基于PID算法的电液比例阀控制系统研究

发布时间：2018-08-18 21:06

【摘要】：传统电液比例阀技术是开关阀技术、比例阀技术和伺服阀技术，这是一种模拟控制技术，它的精确控制是建立在闭环控制基础上的，它依靠各种传感器、伺服阀、伺服放大器、控制器等各种硬件与各种自动控制理论相结合完成。这是一种系统复杂、价钱昂贵、维护麻烦、故障率高的系统，必须是专家设计、专家调试、专家使用、专家维护，给大规模推广应用带来障碍。本文介绍了传统电液比例阀技术存在的一些优点和不足，简单的分析了几种常用的电液比例阀，阐述了现代比例阀的现状和发展。本文研究的基于PID算法的电液比例阀闭环控制系统是一种以软件代替部分复杂硬件的控制系统，这系统可以有效的解决传统比例阀技术的各种问题，且它的控制功能强大，维护成本低，系统控制精度高且系统结构相对比较简单。在电液比例阀的控制电路设计中，以单片机控制系统、数字PID算法和PWM(脉冲宽度调制)技术为研究对象。根据电液比例阀的控制要求，编制了系统控制程序，设计了单片机控制系统的电路和功率放大电路，，使控制电路的精度和可靠性大大提高。本系统中通过MCU的串口通信模块与上位机联接，通过上位机可以实时监测系统的运行状态，也可以通过上位机改变系统的运行状态，从而可以实现人机交互。本文根据控制要求，建立了本控制系统的数学模型，得出系统的传递函数，然后在MATLAB的SIMULINK环境下进行仿真，得出阀的稳态和动态响应特性曲线，从而为进一步优化电液比例阀控制系统提供了理论上的依据。对于电液比例阀的控制水平的提高，促进其现代化、数字化的发展有一定的现实意义。
[Abstract]:Traditional electro-hydraulic proportional valve technology is switch valve technology, proportional valve technology and servo valve technology, this is a kind of analog control technology, its accurate control is based on the closed-loop control, it depends on a variety of sensors, servo valves, servo amplifiers, Controller and other hardware and various automatic control theory combined to complete. This is a complex system, expensive, maintenance trouble, high failure rate system, must be expert design, expert debugging, expert use, expert maintenance, to large-scale promotion and application of obstacles. This paper introduces some advantages and disadvantages of traditional electro-hydraulic proportional valve technology, analyzes several commonly used electro-hydraulic proportional valves, and expounds the present situation and development of modern proportional valves. The electro-hydraulic proportional valve closed-loop control system based on PID algorithm is a kind of control system which uses software instead of some complex hardware. This system can effectively solve all kinds of problems of traditional proportional valve technology, and its control function is powerful. The maintenance cost is low, the system control precision is high and the system structure is relatively simple. In the control circuit design of electro-hydraulic proportional valve, single chip microcomputer control system, digital PID algorithm and PWM (Pulse width Modulation) technology are studied. According to the control requirements of the electro-hydraulic proportional valve, the control program of the system is compiled, and the circuit and power amplifier circuit of the single-chip microcomputer control system are designed. The precision and reliability of the control circuit are greatly improved. In this system, the serial port communication module of MCU is connected with the host computer. Through the upper computer, the running state of the system can be monitored in real time, or the running state of the system can be changed by the upper computer, thus the man-machine interaction can be realized. According to the control requirements, this paper establishes the mathematical model of the control system, obtains the transfer function of the system, and then simulates under the SIMULINK environment of MATLAB to obtain the steady state and dynamic response characteristic curves of the valve. It provides theoretical basis for further optimization of electro-hydraulic proportional valve control system. It has certain practical significance for the improvement of the control level of electro-hydraulic proportional valve, the promotion of its modernization and the development of digitization.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH137.52

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