Interconnection And Damping Assignment Passivity Based Control Controller Research Articles

Fixed-time [formula omitted] tracking control of unmanned underwater vehicles with disturbance rejection via Port-Hamiltonian framework

The fixed-time tracking control schemes of unmanned underwater vehicles (UUVs) are investigated in body-fixed coordinates frame based on Port-Hamiltonian (PH) model with external disturbances. The novel locally and globally fixed-time control laws via the interconnection and damping assignment passivity-based control (IDA-PBC) are designed for trajectory tracking in UUVs. The virtual desired equilibria consisted of the tracking error and the desired trajectory are established by the matching conditions. Moreover, the fixed-time stabilization of the UUV induced of variable parameter matrixes is analyzed. Compared with the traditional IDA-PBC controller, the UUV is guaranteed to achieve the reference trajectory within a fixed time regardless of initial conditions. In the presence of external disturbances, the H∞ laws are incorporated in the fixed-time control for the UUV, which can ensure faster trajectory tracking and strong anti-disturbance. Finally, the simulation results demonstrate the effectiveness of the main schemes.

Control of Photovoltaic Plants Interconnected via VSC to Improve Power Oscillations in a Power System

This paper presents an integrated methodology applied to photovoltaic (PV) plants for improving the dynamic performance of electric power systems. The proposed methodology is based on primary frequency control, which adds an ancillary signal to the voltage reference of the DC-link for the voltage source converter (VSC) in order to reduce power oscillations. This ancillary signal is computed by relating the energy stored in the VSC of the DC-link and the energy stored in the synchronous machine’s shaft. In addition, the methodology considers the operating limits of the VSC, which prioritizes active power over reactive power. Furthermore, the VSC control is assessed with interconnection and damping assignment passivity-based control (IDA-PBC), as well as compared to conventional PI control. IDA-PBC is employed to design a Lyapunov asymptotically stable controller using the Hamiltonian structural properties of the open-loop model of the VSC. A 12-bus test system that considers PV plants is employed to compare the proposed IDA-PBC control with a classical proportional-integral control approach. The impact of the proposed methodology is analyzed in four scenarios with different PV penetration levels (10%, 30%, 50%, and 80%) and four large disturbances in the test power system. In addition, a decrease in the inertia of the synchronous machines from 100 to 25% is analyzed. The time-domain simulation results show that the frequency oscillations are reduced by 16.8%, 38.43%, 37.53%, and 76.94% in comparison with the case where the proposed methodology was not implemented. The simulations were conducted using the SimPowerSystems toolbox of the MATLAB/Simulink software.

Efficient experimental energy management operating for FC/battery/SC vehicles via hybrid Artificial Neural Networks-Passivity Based Control

Nowadays, the energy management of multisource hybrid systems is becoming an interesting and challenging topic for many researchers. The judicious choice of the energy management strategy not only allows for the best distribution of energy between the different sources, but also reduces the system's consumption, increases the life span of the used sources and fulfills the energy demand that affects the autonomy of the electric vehicle (EV). A novel hybrid control strategy based on the interconnection and damping assignment passivity-based control (IDA-PBC) technique is proposed while considering the battery State of Charge (SOC) and the hydrogen level operating conditions. PBC is a very powerful nonlinear technique, which uses important system information such as the system energy information. The Artificial Neural Network (ANN) is used for defining the appropriate references for the proposed controller to properly share the load power demand among the sources. Consequently, the proposed nonlinear control enables dispatching the requested power/energy among sources under source limitations. The real time experimental results demonstrate the enhanced efficiency of the hybridized ANN together with the IDA-PBC control. This work proposes a complete study and solution, from modeling, control, stability proof, simulation to practical validation. New constraints are emerging in anticipation of the real-time use of FC hybrid systems. These constraints and objectives are mainly related to the limitations of energy resources and the minimization of hydrogen consumption. The supervision of hydrogen level and battery SOC resources are proposed by using ANN, which gives the battery current and/or SC set point to the control loops. Experimentation works have validated the feasibility of this optimization technique.

