基于二阶滑模算法的航天器相对位姿耦合控制研究

发布时间：2018-05-03 18:46

本文选题：自主在轨服务 + 自主交会对接　；参考：《哈尔滨工业大学》2015年博士论文

【摘要】：随着空间探索任务取得重大成功,自主在轨服务技术受到了广泛关注。就成本效应而言,对受损卫星进行在轨维修具有潜在的节约效益。因此,对目标航天器进行在轨维修、装配、升级等具有重大意义。未来在轨服务任务需要航天器能够自主执行交会对接操作,甚至涉及对自由翻滚的失控航天器进行在轨服务。于是,与失控目标进行自主交会对接控制成为必需解决的关键技术。本文主要研究了与自由翻滚目标航天器进行自主交会对接过程的相对位姿耦合控制算法,深入讨论了基于二阶滑模算法的航天器对接端口间相对位姿耦合控制器设计方法。针对各控制器对不确定性和有界干扰的鲁棒性、有限时间收敛特性以及抑制执行机构震颤效应的能力进行分析与验证。主要包括以下内容:分析航天器对接端口间相对运动关系,总结出三种可行位置关系端口间的交会对接方式。以此为基础,考虑航天器相对旋转运动对相对平移运动的耦合影响,建立航天器对接端口间相对位姿耦合动力学模型。分析出所建相对运动模型中各耦合项来源:航天器所受干扰力矩产生的动力学耦合;相对姿态四元数、相对姿态角速度与服务航天器绝对姿态角速度产生的运动学耦合。通过数学仿真,在开环无控制情况下验证各耦合项对相对平动运动状态的影响效果。利用MATLAB与STK接口程序实现交会对接控制的可视化设计,并验证三种对接方式的可行性、安全性和可靠性。为改善标准Twisting滑模算法的控制特性,以二阶滑模平面设计改进的Twisting控制器。利用李雅普诺夫稳定性理论分析其有限时间收敛特性,并给出计算收敛时间上界的方法。通过数学仿真,验证所设计改进Twisting算法的控制特性。针对二阶滑模算法对距离原点较远有界干扰鲁棒性较弱的问题,以两种形式滑模平面分别设计含线性补偿项的改进Twisting控制器。选取新的李雅普诺夫函数证明其有限时间收敛特性,同时得到收敛时间的上界。通过数学仿真,验证其抑制距离原点较远有界干扰的鲁棒性;计算稳态阶段控制力与力矩绝对值冲量累积和来检验其减弱执行机构抖颤的效果。利用Super Twisting(ST)控制算法无需计算滑模变量对时间导数的特点,设计航天器对接端口间相对位姿耦合的ST控制器。基于李雅普诺夫方法分析其有限时间收敛的特性,并计算收敛时间上界。通过数学仿真,验证ST控制器的收敛特性以及对模型不确定性和距离原点较远有界干扰的鲁棒性。类似地,将ST算法与线性控制相结合来提高系统对距离原点较远有界干扰的鲁棒性。选取新的李雅普诺夫函数证明改进ST控制器仍然可以在有限时间内收敛到平衡点,并计算出收敛时间上界。通过对比仿真,验证闭环系统对参数不确定性及不同形式有界干扰作用的鲁棒性,同时利用稳态时控制力与力矩的绝对值冲量累积和检验其抑制执行机构震颤作用的能力。为了进一步提高二阶滑模控制器对距离原点较远有界干扰的鲁棒性,利用自适应思想动态计算控制器的增益矩阵。针对已知上界有界干扰与未知上界有界干扰两种情况,考虑模型参数不确定性以及相对导航误差等因素,分别设计基于自适应ST算法的航天器对接端口间相对位姿耦合控制器(记作AST1与AST2)。利用李雅普诺夫稳定性理论证明其有限时间收敛到平衡点的特性,同时给出收敛时间上界的计算方法。通过数学仿真,验证各控制器对不同形式有界干扰作用和模型参数不确定性的鲁棒性,同时根据稳态阶段控制力与力矩绝对值冲量累积和证明其降低执行机构震颤的效果。通过对比可知:AST2在参数不变的情况下具有更广泛的适应性,对距离原点较远有界干扰的鲁棒性更强。
[Abstract]:With the great success of the space exploration task, the independent on orbit service technology has been widely concerned. As far as the cost effect is concerned, the maintenance of the damaged satellite in orbit is of potential saving benefit. Therefore, it is of great significance to carry out on orbit maintenance, assembly and upgrading of the target spacecraft. The master executes rendezvous and docking operations, and even involves in orbit services for free roll out of out of control spacecraft. Therefore, the control of autonomous rendezvous and docking with the runaway target becomes the key technology to be solved. This paper mainly studies the relative position and attitude control algorithm of the free rendezvous spacecraft in the autonomous rendezvous process. The design method of relative position and attitude coupling controller for spacecraft docking port based on the two order sliding mode algorithm is discussed. The robustness of the uncertainties and bounded disturbances, the finite time convergence and the ability to suppress the tremor effect of the actuator are analyzed and verified. The main contents are as follows: the analysis of the docking of spacecraft The relative motion relationship between ports is summarized, and the rendezvous and docking mode between three feasible positions is summarized. On this basis, considering the influence of the relative rotation motion of the spacecraft on the relative translational motion, a dynamic model of the relative position and posture coupling between the docking ports of the spacecraft is set up. The coupling sources in the relative motion model are analyzed. The dynamic coupling of the disturbance caused by the spacecraft, the relative attitude four elements, the relative attitude angular velocity and the kinematic coupling of the absolute attitude angular velocity of the service spacecraft. Through the mathematical simulation, the effects of the coupling items on the relative translational motion state are verified under the open loop uncontrolled condition. The MATLAB and the STK interface program are used. The visual design of the control of the rendezvous and docking (rendezvous