Interconnection And Damping Assignment Passivity-based Control Research Articles

Passivity-based control of nonlinear teleoperation systems with non-passive interaction forces

This paper addresses the problem of asymptotic stability and position tracking in nonlinear teleoperation systems interacting with non-passive operator and environment. A nonlinear control law which is designed based on Interconnection and Damping Assignment Passivity-Based Control (IDA-PBC) scheme, uses the positions and velocities of the joints of manipulators to provide asymptotic stability of tracking errors. Using the Lyapunov–Krasovskii theorem, sufficient conditions are derived in terms of computationally amenable Linear Matrix Inequalities (LMIs), to tune the controller parameters in the presence of asymmetrical varying time delay in the communication channel. The proposed controller synthesis methodology requires no known passive part in the dynamical model of interaction forces. Moreover, using the integral control notion, the asymptotic stability of the synchronization errors is assured. Comparative simulation results are presented to demonstrate the superiority of the proposed method compared to some rival ones. Finally, experimental results from a laboratory teleoperator are reported to confirm the applicability of the introduced scheme.

On universal stabilization property of Interconnection and Damping Assignment Control

It is well-known that the widely popular Interconnection and Damping Assignment Passivity-based Control (IDA-PBC) is “universally stabilizing”, in the sense that it generates all asymptotically stabilizing controllers for general nonlinear systems of the form ẋ=f(x,u). Unfortunately, the proof of this fact relies in the construction of a control law that is not globally defined. Although a standard regularization procedure may be used to enforce the required smoothness properties to the control signal, this procedure is quite technical and not constructive. To overcome this problem we provide an alternative construction that yields a continuous IDA-PBC law.

Control of SMES systems in distribution networks with renewable energy integration: A perturbation estimation approach

Electrical energy storage system (EESS) plays a crucial role to handle the intermittency and randomness of renewable energy, such that the power reliability can be significantly enhanced. This paper attempts to design an adaptive fractional-order sliding-mode control (AFOSMC) approach for a typical EESS technology, e.g., superconducting magnetic energy storage (SMES) systems, to improve its dynamical responses against varirous operation conditions. At first, a sliding-mode state and perturbation observer (SMSPO) is applied to estimate the combined effect of unmodelled dynamics, parameter uncertainties, and external disturbances of SMES systems. Then, a fractional-order sliding-mode control (FOSMC) is utilized to completely compensate the perturbation estimat, such that a noticeable robustness can be achieved. Moreover, only the dq-axis currents need to be measured while the perturbation estimate replaces its upper bound, thus AFOSMC be easily achieved with appropriate control costs. For the purpose of validating its control performance, a distribution network involving SMES system with renewable energy penetration is studied. The control performance of conventional proportional-integral-derivative (PID) control, interconnection and damping assignment passivity-based control (IDA-PBC), sliding-mode control (SMC), and fractional-order sliding-mode control (FOSMC) is compared to that of AFOSMC under three scenarios. Simulation results show that AFOSMC can greatly outperform other approaches in both tracking speed and overall costs, e.g., its active power error is only 63.55%, 83.44%, 69.60%, and 76.67% of that of PID control, IDA-PBC, SMC, and FOSMC under reactive and active power supply, while the required control costs is only 76.69%, 91.28%, 83.50, and 86.76% to the above three controllers. Finally, a hardware-in-the-loop (HIL) test based on dSpace is implemented to verify its practicability under various scenarios.

Interconnection and Damping Assignment Passivity-Based Control Design Under Loss of Actuator Effectiveness

Due to the convenience in applications, interconnection and damping assignment passivity-based control (IDA-PBC) is applied widely to reformulate the nonlinear robust control as the total energy shaping. However, only few researches focus on the fault-tolerant control (FTC) method based on IDA-PBC, which limits its applications under actuator faults. To break this limitation, this paper improves the IDA-PBC with fault-tolerant ability, and the main contributions are to propose high-gain and adaptive IDA-PBC methods under loss of actuator effectiveness. The simulation and experiment results with a rotorcraft unmanned aerial vehicle (RUAV) are presented to illustrate the control effectiveness of the improved IDA-PBC methods.

