非线性奇异系统非交互控制的反馈实现

研究非线性奇异系统的非交互控制的反馈实现问题．首先给出了非线性奇异系统的向量相对阶与其非交互控制实现的关系；然后对正则非线性奇异系统的反馈控制系统的非交互控制的实现问题，给出了一种可使系统实现非交互控制的反馈律的构造方法。     

一种带有界噪声的鲁棒非奇异自适应控制

针对具有未知噪声上界的确定性连续时间系统,给出了一种鲁棒非奇异自适应极点配 置控制算法.解决了受扰非最小相位系统在自适应控制过程中可能出现的奇异性问题,弱化 了控制器对未知受控系统的先验信息需求,给出了BIB0全局渐近稳定性证明.     

电气系统最优控制的计算机辅助设计与仿真

本文考虑了电枢电路方程和电感，研究了第一类电力拖动和最小能耗控制，给出了数学模型，计算方法，程序和计算结果。结果表明，这种最优控制满足各种物理限制的要求，轨线平滑。接近于实际情况，因此便于工程实现。其性能指标（电枢电路损耗）也低于通常的电流Ｂａｎｇ－Ｂａｎｇ型控制。     

滞后离散线性定常系统的准滑模变结构控制

研究了滞后离散线性定常系统的准滑模变结构控制问题,给出了滞后离散线性定常系 统的准滑模,理想准滑模,非理想准滑模与准滑模带的概念;还给出了实现准滑模的条件.通过 非奇异线性变换,将上述系统化成了简约型,并给出了变结构控制律的设计方案.利用Lyapunov 函数法,证明了系统准滑模的稳定性.     

多输入下三角系统的几何描述

针对多输入情形,考虑非线性系统通过坐标变换和状态反馈等价于下三角系统的问题.首先给出了多输入下三角非线性系统的两种基本形式.利用奇异分布的有关理论,给出了多输入非线性系统通过反馈等价于非自治下三角形式系统的充要条件.借助算法说明了如何通过状态反馈和坐标变换实现上述系统间的等价转换.     

离散对象的降阶H∞控制器设计

基于LMI方法,考虑了离散对象的阶数不超过广义对象阶的降阶H∞控制器存在性问题.通过3LMIs可解性条件的等价变换,给出了一个降阶控制器的上界.该上界可适用于奇异和非奇异对象两种情形,且在奇异情形不为已有结果蕴涵.证明是构造性的,当降阶控制器存在时,可以设计出这种控制器.最后给出了两个简单的算例,说明文中方法的可行性.     

一类非线性不确定系统的非奇异Terminal滑模控制

针对一类二阶非线性系统提出新的Terminal滑模控制面以克服传统的Terminal滑模控制的奇异问题，同时确保系统从任何初始状态能在有限时间内收敛至平衡点．进一步考虑系统参数摄动和外界扰动等不确定性因素上界的未知性，用Lyapunov稳定性方法给出了一个带有未知性上界参数估计的自适应非奇异Terminal滑模控制（NTSM）控制．最后通过实例比较三种滑模控制方法，仿真结果验证了非奇异Terminal滑模控制能克服传统的Terminal滑模控制的奇异问题，并说明了自适应非奇异Terminal滑模控制的有效性和可行性．     

奇异Lur'e网络的自适应牵制聚类同步控制

本文分别研究了由奇异和非奇异Lur''e系统组成的具有多种耦合方式时滞复杂动态网络的聚类同步问题. 通过设计一类牵制反馈控制器, 仅控制当前聚类中与其它聚类有直接连接的Lur''e系统, 从而有效减少控制器个数同时降低控制成本. 考虑到网络具有多种耦合方式, 本文合理构造Lyapunov 泛函, 并有效利用扇形条件、非线性函数类概念、S过程以及Lyapunov 稳定性定理等方法, 分别给出奇异和非奇异Lur''e 动态网络实现聚类同步的判定条件. 此外, 为有效节省控制成本, 针对控制强度设计一类自适应更新定律, 从而得到网络实现聚类同步的最优控制强度. 最后, 为了验证所得聚类同步判定条件和控制器的有效性, 对一类典型Lur''e网络聚类同步问题进行了数值仿真.     

