考虑负载均衡的过驱动航天器推力器分配方法

Thruster Allocation for Overactuated Spacecraft with Load Balancing

以过驱动航天器的推力器控制分配误差最小、推力器负载均衡等为设计目标,构建航天器推力分配混合优化模型,并将其转化为线性规划模型进行求解,提出了一种考虑负载均衡的航天器推力器动态分配算法。该算法在确保分配误差最小前提下,能够降低各推力器的最大分配推力之差,有效均衡各推力器总工作时长和开关次数,进而延长推进系统的整体工作寿命。进一步定义了表征负载均衡性能的推力平衡度和干扰敏感度性能指标,并在此基础上给出了一种分配算法负载均能能力的定量化评价方法。在仿真验证中,采用平衡度和敏感度对算法性能进行定量评估,结果表明该方法在保证控制性能和控制分配误差的前提下,能够有效均衡各推力器最大推力,提高了系统的平衡度和对扰动力矩的鲁棒性。

In this paper,a new balanced control allocation algorithm among thrusters in spacecraft is investigated and a new design method variance is proposed to minimize the tracking error and balance the allocated thrusters. Then the problem is formulated as a mixed min-max model and solved by using linear programming method. The algorithm takes tracking error into consideration,reduces the maximum allocated values and balances working time and on-off switches times among thrusters,thus improving the service lifetime of the whole propulsion system. By defining two indexes,thrust balanced level and sensitivity to disturbance torque,it is shown how to evaluate the control allocation algorithm. In simulation,both balanced level and sensitivity are used to evaluate the performance of method. The result shows the algorithm can balance the allocated signals among thrusters,and improve the balanced level and robustness to disturbance torque.