Dynamic IDA-PBC control for weakly-coupled electromechanical systems

In this paper we propose a dynamic feedback controller by adopting the interconnection and damping assignment passivity based control (IDA-PBC) method, to stabilize a class of weakly-coupled electromechanical systems. These systems are characterized by a weak coupling between the electrical and mechanical subsystems (dynamics) which limits the application of classical energy shaping control methods. The proposed design method incorporates a change of coordinates to construct the controller. It also introduces the use of an integral control and damping injection to the mechanical coordinates, to enhance the coupling between the subsystems, ensuring asymptotic stability, while improving the robustness of the systems against external disturbances and noise. The results are applied to two groups of systems; the electrostatic MEMS devices and the magnetic levitation. Numerical simulations are provided to illustrate the use and analyze the performance of the proposed control methods.

Controller design, analysis and testing of a three‐phase VSI using IDA–PBC approach

A voltage-source inverter (VSI) is a key component of a distributed generation unit and an uninterruptible power supply. In this study, a three-phase VSI control using interconnection and damping assignment passivity-based control (IDA-PBC) approach has been revisited and analysed on aspects such as voltage gain, output impedance, transient response, stability and steady-state error. It is shown that in the case of accurately known filter parameters and perfectly zero initial conditions, theoretically, the voltage controller would exhibit unity voltage gain and zero output impedance. It is also shown that the IDA-PBC-based voltage controller exhibits a second-order response to a step input. This property has been utilised to propose a novel systematic procedure for tuning of the IDA-PBC gains based on the transient response specifications. The tuning method reveals that the gains for the outer voltage and inner current loops are related to each other and should not be separately tuned. The presented analysis and the proposed tuning method for controller gain have been tested through simulation studies. The concepts were further validated on a laboratory scale prototype of a three-phase VSI for balanced, unbalanced and non-linear loads.

Spacecraft formation flying in the port-Hamiltonian framework

The problem of controlling the relative position and velocity in multi-spacecraft formation flying in the planetary orbits is an enabling technology for current and future research. This paper proposes a family of tracking controllers for different dynamics of Spacecraft Formation Flying (SFF) in the framework of port-Hamiltonian (pH) systems through application of timed Interconnection and Damping Assignment Passivity-Based Control (IDA-PBC). The leader–multi-follower architecture is used to address this problem. In this regard, first we model the spacecraft motion in the pH framework in the Earth Centered Inertial frame and then transform it to the Hill frame which is a special local coordinate system. By this technique, we may present a unified structure which encompasses linear/nonlinear dynamics, with/without perturbation. Then, using the timed IDA-PBC method and the contraction analysis, a new method for controlling a family of SFF dynamics is developed. The numerical simulations show the efficiency of the approach in two different cases of missions.

Explicit and Implicit IDA-PBC Design and Implementation for a Portal Crane

The interconnection and damping assignment passivity-based control (IDA-PBC) is well-known for regulating the behavior of nonlinear systems. In underactuated mechanical systems (UMSs), its application requires the satisfaction of matching conditions, which in many cases demands to solve partial differential equations (PDEs). Only recently, the IDA-PBC method has been extended to UMSs in implicit representation, where the system dynamics are described by a set of differential-algebraic equations. In some system classes, this implicit model allows to circumvent the PDE obstacle and to construct an output-feedback law. This paper discusses the design and real-system implementation of the total energy shaping IDA-PBC with an optimal local performance for a portal crane system in implicit port-Hamiltonian representation. The implicit controller is compared with the simplified (explicit) IDA-PBC, introduced by Xue and Zhiyong (2017), which also shapes the total energy and avoids PDEs.

Energy Based Control of a Swash Mass Helicopter Through Decoupling Change of Coordinates

We consider a small helicopter structure that is maneuvered through the control of moving masses. It is referred to as a swash mass helicopter (SMH). This paper addresses the trajectory tracking control problem for the SMH, with a specific focus on the decoupling change of coordinates of both rotational and translational dynamics. We propose a control scheme in which position tracking is the primary objective, while the attitude tracking task is considered as a secondary objective. The intermediate control signals related to the attitude dynamics exploit the structural properties of the SMH and are enhanced with terms that grant a more accurate tracking of the target trajectory. The closed-loop system stability under the trajectory tracking objective is obtained following the Interconnection and Damping Assignment Passivity-Based Control (IDA-PBC) approach. In addition, the presence of external disturbances can diminish the trajectory tracking performance. For this reason, a nonlinear outer loop controller is added to the IDA-PBC to compensate the disturbances. Finally, the results of several simulations are reported to evaluate the performance of the control strategy.