可靠通信的多跳水声网络能量最小路径

目前对水声网络能耗的研究并未考虑因数据发送失败而引起的数据重发导致的额外的能耗。研究在给定接收信噪比条件下可靠通信的多跳水声网络能量最小路径问题。首先建立了可靠通信的网络能量模型,通过曲线拟合的方法得到最优频率-距离关系的近似表达,以简化能耗模型;然后分析了可变发送功率和固定发送功率两种模式下的能量最小路径,从理论上证明了直线等距网络的总能耗最小,并给出了直线等距网络最优跳数和最优距离的求解方法。仿真结果验证了该理论的正确性。     

离散对象的降阶H∞控制器设计

基于LMI方法, 考虑了离散对象的阶数不超过广义对象阶的降阶H_∞ 控制器存在性问题. 通过3LMIS可解性条件的等价变换, 给出了一个降阶控制器的上界. 该上界可适用于奇异和非奇异对象两种情形, 且在奇异情形不为已有结果蕴涵. 证明是构造性的, 当降阶控制器存在时, 可以设计出这种控制器. 最后给出了两个简单的算例, 说明文中方法的可行性.     

Minimum-energy cornering trajectory planning with self-rotation for three-wheeled omni-directional mobile robots

A minimum-energy cornering trajectory planning with self-rotation algorithm is investigated for three-wheeled omni-directional mobile robots (TOMRs). First, an generalized minimum-energy point-to-point trajectory planning algorithm is studied, which is obtained using Pontryagin’s minimum principle, a practical cost function as the energy drawn from the batteries to motors, and the accurate TOMR dynamic model including actuator dynamics and the Coriolis force. By analyzing the co-state equation, the minimum-energy rotational velocity trajectory is presented in analytic form. Also a novel algorithm for the minimum-energy translational velocity trajectory is investigated. Second, the minimum-energy cornering trajectory planning algorithm with self-rotation is developed. Simulation results show that the minimum-energy cornering trajectory can save energy up to 15.20%compared with the conventional control using trapezoidal velocity profiles, and up to 3.96 % compared with the loss-minimization control using the armature loss as the cost function. Also a resolved-acceleration controller is implemented to show an actual performance.

     

BLDCM控制系统功率逆变电路发热分析及实验验证

针对BLDCM控制系统功率逆变电路能耗问题,分析了功率器件工作时产生损耗的机理,探讨了PWM斩波方式、斩波频率及BLDCM绕组电感3个因素对功率逆变电路发热的影响并进行了相应实验验证,给出了不同条件下BLDCM电枢绕组电流波形和功率器件温升实验数据,对降低BLDCM控制系统功率逆变电路损耗进而提高控制系统效率、增强工作可靠性、提升BLDCM控制系统使用寿命等具有重要的理论及工程应用价值。     

Minimum-energy time-varying formation of distributed multi-agent systems with interaction constraints

In the current paper, minimum-energy time-varying formation design and analysis problems of distributed multi-agent systems (DMASs) subjected to randomly switching topologies and aperiodic interaction pauses are investigated, which can ensure the time-varying formation achievement with the minimum-energy consumption in the sense of the linear matrix inequality. Firstly, a formation control protocol is designed with local information of neighboring agents, where the total energy consumption during the formation process is constructed and the impacts of interaction constraints are imposed. Then, minimum-energy formation design and analysis criteria of DMASs are presented in terms of the linear matrix inequality tool, which can be checked by the generalized eigenvalue method. Finally, a numerical simulation is shown to verify the effectiveness of the main results.     

Pre- and post-filtering approach to sensorless VSS speed control of a permanent magnet DC motor subject to Hammerstein and Wiener nonlinearities

In this paper, we propose a pre- and post-filtering approach to output feedback variable structure control of a permanent magnet DC servo motor under constant inertial load. The proposed control method is to regulate the motor speed by using the armature current measurement alone. Both the Hammerstein nonlinearity for the system input end and the Wiener nonlinearity for the output end are considered. With these static nonlinear functions carefully identified and their inverses fitted, the linearized model renders a simple dynamic mapping from the armature current to the sliding variable, which is designed as a dynamic function of the motor angular velocity. The pre-filter is the inverse of the Hammerstein function. The post-filter consists of two blocks in series: the inverse of the Wiener function and the concatenating dynamic filter, which is a linear relationship between the armature current and the sliding variable. The proposed method is robust against parameter variations in the electric subsystem such as the armature inductance and resistance.     