Generalized IDA-PBC Control Using Enhanced Decoupled Power Sharing for Parallel Distributed Generators in Standalone Microgrids

The development of an advanced modular control strategy for distributed generation-based islanded MicroGrids (MGs) is proposed in this article. This control strategy aims at achieving robust performances and accurate load power sharing in spite of system architecture. This strategy is based on the interconnection and damping assignment passivity-based control (IDA-PBC), which provides sufficient conditions to ensure the system modularity and stability. The design methodology of the proposed method is declined into three important steps. The whole system is modeled using the port-controlled Hamiltonian (PCH) formalism, the Hamiltonian function is minimized to synthesize the corresponding control laws, and finally, the stability of the synthesized control laws is verified. In this work, the Hamiltonian function is augmented with an enhanced decoupled droop (E2D) control in order to guarantee the stability of the whole system and ensure accurate power sharing when multiple DG units are interconnected. The effectiveness and modularity of the proposed modular IDA-PBC control with the E2D technique are evaluated and compared with a recent control strategy using an inner proportional-integral control with a decoupled droop technique. Experimental results and discussions are provided under resistive-inductive and nonlinear loading conditions.

Particle Swarm Optimization of a Passivity-Based Controller for Dynamic Positioning of Ships

Dynamic positioning (DP) control system is an essential module used in offshore ships for accurate maneuvering and maintaining of ship’s position and heading (fixed location or pre-determined track) by means of thruster forces being generated by controllers. In this paper, an interconnection and damping assignment-passivity based control (IDA-PBC) controller is developed for DP of surface ships. The design of the IDA-PBC controller involves a dynamic extension utilizing the coordinate transformation which adds damping to some coordinates to ensure asymptotic stability and adds integral action to enhance the robustness of the system against disturbances. The particle swarm optimization (PSO) technique is one of the the population-based optimization methods that has gained the attention of the control research communities and used to solve various engineering problems. The PSO algorithm is proposed for the optimization of the IDA-PBC controller. Numerical simulations results with comparisons illustrate the effectiveness of the new PSO-tuned dynamic IDA-PBC controller.

Energy management and damping improvement of a DC microgrid with constant power load using interconnection and damping assignment-passivity based control

This paper deals with (i) damping improvement and (ii) energy management of a DC microgrid for improvement of its stability. The direct current (DC) microgrid has a solar-photovoltaic system as a renewable source and fuel cell-battery combination as a backup system to supply power to constant power loads (CPLs). The presence of CPLs in a DC microgrid makes the stability problem more challenging since the negative impedance characteristics of CPLs bring instability into the system. A control approach using interconnection and damping assignment-passivity based control (IDA-PBC) is proposed in this paper to address both the objectives. The proposed control approach provides an efficient energy management, the required damping and also maintains the stability by making the system passive. The tuning parameters of the control laws are adapted incorporating the state of charge (SoC) for the effective energy management. In addition, an integral action is added with the proposed control laws to eliminate the steady-state error in the voltage level of the DC bus and load bus. The proposed IDA-PBC control along with an integral action is compared with four other control approaches, and reveals its better performances. The MATLAB/Simulink results show that the proposed control technique provides better responses in terms of providing damping and effective energy management.

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.

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.

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.

Interconnection and Damping Assignment Passivity for the Control of PV/Battery Hybrid Power Source in Islanded Microgrid

