数字式大流量2D比例换向阀控制器的设计与研究

发布时间：2018-07-26 21:16

【摘要】：电液控制系统具有功率比量大、动态响应速度快、抗负载刚度大等优点,广泛应用于航空航天、船舶、装备制造等领域。其中比例阀就是一种应用较为广泛的控制元件,相较于伺服阀,具有设计简单、价格便宜、抗污染能力强等特点,在液压界其重要性日益提高。2D比例换向阀是基于阀芯直动和绕轴旋转运动两个自由度,实现直动式与导控式于一体的新型比例阀,具有结构简单,稳定性高,抗污染能力更强,动态性能好以及能驱动大流量负载等优点。而对于一款优秀的比例阀,其性能的优劣不仅仅与阀本身有关,而且与其比例控制器有很大关系。目前市场上比例控制器多以模拟式为主,不仅功耗大,而且设计控制器时多以通用为目的,对于不同的控制对象,其控制效果相差较大。近年来出现数字式比例控制器,相比模拟式,其功耗和控制效果等方面均有很大优势,但也存在不具有针对性的缺点。因此,开发一款针对2D比例换向阀特点的比例控制器,提高2D比例换向阀的动静态性能,具有重要意义。本文在分析2D比例换向阀的工作原理与结构的基础上,并且重点分析了影响2D比例阀动静态性能的因素,针对这些影响因素,开发一款基于DSP2812芯片的数字式比例控制器。该控制器具有电流和位置反馈信号,通过PID可构成双闭环。针对大流量2D比例换向阀惯性环节较大,为了提高频响,本文设计了高低压驱动算法,仅通过软件控制,简单、方便;针对电-机械转换器衔铁位移变化引起磁通变化而导致电流波动,本文采用线性回归算法,提高电流抗干扰能力;针对2D比例换向阀运动过程中摩擦力较大以及压扭联轴器的配合间隙影响其静态特性,本文采用颤振补偿算法,改善静态特性。另外,为了更好的控制2D比例换向阀,还对电-机械转换器进行理论分析和数学建模。为了方便实时调节参数,本文设计了按键和LCD显示。通过搭建实验平台,进行了实验验证,经该控制器调节的2D比例换向阀具有良好的动静态控制性能,其重复精度小于2%,线性度小于3%,最小滞环仅有2.07%,对应-3dB、-90°的频宽约为18Hz,阶跃响应的上升时间约为55ms,控制流量可达270L/min。实验结果表明本文设计控制器具有良好的稳态和动态控制能力,对2D比例换向阀的动静态特性具有较大提升和改善。此外,为了减少对控制器的重复开发,本文设计的控制器对力矩马达、旋转比例电磁铁以及开关电磁铁等电机械转换器进行实验测试,均有较好的控制效果。本文还重点分析了开关电磁铁比例化应用,通过实验分析,开关电磁铁配合具有放大位移作用的压扭,可以实现2D阀的比例化控制。
[Abstract]:The electro-hydraulic control system has many advantages such as large power ratio, fast dynamic response speed, high load stiffness and so on. It is widely used in aerospace, ship, equipment manufacturing and other fields. The proportional valve is a kind of widely used control element. Compared with the servo valve, it has the characteristics of simple design, cheap price, strong anti-pollution ability and so on. In hydraulic field, the importance of .2D proportional directional valve is improved day by day. It is a new type of proportional valve, which is based on the two degrees of freedom of straight motion and rotation around the axis of the valve core and realizes the integration of direct and guide type. It has simple structure, high stability and stronger anti-pollution ability. Good dynamic performance and the ability to drive large traffic load and other advantages. For an excellent proportional valve, its performance is not only related to the valve itself, but also to the proportional controller. At present, most of the proportional controllers in the market are analog, which not only consume a lot of power, but also design the controller for general purpose. For different control objects, the control effect is quite different. In recent years, digital proportional controller (DPC) has great advantages in power consumption and control effect, compared with analog controller, but it also has some disadvantages. Therefore, it is of great significance to develop a proportional controller to improve the dynamic and static performance of 2D proportional directional valve. Based on the analysis of the working principle and structure of 2D proportional directional valve and the factors that affect the dynamic and static performance of 2D proportional valve, a digital proportional controller based on DSP2812 chip is developed in this paper. The controller has current and position feedback signals, and can form double closed loop through PID. In view of the large inertia link of 2D proportional directional valve with large flow rate, in order to improve the frequency response, a high and low pressure drive algorithm is designed, which is only controlled by software, simple and convenient. Aiming at the current fluctuation caused by the change of the armature displacement of the electro-mechanical converter, this paper adopts the linear regression algorithm to improve the anti-interference ability of the current. In view of the large friction force in the movement of 2D proportional directional valve and the influence of the fit clearance of the pressure-torsional coupling on its static characteristics, this paper adopts the flutter compensation algorithm to improve the static characteristics. In addition, in order to better control 2D proportional directional valve, the theory analysis and mathematical model of electro-mechanical converter are also carried out. In order to adjust the parameters in real time, the key and LCD display are designed in this paper. The experimental results show that the 2D proportional directional valve adjusted by the controller has good dynamic and static control performance. The repetition accuracy is less than 2, the linearity is less than 3, the minimum hysteresis is only 2.07, the bandwidth corresponding to -3dBU -90 掳is about 18 Hz, the rising time of step response is about 55 Ms, and the controlled flow rate can reach 270 L / min. The experimental results show that the controller designed in this paper has good steady-state and dynamic control ability, and greatly improves the static and static characteristics of 2D proportional directional valve. In addition, in order to reduce the repetitive development of the controller, the controller designed in this paper has good control effect on torque motor, rotating proportional electromagnet and switch electromagnet. This paper also analyzes the proportional application of switched electromagnets. Through experimental analysis, the proportional control of 2D valves can be realized by using switched electromagnets in combination with pressure-torsion with the effect of magnifying displacement.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH137.52

【相似文献】