Passivity-Based Control for Movable Multi-Load Inductively Coupled Power Transfer System Based on PCHD Model

A passivity-based control strategy for movable multi-load inductively coupled power transfer (ICPT) system based on PCHD (Port-Controlled Hamiltonian Dissipation, PCHD) model is proposed, which can effectively suppress mutual inductance and load interference. During the movement of the secondary coil of the movable multi-load ICPT system, due to the change of mutual inductance and the randomness of the multi-load, it will cause the transmission power and efficiency to oscillate and generate harmonics. Firstly, in view of the above problems, this paper analyzes the ICPT system under movable multiple loads. The DQ transformation method was used to establish the large-signal mathematical model of the system, and PCHD mathematical model in the DQ domain was established to decouple the active and reactive power. Secondly, the passivity-based controller (PBC) is designed by using the principle of interconnection and damping assignment passivity-based control (IDA-PBC). After that, the second method of Lyapunov function is used for stability analysis, and further verifies the asymptotic stability of the closed-loop system. Finally, the proposed method was verified by MATLAB/Simulink simulation. The simulation results show that the passivity-based controller has stronger robustness in both steady and movable states compared with the PI controller, which effectively suppresses the oscillation and total harmonic distortion caused by the change of mutual inductances and the randomness of the loads.

Toward Stabilization of Constant Power Loads Using IDA-PBC for Cascaded LC Filter DC/DC Converters

This article proposes a modified interconnection and damping assignment passivity-based control (IDA-PBC) for dc/dc converter cascaded with an LC filter. The plant is modeled using the port-controlled Hamiltonian (PCH) form. The main objective is to stabilize the cascaded system in case the system supplies constant power load (CPL). To solve the instability issues caused by tightly controlled cascaded systems, the IDA-PBC based on an overall PCH model, including LC input filter and dc/dc converter, is established. Moreover, to ensure that the proposed IDA-PBC admits one unique solution, an adaptive interconnection matrix is designed to build the internal links in the PCH model. Furthermore, in order to improve the implementation on an onboard dc microgrid application with time-varying CPLs, a modified IDA-PBC algorithm is proposed based on the error between the state vector and the desired operating point, which might be variable. The closed-loop Hamiltonian function is chosen as the Lyapunov candidate function to guarantee that the system operates in a stable manner. The virtual damping assignment technique is addressed to tune the dynamic characteristic of the closed-loop system. Simulation and experimental results are carried out to illustrate the proposed method's effectiveness.

Passivity-Based Control of Power Systems Considering Hydro-Turbine With Surge Tank

This paper proposes an interconnection and damping assignment passivity-based control (IDA-PBC) for multimachine power systems including hydro-turbine governing systems (HTGS) with surge tank. The main objective is to stabilize the rotor speed and regulate the terminal voltage of each synchronous machine in a power system. The proposed control is decentralized, thus avoiding challenges of communication between generators. Passivity theory is used since the open-loop of the HTGS presents a port-Hamiltonian structure. IDA-PBC allows a control law that maintains the passive structure in closed-loop, guaranteeing its asymptotic stability using Lyapunov's theory. The dynamics of each HTGS are described by an eleventh-order model, which can be reduced to a tenth-order. The proposed control is tested in a 12-bus test system and compared to a standard control, which considers a voltage regulator and exciter based on the IEEE type ST1A excitation system model and power system stabilizer IEEE-PSS1A. The governing system based on a PID control with static and transient droop is also employed. Additionally, the proposed controller is compared to a sliding mode controller. Time-domain simulations demonstrate the robustness and appropriate performance of the proposed decentralized control under different large disturbances.