This work proposes an Interconnection and Damping Assignment Passivity Based Control (IDA-PBC) to enhance power quality of an islanded Micro-grid (MG) including a photovoltaic main source (PV) and a Li-ion battery based Energy Storage System (ESS). In this MG, the PV generator-unit is controlled to provide its maximum power and the ESS-unit is controlled to ensure the desired voltage waveform at the Point of Common Coupling (PCC) and to support the PV source in order to satisfy the local loads. The IDA-PBC approach is chosen for its proprieties which allow the synthesis of asymptotically stable controllers for passive systems by the mean of the power system energy. In fact, the damping and interconnection coupling matrices of the IDA-PBC controller allows additional degree of freedoms in comparison to classical passivity controllers that enhance the convergence rapidity and the robustness under uncertainties. The mathematical model of the PV source and the Li-ion battery based ESS are presented. The power interface circuits are firstly represented through Park-coordinates then expressed in a Port-Controlled Hamiltonian (PCH) form. The obtained models are used to the design of the proposed IDA-PBC controller where the stability conditions are checked. The proposed control validity and performance are verified through comparison simulation tests with a conventional Proportional-Integral (PI) based control strategy. The obtained results show that the proposed control algorithm allows reducing the current and voltage overshoots under transient’s conditions in comparison to the PI controller. Furthermore, the proposed control achieves better voltage waveform at the PCC in steady state.

Port-Controlled Phasor Hamiltonian Modeling and IDA-PBC Control of Solid-State Transformer

This paper presents an application of interconnection and damping assignment passivity-based control (IDA-PBC) principle to the port-controlled phasor Hamiltonian (PCPH) model of solid-state transformer (SST) (comprising of three stages, namely, ac/dc rectifier, dual active bridge converter, and dc/ac inverter). A PCPH model of SST is established for each individual stages using dynamic phasor concept. In comparison with other PBC approaches, IDA-PBC offers an additional degree of freedom to solve the partial differential equations. According to the target of the controller design at each stage, the desired equilibrium point of the system is obtained. The closed-loop system performance achieves regulation of constant output dc-bus voltage and unity input power factor. Large-signal simulation results for the full system validate the simplifications introduced to obtain the controller and verify the proposed controller. Robustness of the controller is demonstrated with 20% load disturbance and 10% input disturbance. For validation of the proposed approach and its effectiveness, hardware-in-loop simulation is carried out using Opal-RT and dSPACE simulators.

Robustness enhancement of IDA-PBC controller in stabilising the inertia wheel inverted pendulum: theory and real-time experiments

ABSTRACTImproving the robustness, vis-à-vis matched input disturbances of interconnection and damping assignment, passivity based control (IDA-PBC) for a class of underactuated mechanical systems is addressed in this paper. The characterised class of systems is described by a Port Controlled Hamiltonian (PCH) model which represents another alternative to the classical Euler–Lagrange models for which IDA–PBC yields a smooth stabilising controller. Our main contribution consists of combining the so-called IDA-PBC controller with an adaptive control technique. Some sufficient stability conditions on matched input disturbances are given. In order to estimate the stability and performance robustness of both controllers, a stochastic robustness analysis was used. Indeed, we used the Monte Carlo simulation (MCS) based on uncertainties to analyse the behaviour of the closed-loop system. The comparison of the stability robustness between the classical IDA-PBC controller and the proposed one is then provided. As an illustration, we proposed to revisit the application of IDA-PBC controller to the inertia wheel inverted pendulum in the presence of matched disturbances. Simulation and real-time experimental results mirror the theoretical results and prove the efficiency of the proposed controller.

Plasma internal profile control using IDA-PBC: Application to TCV

In this paper, new results of plasma ι-profile and β control on TCV, using total plasma current Ip, and ECCD (Electron Cyclotron heating and Current Drive) heating source have been discussed. The control model is governed by the resistive diffusion equation coupled with the thermal transport equation, written in PCH (Port-Controlled Hamiltonian) formulation. The IDA-PBC (Interconnection and Damping Assignment – Passivity based Control) controller is developed and tested on simulation as well as on TCV real plant. Two test scenarios are considered: ι control only, and ι and β control. The spatial distributions of ECCD profiles are pre-defined and only input powers are used for control design. Thus, a stationary control is defined in order to consider all non-linearity and actuator constraint, and a linear feedback IDA-PBC will ensure the convergence speed and the robustness of the closed-loop system. The obtained results are encouraging towards using routinely such plasma advanced control algorithm in a near future.

