直升机磁流变座椅悬架缓冲系统模糊控制器设计

Design of fuzzy controller for helicopter seat suspension with magnetorheological energy absorber

针对直升机座椅悬架缓冲控制问题,文章建立了结合磁流变耗能器的单自由度磁流变座椅悬架缓冲系统动力学模型。为了保证耗能器在充分耗散冲击能量的同时避免传递到人体的冲击力峰值超出人体的伤害限,以“软着陆”为控制目标,以磁流变耗能器活塞运动速度及位移作为模糊控制器的输入、阻尼器阻尼力作为控制输出设计模糊控制器的结构和控制规则,实现输出力位移曲线的“平台效应”。最后分别在6~12 m/s冲击作用速度下,通过数值仿真验证了所设计的模糊控制器的有效性,即传递到人体的冲击载荷低于人体的伤害限的同时耗能器耗能最大。与现有的线性恒定总力控制器、恒定屈服控制策略进行缓冲效果对比,结果表明:模糊控制器在实现“平台效应”、“软着陆”控制目标的同时能有效避免二次反弹。

This paper focuses on the fuzzy controller design for the helicopter seat suspension with a magnetorheological energy absorber(MREA).Firstly,a single-degree-of-freedom dynamic model of magnetorheological seat suspension system was established.To guarantee that MREA can fully dissipate the impact energy and avoid the peak value of the impact force to exceed the injury limit endured by the human body,“soft landing”and realizing the platform effect of the output force-displacement curve were the control objectives.With consideration of the nonlinear of impact system and varying loads,a fuzzy controller(FC)with the characteristics of nonlinear and strong robustness was designed by employing the piston motion speed and displacement as inputs of FC and the force generated by MREA as output.Finally,under the impact velocity of 6-12 m/s,the effectiveness of the designed FC was verified through numerical simulation.The results show that the impact load transmitted to the human body is lower than the human body’s injury limit,and the impact energy is absorbed fully by MREA.Meanwhile,compared with existing linear constant total force controller and constant yield controller,the proposed FC can effectively avoid the secondary rebound while achieving the objectives of the platform effect and soft landing.