火星着陆器的大气进入段有限时间抗干扰制导律设计
Finite Time Anti-Disturbance Guidance Law Design for Mars Entry
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摘要: 考虑含有外部干扰影响下的火星着陆器的大气进入段制导律设计问题,提出一种基于阻力跟踪的复合制导策略。首先,根据火星着陆器的动力学模型,并结合阻力曲线定义,给出了含有外部干扰的阻力剖线动态方程;其次,为了保证系统有良好的抗干扰性能和较快的跟踪速度,基于阻力剖线动态方程,设计了有限时间反馈制导律;然后,为进一步提高系统的抗干扰能力,设计了干扰观测器,估计未知干扰,利用干扰估计值前馈补偿,最终形成复合制导律。最后,通过对比仿真验证了该方法的有效性和优越性。Abstract: This paper considers the guidance design for Mars entry vehicles with disturbance modulation, providing a composite strategy based on drag. First, according to dynamic equations of the vehicle and combining with the definition of drag, the drag dynamic equation contained with disturbance is given. Second, in order to make sure the system obtain a better anti-disturbance performance and more quickly track speed, the finite time feedback guidance law is designed based on drag dynamic equation. With the purpose of further improving the anti-disturbance ability, a disturbance observer is designed to estimate unknown disturbance and the estimated value is used for feed-forward compensation, then a composite law is obtained. In the end, a comparison simulation is carried out to examine the efficiency and superiority of this strategy.