Port Controlled Hamiltonian Modeling and IDA-PBC Control of Dual Active Bridge Converters for DC Microgrids

Power electronics-based medium-voltage direct current (MVdc) microgrids consist of several interconnected feedback-controlled switching converters. Such systems experience bus voltage stability challenges owing to the negative incremental resistance of constant power loads and converter control loop interactions. To tackle the stability challenges, this paper presents the application of the interconnection and damping assignment passivity-based control (IDA-PBC) approach to the port-controlled Hamiltonian model of dual active bridge (DAB) source-side converters in an MVdc microgrid. For the DABs, a fundamental average model approach considering phase shift modulation is provided and used for deriving the corresponding IDA-PBC control law. We analyze the effectiveness of the controller on large signal scenarios considering disturbances such as load step up, and DAB disconnection. Hardware-in-the-Loop experiments using Opal-RT and Labview field programmable gate arrays (FPGAs), as well as, low power prototype tests are carried out to demonstrate the validity and feasibility of the proposed approach.

Abstract # 4403 CLARITY and immunofluorescence provides a sensitive method to determine changes to myelin volume in the prefrontal cortex

This work presents a new contribution on energy management of hybrid electric systems for vehicle applications. The studied hybrid electrical vehicle is composed of fuel cell as a main source and the auxiliary system containing the battery and supercapacitor. A programmable load is used to emulate a vehicle load profile. Two methods are combined to smartly and optimally control the energy flow between the used sources. These methods are the Interconnection and Damping Assignment Passivity Based Control (IDA-PBC) and the Hamilton-Jacobi Bellman (HJB) optimization. The source limitation is considered here in terms of the battery state of charge. The experimental works validate the efficiency of the proposed control where the obtained results demonstrate that the used strategy allows regulating the power flow under a realistic load drive profile. The global stability proof is demonstrated using Lyapunov theory.

A Passivity-Based Control of Euler–Lagrange Model for Suppressing Voltage Low-Frequency Oscillation in High-Speed Railway

The traction network voltage low-frequency oscillation (LFO) in high-speed railways easily leads to the traction blockade of electric multiple units (EMUs), which seriously affects the normal operation of high-speed railways. A passivity-based control (PBC) strategy for single-phase EMUs rectifier is proposed in this paper. First, for the single-phase EMU rectifier, the Euler–Lagrange (EL) mathematical model in dq frame is built, which can realize the decoupling of active power and reactive power. Second, according to the unique characteristics of the rectifier, it is proven that the rectifier is strictly passive, which is the premise of PBC controller design. Third, using the deduced EL mathematical model and the passivity of rectifier, the PBC controller for the single-phase rectifier of EMUs is designed using the damping injecting method. Next, compared with dq current control and interconnection and damping assignment PBC (IDA-PBC), it can be verified that the PBC controller has better dynamic and static characteristics, and can significantly suppress the voltage LFO of traction network. In these strategies listed in this paper, using the PBC, the single-phase rectifier input current has minimal total harmonic distortion, and the dc-link voltage has minimal oscillation. Finally, the dSPACE semiphysical experiment platform of the cascade system of EMUs and traction network is built. Simulation results are validated by the dSPACE semiphysical experiments, which indicate that the PBC has the better inhibitory effect for LFO as compared with that of the IDA-PBC and dq current control in single-phase EMUs rectifier.

Applications of supercapacitor energy storage systems in microgrid with distributed generators via passive fractional-order sliding-mode control

This paper develops a novel passive fractional-order sliding-mode control (PFOSMC) of a supercapacitor energy storage (SCES) system in microgrid with distributed generators. Firstly, a storage function is constructed and thoroughly analysed to investigate the inherent physical characteristics of SCES systems. Then, the beneficial terms are carefully retained for the sake of transient responses improvement, while the other detrimental terms are fully removed to achieve a globally control consistency. In order to further enhance the robustness of the closed-loop system, a fractional-order sliding-mode control (FOSMC) framework is synthesized as an additional input, which employs the fractional-order PDα sliding surface as well as an energy reshaping mechanism to realize a more flexible control performance. Four case studies, including (a) Active power and reactive power supply, (b) System restoration under power grid fault, (c) Power support under stochastic solar energy and wind energy integration, and (d) Robustness with system parameter uncertainties, are carried out to study the control performance of PFOSMC compared to that of PID control, interconnection and damping assignment passivity-based control (IDA-PBC), and FOSMC, Finally, a hardware-in-the-loop (HIL) experiment using dSpace platform is undertaken to validate its implementation feasibility.

