嫦娥三号着陆控制研究与软件仿真

Soft Landing Process Control of Chang'e 3 Lunar Probe and Software Simulation

嫦娥工程分为3个阶段,目前已经进行到第二阶段,即发射可在月球表面软着陆的登陆器,这便是嫦娥三号的主要任务。为了保证登月探测器在月球表面平稳地降落并且能够有效应对外太空环境下各种因素造成的干扰,需要对控制方案进行深入的研究和认真的设计。选择非线性变结构控制与状态反馈相结合的办法设计控制方案,设定关于系统高度、速度以及加速度等状态变量的性能指标,通过对相应的哈密尔顿函数采用极小值原理来得到变结构控制的相关输入,从而完成控制方案的数学模型。使用Simulink软件对所得到的数学模型分别在理想的情况以及存在干扰的情况下进行仿真,并且得到了满意的仿真结果。所设计的控制方案有一定的可行性,但因为大多数工作只是理论层次的分析,因此还需要进一步的研究。

Chang'e Project can be divided into three steps, and now we are approaching the second step that a lunar probe will be able to land softly on thesurface of the moon, which is also the main task for Chang'e 3. In order to confirm that the lunar probe can land steadily and also have the ability toendure interferes caused by a lot of factors in the space environment, more careful research is needed during the process of designing the control schemeabout the landing of the probe. We have decided to choose a method which combines non-linear variable structure control and state feedback, whichrequires us to set a indicators firstly about the state of the probe system such as height, speed, and acceleration, etc. and then apply minimum principle tothe Hamilton function, which is established from the indicator, so that we can get the proper input of the variable structure control. Thus we have got themathematical model of our control method. Then we use Simulink to do software simulation with the mathematical model in both ideal situation andsituation with interferes, and the result is satisfying. Generally speaking, the control method we have designed have practicality to some extent and workswell, but since most of our work stays on the level of analysis of theories, more practical work is needed.