Passivity-Based Control Research Papers - Academia.edu (original) (raw)

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- Passivity-Based Control, Impedance Control

The purpose of this paper is to show how the Timoshenko beam can be fruitfully described within the framework of distributed port Hamiltonian (dpH) systems so that rather simple and elegant considerations can be drawn regarding both the modeling and control of this mechanical system. After the dpH model of the beam is introduced, the control problem is discussed. In particular, it is shown how control approaches already presented in the literature can be unified, and a new control methodology is presented and discussed. This control methodology relies on the generalization to infinite dimensions of the concept of structural invariant (Casimir function) and on the extension to distributed systems of the so-called control by interconnection methodology. In this way, finite dimensional passive controllers can stabilize distributed parameter systems by shaping their total energy, i.e., by assigning a new minimum in the desired equilibrium configuration that can be reached if a dissipative effect is introduced.

This article presents an Active Disturbance Rejection
(ADR) approach for the control of a buck-boost converter
feeding a DC motor. The presence of arbitrary, time-varying,
load torque inputs on the DC motor and the lack of direct
measurability of the motor’s angular velocity variable, prompts
a Generalized Proportional Integral (GPI) observer based active
disturbance rejection controller which is synthesized on the basis
of passivity considerations. The GPI observer simultaneously
estimates the angular velocity and the exogenous disturbance
torque input in an on-line cancellation scheme, known as the ADR
control. The proposed control scheme is thus a sensorless one
with robustness features added to the traditional Energy Shaping
plus Damping Injection Methodology. The discrete switching
control realization of the designed continuous feedback control
law is accomplished by means of a traditional PWM-modulation
scheme. Additionally an Input to State Stability property of the
closed loop system is established. Experimental and Simulation
results are provided.

- by Jorge Luis Barahona Avalos and +1
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- Passivity-Based Control, Active Disturbance Rejection Control

In this note, the regulation problem for mixed finite and infinite dimensional port Hamiltonian systems (m-pHsystems) is discussed. A m-pH system results from the power conserving interconnection of finite and infinite dimensional systems in port Hamiltonian form. In particular, the system given by the interconnection of two finite dimensional systems, one of which is the controller, by means of an infinite dimensional connection is studied. The proposed control methodology is a generalization to the infinite dimensional case of a well-established passivity-based control technique for finite-dimensional port Hamiltonian systems, the control by interconnection and energy shaping, according to which the open-loop energy function is shaped so that a minimum in the desired configuration is introduced. This procedure is possible once the state variable of the controller is related to the state variable of the plant by constraining the state of the closed-loop system on a structural invariant (defined by a set of Casimir functions). In this way, the energy function of the controller, which is freely assignable, becomes a function of the configuration of the plant and, then, it can be easily shaped in order to solve the regulation problem.

- by Alessandro Macchelli
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- Passivity-Based Control, Port Hamiltonian system

The possibility of operating in remote environments using teleoperation systems has been considered widely in the control literature. This paper presents a review on the discrete-time teleoperation systems, including issues such as stability, passivity and time delays. Using discrete-time methods for a master-slave teleoperation system can simplify control implementation. Varieties of control schemes have been proposed for these systems and major concerns such as passivity, stability and transparency have been studied. Recently, unreliable communication networks affected by packet loss and variable transmission delays have been received much attention. Thus, it is worth considering discrete-time theories for bilateral teleoperation architectures, which are formulated on the same lines as the continuous-time systems. Despite the extensive amount of researches concerning continuous-time teleoperation systems, only a few papers have been published on the analysis and controller design for discrete bilateral forms. This paper takes into account the challenges for the discrete structure of bilateral teleoperation systems and notifies the recent contributions in this area. The effect of sampling time on the stability-transparency trade-off and the task performance is taken into consideration in this review. These studies can help to design guidelines to have better transparency and stable teleoperation systems.

This paper focuses on the temperature control in a multi-zone building. The lumped heat transfer model based on thermal resistance and capacitance is used to analyze the system dynamics and control strategy. The resulting thermal network, including the zones, walls, and ambient environment, may be represented as an undirected graph. The thermal capacitances are the nodes in the graph, connected by thermal resistances as links. We assume the temperature measurements and temperature control elements (heating and cooling) are collocated. We show that the resulting input/output system is strictly passive, and any passive output feedback controller may be used to improve the transient and steady state performance without affecting the closed loop stability. The storage functions associated with passive systems may be used to construct a Lyapunov function, to demonstrate closed loop stability and motivates the construction of an adaptive feedforward control. A four-room example is included to illustrate the performance of the proposed passivity based control strategy.

- by Sumit Mukherjee
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- Control Systems Engineering, Control Theory, Renewable Energy, Energy

The main contribution of this paper is a procedure for the control by energy shaping via Casimir generation of infinite dimensional port-Hamiltonian systems based on a particular finite element approximation. The proposed approach is justified by the fact that the adopted spatial discretization technique is able to preserve Casimir functions in the closed-loop system when going from the distributed to the (approximated) lumped parameter system. Besides the intrinsic difficulties related to the large number of state variables, the finite element model is generally given in terms of a Dirac structure and is completely a-causal, which implies that the plant dynamics is not given in standard input-state-output form, but as a set of DAEs. Consequently, the classical energy Casimir method has to be extended in order to deal with dynamical systems with constraints, usually appearing in the form of Lagrangian multipliers. The general methodology is illustrated with the help of an example in which the distributed parameter system is a lossless transmission line.

