高超声速飞行器要求其伺服作动系统具有高动态高精度的特性,针对传统控制方法难以兼顾系统动态和精度的难题,本文设计了一种近似时间最优的舵机多模位置控制策略.首先建立了以一阶惯性环节串联积分器表征舵机输入输出特性的特征模型.然后以相平面为分析工具,给出了其近似时间最优控制的切换区;在切换区外以快速性为目标而采用bang-bang最优控制,在切换区内以避免振荡和超调为目标而采用bang-bang次优控制;为提高稳态性能,在小误差时时采用线性控制.实验表明,该方法响应快速,避免了振荡和超调,很好地满足了对伺服作动系统高动态高精度的要求.%Hypersonic vehicle requires its servo actuator systems have high dynamic and high precision features.Due to conventional control methods are difficult to balance system dynamics and precision,a multi-mode position control strategy with approximate time-optimal for actuator is designed in this paper. First,the actuator characteristic model,which is a first order inertia link in series with integrator,is established to express its input-output feature. Then,with phase plane as the analysis tool,the switching zone of approximate time-optimal control is given. At the outside of switching zone,the bang-bang optimal control is applied for rapidity. And at the inside of switching zone,the bang-bang suboptimal control is proposed to avoid oscillation and overshoot. PD control is used at the linear zone for high accuracy in steady state. Experiments indicate that the system response under the algorithm is rapid,with almost zero oscillation and zero overshoot. The control strategy satisfies the requirement of high dynamic and high precision on the servo actuator systems very well.
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