基于双闭环速度控制的捕获轨迹系统

中国现有高速风洞捕获轨迹（CTS）试验采用闭环形式的位置控制方式，外挂物模型处于间歇式运动模式，导致试验效率较低和可能出现“假碰撞”。鉴于此，提出了一种双闭环速度控制策略，通过建立外挂物模型的气动力/力矩误差控制环，动态产生最优速度变换尺度，在试验过程中始终以外挂物模型运动速度为控制目标，实现了CTS试验速度控制方式。地面仿真和风洞试验结果表明：双闭环速度控制策略原理正确，获得的轨迹与位置控制方式具有较好的一致性，而且克服了可能出现的“假碰撞”现象，试验时间缩短一半，数据重复性好，获得的轨迹数据信息大幅增加。证明该双闭环速度控制策略具有广阔的应用前景。

A Captive Trajectory System Using Double Closed-loop Velocity Control

The captive trajectory simulation (CTS) system can be operated in two modes, the position control mode and the velocity control mode. Position control mode with closed-loop is employed in existing CTS systems of high-speed wind tunnels. Its disadvantages are low efficiency and possible off-trajectory collisions caused by positioning the store model using a "move and pause" technique. Therefore, a velocity control strategy with a double closed-loop is investigated in this paper by establishing an error control loop for the forces and moments caused by the airflow on the store model. The velocity control strategy allows the store model to move continuously along the trajectory, dynamically generating the proper velocity scaling and always positioning the store using velocity control commands while a trajectory is being generated thus finally realizing the velocity control of the CTS. Simulation experiments and wind tunnel tests show that the principle is correct, its trajectories compare favorably with those obtained by the position control mode, while the productivity is increased by about 50%. A greater number of points on the trajectory can be obtained, and the off-trajectory collisions are eliminated. Therefore the double closed-loop strategy is satisfactory and has broad application prospects.