某高超声速风洞攻角机构参数辨识与控制方法

Parameter Identification and Control Method of a Hypersonic Wind Tunnel Attack Angle Mechanism

针对某高超声速风洞攻角机构,分析其特殊结构特点和运动学规律,对其参数辨识和控制方法进行了研究。首先,对攻角机构进行运动学建模,讨论了俯仰和偏航自由度的非线性运动学模型;针对俯仰和偏航自由度传动链误差因素多的特点,采用激光跟踪仪进行检测,并结合非线性最小二乘方法对其运动学模型中的参数进行了精确拟合。试验结果表明,参数辨识结果满足机构精确定位要求,定位精度优于1'的精度指标。针对俯仰和偏航机构非线性传动的特点和风洞试验对机构速度准确控制的需求,在参数辨识的基础上,采用虚轴、电子凸轮和电子齿轮技术,实现了对俯仰和偏航自由度速度的精确控制,速度控制精度优于0.5(°)/s的精度指标。

Aiming at a hypersonic wind tunnel angle of attack mechanism,its special structural characteristics and kinematics are analyzed,and its parameter identification and control methods are studied.Firstly,the attack angle mechanism is modeled with kinematics,and the nonlinear kinematics models of pitch and yaw degrees of freedom are discussed.Aiming at the characteristics of many error factors in the pitch and yaw degrees of freedom transmission chain,the laser tracker is used to detect and the parameters in the kinematic model are accurately fitted with the nonlinear least square method.The experimental results show that,the parameter identification results meet the precise positioning requirements of the mechanism,the positioning accuracy is better than the accuracy index of 1'.In view of the characteristics of the nonlinear transmission of the pitch and yaw mechanism and the need for accurate control of the mechanism speed in the wind tunnel test,on the basis of parameter identification,the virtual axis,electronic cam and electronic gear technology are used to achieve the speed of pitch and yaw degrees of freedom precise control,speed control accuracy is better than the accuracy index of 0.5(°)/s.