This paper presents a novel optimization-based passivity control algorithm for haptic-enabled bilateral teleoperation systems involving multiple degrees of freedom. In particular, in the context of energy-bounding control, the contribution focuses on the implementation of a passivity layer for an existing time-domain scheme, ensuring optimal transparency of the interaction along subsets of the environment space which are preponderant for the given task, while preserving the energy bounds required for passivity. The involved optimization problem is convex and amenable to real-time implementation. The effectiveness of the proposed design is validated via an experiment performed on a virtual teleoperated environment.

- by Gianni Bianchini and +2
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- Haptics, Teleoperation, Passivity-Based Control

The main contribution of this paper is a procedure for the control by energy shaping via Casimir generation of high-order port-Hamiltonian systems obtained from the spatial discretization of infinite dimensional dynamics. Beside the intrinsic difficulties related to the large number of state variables, the finite element model is generally given in terms of a Dirac structure and is completely a-causal, which implies that the plant dynamics is not given in standard input-state-output form, but as a set of DAEs. Consequently, the classical energy-Casimir method has to be extended in order to deal with dynamical systems with constraints, usually appearing in the form of Lagrangian multipliers. The methodology is illustrated with reference to a particular example, i.e. an hinged-hinged Timoshenko beam with torque actuators at both sides.

This paper presents an exact static error dynamics
passive output feedback controller to regulate the output voltage
of the DC-to-DC power converter 􀃻uk type; this controller is
obtained from the error dynamics of the nonlinear average model
of the converter. In order to compensate the effects of sudden
changes in the load resistance, the desired reference variables for
the regulation task are calculated using the estimated load value
obtained via an algebraic estimator. The results are validated in
an experimental laboratory setup.

This paper presents the design of a passivity-based iterative learning control (ILC) algorithm for coupled temperature and humidity in buildings. Since buildings are subjected to repeating diur-nal patterns of disturbances, ILC algorithms can significantly improve performance. Moreover, since it is a feedforward control scheme, it can be used in conjunction with either model-free or model-based approaches such as the popular model predictive control techniques. However, model-based control is challenging for buildings because of the difficulty in identifying building thermohygrometric models. Furthermore, the control law should be designed in such a way as to address both temperature and humidity set points. We propose a model-free ILC design approach facilitated by the inherent passivity of building thermohygrometric dynamics. We first demonstrate that the building dynamics are strictly output-incremental passive. This property is then exploited to design ILC laws that guarantee convergence in the iteration domain, while being robust to model uncertainty. Since we wish to control both temperature and humidity using only one input-mass flow rate of supply air, convergence to a point is not guaranteed; instead convergence to an ellipse on the temperature-humidity plane is shown. The controller performance is demonstrated through simulation examples.

— This paper presents a modeling and control strategy for comfort zone set-based control of temperature and humidity in buildings. We first propose a coupled model for humidity and temperature dynamics based on lumped parameter analysis. The interconnection of rooms/zones is captured through an undirected graph, with rooms represented as capacitances and walls and doors/windows as resistances. Unlike traditional RC-models, however, this model captures both mass and heat transfer between zones as well as the bilinearity in the input mass flow-rate. Key parameters are identified by the model, such as mass (and thermal) conductance between zones as well as mass (and thermal) capacitance and this model structure is then validated using physics-based Computational Fluid Dynamics (CFD) simulations. The control inputs to the system are the mass flow rates into each zone and the control objective is to drive the system state into a comfort zone set (a humidity and temperature region defined on the psychometric chart). The dynamic system is shown to be passive, hence any passive controller is stabilizing and able to drive both temperature and humidity to steady states within the thermal comfort region for given ambient conditions. We then propose a set-based (passive) controller to regulate the system outputs within the comfort region. Simulation results from implementing the controller on the lumped model are then compared with CFD simulations, for a design model of an existing experimental 6-room test bed. The proposed controller design methodology is also shown to be model-independent with results of the CFD simulations verifying this feature.