IDA-PBC control for the coupled plasma poloidal magnetic flux and heat radial diffusion equations in tokamaks

The IDA-PBC control of plasma dynamics in a tokamak is investigated. It is based on a model made of the two coupled PDEs of resistive diffusion for the magnetic poloidal flux and of radial thermal diffusion. The used Thermal-Magneto-Hydro-Dynamics (TMHD) couplings are the Lorentz forces (with non-uniform resistivity) and the bootstrap current. The control model is obtained with the coupling of the two finite dimensional approximations obtained from the two diffusion models, using two geometric reduction schemes. A feedforward control is used to ensure the compatibility with the actuator physical ability. Then, an IDA-PBC (Interconnection and Damping Assignment - Passivity Based Control) controller is proposed for the coupled model to improve the system stabilization and convergence speed. The obtained numerical results are validated against the simulation data obtained from the RAPTOR (RApid Plasma Transport simulatOR) code for the TCV (Tokamak of Configuration Variable at CRPP, EPFL, Lausanne, Switzerland) tokamak real-time control system.

On the equivalence of two nonlinear control approaches: Immersion and invariance and IDA-PBC

In this paper we compare the two well-known nonlinear control design techniques Interconnection and Damping Assignment Passivity Based Control (IDA-PBC) and Immersion and Invariance (I&I) at the example of the so-called Acrobot underactuated mechanical system. The immersion and matching equations in both approaches have a similar structure which is exploited to derive equivalent control laws, each of them providing a different perspective on the stabilization problem. In particular, the coordinate change which renders the potential energy matching PDE in IDA-PBC an ordinary differential equation is used to define the immersion map in I&I. It is shown that the energy shaping part of the IDA-PBC controller makes the closed-loop system an interconnection of two lower-dimensional port-Hamiltonian (pH) systems in the on- and off-manifold coordinates that appear in the I&I framework. The effect of damping injection output feedback can be identified with dissipation in the off-manifold part of the interconnected system. Dissipation is propagated to the on-manifold part which results in asymptotic stability of the system's equilibrium. The particular choice of the I&I design parameters in the present example, including the unconventional definition of coordinates on the invariant manifold, provides an interesting re-interpretation of the IDA-PBC control law from the I&I perspective. Finally, a discussion on the equivalence of the two approaches is presented by examining the cases of linear mechanical systems with one unactuated pivot as well as of general linear mechanical systems.

Equivalence of Immersion and Invariance and IDA-PBC for the Acrobot

In this note the two well known nonlinear control design techniques Interconnection and Damping Assignment Passivity Based Control (IDA-PBC) and Immersion and Invariance (I&I) are compared through the example of the so-called Acrobot underactuated mechanical system. Equivalences of both procedures become obvious from the corresponding immersion and matching equations. In particular, the coordinate change which renders the potential energy matching PDE in IDA-PBC an ordinary differential equation is used to define the immersion map in I&I. It is shown that the energy shaping part of the IDA-PBC controller makes the closed-loop system an interconnection of two lower-dimensional port-Hamiltonian (pH) systems in the on- and off-manifold coordinates. The effect of damping injection output feedback can be identified with dissipation in the off-manifold part of the interconnected system. Dissipation is propagated to the on-manifold part which results in asymptotic stability of the system's equilibrium. The analysis in the present work provides an interesting interpretation of the effect of the IDA-PBC control law using the I&I framework.

