designed based on the traditional theory and technology.Aiming at this problem,this paper studies the construction principle and implementation method of the new type of machine tool on the basis of superconducting magnetic levitation,magnetic force driving,information guidance,which is supported by the National Natural Science Foundation of China.In this paper,firstly,the core concept of the structural principle of the superconducting machine is presented: By adopting superconducting magnetic levitation and magnetic force direct driving approaches,the influence of such factors as mechanical error,forced deformation,thermal deformation on the precision of the machine tool can be reduced effectively,and the limits of working speed caused by the influence of friction,heat,vibration can also be eliminated.Then we propose to use the high precision information benchmark to achieve the active guidance control,which improves the working accuracy of the machine tool effectively.According to the above principle,we have studied the structure of the superconducting machine tool further,which builts the basis for the construction of the superconducting machine tool.Based on the above,we have carried out researches on the three key problems of superconducting machine tool.First,aiming at the problem that the hidden close loop superconducting bearing system is difficult to ensure the accuracy of the levitation position,since the hanging buoyancy cannot be effectively controlled by external,the principle and implementation of active control for superconducting machine tool is presented.We eliminate the effect caused by inherent instability of superconducting part,and effectively inhibit the influence of the magnetic nonlinearity and the saturation for power drives,by use of feedback linearization and close loop correction methods,so as to realize accurate control of the suspension position for the moving part,and lay the foundation for the construction of non-contact bearing system satisfying the requirements of superconducting machine tool.Second,to improve the dynamic performance of superconducting machine suspension bearing system,we proposed a novel suspension control method based on synergistic magnetic flux linkage regulation.And accordingly we study the construction and implementation of two kinds of composite bearing system,namely,"superconducting bearing + magnetic flux density regulation" and "superconducting bearing + magnetic force regulation”.We have paid much attention on solving the problems existed in superconducting bearing tracking control and magnetic control regulating cooperative control and so on,and the dynamic performance of the system is improved effectively,which offers a valid guarantee to the construction of the non-contact motion system with large load capacity and high dynamic performance for the superconducting machine tool.Third,we have studied the principle of the information benchmark of the superconducting machine tool,and the construction and implementation of a new type of laser guide rail based on the principle is proposed.On this basis,we have researched the information guidance(active guidance control)technology adopting the laser guide rail,and the anti-disturbance control method of the information guidance system.It is a fundamental solution for the working reference and motion guide of the superconducting machine tool,so as to improve the working accuracy of the machine tool.Finally,on the basis of the above work,the experimental system of the superconducting machine tool is developed.Experiments have been carried out on the system,and the results verify the principle,method and key technology of the system well.Experimental results show that the proposed principle,method and technology are feasible,and the system technical specifications meet the project demands.