— This paper presents a modeling and control method for the thermohygrometric condition (temperature and humidity) in a multizone building. The interconnection between the zones is captured through an undirected graph. Employing an electrical circuit analogy, rooms represent capacitances, and walls and doors/windows are resistances. This model characterizes both mass and heat transfer between the zones and their coupling within each zone, extending the temperature-only resistance– capacitance models commonly used in the building control literature. By using physics-based computational fluid dynamics (CFD) simulation, we verify that this lumped-parameter model is a reasonable approximation of the physical system. The control objective is to drive the temperature and humidity of each zone into the comfort region in the psychrometric chart, using the mass-flow rate of the supplied air into the zone as the control input. In contrast to thermal-only building control, the challenge of this problem is to use a single control variable, mass-flow rate, to regulate both temperature and humidity. Our approach is to first design a feedforward control based on the desired steady-state condition within the comfort zone. We then draw on our previous work on passivity-based building temperature control to show that the thermohygrometric model around the steady state is strictly passive, from the mass-flow rate to a synthetic output combining temperature and humidity. This allows the use of any passive feedback controller combined with the feedforward to achieve robust stabilization about the desired operating point. The feedforward may be further adaptively updated, resulting in an integral-control term in the controller. Finally, to reduce the energy usage, we only apply the controller outside of the comfort zone and turn OFF the controller within the comfort zone. To illustrate the effectiveness of the proposed control strategy, simulation results using both the lumped and CFD models are presented for an existing physical six-room testbed.

— Heating, Ventilating and Airconditioning (HVAC) systems play a major role in controlling the distribution of indoor air, thereby providing building occupants a comfortable environment. Power shaping is a general methodology for the control of nonlinear dynamical systems. This paper proposes a novel perspective to modeling of HVAC systems using power and aimed to analyze temperature regulation in a multi-zone building. The resulting dynamics can be written in the Brayton-Moser form, the power function is used as a Lyapunov function and is modified based on the power shaping outputs of the system. The performance of the resulting controller is tested on two different HVAC subsystems to stabilize the system around the equilibrium point.

- by Krishna chaitanya Kosaraju and +1
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- Passivity-Based Control, Control Systems, HVAC Control, Building Systems

Motivated by the increasing interest in networked multi-agent systems and the wide number of applications in decentralized distributed control of smart grids, we address the problem of synchronization when each node (e.g., a microgrid, a distributed generator) is modeled as a linear-time continuous system whose output measurements are sent through communication links. However, the inclusion of a communication infrastructure adds new challenges to control strategies and some problems may arise such as time delays, packet losses, sampling period, just to name a few. In this work, we consider that data is sampled with homogeneous sampling periods. Then, using the novel concept of average passivity, we define the conditions for synchronizability when all nodes are identical and unstable dynamics are present. Additionally, results are extended to the case of non-uniform agents, and some simulations of synchronization in smart grids are introduced.

- by Jairo Giraldo and +2
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- Synchronization, Passivity-Based Control, Sampled-data Control

This paper presents the model of a fuel cell and the design and simulation of a cascade of two DC-DC converters. First, a detailed mathematical model of fuel cell is presented and simulated. Then, a nonlinear model of the whole controlled system is developed and a robust nonlinear controller of currents is synthesized using a passivity-based control. A formal analysis based on Lyapunov stability and average theory is developed to describe the control currents loops performances. A classical PI controller is used for the voltages loops. The simulation models have been developed and tested in the Matlab/Simulink. Simulated results are displayed to validate the feasibility and the effectiveness of the proposed strategy.

- by IAES Journals and +1
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- Fuel Cell, Passivity-Based Control, Lyapunov, Cascaded boost

This paper presents a novel control algorithm for haptic-enabled bilateral teleoperation systems involving several degrees of freedom. In particular, the contribution focuses on the implementation of a passivity layer for an established time domain scheme. The proposed approach aims at preserving transparency of interaction along subsets of the environment space which are preponderant for the given task, while guaranteeing the energy bounds required for passivity. The effectiveness of the proposed design is validated via an experiment performed on a virtual teleoperated environment.

- by Gianni Bianchini and +2
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- Haptics, Teleoperation, Passivity-Based Control

In the last decades, researchers and scientists have been trending towards photovoltaic (PV) solar energy research as one of the noteworthy renewable energies. As a matter of fact, the need for a laboratory system devoted to performing measurements and experimentation on PV systems is being increased. The PV array emulator is designed to accomplish this task by reproducing accurately the electrical behavior of real PV sources. The present paper proposes thus a new control and design of PV array emulators. It is based essentially on a hybrid Damping Injection controller. The proposed control strategy circumvents obviously the existing PV emulator's limitations in terms of accuracy, speed and partial shading emulation. Several results are given and discussed to show the efficiency of the proposed system to emulate PV modules and different PV array configurations under uniform solar irradiance and partial shading conditions.

- by Mustapha ALAOUI
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- Power Electronics, Renewable Energy, Nonlinear dynamics, Passivity-Based Control

This paper presents an analysis of the passivity condition for discrete-time bilateral teleoperation systems. Considering discrete-time controllers for a master-slave teleoperation system can simplify its implementation. Varieties of control schemes have been utilized for the position error based architecture of bilateral teleoperation systems and major concerns such as passivity and transparency have been studied. This paper takes into account the passivity conditions for the discrete counterparts of P-like, PD-like, and PD-like + dissipation controllers. These conditions impose bounds on the controller gains, the damping of the master and slave robots, and the sampling time which help researchers to provide guidelines to have better transparency and passive teleoperation systems. Simulation results are performed to show the effectiveness of the proposed criteria.

- by Amir A. Ghavifekr and +1
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- Teleoperation, Digital Control, Passivity-Based Control, Teleoperation & Time Delayed Control