This paper considers minimization of resistive and frictional power dissipation in a separately excited DC motor based incremental motion drive （IMD）. The drive is required to displace a given, fixed load through a ...This paper considers minimization of resistive and frictional power dissipation in a separately excited DC motor based incremental motion drive （IMD）. The drive is required to displace a given, fixed load through a definite angle in specified time, with minimum energy dissipation in the motor windings and minimum frictional losses. Accordingly, an energy optimal （EO） control strategy is proposed in which the motor is first accelerated to track a specific speed profile for a pre-determined optimal time period. Thereafter, both armature and field power supplies are disconnected, and the motor decelerates and comes to a halt at the desired displacement point in the desired total displacement time. The optimal time period for the initial acceleration phase is computed so that the motor stores just enough energy to decelerate to the final position at the specified displacement time. The parameters, such as the moment of inertia and coefficient of friction, which depend on the load and other external conditions, have been obtained using system identification method. Comparison with earlier control techniques is included. The results show that the proposed EO control strategy results in significant reduction of energy losses compared to the existing ones.展开更多
针对中国首次自主火星探测任务——“天问一号”行星际转移及环绕飞行过程面临的器–地数据传输延时长、飞行过程指向约束多、自主可靠要求高等难题,提出了基于火星光学目标特性测量的自主导航、推力方向补偿的速度矢量控制以及多目标...针对中国首次自主火星探测任务——“天问一号”行星际转移及环绕飞行过程面临的器–地数据传输延时长、飞行过程指向约束多、自主可靠要求高等难题,提出了基于火星光学目标特性测量的自主导航、推力方向补偿的速度矢量控制以及多目标指向基准优化的角动量管理方法。通过对火星时变目标特性的自适应边缘提取和基于椭球模型的边缘精确拟合,获得目标高精度导航观测信息,实现近火导航精度优于100 km、环火导航精度优于2 km;采用基于加速度计测量的推力方向实时估计及姿态前馈补偿,使制动捕获控制精度达到mm/s量级;结合多目标指向约束,以干扰力矩全局最优为目标进行姿态基准优化设计,保障超过30天无地面支持下的自主飞行控制。将其应用于“天问一号”环绕器制导、导航与控制(Guidance,Navigation and Control,GNC)分系统中,“天问一号”在轨飞行结果表明,所提方法能够满足星际飞行自主控制和自主管理的约束,为后续深空探测型号任务提供重要参考。展开更多
文摘This paper considers minimization of resistive and frictional power dissipation in a separately excited DC motor based incremental motion drive （IMD）. The drive is required to displace a given, fixed load through a definite angle in specified time, with minimum energy dissipation in the motor windings and minimum frictional losses. Accordingly, an energy optimal （EO） control strategy is proposed in which the motor is first accelerated to track a specific speed profile for a pre-determined optimal time period. Thereafter, both armature and field power supplies are disconnected, and the motor decelerates and comes to a halt at the desired displacement point in the desired total displacement time. The optimal time period for the initial acceleration phase is computed so that the motor stores just enough energy to decelerate to the final position at the specified displacement time. The parameters, such as the moment of inertia and coefficient of friction, which depend on the load and other external conditions, have been obtained using system identification method. Comparison with earlier control techniques is included. The results show that the proposed EO control strategy results in significant reduction of energy losses compared to the existing ones.
文摘针对中国首次自主火星探测任务——“天问一号”行星际转移及环绕飞行过程面临的器–地数据传输延时长、飞行过程指向约束多、自主可靠要求高等难题,提出了基于火星光学目标特性测量的自主导航、推力方向补偿的速度矢量控制以及多目标指向基准优化的角动量管理方法。通过对火星时变目标特性的自适应边缘提取和基于椭球模型的边缘精确拟合,获得目标高精度导航观测信息,实现近火导航精度优于100 km、环火导航精度优于2 km;采用基于加速度计测量的推力方向实时估计及姿态前馈补偿,使制动捕获控制精度达到mm/s量级;结合多目标指向约束,以干扰力矩全局最优为目标进行姿态基准优化设计,保障超过30天无地面支持下的自主飞行控制。将其应用于“天问一号”环绕器制导、导航与控制(Guidance,Navigation and Control,GNC)分系统中,“天问一号”在轨飞行结果表明,所提方法能够满足星际飞行自主控制和自主管理的约束,为后续深空探测型号任务提供重要参考。
