基于高速開關閥的液壓缸速度控制系統(tǒng)仿真研究
發(fā)布時間：2018-11-08 06:51
【摘要】：如今,隨著計算機的迅速發(fā)展和廣泛應用,液壓工業(yè)作為全球性的工業(yè),也在不斷與計算機結合走向數(shù)字化。所以在液壓系統(tǒng)中的閥也多用比例閥、數(shù)字閥、伺服閥作為放大元件。閥作為液壓系統(tǒng)的重要元件,影響著整個系統(tǒng)的性能,甚至影響著整個機械設備的優(yōu)越性、可靠性、效率以及壽命,所以閥的選取顯得尤為重要。高速開關閥由脈沖信號對電磁鐵的控制來實現(xiàn)對閥芯的推動作用。高速開關閥只有“開”和“關”兩種形式,只要控制脈沖頻率或脈沖寬度,就可以控制“開”和“關”的時間。高速開關閥以其結構簡單,抗污染能力強等優(yōu)點被廣泛應用。本文對將高速開關閥應用于高速滾珠旋壓系統(tǒng)的壓下平臺的速度控制系統(tǒng)進行了可行性分析與性能研究,以高效、經(jīng)濟、結構簡單、容易操作為出發(fā)點設計出用高速開關閥代替其他伺服換向閥的液壓系統(tǒng),由高速開關閥獨立控制流量,同時也為滾珠旋壓機的更新優(yōu)化提供參考。根據(jù)高速滾珠旋壓機的原理與工況要求,確定液壓系統(tǒng)執(zhí)行元件及液壓缸所承受負載力,液壓缸所要達到的最大工作速度等,從而設計計算出液壓缸尺寸,確定液壓系統(tǒng)工作壓力以及所需流量。為了驗證基于高速開關閥的液壓系統(tǒng)對液壓缸控制的可行性與穩(wěn)定性,本文根據(jù)所建立的系統(tǒng)基本方程,搭建開環(huán)系統(tǒng)的Simulink仿真模型,得到變占空比定負載下的液壓缸速度曲線等,定占空比變負載下的液壓缸速度曲線等,對占空比與負載對系統(tǒng)的影響進行分析與總結。建立系統(tǒng)傳遞函數(shù),在Simulink中搭建傳遞函數(shù)模型,繪制Bode圖,判定系統(tǒng)穩(wěn)定性。仿真結果表明:此液壓系統(tǒng)對液壓缸速度控制是可行的,且系統(tǒng)穩(wěn)定。但負載按照不同線性變化規(guī)律變化時,對液壓缸速度影響較大。在滾珠旋壓過程中,滾珠旋壓機軸向力不斷變化會使進給速度發(fā)生變化,而進給速度穩(wěn)定與否直接影響著旋壓精度,為消除負載變化對液壓缸速度的影響,本文在系統(tǒng)中引入PID控制器,組成速度控制閉環(huán),利用AMESim模型仿真出液壓缸受到不同變化規(guī)律的負載作用下、通過對PID參數(shù)整定后的液壓缸速度仿真曲線。仿真結果表明:此方法可使液壓缸速度基本不受負載的影響,可進一步提高系統(tǒng)抵抗負載變化的能力,保證旋壓進給速度不變,從而進一步提高旋壓精度。最后實驗得到有電磁換向閥的液壓缸位移歷史趨勢,與無電磁換向閥的仿真結果進行對比,并分析前者波動原因與劣勢。
[Abstract]:Nowadays, with the rapid development and wide application of computer, hydraulic industry, as a global industry, is constantly combined with computer to digitize. So the valves in hydraulic system also use proportional valves, digital valves, servo valves as amplifiers. As an important component of hydraulic system, valve affects the performance of the whole system, and even affects the superiority, reliability, efficiency and life of the whole mechanical equipment, so the selection of valve is particularly important. High-speed on-off valve is controlled by pulse signal to drive the valve core. There are only two types of "open" and "close" of high speed valve. As long as the pulse frequency or pulse width is controlled, the time of "on" and "off" can be controlled. High-speed on-off valve is widely used because of its simple structure and strong anti-pollution ability. In this paper, the feasibility analysis and performance study of the speed control system of the high speed switch valve applied to the high speed ball spinning system are carried out in order to be efficient, economical and simple in structure. The hydraulic system with high speed switch valve instead of other servo directional valve is designed for easy operation. The flow rate is independently controlled by high speed switch valve, and it also provides a reference for the renewal and optimization of ball spinning machine. According to the principle and working condition requirement of high-speed ball spinning machine, the load force and maximum working speed of hydraulic system actuator and hydraulic cylinder are determined, and the size of hydraulic cylinder is designed and calculated. Determine the working pressure and required flow rate of hydraulic system. In order to verify the feasibility and stability of the hydraulic system based on high speed switch valve to control the hydraulic cylinder, the Simulink simulation model of the open loop system is built according to the basic equations of the system. The hydraulic cylinder velocity curves under the variable duty cycle and the constant duty cycle load are obtained. The effects of duty cycle and load on the system are analyzed and summarized. The system transfer function is established, the transfer function model is built in Simulink, the Bode diagram is drawn, and the stability of the system is judged. The simulation results show that the hydraulic system is feasible to control the speed of the hydraulic cylinder and the system is stable. But when the load changes according to the different linear variation law, it has a great influence on the hydraulic cylinder speed. In the process of ball spinning, the constant change of axial force of the ball spinning press will change the feed speed, and whether the feed speed is stable or not will directly affect the spinning precision, in order to eliminate the influence of the load change on the hydraulic cylinder speed, In this paper, a PID controller is introduced into the system to form a speed control closed-loop. The hydraulic cylinder is simulated by using AMESim model under the load of different changing laws, and the simulation curve of the cylinder speed is obtained by setting the PID parameters. The simulation results show that this method can make the speed of the hydraulic cylinder almost independent of the load, and further improve the system's ability to resist the change of the load, ensure the constant speed of spinning feed, and further improve the spinning accuracy. Finally, the historical trend of displacement of hydraulic cylinder with electromagnetic directional valve is obtained, and the simulation results of non-electromagnetic directional valve are compared, and the reason of fluctuation and disadvantage of the former are analyzed.
