Induction motor control based on adaptive passivity

In this paper two new schemes for induction motor control are proposed and compared. Both approaches are based on the concept of adaptive passivity. First, a technique using the scheme of field oriented control (FOC) is proposed, and by means of an adaptive state feedback, a passive equivalent system is obtained. Furthermore, making use of the novel torque‐flux control principle (TFCP), the proposed scheme is greatly simplified. Second, a technique based on energy shaping approach, which does not make use of the FOC scheme, is proposed. The technique is based on interconnection and damping assignment (IDA) control transforming the original system into a passive one. Since this technique does not use the FOC scheme, it gives more flexibility in the implementation. Both techniques are then implemented at laboratory level and compared from experimental viewpoint using as benchmark the standard FOC scheme with PI controllers. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Adaptive speed/position control of induction motor based on SPR approach

A sensorless speed/position tracking control scheme for induction motors is proposed subject to unknown load torque via adaptive strictly positive real (SPR) approach design. A special nonlinear coordinate transform is first provided to reform the dynamical model of the induction motor. The information on rotor fluxes can thus be derived from the dynamical model to decide on the proportion of input voltage in the d-q frame under the constraint of the maximum power transfer property of induction motors. Based on the SPR approach, the speed and position control objectives can be achieved. The proposed control scheme is to provide the speed/position control of induction motors while lacking the knowledge of some mechanical system parameters, such as the motor inertia, motor damping coefficient, and the unknown payload. The adaptive control technique is thus involved in the field oriented control scheme to deal with the unknown parameters. The thorough proof is derived to guarantee the stability of the speed and position of control systems of induction motors. Besides, numerical simulation and experimental results are also provided to validate the effectiveness of the proposed control scheme.     

A new family of interconnection and damping assignment passivity‐based controllers

The by‐now standard formulation of interconnection and damping assignment passivity‐based control (for input‐affine systems) proposes the solution of a partial differential equation (PDE) that defines the assignable energy functions and computes the control using the input matrix pseudo‐inverse. However, in its original formulation—a more general design procedure was proposed, which was essentially abandoned because of the difficulties in solving the PDE. In this note, a new family of interconnection and damping assignment passivity‐based controls is proposed by extending this method in the following directions: (i) It allows the desired interconnection and damping matrices to depend on the control signal, giving the possibility to shape the PDE to ensure its solvability; (ii) the PDE directly generates the control signal that have, in general, simpler expressions; and (iii) it is applicable for general nonlinear systems possibly not affine in the control. The technique is illustrated with three examples, including the well‐known boost power converter for which it yields a simple, high‐performance controller. Copyright © 2016 John Wiley & Sons, Ltd.     

Swing-up control strategies for a reaction wheel pendulum

Control of a reaction wheel pendulum, a prototype of an under-actuated system, is easily done using switching control strategies, which combines swing-up control and balancing control schemes. In this article, two novel swing-up control strategies for a reaction wheel pendulum have been proposed. The first swing-up control strategy treats the oscillations of the pendulum as perturbations from the bottom equilibrium point. The second swing-up control is based on interconnection and damping assignment-passivity based control (IDA-PBC). IDA-PBC preserves Euler Lagrangian structure of the system and gives more physical insight about any mechanical system. Any balancing controller can be coupled with the proposed swing-up control strategies to stabilise the pendulum at the top unstable equilibrium position. The control task of balancing the pendulum in top upright position is completed by switching from swing-up scheme to the balancing scheme at the point where the pendulum is very near to the top equilibrium point. Proposed swing-up control strategies have been implemented in real time in switching mode. The two proposed swing-up control schemes provide fast responses as compared to existing energy based schemes.     

Robust IDA‐PBC for underactuated mechanical systems subject to matched disturbances

The problem of robustification of interconnection and damping assignment passivity‐based control for underactuated mechanical system vis‐à‐vis matched, constant, and unknown disturbances is addressed in the paper. This is achieved adding an outer‐loop controller to the interconnection and damping assignment passivity‐based control. Three designs are proposed, with the first one being a simple nonlinear PI, while the second and the third ones are nonlinear PIDs. While all controllers ensure stability of the desired equilibrium in spite of the presence of the disturbances, the inclusion of the derivative term allows us to inject further damping enlarging the class of systems for which asymptotic stability is ensured. Numerical simulations of the Acrobot system and experimental results on the disk‐on‐disk system illustrate the performance of the proposed controller. Copyright © 2016 John Wiley & Sons, Ltd.     

Pose consensus in networks of heterogeneous robots with variable time delays

This paper proposes a novel pose (position and orientation) consensus controller for networks of heterogeneous robots modeled in the operational space. The proposed controller is a distributed proportional plus damping scheme that, with a slight modification, solves both the leader–follower and leaderless consensus problems. A singularity‐free representation, unit quaternion, is used to describe the robots orientation, and the network is represented by an undirected and connected interconnection graph. Furthermore, it is shown that the controller is robust to interconnection variable time delays. Experiments with a network of two 6‐degrees‐of‐freedom robots are presented to illustrate the performance of the proposed scheme. Copyright © 2014 John Wiley & Sons, Ltd.     