Stabilization of a Mobile Inverted Pendulum with IDA-PBC and Experimental Verification

Mobile inverted pendulums are needed to be stabilized at all times using a safe control method. Previous approaches were based on a linearized model or feedback linearization. In this study, interconnection and damping assignment passivity-based control (IDA-PBC) is applied. The IDA-PBC is a nonlinear control method which has been shown to be powerful to stabilize underactuated mechanical systems. Although partial differential equations (PDEs) must be solved to derive the IDA-PBC controller and it is a difficult task in general, we show that the controller for the mobile inverted pendulum can be constructed. A systematic graphical method to select controller parameters that guarantee asymptotic stability and a procedure to estimate the domain of attraction are also proposed. Using this method, the pendulum is stabilized by restricting it to a predefined angle range. Simulation results show that the IDA-PBC controller performs fast responses theoretically ensuring sufficient domain of attraction. The effectiveness of the IDA-PBC controller is also verified in experiments. Especially control performance under an impulsive disturbance on the mobile inverted pendulum is verified. The IDA-PBC achieves as fast transient performance as a linear-quadratic regulator (LQR). In addition, we show that when the pendulum inclines quickly and largely due to the disturbance, the IDA-PBC controller can stabilize it whereas the LQR cannot.

Stabilization of a Mobile Inverted Pendulum with IDA-PBC and Experimental Verification

Mobile inverted pendulums are expected to be applied to personal mobility and robots which are used in human living space. Although this mobility always needs to be stabilized, previous approaches were based on a linearized model or feedback linearization. In this study, interconnection and damping assignment passivity-based control (IDA-PBC) is applied. The IDA-PBC is a nonlinear control method which has been shown to be powerful to stabilize underactuated mechanical systems. Although partial differential equation (PDE) must be solved to derive the IDA-PBC controller and it is a difficult task in general, we show that the controller for the mobile inverted pendulum can be constructed. A systematic graphical method to select controller parameters which guarantee asymptotic stability and estimate the domain of attraction is also proposed. Simulation results show that the IDA-PBC controller performs fast responses theoretically ensuring sufficient domain of attraction. The effectiveness of the IDA-PBC controller is also verified in experiments. Especially control performance under an impulsive disturbance on the mobile inverted pendulum is verified. The IDA-PBC achieves as fast transient performance as a linear-quadratic regulator (LQR). In addition, we show that when the pendulum inclines quickly and largely due to the disturbance, the IDA-PBC controller can stabilize it whereas the LQR can not.

Transparent Parametrization of Nonlinear IDA-PBC for a Hydraulic Actuator

In this contribution the application of local linear dynamics assignment for the parametrization of nonlinear passivity based setpoint-control of a double-acting hydraulic cylinder is presented. The focus is on the systematic derivation of the stabilizing nonlinear state feedback control law using Interconnection and Damping Assignment Passivity Based Control (IDA-PBC) such that desired predefined local linear dynamics of the closed loop system is realized exploiting the maximum initial design freedom provided by constant interconnection and dissipation matrices. The paper provides a step-by-step approach to find the IDA-PBC controller for the hydraulic system applying a series of simple algebraic manipulations and is complemented by experimental results on a hydraulic actuator as a part of a quarter-car testrig.

Discussion on: “Stabilization of the Experimental Cart-Pendulum System with Proven Domain of Attraction”

The article presents an experimental implementation of an Immersion & Invariance (I&I), [2], controller design to an experimental cart-pendulum system. The I&I controller was developed in [1], and in the paper under discussion the domain of attraction is proven to be the open upper half plane. The article serves merely as an experimental proof of principle for the I&I method, where in addition to the I&I controller, extra control actions are taken in order to deal with practical issues such as friction, and the fact that the velocities are not measured. It is interesting to compare these results with another controller implementation on the same set up. In [5] an IDA-PBC (Interconnection and Damping Assignment Passivity Based Control) controller was developed and implemented on the same set up. Even though it is argued in the introduction of the article under discussion that the controller of [5] is rather complicated in comparison to the I&I control, the level of complexity or simplicity of the I&I controller given by expression (19) is not discussed later on in the article. For that, we can consider the IDA-PBC design of [5]. The controller expression is derived by construction of a newmass inertia matrix (Md), interconnection matrix (J2), and damping matrix (Kv), along with a new energy function (Hd), and the overall expression for the control law is obtained by substituting these new matrices and functions into the control law given by