【作者】 于明礼；

【导师】 胡海岩；

【作者基本信息】 南京航空航天大学 ， 固体力学， 2006， 博士

【摘要】 本研究旨在尝试通过超声电机驱动的控制面来实现二维翼段颤振的主动抑制。超声电机以其结构简单紧凑、转矩/质量比大、低速大扭矩、直接驱动,动态响应快、断电自锁和不产生磁场且不受外界磁场干扰等优点,有望成为一种非常有前途的作动器,用于小型飞机的机翼颤振主动抑制。本文通过理论分析、数值仿真与风洞实验相结合的方法,研究了超声电机作动器建模、翼段颤振实验装置和控制系统设计、二维翼段气动弹性系统建模、颤振抑制控制律设计以及数字滤波器群时延对颤振抑制闭环系统稳定性影响等问题。论文的主要工作与学术贡献如下:(1)设计了以超声电机为作动器驱动控制面的二维翼段模型,并建立了作动器的传递函数模型。采用独立的控制电路来控制电机动作,此电路接收上位计算机的控制面转角指令,驱动电机来实现控制面的转角。针对该作动器和控制面建立一个单输入单输出的二阶动力学模型,进而可大大简化控制律设计。通过扫频实验和非线性最小二乘法进行参数识别,得到传递函数模型中各参数的值,并通过和风洞实验验证了模型的有效性。(2)设计了二维翼段颤振主动抑制实验装置并编制了相应的测试和控制系统软件。实验装置包含翼段模型、相关的传感器及作动器、翼段安装机构和保护装置。由于导轨滑块之间即使充分润滑也有一定的干摩擦阻尼,使得整个系统的阻尼特性比较复杂,为此,通过实验建模确定了实验模型的结构参数。(3)针对上述二维翼段颤振主动抑制系统,采用Theodorsen非定常气动力的Jones近似模型,建立了以超声电机为作动器的三自由度二维翼段气动弹性模型,设计了二维翼段颤振的次最优控制律。数值仿真和风洞实验研究表明,以超声电机为控制面作动器可以有效地抑制翼段模型的颤振,颤振临界速度提高了13.4%,数值仿真和风洞实验结果基本吻合。(4)考虑沉浮方向、俯仰方向的阻尼不确定因素以及作动器建模误差,采用鲁棒控制,分别设计了H∞控制器和μ控制器。数值仿真和风洞实验表明,这两种控制器是有效的,可将系统的颤振临界速度提高23.4%。与H∞控制器相比,μ控制器的控制效果更好,特别是抵抗控制回路时延的鲁棒性更强。(5)研究了颤振抑制系统中引入数字滤波器后,数字滤波器群时延对闭环系统稳定性的影响。在颤振主动抑制系统中,数字滤波器群时延较大时,即使在较低的风速下,也会造成闭环系统的不稳定。在稍大于颤振临界速度的风更多还原

【Abstract】 This dissertation presents how to use the ultrasonic motor as an actuator to suppress the flutter of a two-dimensional airfoil section with a control surface. The ultrasonic motor, which features simple structure, high torque at low speed, small size, low weight and no electromagnetic contamination, is a promising actuator for the flutter suppression of small aircraft. The dissertation presents the combined theoretical, numerical and experimental studies on the experimental modeling of the actuator, the design of test rig and control system, the modeling of two-dimensional airfoil aeroelastic system, the control design of active flutter suppression, and the effect of group delay in the digital filter on the stability of aeroelastic closed-loop system. The main contributions of the dissertation are as follows.In Chapter 2, the dissertation demonstrates the design of an airfoil model with a control surface driven by an ultrasonic motor as the actuator first, and then presents the experimental modeling of the actuator. The ultrasonic motor is controlled by an independent control circuit, which receives rotate angle commands from an upper computer and drives the ultrasonic motor to reach the rotation angle of the control surface. For the actuator and control surface, a dynamic model of single degree of freedom is constructed so that the design of control law can be greatly simplified. The parameters of the actuator model are estimated via the tests under sweep sinusoidal excitation. The effectiveness of the model is validated through wind tunnel tests.Chapter 3 presents the design of the test rig and the measurement/control system software. The test rig includes the airfoil model, the accompanied sensors, the actuator and the protecting mechanism. There exists remarkable dry friction along the guide rail, which makes the system damping very complex, even though the track is well lubricated. Therefore, the experimental modeling is made to estimate the structural parameters of the test rig.In Chapter 4, the aeroelastic model of the whole test rig is first established by using Jones’s approximation of Theodorsen’s unsteady aerodynamics load. Then, the numerical simulations and wind tunnel experiments for the sub-optimal flutter suppression of the airfoil model are presented. The numerical simulations agree well with the wind the tunnel experiments, and the critical speed is increased by 13.4%. Chapter 5 presents the robust flutter suppression of the airfoil. Both H∞controller andμsynthesis are designed when the damping uncertainties in plunge更多还原