Interconnection And Damping Assignment Passivity-based Control Research Articles

Robust interconnection and damping assignment energy-based control for a permanent magnet synchronous motor using high order sliding mode approach and nonlinear observer

Several advantages are provided by the permanent magnet synchronous motor (PMSM) over DC motors and is gradually replacing them in industry. The dynamics of the PMSM can be described by time-varying non-linear equations considering unknown external disturbances (load). However, the control task is complicated due to the associated constraints. Non-linear controls are required to correct for non-linearities, external disturbances, and parametric fluctuations. This paper investigates a new robust interconnection and damping assignment passivity-based control (IDA-PBC) paired with a non-linear observer technique and the dq-frame model of the PMSM. The IDA-PBC method has the advantage of not canceling non-linear features but compensating them in a damped manner. The proposed IDA-PBC is in charge of creating the system’s desired dynamic, while the nonlinear observer is in charge of reconstructing the measured signals in order to force the PMSM to track speed. The main contribution of this paper is to synthesize the controller while taking into account the PMSM’s entire dynamic and making the system passive. It is achieved by rearranging the energy of the proposed IDA-PBC and inserting a damping factor that compensates the non-linear terms in a damped rather than canceled manner, so establishing a duality concept between the observer and the IDA-PBC. IDA-PBC can be computed in three ways: parametrically, nonparametrically, and algebraically. To control the PMSM’s speed, the parameterized IDA-PBC approach is employed. In general, the presented candidate outperforms the conventional IDA-PBC in terms of resilience, speed of convergence, efficiency, and high robustness. The efficiency of the proposed technique is investigated numerically using MATLAB/Simulink software.

Robust passivity‐based control design for active nonlinear suspension system

AbstractIn this article, we propose a novel interconnection and damping assignment passivity‐based control (IDA‐PBC) design for a quarter car nonlinear active suspension system. As an energy shaping method, IDA‐PBC is suitable for applying the main concept of skyhook (SH) control. In addition to the damping term, we utilize the characteristics of the energy shaping method to change the sprung and unsprung masses, thereby strengthening the vibration suppression effect. An IDA‐PBC‐based controller design for an active suspension system, which includes a nonlinear spring, a nonlinear damper, and mass uncertainty, is proposed. Different from most IDA‐PBC applications, which tend to control the position or the velocity, our methods focus on transforming a nonlinear suspension system into a desired linear system with ideal aseismatic properties. Unlike a conventional controller using the SH control strategy, we design a virtual vehicle body and an unsprung mass in addition to the damper coefficients. By deriving the port‐Hamiltonian form of the suspension system from its dynamics and rewriting it based on the relative coordinates, we obtain a feedback law that only uses the relative displacement and velocity of the suspension system. We derive the conditions for ensuring the global asymptotical stability of the suspension system and propose the guidelines for parameter selection that can guarantee robust stability against parameter uncertainties.

Solution of matching equations of IDA-PBC by Pfaffian differential equations

Finding the general solution of partial differential equations (PDEs) is essential for controller design in newly developed methods. Interconnection and damping assignment passivity-based control (IDA-PBC) is one of such methods in which the solution to corresponding PDEs which are called matching equations is needed to apply it in practice. In this paper, these matching equations are transformed to corresponding Pfaffian differential equations. Furthermore, it is shown that upon satisfaction of the integrability condition, the solution to the corresponding third-order Pfaffian differential equation may be obtained quite easily. The method is applied to the PDEs of IDA-PBC in some benchmark systems such as Magnetic levitation system, Pendubot, and underactuated cable-driven robot to verify its applicability.

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.

Large-Signal Stabilization of Power Converters Cascaded Input Filter Using Adaptive Energy Shaping Control

Series connection of input filters with static converters might lead to instability. However, the input filter has rarely taken into account in the stable design of power converters. Indeed, an input LC filter cascaded with a converter can become unstable even if the converter is regulated by a tight controller ensuring its stability alone. This fact is due to the interactions between the filter and the converter. To tackle the instability potential, an adaptive energy shaping control (AESC), which is based on the interconnection and damping assignment passivity-based control (IDA-PBC), is addressed in this article to regulate the cascaded system and achieve the following attractive features: 1) the input filter's dynamics are considered in the control law, so the interactions between the filter and the converter are taken into account during the controller design and 2) the influence between several subsystems, put in cascade, is considered by the proposed method, and the new large-signal stability proof is given accordingly. Simulation and experimental results from a 3.5-kW, 270-200-V buck converter cascaded with an input filter under different load conditions, i.e., constant impedance load (CIL), constant current load (CCL), and constant power load (CPL), are presented to demonstrate the proposed approach.

