Adaptive Fuzzy PD+ Control for Attitude Maneuver of Rigid Spacecraft

In this paper, an adaptive fuzzy PD+ controller is proposed for the attitude maneuver of rigid spacecraft. The novel controller adjusts the gains of the PD+ attitude controller online according to attitude errors and angular velocity errors during the maneuver procedure. Therefore, quick response and avoidance of actuator saturation can be achieved simultaneously. Furthermore, the adaptation mechanism is designed, based on Lyapunov theory, to guarantee the stability of the closed‐loop system. To achieve good performance of the closed‐loop system under the constraint of actuator saturation, controller parameter optimization is developed on the basis of a genetic algorithm. Simulation results show that the transient performance and robustness against parametric uncertainty and environmental disturbance of the adaptive fuzzy PD+ controller are better than those of a constant PD+ controller.     

带温度补偿的双余度舵机伺服控制算法研究

针对双余度舵机不同控制通道间速度环输出指令存在偏差、电流冲击和输出转矩波动等问题,本文提出了一种带温度补偿的双余度舵机伺服控制算法。首先,采用积分均衡的方法抑制传感器和双通道控制器解算误差引起的速度环输出指令的差异,然后采用电流截止负反馈的方法减小负载扰动和电机过渡过程带来的电流冲击,最后通过对电机进行温度补偿来减小环境温度和本体升温对输出转矩的影响。仿真结果表明,该算法能够有效抑制速度环输出指令误差和减小电流冲击,使电机在不同的工作温度下保持良好的性能。     

Robust non‐fragile H ∞ ∕ L2 − L ∞ control of uncertain linear system with time‐delay and application to vehicle active suspension

This paper presents an approach to design robust non‐fragile H _∞ ∕ L₂ ? L _∞ static output feedback controller, considering actuator time‐delay and the controller gain variations, and it is applied to design vehicle active suspension. According to suspension design requirements, the H _∞ and L₂ ? L _∞ norms are used, respectively, to reflect ride comfort and time‐domain hard constraints. By employing a delay‐dependent Lyapunov function, existence conditions of delay‐dependent robust non‐fragile static output feedback H _∞ controller and L₂ ? L _∞ controller are derived, respectively, in terms of the feasibility of bilinear matrix inequalities. Then, a new procedure based on LMI optimization and a hybrid algorithm of the particle swarm optimization and differential evolution is used to solve an optimization problem with bilinear matrix inequality constraints. Simulation results show that the designed active suspension system still can guarantee their own performance in spite of the existence of the model uncertainties, the actuator time‐delay and the controller gain variations. Copyright © 2014 John Wiley & Sons, Ltd.     

半被动双足机器人控制系统设计

为有针对性地根据不同干扰类型选择正确的抗干扰措施,有必要对无人机数据链所处环境的干扰信号进行分析和分类识别。本文以变换域通信系统(Transform Domain Communication System,TDCS)为载体,对无人机数据链常面临的干扰类型的自动识别进行研究,采用时域、频域、时频联合分析的方法,提出了一组对干信比变化不敏感的特征参数,并利用这组参数提出一种基于决策树理论的干扰分类识别方法,仿真结果表明,该方法能够快速准确地识别出干扰类型,具有很好的鲁棒性,并且在干信比和干噪比在0dB以上时,正确识别率均在90%以上。     

基于光电编码的电动执行机构行程部件的开发

介绍光电编码器的工作原理,提出电动执行机构电子行程部件的设计方法,分析光电编码器在电动执行机构应用中遇到的问题,并提出了解决方案.     

Dynamic behavior of the discrete‐time double integrator with saturated locally stabilizing linear state feedback laws

The main contribution of this paper is to completely characterize the dynamic behavior of the discrete‐time double integrator with a saturated locally stabilizing linear state feedback law. In continuous‐time setting, any linear state feedback control law that locally stabilizes the double integrator also globally stabilizes the system in the presence of actuator saturation. In discrete‐time setting, the equivalent of the double integrator does not have the same property. In this paper, we completely characterize the global behavior of saturated locally stabilizing linear state feedback laws for the discrete‐time double integrator. Copyright © 2012 John Wiley & Sons, Ltd.     

Position control of electro-hydraulic actuator system using fuzzy logic controller optimized by particle swarm optimization

The position control system of an electro-hydraulic actuator system (EHAS) is investigated in this paper. The EHAS is developed by taking into consideration the nonlinearities of the system: the friction and the internal leakage. A variable load that simulates a realistic load in robotic excavator is taken as the trajectory reference. A method of control strategy that is implemented by employing a fuzzy logic controller (FLC) whose parameters are optimized using particle swarm optimization (PSO) is proposed. The scaling factors of the fuzzy inference system are tuned to obtain the optimal values which yield the best system performance. The simulation results show that the FLC is able to track the trajectory reference accurately for a range of values of orifice opening. Beyond that range, the orifice opening may introduce chattering, which the FLC alone is not sufficient to overcome. The PSO optimized FLC can reduce the chattering significantly. This result justifies the implementation of the proposed method in position control of EHAS.     

Adaptive type-2 fuzzy sliding mode controller for SISO nonlinear systems subject to actuator faults

In this paper, an adaptive type-2 fuzzy sliding mode control to tolerate actuator faults of unknown nonlinear systems with external disturbances is presented. Based on a redundant actuation structure, a novel type-2 adaptive fuzzy fault tolerant control scheme is proposed using sliding mode control. Two adaptive type-2 fuzzy logic systems are used to approximate the unknown functions, whose adaptation laws are deduced from the stability analysis. The proposed approach allows to ensure good tracking performance despite the presence of actuator failures and external disturbances, as illustrated through a simulation example.     

用计算机推理的方法求解数字填图问题

模拟人思考问题的过程．尝试用计算机推理的方法求解数字填图问题。     

一类不确定线性系统圆盘极点鲁棒可靠配置

针对一类不确定线性系统,基于线性矩阵不等式（LMI）,给出状态反馈鲁棒控制器的设计算法。利用比离散故障模型更具有实际意义的连续故障模型,给出确定状态反馈鲁棒可靠控制器存在的充分条件,通过求解LMI,确定鲁棒可靠控制器的参数矩阵。所给出的鲁棒可靠控制器,不仅可以保持不确定闭环系统的极点保持在圆盘内,而且能够抵御执行器故障对圆盘极点的影响。一个数值例子说明所给出方法的有效性及可行性。