| In recent years,with the development of intelligent manufacturing industry,Spinning machines are playing an increasingly important role in the manufacturing industry,and their machining accuracy has a crucial impact on the quality of the work-piece.In order to improve the machining accuracy of the spinning machine,a hydraulic feed system with a maximum spinning pressure of 400 k N is designed and studied according to the technical requirements of a certain company’s spinning machine.Firstly,this thesis combines the technical requirements and actual working conditions of this spinning machine tool to study the hydraulic collaborative control system scheme for two servo hydraulic cylinders in the feeding system of the spinning machine.Based on the determination of the collaborative control scheme,a hydraulic collaborative control schematic diagram is drawn,and various components of the hydraulic system are selected.Secondly,this thesis establishes a mathematical model for the closed-loop position collaborative control system and completes the derivation of the control system transfer function.The open-loop transfer function Bode diagram is drawn using AMESim simulation software to verify the stability of the closed-loop system.In order to further study the dynamic response performance of the position collaborative control system,combined with the selected hydraulic component sample parameters,a dynamic simulation model of hydraulic components such as servo valves,hydraulic cylinders,and hydraulic pumps was built in AMESim software,and various simulation models were combined to establish a simulation model of the closed-loop position collaborative control system of the entire rotary press feed system.The simulation result curve of the uncorrected control system was analyzed and demonstrated,Verified the correctness of the simulation model establishment.Finally,in response to the insufficient accuracy of the uncorrected feed system and the problem of speed fluctuations in the feed cylinder during the feeding process,a traditional PID correction scheme was introduced to correct the system.The corrected system error accuracy and response speed have significantly improved compared to the uncorrected system,but the problem of speed fluctuations in the feed cylinder in the uncorrected system still exists.To solve this problem,a demonstration analysis was conducted on the frictional force acting on the feed cylinder.It was found that the difference in dynamic and static frictional forces among the three constituent elements of frictional force was the main reason affecting the system accuracy.A simulation method of adding low amplitude and high frequency vibration signals to the control signal was used to compensate for the frictional force on the feed cylinder,thus completing the adjustment of the valve amplifier vibration value.However,during the machining process of the spinning machine,due to the presence of elastic loads in the feed system,traditional PID control schemes are relatively exhausted in response to variable load conditions.A fuzzy PID control strategy is adopted to further optimize the feed system,so that the dynamic response and steady-state error of the feed system can achieve ideal goals while meeting accuracy requirements.On the premise that the feed system meets the control accuracy,this thesis further studies the influence of system oil supply pressure and accumulator capacity on the control accuracy of the system.It compares the energy-saving effect of energy-saving power source and quantitative pump oil supply separately,and the results show that energy-saving power source has significant energy-saving effect. |
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