变流量整体式固冲发动机控制系统研究

发布时间：2018-12-28 19:47

【摘要】：固体火箭冲压发动机在飞行器上越来越广泛的运用,促使对燃气发生器流量调节技术的研究。随着对整体式固体火箭冲压发动机的要求不断提高,燃气流量调节技术及控制方法成为各国研究的热点。本文围绕变流量整体式固体火箭冲压发动机燃气流量调节技术以及发动机控制展开相关研究工作。首先,根据执行机构设计指标设计气动式燃气流量执行机构。建立其数学模型,对模型进行了降阶简化。对其进行动态响应和静态跟踪测试,测试结果表明,所设计的执行机构的性能参数基本能够满足指标要求。其次,分析燃气发生器的工作特性,分别建立了调节系统的稳态模型以及动态模型。对模型线性化后为一个非最小相位系统,具有逆响应特性。并从阶跃调节状况和动态调节状况两种情况对燃气流量的逆响应产生的原因进行了分析,得出逆响应是伴随燃气流量调节的过程必然存在的一种现象。并通过系统仿真讨论了燃速压强指数,燃气发生器自由容积,初始稳态喉道面积,喷管喉道面积变化率对绝对逆响应量以及逆响应持续时间的影响。然后,针对流量调节方式,讨论三种不同的控制方式:喷管喉道面积控制,燃烧室压强控制,考虑逆响应现象的过渡过程设计。从这三个方面分别对燃气发生器进行了控制方法的研究和设计。在对喷管喉道面积控制时,研究一种基于逆响应限制下的控制系统。在要求的逆响应限制下有效的提高了系统的响应速度。针对其压强系统特性,设计线性自抗扰控制器。在长时间的工作和不同调节范围内,能够很好实现对压强的快速无超调控制。以压强控制系统为基础,采用了模糊微分跟踪器作为系统的过渡函数,在对响应速度影响较小的情况下,有效的减小了逆响应量的大小。对燃气流量调节系统进行了冷调实验和热调实验。在冷调实验中,验证了压强控制系统的可行性。研究了控制信号变化率对逆响应现象的影响。在热调实验中,验证执行机构的的稳定性,实验结果在一定程度上反映了燃气流量调节系统的特性。分析了机械空程对压强控制系统的影响。最后,对变流量固体火箭冲压发动机进行分析并建立数学模型。针对系统的变参数特性和逆响应特性,采用广义预测控制算法对长时间工作情况下的系统进行控制。仿真表明,相比与传统的控制器,广义预测控制能够在一定程度上减小系统的逆响应现象,降低系统的超调与不稳定现象,提高系统的控制精度。
[Abstract]:Solid rocket ramjet is more and more widely used in aircraft, which promotes the research of flow regulation technology of gas generator. With the increasing demand for integral solid rocket ramjet, gas flow regulation technology and control methods have become a hot topic in many countries. This paper focuses on variable flow integral solid rocket ramjet gas flow regulation technology and engine control. Firstly, the pneumatic gas flow actuator is designed according to the design index of the actuator. The mathematical model of the model is established, and the order reduction of the model is simplified. The dynamic response and static tracking tests show that the performance parameters of the designed actuator can basically meet the requirements. Secondly, the operating characteristics of the gas generator are analyzed, and the steady-state model and the dynamic model of the regulating system are established respectively. The model is linearized as a non-minimum phase system with inverse response. The causes of the inverse response of gas flow are analyzed from the two situations of step regulation and dynamic regulation. It is concluded that the inverse response is an inevitable phenomenon in the process of gas flow regulation. The effects of burning rate pressure index, free volume of gas generator, initial steady throat area and nozzle throat area on the absolute inverse response and the inverse response duration are discussed by systematic simulation. Then, three different control methods are discussed: nozzle throat area control, combustion chamber pressure control, and transition process design considering inverse response. The control method of gas generator is studied and designed from these three aspects. In the control of nozzle throat area, a control system based on inverse response is studied. The response speed of the system is improved effectively under the restriction of the required inverse response. According to the characteristics of the pressure system, a linear ADRC controller is designed. In the long working hours and different adjustment range, it can realize the fast and no overshoot control of the pressure. Based on the pressure control system, the fuzzy differential tracker is used as the transition function of the system. In the case of less influence on the response speed, the size of the inverse response is reduced effectively. The cold regulation experiment and the heat regulation experiment are carried out on the gas flow regulation system. The feasibility of the pressure control system is verified in the cold adjustment experiment. The effect of the change rate of control signal on the inverse response is studied. The stability of the actuator is verified in the heat regulation experiment, and the experimental results reflect the characteristics of the gas flow regulation system to some extent. The influence of mechanical airspeed on pressure control system is analyzed. Finally, the variable flow solid rocket ramjet is analyzed and the mathematical model is established. The generalized predictive control (GPC) algorithm is used to control the system with long working time according to the variable parameter and inverse response characteristics of the system. The simulation results show that compared with the traditional controller, the generalized predictive control can reduce the inverse response of the system to a certain extent, reduce the overshoot and instability of the system, and improve the control accuracy of the system.
【学位授予单位】：北京理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：V435

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