全液压矫直机位置—压力协同控制策略研究

发布时间：2018-04-09 16:50

本文选题：液压传动与控制　切入点：全液压矫直机　出处：《太原科技大学》2017年硕士论文

【摘要】：全液压矫直机的液压系统是一个高速、大惯量、高频响、多自由度的电液伺服系统。在中厚板的矫直过程中,传统的控制方式主要以位置闭环为主,位置闭环能很好地保证对液压缸输出位移的控制和跟踪,但是不能实现压力的在线无级改变,保证矫直力的稳定输出;而且传统的液压系统泵源处使用的是电磁溢流阀调定系统的工作压力,在矫直钢板的过程中会有溢流损失,造成能量的损失,自动化程度不高。随着科技的不断发展,对自动化程度和板型控制精度要求的不断提高,单纯的位置闭环已经不能满足现代矫直工艺的需要。针对上述问题本文提出了全液压矫直机位置——压力协同控制策略。本文提出的位置——压力协同控制策略的核心思想是:在矫直辊系压下及矫直的过程中,系统通过压力——位置转换增益将液压缸大小腔的动态工作压力信号实时转换为一个位置补偿信号补偿到位置闭环内,从而提高系统的响应速度;同时将液压缸大腔的压力信号反馈到泵源处比例溢流阀的输入端,根据不同的板厚实现快速无级改变系统的工作压力,从而提高整机的自动化程度。本文通过对全液压矫直机工作原理及电液伺服系统的详细分析、理论推导和计算,构建了全液压矫直机位置——压力协同控制策略的单缸数学模型,并且与单纯的位置闭环做了比较,分析了其控制效果。首先在AMESim软件中进行单缸协同控制和四缸同步协同控制模拟仿真,通过仿真运行证明了该控制策略的可行性和正确性,然后通过实验室的小型阀控缸实验台验证压力信号补偿到位置闭环以后的控制效果,最后在现场的十一辊矫直机上实验验证位置——压力协同控制四缸同步的可行性和实用性。全液压矫直机位置——压力协同控制策略不仅提高了矫直机液压系统的响应速度,还实现了液压系统压力的快速无级改变,提高了整机的自动化程度。全液压矫直机位置——压力协同控制策略的实现为我国大型冶金设备的自主创新和自主知识产权产品开发提供了可靠的理论依据和技术支撑。
[Abstract]:The hydraulic system of full hydraulic straightening machine is a high speed, large inertia, high frequency sound, multi-degree of freedom electrohydraulic servo system.In the straightening process of medium and thick plate, the traditional control method is mainly the position closed loop, which can ensure the control and tracking of the displacement of the hydraulic cylinder output, but it can not realize the on-line stepless change of the pressure.It ensures the steady output of straightening force, and the traditional pump source of hydraulic system uses electromagnetic relief valve to set the working pressure of the system, which will have overflow loss in the process of straightening steel plate, resulting in energy loss and low degree of automation.With the development of science and technology and the improvement of automation and precision of plate shape control, the simple position closed loop can not meet the needs of modern straightening technology.In view of the above problems, this paper puts forward the position-pressure cooperative control strategy of full hydraulic straightening machine.The core idea of the position-pressure cooperative control strategy proposed in this paper is: in the process of straightening roll down and straightening,The system converts the dynamic working pressure signal of the cylinder size cavity into a position compensation signal in real time through the pressure-position conversion gain to compensate the position closed loop, thus improving the response speed of the system.At the same time, the pressure signal of the large cavity of the hydraulic cylinder is fed back to the input end of the proportional relief valve at the source of the pump. According to the different plate thickness, the working pressure of the system can be changed quickly and stepless, thus improving the automation degree of the whole machine.Through the detailed analysis, theoretical derivation and calculation of the working principle and electro-hydraulic servo system of the all-hydraulic straightening machine, a single-cylinder mathematical model of the position-pressure synergistic control strategy of the all-hydraulic straightener is constructed in this paper.And compared with the simple position closed loop, the control effect is analyzed.First, the simulation of single cylinder cooperative control and four cylinder synchronous cooperative control is carried out in AMESim software. The simulation results show that the control strategy is feasible and correct.Then, the control effect after the pressure signal compensation to the position closed loop is verified by the small experimental bench of the valve control cylinder in the laboratory. Finally, the feasibility and practicability of the position-pressure synergistic control of four-cylinder synchronization are verified in the field of the 11-high straightener.The position and pressure cooperative control strategy not only improves the response speed of hydraulic system, but also realizes the rapid stepless change of hydraulic system pressure and improves the automation degree of the whole machine.The realization of position-pressure cooperative control strategy of hydraulic straightener provides reliable theoretical basis and technical support for independent innovation and independent intellectual property product development of large metallurgical equipment in China.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG333.23

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