A minimum-energy path-preserving topology control algorithm for wireless sensor networks

The topology control strategies of wireless sensor networks are very important for reducing the energy consumption of sensor nodes and prolonging the life-span of networks. In this paper, we put forward a minimum-energy path-preserving topology control （MPTC） algorithm based on a concept of none k-redundant edges. MPTC not only resolves the problem of excessive energy consumption because of the unclosed region in small minimum-energy communication network （SMECN）, but also preserves at least one minimum-energy path between every pair of nodes in a wireless sensor network. We also propose an energy-efficient reconfiguration protocol that maintains the minimum-energy path property in the case where the network topology changes dynamically. Finally, we demonstrate the performance improvements of our algorithm through simulation.     

Optimal control of 2-D systems

Two-dimensional (2-D) optimal control theory that parallels one-dimensional (1-D) optimal control is developed. A generalized performance measure suited to 2-D systems is introduced. The canonical equations associated with this performance measure and a general nonlinear model are obtained. The 2-D linear quadratic regulator problem is formulated, and its canonical equations are derived for the Roesser model. An earlier result by T. Kaczorek and J. Klamka (1986) for the solution of the minimum-energy problem with fixed-final local state is rederived using this approach. A new problem, minimum-energy with fixed-final-pass local states is formulated and solved, and a numerical example is given     

A spline-theoretic approach to minimum-energy control

The problem of minimum-energy control of linear systems with linear functional constraints on the output is considered from a spline-theoretic viewpoint. It is shown that constrained minimum-energy control and spline interpolation are dual projection problems: if the given system is driven by the minimum-energy control, the system output will be the spline that interpolates the output constraints. This duality result is used to obtain a simple formula for the exact optimal control under very general constraints.     

Self-sensing magnetic levitation using a LC resonant circuit

A self-sensing magnetic levitation system utilizing a LC resonant circuit is proposed by using the characteristic that the inductance of the magnetic system is varied with respect to the air gap displacement. An external capacitor is added into the electric system to make the levitation system statically stable, which much relieves the control effort required to stabilize the magnetic levitation system of having an intrinsic unstable nature. For the realization of the self-sensing magnetically levitated system, an amplitude modulation/demodulation method is used with a positive position feedback controller. Experimental results are presented to validate the proposed method.     

Performance capabilities of two types of variable-reluctance stepping motors

The question considered in this paper is the ultimate performance limitations of variable-reluctance stepping motors. It has been shown that solving the problem of matching a stepping motor to a load reveals two key parameters needed to characterize its performance for point-to-point positional control. These parameters are the work per step and the upper limit on stepping frequency when the motor runs free of its load. These parameters apply when certain operating conditions, termed “Class I operation”, are satisfied.The electromagnetically limited performance capability of two types of stepping motors is examined in terms of the above two parameters. The types considered are machines with armature motion parallel to the air gap and those with armature motion normal to the air gap. Expressions are derived that relate the key performance parameters to the physical dimensions of the machines and to basic properties of materials. It is concluded that the machines with motion normal to the air gap potentially offer superior performance to those with parallel motion, at least over size ranges of greatest interest. However the full realization of this superior performance will not be possible until the mechanical problem of converting small linear displacements into shaft rotation is solved in an efficient manner.     

Minimum-Energy Trajectory Generation for Cornering with a Fixed Heading for Three-Wheeled Omni-Directional Mobile Robots

The minimum-energy trajectory generation problem of cornering with a fixed heading is solved for three-wheeled omni-directional mobile robots (TOMRs). To maximize the total operation time of a mobile robot with carried batteries having finite energy, we have chosen a practical cost function to be the total energy drawn from the batteries. Then, we formulate the minimum-energy trajectory generation problem of executing a cornering motion with a fixed heading for TOMRs with given dynamics including actuator motors. The optimal control theory using a Hamiltonian function and a numerical method are used to obtain the minimum-energy trajectory, which gives the velocity profile in analytic form. Performance analyses are conducted with various simulations and the consumed energy using obtained minimum-energy trajectory is compared with a typical conventional trajectory with a trapezoidal velocity profile, which reveals that an energy savings of up to 18.7 % is achieved. To validate the actual performance of our trajectory, we implemented and tested an accurate trajectory following system which utilizes a resolved acceleration controller.