基于IDRA法的直升机动力学建模

Dynamics modeling for helicopter based on IDRA approach

为加快直升机动力学模型的解算速度,基于拉格朗日方程,以一个仿真步长内机身的微小位移和转角(IDRA)为广义坐标,提出了直升机动力学建模的IDRA法,简化了相邻步长间机体坐标系的转化矩阵,节省了CPU计算时间.同时,将直升机轮胎视为带有黏性阻尼的三维线性弹簧,将其势能、动能和耗散能用新的广义坐标表示,建立了集飞行与着陆于一身的机身动力学模型.实验结果表明:与传统方法相比,利用IDRA法可以节省1/3的CPU计算时间,飞行与着陆之间曲线过渡合理,从而验证了该方法的可靠性和实时性.

In order to speed up the algorithm of helicopter dynamics model,based on Lagrange equa-tion,treating micro displacements and rotating angles of airframe in a simulation step as generalized coordinates ,an IDRA （infinitesimal displacements and rotation angle）approach for helicopter dynam-ics modelling was presented,which simplified transformation matrixes of airframe coordinates be-tween adjacent simulation steps.In this way,the CPU computing time was greatly saved.Mean-while,each tyre of helicopter was viewed as three-dimensional linear springs with viscous dampings, and its potential energy,kinetic energy and energy dissipation of airframe were expressed in the pres-ented generalized coordinates.So,the dynamic model of airframe which involved flight as well as landing was established.Experimental results show that IDRA approach can save 1/3 amount of CPU time that was spent in computing compared with the traditional approach and transition curves be-tween flight and landing are reasonable,which can verify the relilability and real-time of the method.