反馈控制旋转式流量阀设计及实验研究

发布时间：2018-07-13 15:14

【摘要】：随着微电子技术的发展,特别是单片机价格低廉,液压数字阀应运而生,成为了连接大功率控制对象和微电子技术的桥梁。数字阀是用数字信号直接控制液压阀的流量、压力和方向。数字阀与传统液压阀相比,数字阀直接与计算机或者单片机相连、不需要DA转换器、性价比高、对污染敏感度低,操作简单灵活。在液压控制技术方面具有广泛的应用前景,是目前流体传动发展的一个重要方向。本文设计了一种旋转式流量阀,可与步进电动机直接相连,单片机发出脉冲序列,控制步进电动机转动,步进电动机直接驱动阀芯转动,改变流量阀的开口面积,从而控制流量阀的流量。省去传统流量阀与步进电动机之间的机械式转换器(滚珠丝杠或凸轮机构)。对流量阀进行结构分析、计算后,得出流量阀节流口面积与步进电机转角之间的关系,将流量阀流量控制转化为对步进电机转角的控制,使控制变得简单。并依据易于控制原则设计了单片机硬件电路和系统软件,本反馈控制系统主要由流量阀进出口压力传感器、步进电动机转角传感器、步进电动机、单片机以及接口电路组成,单片机是本控制系统的核心。流量阀实时流量依据流量公式计算得出,流量系数C和节流口形式参数m的选择不准确,会造成实时流量的计算不准确,流量阀流量得不到准确控制。本文进行了实验台搭建,计算出流量阀在不同开口角度下的流量系数C和节流口形式参数m,最后用最小二乘法拟合出曲线并得出奇函数。单片机根据此流量阀在各开口下的实际流量系数C和节流口形式参数m计算出实时流量与所需流量进行比较,计算出偏差,得出步进电动机的转动方向及转动角度,并控制步进电动机转动,实现对流量阀流量的精确控制。
[Abstract]:With the development of microelectronic technology, especially the low price of single-chip microcomputer, hydraulic digital valve emerges as the times require, and becomes the bridge between high-power control object and microelectronics technology. Digital valves use digital signals to directly control the flow, pressure and direction of hydraulic valves. Compared with the traditional hydraulic valve, the digital valve is directly connected to the computer or the single chip microcomputer. It does not need DA converter, has high performance-price ratio, low sensitivity to pollution and simple and flexible operation. It has a wide application prospect in hydraulic control technology and is an important direction of fluid transmission development. In this paper, a kind of rotary flow valve is designed, which can be connected directly with step motor, and the single chip microcomputer sends out pulse sequence to control the rotation of step motor, and step motor drives valve core rotation directly to change the opening area of flow valve. Thus control the flow of the flow valve. Eliminate mechanical converters (ball screw or cam mechanism) between conventional flow valves and stepping motors. By analyzing the structure of flow valve and calculating, the relationship between throttle area of flow valve and the angle of step motor is obtained, and the flow control of flow valve is transformed into the control of rotation angle of step motor, which makes the control become simple. According to the principle of easy control, the MCU hardware circuit and system software are designed. The feedback control system is mainly composed of flow valve inlet and outlet pressure sensor, step motor angle sensor, step motor, single chip microcomputer and interface circuit. Single-chip microcomputer is the core of this control system. According to the calculation of flow formula, it is concluded that the choice of flow coefficient C and throttle form parameter m is not accurate, which will result in inaccurate calculation of real-time flow rate, and the flow rate of flow valve can not be controlled accurately. The flow coefficient C and throttle form parameter m of the flow valve at different opening angles are calculated. Finally, the curve is fitted with the least square method and the odd function is obtained. According to the actual flow coefficient C and throttle shape parameter m of this flow valve under each opening, the real-time flow rate is compared with the required flow rate, the deviation is calculated, and the rotation direction and angle of the stepping motor are obtained. And control the stepping motor rotation to achieve accurate flow control of the flow valve.
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH134

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