A global asymptotical stable control scheme for a Hexverter in fractional frequency transmission systems

A fractional frequency transmission system (FFTS) is the most competitive choice for long distance transmission of offshore wind power, while the Hexverter, as a newly proposed direct AC/AC converter, is an attractive choice for its power conversion. This paper proposes a novel control scheme characterizing the global stability and strong robustness of the Hexverter in FFTS applications, which are based on the interconnection and damping assignment passivity-based control (IDA-PBC) methodology. Firstly, the frequency decoupled model of the Hexverter is studied and then a port-controlled Hamiltonian (PCH) model is built. On this basis, the IDA-PB control scheme of the Hexverter is designed. Considering the interference of system parameters and unmodeled dynamics, integrators are added to the IDA-PB controller to eliminate the steady-state error. In addition, the voltage-balancing control is applied in order to balance the capacitor DC voltages to obtain a better performance. Finally, the simulation results and experimental results are presented to verify the effectiveness and superiority of the IDA-PB controller.

Fixed-Time $\mathcal {H}_{\infty }$ Control for Port-Controlled Hamiltonian Systems

In this paper, the locally fixed-time and globally fixed-time $\mathcal {H}_{\infty }$ control problems for the port-controlled Hamiltonian (PCH) systems are investigated via the interconnection and damping assignment passivity-based control (IDA-PBC) technique. Compared with finite-time stabilization, where the convergence time of the closed-loop system's states relies on the initial values, the settling time of fixed-time stabilization can be adjusted to achieve desired equilibrium point regardless of initial conditions. The concepts of fixed-time $\mathcal {H}_{\infty }$ control, fixed-time stability region (or region of attraction), and fixed-time stability boundary are presented in this paper, and the criterions of globally fixed-time attractivity of a prespecified locally fixed-time stability region are obtained. Combining the locally fixed-time stability of an equilibrium point and the globally fixed-time attractivity of a prespecified fixed-time stability region, the globally fixed-time $\mathcal {H}_{\infty }$ control problem of PCH system is effectively solved. Two novel control laws are designed to deal with the globally fixed-time $\mathcal {H}_{\infty }$ control problem, and the conservativeness in estimating the settling time is also briefly discussed. An illustrative example shows that the theoretical results obtained in this paper work very well in the fixed-time $\mathcal {H}_{\infty }$ control design for PCH systems.

IDA-PBC with adaptive friction compensation for underactuated mechanical systems

In this work the control of underactuated mechanical systems with dry friction on actuated and unactuated joints is investigated. A new interconnection-and-damping-assignment passivity-based-control (IDA-PBC) design is presented, which includes the adaptive estimation of the friction forces and the introduction of a nonlinear dissipative term in the closed-loop system dynamics. As a result, the traditional IDA-PBC is complemented with an additional matching condition and the control law is augmented with a new term that accounts for the Coulomb friction forces on all joints. Two adaptive control paradigms are considered for comparison purposes and stability conditions are discussed. The control design is detailed for two demonstrative examples: the disk-on-disk system; the Acrobot system. The effectiveness of the proposed design is demonstrated with numerical simulations.

Distributed energy resources integration in single-phase microgrids: An application of IDA-PBC and PI-PBC approaches

This paper presents a unified Hamiltonian formulation for controlling distributed energy resources (DERs) in ac single-phase microgrids (SP-MGs) via proportional-integral passivity-based control (PI-PBC), and interconnection and damping assignment passivity-based control (IDA-PBC). The proposed Hamiltonian formulation allows us to consider both pulse-width modulated voltage source converters (PWM-VSC) and pulse-width modulated current source converters (PWM-CSC) under a unified model. Renewable generation and supercapacitor energy storage systems are integrated via PWM-VSC technologies, while superconducting coils are integrated through PWM-CSC technologies. IDA-PBC and PI-PBC theories enable us to design control strategies begin that consider Lyapunov’s stability theory combined with the well-known advantages of proportional and integral control actions. Our simulation’s results corroborate the applicability of the proposed control approaches under stability paradigm. MATLAB/Simulink is employed for computational implementations via begin the SimPowerSystems toolbox.