Passivity‐based control laws for an unmanned powered parachute aircraft

AbstractIn this paper, the development of passivity‐based control (PBC) algorithms to stabilize an unmanned powered parachute aerial vehicle is presented. The equations of motion of the system are presented in both Lagrangian and Hamiltonian formalisms. The proposed controllers are based on the Hamiltonian function of the system and guarantee the parachute aircraft system stabilization. In the first control law a classic PBC strategy is proposed, and in the second, an interconnection and damping assignment‐passivity‐based control (IDA‐PBC) is chosen because of its inherent robustness against parametric uncertainty and unmodeled dynamics. The control objective is to reach a desired final position despite the initial launch conditions. Numerical simulations with variation in the parachute mass weight and in the presence of wind are carried out to validate our proposed schemes.

Control of Teleoperation Systems in the Presence of Varying Transmission Delay, Non-passive Interaction Forces, and Model Uncertainty

SUMMARYThis paper addresses robust stability and position tracking problems in teleoperation systems subject to varying delay in the communication medium, uncertainties in the models of manipulators, and non-passive interaction forces in the terminations. Fixed-structure nonlinear control law is developed based on the notion of Interconnection and Damping Assignment Passivity-Based Control (IDA-PBC) scheme. Then, utilizing the Lyapunov–Krasovskii theorem, sufficient conditions are derived in terms of Linear Matrix Inequalities (LMIs) to tune the controller parameters. Differently from literature, the objectives are achieved without requirement for any passive parts in the model of interaction forces. Comparative simulations and experimental results demonstrate the applicability and superiority of the proposed method.

Distributed IDA-PBC for a Class of Nonholonomic Mechanical Systems

Nonholonomic mechanical systems encompass a large class of practically interesting robotic structures, such as wheeled mobile robots, space manipulators, and multi-fingered robot hands. However, few results exist on the cooperative control of such systems in a generic, distributed approach. In this work we extend a recently developed distributed Interconnection and Damping Assignment Passivity-Based Control (IDA-PBC) method to such systems. More specifically, relying on port-Hamiltonian system modelling for networks of mechanical systems, we propose a full-state stabilization control law for a class of nonholonomic systems within the framework of distributed IDA-PBC. This enables the cooperative control of heterogeneous, underactuated and nonholonomic systems with a unified control law. This control law primarily relies on the notion of Passive Configuration Decomposition (PCD) and a novel, non-smooth desired potential energy function proposed here. A low-level collision avoidance protocol is also implemented in order to achieve dynamic inter-agent collision avoidance, enhancing the practical relevance of this work. Theoretical results are tested in different simulation scenarios in order to highlight the applicability of the derived method.

Stabilization of wind farm integrated transmission system with input delay

<abstract> In the process of large-scale wind farms integration, the time delay is usually caused by the introduction of wide area control signal, which leads to the unstable operation of integrated transmission system. In order to solve this problem, using the control principle of interconnection and damping assignment passivity-based (IDA-PB), this paper puts forward a control method which applies voltage source converter high voltage direct current (VSC-HVDC) technology to the integrated system of time-delay wind farm and keeps the system running stably. In this method, the framework of time-delay port controlled Hamiltonian (PCH) system is constructed, and the energy shaping of the system is carried out by extending the IDA-PB control principle, thus the feedback controller of the system is designed. Around the problem of time-delay stabilization, the stability criterion is obtained by constructing Lyapunov-Krasovskii functional and introducing free weighting matrices. Finally, the simulation results show that the proposed method can effectively solve the time delay problem of the integrated transmission system and avoid the performance deterioration of the system. </abstract>

Filtered Observer-Based IDA-PBC Control for Trajectory Tracking of a Quadrotor

In this paper, a new filtered observer-based IDA-PBC (Interconnection and Damping Assignment-Passivity Based Control) strategy is developed for trajectory tracking of a quadrotor in the presence of disturbances and model uncertainties. The proposed algorithm allows the control of the quadrotor in all its states. It can deal with the noisy output measurements and uncertainties in the translational and rotational dynamics, as unmodeled dynamics inherent to real systems or unknown external signals (exogenous signals). The designed filtered observer estimates the state from noisy output measurements, and it depends only on two design parameters. Numerical simulation tests are carried out to highlight the overall controller approach in a realistic scenario.

Optimal Task-Invariant Energetic Control for a Knee-Ankle Exoskeleton

Task-invariant control methods for powered exoskeletons provide flexibility in assisting humans across multiple activities and environments. Energy shaping control serves this purpose by altering the human body's dynamic characteristics in closed loop. Our previous work on potential energy shaping alters the gravitational vector to reduce the user's perceived gravity, but this method cannot provide velocity-dependent assistance. The interconnection and damping assignment passivity-based control (IDA-PBC) method provides more freedom to shape a dynamical system's energy through the interconnection structure of a port-controlled Hamiltonian system model. This letter derives a novel energetic control strategy based on IDA-PBC for a backdrivable knee-ankle exoskeleton. The control law provides torques that depend on various basis functions related to gravitational and gyroscopic terms. We optimize a set of constant weighting parameters for these basis functions to obtain a control law that produces able-bodied joint torques during walking on multiple ground slopes. We perform experiments with an able-bodied human subject wearing a knee-ankle exoskeleton to demonstrate reduced activation in certain lower-limb muscles.

