电磁刺激对FHN神经元系统的调控作用

本文系统地研究了外加电磁刺激对FitzHugh-Nagum。(FHN)神经元系统动力学行为的调控作用。首先,在强非线性电磁感应的作用下,FHN神经元对外加电磁刺激的响应呈现显著的非线性变化特点,不仅能够产生混沌的放电现象,而且还出现了不同放电模式之间的转迁。其次,在电磁感应的作用下,周期振g的电磁刺激对Newman-Watts小世界的神经元网络的脉冲放电频率和同步性都能够进行有效地调控,不仅提高了神经元网络对局部弱激励信号的探测和响应能力,而且能有效地控制网络时空斑图从相位同步到完全同步的演化。本文的研究揭示了电磁刺激对单个神经元和神经元网络系统动力学行为的显著调控能力,有待为生理上应用电磁刺激辅助治疗精神疾病提供理论指导。     

直线电机直接驱动的伺服刀架控制器的研究

分析了以直线电机直接驱动下的高频响伺服刀架为核心的非圆截面加工系统的控制结构 ;从小增益定理出发, 阐述了伺服刀架的最大动态柔度与系统稳定性的关系 ;分别分析了速度单闭环、速度位置双闭环控制对性能的影响. 在双闭环控制器的设计中, 运用了H∞ 控制理论, 综合考虑了跟踪性能、动态柔度、控制能量等因素, 所设计的控制器较传统的超前_滞后网络有明显的改进.     

Neural oscillator based control for pathological tremor suppression via functional electrical stimulation

This paper explores the possibility to adopt neural oscillators for pathological tremor attenuation. The objective is to suppress the tremor of a single joint of upper limb via functional electrical stimulation (FES). A biologically inspired neural oscillator is developed, which generates the anti-tremor rhythmic stimulation patterns to stimulate a pair of antagonist muscles. Surface electromyographic (EMG) signal is used to entrain the neural oscillator reciprocally and shape the stimulation pattern adaptively. The neural oscillator serves as an adaptive feedforward controller, which is combined with a feedback regulator. Simulation study is performed on musculoskeletal models of wrist joint and elbow joint separately, and some promising results are presented.     

Nonlinear model predictive control of functional electrical stimulation

Minimizing the amount of electrical stimulation can potentially mitigate the adverse effects of muscle fatigue during functional electrical stimulation (FES) induced limb movements. A gradient projection-based model predictive controller is presented for optimal control of a knee extension elicited via FES. A control Lyapunov function was used as a terminal cost to ensure stability of the model predictive control. The controller validation results show that the algorithm can be implemented in real-time with a steady-state RMS error of less than 2°. The experiments also show that the controller follows step changes in desired angles and is robust to external disturbances.     

船舶航向模型参考模糊自适应控制器的设计

本文介绍了模型模糊自适应控制器的结构，调节机理。针对船舶航向控制，设计了参考模型模糊自适应控制器，并进行了仿真。与普通模糊控制器控制效果进行了比较，仿真表明参考模型模糊自适应控制有良好的控制性能。     

Robust distributed MPC for load frequency control of uncertain power systems

Reliable Load frequency control (LFC) is crucial to the operation and design of modern electric power systems. However, the power systems are always subject to uncertainties and external disturbances. Considering the LFC problem of a multi-area interconnected power system, this paper presents a robust distributed model predictive control (RDMPC) based on linear matrix inequalities. The proposed algorithm solves a series of local convex optimization problems to minimize an attractive range for a robust performance objective by using a time-varying state-feedback controller for each control area. The scheme incorporates the two critical nonlinear constraints, e.g., the generation rate constraint (GRC) and the valve limit, into convex optimization problems. Furthermore, the algorithm explores the use of an expanded group of adjustable parameters in LMI to transform an upper bound into an attractive range for reducing conservativeness. Good performance and robustness are obtained in the presence of power system dynamic uncertainties.     

SR电机单神经元PID直接转矩控制系统

针对采用常规PID控制器很难取得很好的控制效果,提出了单神经元PID与常规PID复合控制的开关磁阻电机调速系统的新方法,利用具有自学习和自适应能力的单神经元来构成开关磁阻电机的单神经元自适应控制器,不但结构简单,而且能适应环境变化,具有较强的鲁棒性。以速度误差为系统外环输入,大偏差时采用常规PID控制,小偏差时采用单神经元控制。外环的输出变量为内环的目标转矩,送入60kW三相6/4结构的开关磁阻电机直接转矩调速系统内环。仿真结果表明,这种复合控制方法解决了常规控制方法因电机数学模型难以精确确定而无法确定控制参数的问题,并克服了常规P I D控制器参数固定,控制非线性系统差的缺点,很好的解决了系统上升时间与超调的矛盾。系统具有很好的抗干扰能力与鲁棒性。     

The Trace Model: A model for simulation of the tracing process during evacuations in complex route environments

In emergency evacuations, not all pedestrians know the destination or the routes to the destination, especially when the route is complex. Many pedestrians follow a leader or leaders during an evacuation. A Trace Model was proposed to simulate such tracing processes, including (1) a Dynamic Douglas–Peucker algorithm to extract global key nodes from dynamically partial routes, (2) a key node complementation rule to address the issue in which the Dynamic Douglas–Peucker algorithm does not work for an extended time when the route is straight and long, and (3) a modification to a follower’s impatience factor, which is associated with the distance from the leader. The tracing process of pupils following their teachers in a primary school during an evacuation was simulated. The virtual process was shown to be reasonable both in the indoor classroom and on the outdoor campus along complex routes. The statistical data obtained in the simulation were also studied. The results show that the Trace Model can extract relatively global key nodes from dynamically partial routes that are very similar to the results obtained by the classical Douglas–Peucker algorithm based on whole routes, and the data redundancy is effectively reduced. The results also show that the Trace Model is adaptive to the motions between followers and leaders, which demonstrates that the Trace Model is applicable for the tracing process in complex routes and is an improvement on the classical Douglas–Peucker algorithm and the social force model.     

永磁直线同步电动机的模型参考逆方法控制

由于永磁直线同步电动机结构方面的特殊性,存在边端效应、铁心开断、初级绕组分布不对称等,具有很强的耦合性。文章对此提出采用模型参考逆方法控制方案,该控制方案兼有模型自适应控制及逆系统控制等方案的特点,且具有很强的抗干扰能力。仿真结果表明,在达到同一性能要求下,该控制方案简单,更具实用性。