基于能量整形方案实现具有通讯时滞欠驱动Euler-Lagrange网络的一致性

本文主要基于能量整形方案研究具有通讯时滞网络化欠驱动Euler-Lagrange (EL)系统的一致性问题,通过利用阻尼注入和互连分配的无源控制(PBC)技术,在有向连通网络拓扑下提出了一个简单的分布式协议,来实现在无引导者和有引导者-跟随者两种情形下欠驱动EL网络的一致性. 本文提出的一致性能量整形方案的主要特点是有机地整合了系统欠驱动和驱动部分以及控制器三部分能量作为整个系统的总能量,这个总能量被利用作为一个合适的Lyapunov函数,它能够充分确保网络化欠驱动EL系统达到所期望的分布式一致性. 最后,通过由欠驱动EL网络所描述柔性关节机械臂系统的数值模拟,来分析通讯时滞对一致性的效应和验证所提出控制算法的正确性.     

考虑铁损的电动汽车用永磁同步电机Hamilton镇定控制

电动汽车用永磁同步电机(PMSM)工作于有限能量供电条件下,其铁损对驱动系统的影响不容忽略.对此,首先推导了考虑铁损的PMSM完整动态数学模型,并建立了其端口受控Hamilton模型;然后利用互联和阻尼配置及能量整形方法实现了考虑铁损的PMSM驱动系统的Hamilton镇定控制;最后分析了阻尼参数和铁损对电机转速的影响.仿真结果表明,Hamilton控制可实现系统的快速镇定;系统可有效抑制负载扰动;考虑铁损有助于提高电动汽车PMSM驱动系统的控制性能和控制精度.     

RBFN-based decentralized adaptive control of a class of large-scale non-affine nonlinear systems

For a class of large-scale decentralized nonlinear systems with strong interconnections, a radial basis function neural network (RBFN) adaptive control scheme is proposed. The system is composed of a class of non-affine nonlinear subsystems, which are implicit function and smooth with respect to control input. Based on implicit function theorem, inverse function theorem and the design idea of pseudo-control, a novel control algorithm is proposed. Two neural networks are used to approximate unknown nonlinearities in the subsystem and unknown interconnection function, respectively. The stability is proved rigidly. The result of simulation validates the effectiveness of the proposed scheme.     

Output control design and separation principle for a class of port‐Hamiltonian systems

Using a structure preserving observer, a dynamic output controller is proposed for a class of port‐Hamiltonian systems. The core of this method is based on the notion of contractive port‐Hamiltonian systems. The proposed method utilizes an extended form of IDA‐PBC (interconnection and damping assignment passivity‐based control), a well‐known controller design method for port‐Hamiltonian systems and paves the way for using IDA‐PBC in output control design of challenging control objectives, such as output tracking for underactuated mechanical systems. In the line of output control design, a useful separation principle for a class of port‐Hamiltonian systems is achieved, which is valuable in the field of nonlinear systems. Some simulations on magnetic levitation and ball on wheel testbeds show the potency and applicability of the proposed method.     

A Nonlinear Coordinated Approach to Enhance the Transient Stability of Wind Energy-Based Power Systems

This paper proposes a novel framework that enables the simultaneous coordination of the controllers of doubly fed induction generators (DFIGs) and synchronous generators (SGs). The proposed coordination approach is based on the zero dynamics method aims at enhancing the transient stability of multi-machine power systems under a wide range of operating conditions. The proposed approach was implemented to the IEEE 39-bus power systems. Transient stability margin measured in terms of critical clearing time along with eigenvalue analysis and time domain simulations were considered in the performance assessment. The obtained results were also compared to those achieved using a conventional power system stabilizer/power oscillation (PSS/POD) technique and the interconnection and damping assignment passivity-based controller (IDA-PBC). The performance analysis confirmed the ability of the proposed approach to enhance damping and improve system’s transient stability margin under a wide range of operating conditions.      

计及铁损时电动汽车用感应电机的Hamilton建模及无源控制

针对电动汽车电驱动系统的非线性特点,采用端口受控Hamilton系统理论与无源性控制原理研究了计及铁损的电动汽车用感应电机系统的建模和控制问题.首先,选取系统的总能量作为Hamilton函数,推导出考虑铁损的感应电机端口受控Hamilton模型,然后利用系统的互联和阻尼配置以及能量成形对闭环电动汽车电驱动系统进行无源控制,并分析了闭环系统的稳定性.由于闭环系统的Hamilton函数可作为Lyapunov存储函数,从而使控制器设计和稳定性分析更容易,控制器更加简单和易于实现.仿真结果验证了新控制策略的有效和快速性.     

A nonlinear sliding surface to improve performance of a discrete-time input-delay system

A sliding mode controller is proposed for an uncertain input-delay system to enhance performance. A nonlinear sliding surface is proposed to achieve better transient response for general uncertain discrete SISO linear systems with input delay. Both matched and unmatched perturbations are considered and ultimate boundedness of motion is proved. The step tracking problem is analysed. The proposed surface increases the damping ratio of the transformed system (delay free) as the output moves nearer to the setpoint. To simplify the surface design, a linear matrix inequality based tuning procedure is proposed. The control law is designed based on an equivalent control approach which guarantees one step reaching. The scheme is able to achieve low overshoot and low settling time simultaneously which is not possible with a linear sliding surface. Simulation results verify the effectiveness of the proposed nonlinear surface over different linear surfaces.     

