新型液压旋转高速开关阀的动态性能及信号处理研究

发布时间：2018-10-04 21:05

【摘要】：随着社会的不断发展,液压控制技术和计算机控制技术都在不断地飞速进步。在现代液压控制系统中,高速开关阀作为一种控制元件,一般工作于开关两种状态,广泛应用在工业控制中。高速开关阀具有控制精度高、响应速度快、能量损失小以及提供数字接口便于计算机连接控制等特点。高速开关阀性能的优劣决定着液压系统的稳定性,高效性和输出流量变化快速性。由于高速开关阀本身的特点,大流量与快速响应存在矛盾,国内外主要研究集中围绕着这个矛盾的解决展开。在大多数液压控制系统中,一般使用计量阀或者变量泵来控制。计量阀控制系统的特点是系统简单和控制带宽大,但是其节流损失的能量非常大。变量泵因为只产生所需要的能量,所以比计量阀更有效率,但增加了额外的体积,呆滞效应以及成本。因此,为了解决上述的问题,本文提出了一种新型自旋式高速开关阀。新型旋转高速开关阀利用了流体自身动能冲击阀芯旋转,这样就无须外加驱动,当阀芯旋转时,流体选择性的流向应用(开)或流回油箱(关)。开关阀的PWM调节占空比由阀芯轴向位置决定,阀芯轴向位置的变化是利用了流体的静压力,即通过控制直流电机驱动小型摆线泵把流体从阀芯的一端抽向另一端来实现。由于要实现轴向位移的精确控制和快速响应,本文在PID控制算法和模糊控制的基础上提出了参数自整定模糊PID控制的算法原理,并建立了控制器模型,接着运用Matlab/Simulink进行了参数自整定模糊PID控制器与常规经典PID控制效果对比性实验,实验结果验证了所设计的控制器提高了系统的响应速度,改善了直流电机控制系统的特性。根据新型旋转高速开关阀的模型,轴向位置和旋转状态的测量使用的是非接触式光电传感方法,阀芯旋转时系统中存在周期性测量噪声和过程噪声。本文在研究了几种基于卡尔曼滤波的算法基础上,提出了使用改进的卡尔曼滤波算法来对开关阀系统中阀芯轴向位置及对阀芯旋转位置和阀芯旋转角速度进行滤波和估计,并建立了卡尔曼滤波模型,最后在Matlab/Simulink中对模型进行仿真,实验结果验证了改进型卡尔曼滤波算法的有效性。
[Abstract]:With the development of society, hydraulic control technology and computer control technology are making rapid progress. In modern hydraulic control system, high speed switch valve, as a control element, generally works in two states of switch, and is widely used in industrial control. The high speed switch valve has the advantages of high control precision, fast response speed, low energy loss and easy computer connection and control by providing digital interface. The performance of high-speed on-off valve determines the stability, efficiency and fast change of output flow of hydraulic system. Because of the characteristics of the high speed switch valve, there is a contradiction between the large flow rate and the fast response. The main research at home and abroad focuses on the solution of this contradiction. In most hydraulic control systems, metering valves or variable pumps are commonly used to control. The metering valve control system is characterized by simple system and large control bandwidth, but its throttling loss of energy is very large. Variable pumps are more efficient than metering valves because they produce only the required energy, but add additional volume, hysteresis, and cost. Therefore, in order to solve the above problems, a new spin high-speed switch valve is proposed in this paper. The new rotary high speed switch valve uses the kinetic energy of the fluid itself to impact the valve core rotation, so that there is no need for additional drive. When the valve core rotates, the fluid selective flow direction is applied (open) or flow back to the tank (close). The PWM duty cycle of the switch valve is determined by the axial position of the valve core. The change of the axial position of the valve core is based on the static pressure of the fluid, that is, the fluid is drawn from one end of the valve core to the other by controlling the small cycloidal pump driven by the DC motor. In order to realize the accurate control and fast response of axial displacement, this paper presents the algorithm principle of parameter self-tuning fuzzy PID control based on PID control algorithm and fuzzy control, and establishes the controller model. Then a comparative experiment of parameter self-tuning fuzzy PID controller and conventional classical PID controller is carried out by using Matlab/Simulink. The experimental results show that the designed controller improves the response speed of the system and the characteristics of the DC motor control system. According to the model of the new rotary high speed switch valve, the non-contact photoelectric sensing method is used to measure the axial position and the rotating state. The periodic measurement noise and the process noise exist in the system when the valve core rotates. Based on the study of several Kalman filtering algorithms, an improved Kalman filtering algorithm is proposed to filter and estimate the axial position of the spool, the rotation position of the spool and the rotational angular velocity of the spool in the switch valve system. Finally, the model is simulated in Matlab/Simulink. The experimental results show that the improved Kalman filter algorithm is effective.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH137.52

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