Research On Characteristics And Control Method Of Hydraulic Excitation System Controlled By Alternating Flow Distribution Pump

Vibration is a widespread physical phenomenon in nature.The excitation system is a kind of equipment that produces vibration waveform manually,and it is widely used in engineering field.In recent years,valve-controlled excitation system controlled by servo valve or rotary valve has been widely used,but there are still some problems such as high energy consumption and complex system structure.In view of the high energy consumption of valve-controlled hydraulic excitation system and the shortcomings of valveless excitation system in high-frequency loading,a new method of pump-controlled hydraulic excitation is proposed,which directly outputs alternating liquid flow through the continuous rotation of the valve plate and drives the actuator to complete the excitation loading.With the support of the National Natural Science Foundation of China,theoretical analysis and experimental research are carried out on the flow characteristics of the alternating flow distribution pump,the influencing factors of flow pulsation and the control strategies of the pump-controlled cylinder excitation system.The research has made the following progress:According to the new principle of alternating flow distribution method,the design scheme of alternating flow distribution pump is put forward.By rotating the valve plate,the piston pump directly generates alternating flow to drive the hydraulic cylinder to vibrate,and the control valve is eliminated,thus overcoming the shortcoming of high energy consumption of the traditional valve-controlled excitation system.A piston pump flow model is established under the condition that the phase angle of the swash plate is continuously changed with the valve plate,and the influence of the structural parameters and motion parameters of the main components of the alternating flow distribution pump on the amplitude and frequency of alternating flow is analyzed.The simulation model is established and the correctness of theoretical analysis is verified.For the discontinuity of output flow of alternating flow distribution pump,the evaluation index of flow pulsation of alternating flow distribution pump is established.The mechanism of flow pulsation is studied,and the influence law of structural parameters and motion parameters of main components of alternating distribution pump on flow pulsation is analyzed.For the minimum flow pulsation,the basic control strategy of the pump-controlled cylinder system driven by alternating flow distribution pump is put forward,which lays the foundation for decoupling control of the pump-controlled cylinder excitation system in amplitude and frequency.The identification method of displacement amplitude of pump-controlled cylinder system based on least square curve fitting smoothing method and the displacement amplitude control method based on iterative learning are designed to realize accurate control of displacement amplitude of pump-controlled cylinder excitation system.The system simulation model is established and the effectiveness of the control method is verified.Finally,the test platform of alternating distribution pump and pump-controlled cylinder excitation system is established.The experiment verifies the influence of the motion characteristics of components such as the angle of swash plate,the rotation speed of cylinder block and the rotation speed of rotating valve plate on the amplitude and frequency of the excitation waveform of the system.The effectiveness of the proposed amplitude identification and control method on the pump-controlled cylinder system is also verified.The experimental results show that the theoretical model is correct and the control method is feasible.