Practical considerations of nonlinear control techniques applied to static power converters: A survey and comparative study

In light of robustness and specific characteristics of the semiconductor switches and converters, nonlinear controllers perceive power electronics as an important application field. As there is still a gap between theory and practice because of the complexity of this theme for an initial contact, many students and industrial engineers are discouraged. Generally and intuitively, the aim of this paper is to present some practical considerations such as: simple procedure to obtain nonlinear equations, sinusoidal, three-phase and isolated cases, indispensable techniques like load estimation and PI controller for output voltage regulation, Hardware in The Loop (HIL) Simulation and hybrid solutions. An additional goal is the comparative study of three nonlinear control methods - state feedback linearization (SFL), passivity based control (PBC) and interconnection and damping assignment passivity based control (IDA-PBC), all of which are applied to seven static power converters: buck, boost, buck-boost, flyback, 3-phase boost, CUK and SEPIC. Comparative figures and tables are constructed to evidence the similarities and differences between the techniques and converters. The results are shown from a qualitative viewpoint.

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.

Adaptive interconnection and damping assignment passivity‐based control for linearly parameterized discrete‐time port controlled Hamiltonian systems via I&amp;I approach

SummaryIn this paper, discrete‐time adaptive control of linearly parameterized fully actuated Port‐controlled Hamiltonian systems with parameter uncertainties in energy function is considered. A discrete‐time adaptive interconnection and damping assignment passivity‐based control (IDA‐PBC) method, utilizing the immersion and invariance (I&amp;I) approach, for the considered uncertain Hamiltonian system, is presented. A discrete‐time parameter estimator based on the immersion and invariance approach is derived to obtain an automatic tuning mechanism for the IDA‐PBC controller. The stability analysis for the estimator and the closed‐loop system is done using the Lyapunov theory. The proposed method is applied to two fully actuated physical systems and its performance is tested by simulations. Simulation results show that the proposed I&amp;I‐based adaptive IDA‐PBC controller successfully preserves the performance of the IDA‐PBC controller designed with true parameters under a large amount of uncertainty.

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.

Advanced passivity-based, aging-tolerant control for a fuel cell/super-capacitor hybrid system

This paper proposes an advanced aging-tolerant control for a fuel cell/super-capacitor hybrid system applied to a commercial vehicle. The controller is designed with the Interconnection and Damping Assignment-Passivity-Based Control (IDA-PBC) method to solve the converters coordination problem, where the state-of-charge of the super-capacitors and all current limitations are considered into the non-linear controller. The aging of the fuel cell is estimated in real-time by an extended Kalman filter and is integrated in the controller in order to preserve the stability of the whole system. Finally, a hardware-in-the-loop platform based on an INTEL/ALTERA FPGA is designed in order to validate the real-time operation of the algorithms for a specific case study with a fuel cell vehicle.

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.

Design of Passivity-Based Damping Controller for Suppressing Power Oscillations in DC Microgrids

In this article, a novel damping control scheme for V/I droop-controlled direct current (dc) microgrids is proposed to attenuate the oscillatory components in the power and current. At first, the model of the dc microgrid is introduced providing stability analysis. Then, the damping controller is designed using the interconnection and damping assignment passivity-based control (IDA-PBC) methodology. In addition, the gain selection technique for the IDA-PBC is developed. The proposed control scheme ensures that the oscillations of the output power and current are effectively attenuated. The validity of the proposed control algorithm has been verified by the results from both hardware-in-the-loop simulation and proto-type experiments.

Controller design for nonlinear bilateral teleoperation systems via total energy shaping

In this paper, Interconnection and Damping Assignment Passivity Based Control (IDA-PBC) notion is utilized to design a novel controller for teleoperation systems with asymmetric variable time delay in the communication channel and passive/non-passive interaction forces. By shaping both of the kinetic and potential energies, the performance of position and force tracking is improved compared to conventional controllers. Using the Lyapunov–Krasovskii theorem, sufficient synthesis conditions are derived in terms of Linear Matrix Inequalities (LMIs) to ensure stable position and force tracking in the system. The dynamical models of actuators, i.e. Direct Current (DC) motors, are considered in the design of control law. Finally, comparative simulation results are presented to demonstrate the superiority of the proposed method contrasted to some recent rival methods in the literature. The real-world applicability of the proposed control strategy is verified by the laboratory experiments.

An Improved Passivity-based Control of Electrostatic MEMS Device.

It is commonly known that the performance of an electrostatic microelectromechanical system (MEMS) device is limited to a specific range of the full gap distance due to the inherited “pull-in instability” phenomenon. In this work, we design a controller to extend the stabilization range of an electrostatic MEMS device and to enhance its performance. The interconnection and damping assignment-passivity based control (IDA-PBC) method is used and the controller design involves coordinate transformations and a coupling between the mechanical and electrical subsystems of the device. The method deploys a design of a speed observer to estimate the speed, which cannot be directly measured by sensors. The effectiveness of the dynamical controller is verified via numerical simulations; it is evident by the extended travel range of the parallel plates as well as the improved performance of the plates, even with a naturally lighter damping ratio.