Research On Key Technologies Of Active Adaptive Hydraulic Buffer

With the development of equipment towards intellectualization,high-speed and large-scale,higher requirements are put forward to mitigate the rigid impact between equipment or mechanical structure.In the process of Engineering application,in order to improve the buffer capacity of hydraulic buffer,the buffer capacity of hydraulic buffer is generally increased by increasing the diameter of the buffer cylinder or the buffer displacement,but it will inevitably increase the volume of the hydraulic buffer,the installation area,and the application is reduced scope of use.Therefore,Traditional hydraulic buffer can not meet the requirements of use because of its narrow installation space and large impact load,and the control of the existing semi-active buffer is worse than the active buffer,But at present,active buffer is based on hydraulic servo system or hydraulic actuator to realize active buffer,which has the problems of high cost,low reliability and safety.In view of the shortcomings mentioned above,this paper designs an active adaptive hydraulic buffer with low cost,strong control and high reliability,and studies its energy loss mechanism,energy dissipation element design and control strategy.On the basis of fluid theory and energy dissipation analysis,the mathematical model of energy loss of digital buffer unit is established.The mechanism of sudden expansion ratio of different sections,sudden expansion of chamfered sections and pressure loss of different angle of cone valve core are studied by CFD technology,which lays the foundation for high efficiency buffer of active adaptive hydraulic buffer.Buffer time is a key factor affecting the performance of hydraulic buffers.Because the energy dissipation element and control element of the active adaptive hydraulic buffer are digital damping elements,the response speed of the control system to the digital damping element is required to be higher.The structure,magnetic circuit and driving circuit of digital buffer element are studied and analyzed,a fast response digital buffer unit is designed.A simulation model of digital buffer unit based on AMESI is established,and the driving frequency and occupancy are studied.The influence of air-to-air ratio on the characteristics of digital damping elements.On the basis of the above research,the dynamic characteristics of the active adaptive hydraulic buffer are studied,and the hydraulic and mechanical subsystems of the active adaptive hydraulic buffer are designed.Five working modes are designed to meet the requirements of completing the buffer task under complex working conditions.The core components of the active adaptive hydraulic buffer are designed and checked.Focusing on the disadvantage of the traditional flow calculation formula of hydraulic valve,the flow characteristic data model of digital buffer unit based on BP neural network is established,and the accurate flow numerical calculation method is obtained,which provides basic data for the pressure control of active adaptive hydraulic buffer.In order to meet the requirement of adaptive control,the iterative optimization of the number of digital damping elements(damping area)and the search space of PWM pulse width duty cycle is realized based on particle swarm optimization.In order to solve the contradiction between impact rapidity and system delay in actual system,a predictive optimization control method based on BP neural network and particle swarm optimization algorithm is constructed according to the mathematical model of energy loss of digital damping unit.The collaborative simulation technology of active adaptive hydraulic buffer based on AMESim and Simulink is studied.Based on the above research,the hydraulic model and control system model of the active adaptive hydraulic buffer are established based on AMESim and Simulink respectively,and the comparison between the model predictive optimal control and the PID control is made.It is proved that the characteristics of the model predictive optimal control are superior to those of the PID control in all aspects,and the rationality of the subsystems of the active adaptive hydraulic buffer is also verified.It provides guidance.