【作者】 牛文玉；

【导师】 鲍文；

【作者基本信息】 哈尔滨工业大学 ， 动力机械及工程， 2010， 博士

【摘要】 燃气流量调节是固体火箭冲压发动机的一项关键技术,燃气流量能否调节决定了固体火箭冲压发动机的性能好坏及能否安全工作。随着对固体火箭冲压发动机性能要求的不断提高,燃气流量调节成为国内国际研究的一个热点问题。本文围绕燃气流量可调的固体火箭发动机的燃气流量调节及发动机控制开展了相关研究工作。首先,对气动针阀型燃气流量调节阀的结构进行了设计,并分析了该种燃气调节阀的调节特性。围绕燃气调节阀的基本结构给出了初步设计方法和设计结果;选取了燃气调节阀所用的密封材料及压力控制阀;利用数值模拟方法分析了燃气流量调节阀的调节特性,给出了燃气流量调节特性的参数化表达式。其次,研究了燃气流量调节系统的建模及控制问题。建立了针阀型燃气流量调节系统的两种调节模式的动态模型;引入非线性测度对比分析了两种调节模式的特性,分析了燃气流量调节系统的变参数特性及负调特性,研究结果表明本文设计的燃气流量调节系统非线性较弱并且系统特性对推进剂等参数的摄动并不十分敏感;考虑到气动伺服系统具有较强的非线性及不确定性,引入PI反馈控制降低了非线性和不确定性的影响;为了实现燃气流量的稳定调节,对燃气流量调节系统的外回路进行了控制器设计;燃气流量调节系统具有摩擦力,为了降低摩擦力对燃气流量调节的影响,研究了基于自适应颤振的摩擦力补偿方法及基于准积分控制器的摩擦力补偿方法,通过仿真表明这两种方法对燃气流量调节系统均能很好地进行摩擦力补偿。然后,对燃气流量调节系统进行了冷态及热态试验研究。为了进行燃气流量调节试验,搭建了燃气流量调节系统的冷态和热态试验台;进行了基于颤振的燃气调节阀的摩擦力补偿试验和气动伺服系统的控制试验;针对燃气调节系统的耗气量及沉积进行了热态试验,通过试验分析了降低调节阀耗气量的方法及调节阀结构及阀体所用材料对沉积的影响;并多次进行了燃气流量调节试验,试验表明气动针阀型燃气流量调节阀能够有效地调节燃气流量,燃气流量控制系统具有良好的性能,最大燃气流量调节比达到了4.36:1,燃气流量调节阀连续工作时间超过100秒。最后,提出了燃气流量可调的固体火箭冲压发动机基本控制结构,研究了固体火箭冲压发动机的推力控制和进气道不起动保护控制。为了提高发动机的性能,提出固体火箭冲压发动机控制除了推力控制还应包括各种保护控制及控制回路的切换;建立了燃气流量可调的固体火箭冲压发动机动态模型,基于模型分析了固体火箭冲压发动机的变参数特性和负调特性;针对燃气流量负调使得固体火箭冲压发动机具有非最相位系统的特性,提出了基于频域信息融合的推力控制方法和进气道等裕度控制方法,分析了固体火箭冲压发动机进气道等裕度控制由于燃气流量负调带来的不同之处;最后提出固体火箭冲压发动机切换控制系统结构,分析推力控制回路和进气道不起动保护控制回路的切换过程及积分限幅对切换过程的影响。更多还原

【Abstract】 The control of gas generator is a key technology for ducted rockets. With the improved performance of ducted rocteks, research on gas control of gas generator has been enhanced in resently years. The gas regulation and engine control for variable flow ducted rockets were investigated in the paper.Firstly, the structure of pneumatic needle-type gas control valve was deisigned, and the regulating property of gas control valve was analyzed. With respect to the basic structure of gas control valve, the design methods and design results were presented. The sealing material of gas control valve and pressure control valve were selected. The regulation property of gas control valve was analyzed through numerical simulation, and the parametric expression of regulating property for gas control valve was obtained.Secondly, the modeling and control system of gas regualtion system were studied. The dynamic models of two regulating modes of gas regulation system were established, and the characteristic of these two modes were compared by introducting nonlinearity measure. The parameter varying characteristic and negative modulation were analyzed. Studies show that the nonlinearity of the pressure-balanced mode is weaker and the output is less sensitive to parameter uncertainty. The introduction of high-gain feedback suppresses the effects of nonlinearity and uncertainties of the pneumatic servo system and a proportional-integral (PI) controller for gas regulating system was designed. Two friction compensation methods were studied in the paper, one method is based on the adaptive dither signals, and the other is based on the quasi-integral controller. Simulations show that these two methods can compensate the friction in gas regulation system.Then, cold experiments and hot experiments of gas regulation system were conducted. Firstly, cold test-bed and hot test-bed were designed. The cold experiments of friction compensation based on dither signals and control of pneumatic servo system were conducted. And the hot experiments of gas depositon and gas consumption in gas regulation systm were controducted. The method of reducing gas consumption and the fluence of structure and material of control valve to gas depositon were analyzed. Extensive closed-loop control experiments were conducted, and the results of experiment show that pneumatic needle-type gas control valve can effectively control the pressure in gas generator, and gas control system has good performance. The turndown ratio of mass flow is up to 4.36:1, and the time of gas regulation is greater than 100 seconds.Finally, the basic control structure of variable flow ducted rockets was proposed, and the control system of ducted rockets was investigated. A dynamic model of varlable flow ducted rockets was established. Based on the model, the parameter varying characteristic and negative regulation were analyzed. According to the characteristic of non-minimum phase system extised in variable flow ducted rockets, a thrust contol method based on data fusion in frequency domain and the unstart margin control of hypersonic inlets were proposed for preventing inlet unstart. The defference of inlet unstart margin control was discussed because of negative regulation in ducted rockets. And switch system of ducted rockets was investigated, the switch process of thrust control loop and inlet unstart control loop was analyzed, and the fluence of integration limits in thrust loop and inlet margin loop to switch process was discussed.更多还原