In order to effectively reduce the vibration of the helicopter rotor transmitted from the main reducer to the fuselage, a semi-active vibration isolation system (SAVIS) with a magnetorheological (MR) damper was proposed and effective control strategies were designed. Firstly, the structural scheme and working principle of helicopter main reducer SAVIS were proposed. Secondly, the mechanical properties of the MR damper were tested, and the dynamic model of the MR damper was established based on the hyperbolic tangent model. In addition, the model errors of MR damper were analyzed and quantified. Thirdly, according to the design requirements and parameters of a helicopter, the structural parameters of SAVIS were designed. Then, the virtual prototype of helicopter main reducer SAVIS was established by using 3D drawing software and ADAMS software, and the vibration characteristics of three directions were analyzed. Finally, two controllers of equivalent skyhook and continuous skyhook were designed. The numerical analysis results indicate that compared with passive vibration isolation and equivalent skyhook controller, the continuous skyhook controller has the best vibration isolation performance and disturbance resistance, which can effectively reduce the vibration transmitted from helicopter rotor to fuselage.

To improve the handling comfort of Helicopter Flight Control System (HFCS), an adaptive particle swarm optimization optimized variable universe fuzzy proportional-integral-derivative (APSO-VUFPID) strategy for damping force control is proposed. First of all, by the results of the controllable semi-rotary fluid viscous damper (CSFVD) mechanical tests, a hyperbolic tangent model is developed. Afterwards, an equivalent model of HFCS is established. In the next part, aiming at improving the vibration suppression performance of the joystick system, an APSO-VUFPID is proposed to generate the desired damping force in real-time. Finally, numerical simulation and experimental tests are carried out to verify the vibration reduction effect of the proposed APSO-VUFPID method with respect to passive, proportional-integral-derivative (PID), adaptive particle swarm optimization optimized proportional-integral-derivative (APSO-PID) and adaptive particle swarm optimization optimized fuzzy proportional-integral-derivative (APSO-FPID) methods. The results show that the hyperbolic tangent model can accurately describe the nonlinear mechanical characteristics of the CSFVD. Moreover, under the proposed APSO-VUFPID control method, the amplitude of acceleration and velocity of the joystick system are smaller than those obtained from passive, PID, APSO-PID and APSO-FPID methods. Therefore, the proposed APSO-VUFPID controller has better handling comfort compared to passive, PID, APSO-PID and APSO-FPID controllers and can be employed in real applications.

叶片式阻尼器是一种新型的耗能装置,用于吸收能量和减小振动,以实现系统的结构保护.该文提出一种用于直升机操纵系统减振的半主动叶片式阻尼器,通过电机带动调整螺钉以改变阻尼间隙的大小,进而实现对阻尼力矩的控制.基于MTS试验机对该阻尼器进行示功试验并研究其动态特性.为准确地跟踪该阻尼器高度非线性的力学特性,提出一种改进的双曲正切模型,并采用修正的自适应遗传算法对模型进行参数辨识.通过仿真数据和试验数据之间的误差分析,得出结论:与其它两种现有模型相比,改进的双曲正切模型能够更精准地模拟阻尼器的出力特性;将模型参数与电机位置之间的关系用多项式整合后,模型在不同工况下仍能保持一定的精度,表明此模型可用于半主动控制.

为建立准确的磁流变悬架系统动力学仿真模型,通过采集试验数据对仿真模型进行参数辨识与模型修正.结果表明通过参数辨识与模型修正建立的磁流变悬架系统动力学仿真模型能模拟实际模型在不同激励信号下的振动响应.通过修正后的模型分析磁流变阻尼器各结构参数对磁流变悬架减振性能的影响,结果表明无论是在何种类型的激励下阻尼间隙与活塞直径这两种结构参数对磁流变悬架的减振性能影响较大,在正弦激励下活塞直径对悬架的加速度与动载荷影响因子最大,分别为1.2875、1.0727.在道路谱激励下活塞直径对悬架的动载荷影响因子最大,其值为0.8104;而阻尼间隙对车身加速度影响因子最大,其值为0.6355.

The semi-rotary fluid damper is a shock-absorbing device that is widely used for the protections of various mechanical structures. In this research, a new small semi-rotary fluid damper for vibration reduction of helicopter control system is introduced. The damping medium used in the damper is hydraulic oil with a high shear thinning rate, which has a high degree of nonlinear hysteresis and viscoelastic properties. The accuracy of the mechanical model of the damper is of great significance to the design of control strategies for effective vibration reduction. Based on the adaptive genetic algorithm, the parameter identification of the semi-rotary fluid damper is studied with the objective function of minimizing the square of the difference between the analytical force and the experimental force. The Kelvin and generalized Kelvin with friction models lack parameters to properly describe the frequency and amplitude dependence. Therefore, an improved Kelvin model which is based on generalized Kelvin is proposed to capture the nonlinear dynamic characteristics of the damper. Through error analysis, it is concluded that the improved Kelvin model can more accurately describe the nonlinear damping characteristics of the semi-rotary fluid damper subjected to different amplitudes and frequencies.

叶片式阻尼器出力特性具有较强的非线性,为建立准确的力学模型,以实验室的一种叶片式阻尼器为研究对象,对其进行示功试验以获得它的出力特性;以双曲正切模型和双曲正切改进模型为基础,依据示功试验的实验数据选用顺序选择遗传算法辨识出这两种模型的参数,并在Matlab中进行出力仿真.结果表明:仿真得到的示功曲线与实验的示功曲线较为吻合,验证了这两种模型的准确性,双曲正切改进模型对比原模型具有更高的精度.