【學位授予單位】：太原科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TH137.51;TG305
[Abstract]:Nowadays, with the rapid development and wide application of computer, hydraulic industry, as a global industry, is constantly combined with computer to digitize. So the valves in hydraulic system also use proportional valves, digital valves, servo valves as amplifiers. As an important component of hydraulic system, valve affects the performance of the whole system, and even affects the superiority, reliability, efficiency and life of the whole mechanical equipment, so the selection of valve is particularly important. High-speed on-off valve is controlled by pulse signal to drive the valve core. There are only two types of "open" and "close" of high speed valve. As long as the pulse frequency or pulse width is controlled, the time of "on" and "off" can be controlled. High-speed on-off valve is widely used because of its simple structure and strong anti-pollution ability. In this paper, the feasibility analysis and performance study of the speed control system of the high speed switch valve applied to the high speed ball spinning system are carried out in order to be efficient, economical and simple in structure. The hydraulic system with high speed switch valve instead of other servo directional valve is designed for easy operation. The flow rate is independently controlled by high speed switch valve, and it also provides a reference for the renewal and optimization of ball spinning machine. According to the principle and working condition requirement of high-speed ball spinning machine, the load force and maximum working speed of hydraulic system actuator and hydraulic cylinder are determined, and the size of hydraulic cylinder is designed and calculated. Determine the working pressure and required flow rate of hydraulic system. In order to verify the feasibility and stability of the hydraulic system based on high speed switch valve to control the hydraulic cylinder, the Simulink simulation model of the open loop system is built according to the basic equations of the system. The hydraulic cylinder velocity curves under the variable duty cycle and the constant duty cycle load are obtained. The effects of duty cycle and load on the system are analyzed and summarized. The system transfer function is established, the transfer function model is built in Simulink, the Bode diagram is drawn, and the stability of the system is judged. The simulation results show that the hydraulic system is feasible to control the speed of the hydraulic cylinder and the system is stable. But when the load changes according to the different linear variation law, it has a great influence on the hydraulic cylinder speed. In the process of ball spinning, the constant change of axial force of the ball spinning press will change the feed speed, and whether the feed speed is stable or not will directly affect the spinning precision, in order to eliminate the influence of the load change on the hydraulic cylinder speed, In this paper, a PID controller is introduced into the system to form a speed control closed-loop. The hydraulic cylinder is simulated by using AMESim model under the load of different changing laws, and the simulation curve of the cylinder speed is obtained by setting the PID parameters. The simulation results show that this method can make the speed of the hydraulic cylinder almost independent of the load, and further improve the system's ability to resist the change of the load, ensure the constant speed of spinning feed, and further improve the spinning accuracy. Finally, the historical trend of displacement of hydraulic cylinder with electromagnetic directional valve is obtained, and the simulation results of non-electromagnetic directional valve are compared, and the reason of fluctuation and disadvantage of the former are analyzed.
【學位授予單位】：太原科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TH137.51;TG305
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