Research On Energy Saving Method Of Direct-drive Stage Based On Sliding Mode Control

As one of the most basic equipment in the industry,linear motors are widely used in ultra-precision drive,military,rail transit,medical and semiconductor fields,their performance determines the performance and cost of the final product.However,the direct-drive stage is extremely susceptible to interference from unfavorable factors such as vibration,friction,and noise during operation,which will affect its tracking accuracy to a certain extent,thereby increasing the energy consumption of the system.Therefore,under the premise of ensuring the tracking accuracy of the direct-drive stage is not affected,how to adjust the driving force of each motion axis through the control algorithm,thereby reducing the system energy consumption and improving the energy utilization rate,has become a hot and important issue in the field of linear motor research.In response to this problem,this paper proposes a sliding mode control energy saving algorithm based on the law of conservation of energy,which provides a new method and new idea for solving energy consumption problems in the field of linear motors.The main work of this paper includes:In-depth analysis of the basic composition and basic working principles of linear motors,clarified the law of the end-effect and air gap on the linear motor performance and the track tracking accuracy of the stage,and provided solutions to reduce the effects of end-effects.The mechanical structure and transmission characteristics of the stage used in this article are analyzed in detail,and the performance characteristics of the built-in linear motor in the stage are deeply understood.Based on the above analysis,the classical modeling method of the feed drive system is adopted,the coulomb friction and viscous friction were taken into account to establish the dynamic model of the direct-drive system.Starting from the perspective of energy conservation,the total energy consumption expression of the direct-drive system is deduced,and the corresponding Hamiltonian equation is established by using the Pontryagin minimum principle,and then the analytical expression of the sliding surface under the lowest energy consumption state is derived.After selecting the appropriate control gain,a sliding mode control energy-saving algorithm based on the law of conservation of energy is developed.The Lyapunov candidate function is introduced to verify the stability of the proposed sliding mode control energy-saving algorithm.A numerical example is used to simulate and analyze the proposed sliding mode control energy-saving algorithm.Based on the aforementioned related theories,a sliding mode control energy-saving algorithm program based on the law of conservation of energy was written,and the dSPACE semi-physical real-time simulation system was used to complete the energy-saving algorithm verification task on the direct-drive stage,the energy-saving algorithm was compared with the traditional sliding mode control algorithm and the adaptive sliding mode control algorithm proposed by Farrage et al.The current size and trajectory tracking performance of each axis under different algorithms are analyzed.It is verified that the sliding mode control energy-saving algorithm proposed in this article can reduce the system energy consumption and improve the energy utilization rate under the premise that the trajectory tracking accuracy of direct-drive stage is not affected.Related research results have certain reference value in engineering applications.