and docking) is designed, and the feasibility, security and reliability of the three kinds of docking methods are verified. In order to improve the control characteristics of the standard Twisting sliding mode algorithm, the improved Twisting controller is designed with the two order sliding mode plane design. The finite time convergence characteristic of the method is analyzed by Lyapunov stability theory, and the convergence of the calculation is given. The method of time upper bound is used to verify the control characteristics of the improved Twisting algorithm by mathematical simulation. Aiming at the problem that the two order sliding mode algorithm has weak robustness to the far bounded disturbance in the distance origin, the improved Twisting controller with linear compensation terms is designed by the sliding mode plane in two forms. The new Lyapunov function is selected to prove the new Lyapunov function. The finite time convergence characteristic and the upper bound of the convergence time are obtained. Through mathematical simulation, the robustness of the far bounded disturbance is verified by the mathematical simulation. The effect of calculating the absolute value impulse of the control force and torque in the steady stage is calculated and the effect of reducing the tremor of the actuator is tested. The Super Twisting (ST) control algorithm does not need to calculate the sliding mode The characteristic of the variable to the time derivative is designed to design the relative position and pose coupling ST controller between the docking ports of the spacecraft. Based on the Li Yapu method, the characteristics of the finite time convergence are analyzed and the upper bound of the convergence time is calculated. Through the mathematical simulation, the convergence characteristics of the ST controller and the far bounded disturbance to the model uncertainty and the distance origin are verified. In the same way, the ST algorithm is combined with linear control to improve the robustness of the system to the far bounded disturbance. A new Lyapunov function is selected to prove that the improved ST controller can still converge to the equilibrium point in a limited time and calculate the convergence time. In order to further improve the robustness of the two order sliding mode controller to the far bounded disturbance, the adaptive thought dynamic calculation is used to further improve the robustness of the two order sliding mode controller to the far bounded disturbance of the distance origin. The gain matrix of the controller is used to design the relative position and attitude coupling controller (AST1 and AST2) for spacecraft docking port based on the uncertainties of the model parameters and relative navigation error, considering the two known upper bound bounded disturbance and the unknown upper bound interference, and the adaptive ST algorithm is designed to use Lyapunov stability. The theory proves that the finite time converges to the characteristic of the equilibrium point, and gives the calculation method of the upper bound of the convergence time. Through the mathematical simulation, the robustness of the controllers to different forms of bounded interference and model parameter uncertainty is verified. At the same time, the control of the absolute value of the control force and torque in the steady state is accumulated and its execution is proved to be reduced. The effect of mechanism tremor shows that AST2 has more extensive adaptability in the condition of constant parameters, and is more robust to distant and bounded disturbance.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：V448.2

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