An Adaptive Passivity‐Based Controller of a Buck‐Boost Converter with a Constant Power Load

This paper addresses the problem of regulating the output voltage of a DC‐DC buck‐boost converter feeding a constant power load, which is a problem of current practical interest. Designing a stabilising controller is theoretically challenging because its average model is a bilinear second order system that, due to the presence of the constant power load, is non‐minimum phase with respect to both states. Moreover, to design a high‐performance controller, the knowledge of the extracted load power, which is difficult to measure in industrial applications, is required. In this paper, an adaptive interconnection and damping assignment passivity‐based control—that incorporates the immersion and invariance parameter estimator for the load power—is proposed to solve the problem. Some detailed simulations are provided to validate the transient behaviour of the proposed controller and compare it with the performance of a classical PD scheme.     

分数微积分理论在非线性车辆悬架滑模控制中的应用

基于分数微积分理论,提出分数阶”天棚”阻尼控制概念,并以它控制的悬架为参考模型,提出一个控制效果理想、鲁棒性好的悬架滑模控制的新策略,并应用于非线性悬架的动力学控制中．文中给出了一种精度较高,收敛稳定的分数阶系统的数值算法,最后对非线性悬架的滑模主动控制进行数值仿真,验证了新控制策略优良的控制效果．     

Robust dynamic state feedback for underactuated systems with linearly parameterized disturbances

This article investigates the control problem for underactuated port‐controlled Hamiltonian systems with multiple linearly parameterized additive disturbances including matched, unmatched, constant, and state‐dependent components. The notion of algebraic solution of the matching equations is employed to design an extension of the interconnection and damping assignment passivity‐based control methodology that does not rely on the solution of partial differential equations. The result is a dynamic state‐feedback that includes a disturbance compensation term, where the unknown parameters are estimated adaptively. A simplified implementation of the proposed approach for underactuated mechanical systems is detailed. The effectiveness of the controller is demonstrated with numerical simulations for the magnetic‐levitated‐ball system and for the ball‐on‐beam system.     

矩阵变换器输入侧端口受控耗散哈密尔顿算子建模及无源控制

矩阵变换器无中间直流环节,易受电网扰动和负载扰动的影响.针对这一问题,本文设计了矩阵变换器输入侧无源性控制器以改善控制系统特性.首先,在直–交坐标系下建立输入侧的端口受控耗散哈密尔顿(port-controlled Hamiltonian with dissipation,PCHD)算子模型.然后,设计了基于互联和阻尼配置的无源性控制器,用来实现对输入电流快速准确的跟踪.重新配置了系统的平衡点,通过注入阻尼提高系统的收敛速度,并从理论上对闭环系统的渐进稳定性进行了分析.仿真结果表明,系统在非正常工况下仍能保证输入电流为正弦,相比传统偏差修正法,该控制策略具有更好的动态性能和抗干扰能力.     

Interconnection and damping assignment passivity‐based control of a class of underactuated mechanical systems with dynamic friction

This paper considers the extension of the interconnection and damping assignment passivity‐based control methodology for a class of underactuated mechanical systems with dynamic friction. We present a new damping assignment approach to compensate friction by means of a nonlinear observer. Friction at the actuated joints is assumed to be captured by a bristle deflection model: the Dahl model. Based on the Lyapunov direct method we show that, under some conditions, the overall closed‐loop system is stable and, by invoking the theorem of Barbashin–Krasovskii, we arrive to asymptotic stability conditions. Experiments with an underactuated mechanical system, the Furuta pendulum, show the effectiveness of the proposed scheme when friction is compensated. Copyright © 2010 John Wiley & Sons, Ltd.     

一种VLSI高层综合低功耗设计方案及实现

提出VLSI高层综合设计方案,该方案基于多电压在时间及资源约束条件下,综合考虑了调度及互连,从调度互连两个角度达到低功耗的目的.该方案提出了基于Gain大小搜索的调度,将功耗增益、灵活度和行为执行密度因素作为折中函数,考虑操作的属性更加全面.在互连中基于分布式的RS互连模型得出互连单元在执行时段里的动态功耗,同时考虑单根总线上的翻转和邻线的耦合.该方案在CDFG工具包中实现并证明了它的有效性.     

Transient stability improvement of multi-machine power systems using on-line fuzzy control of SMES

Fuzzy control of the super-conducting magnetic energy storage (SMES) is proposed here to improve the transient stability and damping requirements of multi-machine power systems. The effects of the SMES control on the line power transfer are considered in the design of the fuzzy controller. A theoretical realisation of the proposed control scheme is presented and a simulation study on the New-England test system is carried out. A practical implementation, based on local measurements, is explained. The improvement of the system’s critical clearing time, and also the system damping requirements, are clearly demonstrated. Finally, a conclusion is provided.