Types Of Control Laws Research Articles

Helicopter augmented control laws for ship deck landing: HACLAS ONERA/DLR Joint Team

Different types of control laws are implemented, tested and compared for maritime operations particularly ship deck landing maneuvers at the flight simulation facilities at both DLR (German Aerospace Center) and ONERA (The French Aerospace Lab). At DLR, “classical” cyclic and collective stick flight controls were used during the piloted simulator trials while active side-sticks were operated at ONERA. A joint maritime scenario for ship deck landing in the simulation environments of both institutes is presented. Test methodologies and assessment techniques to evaluate the ship deck landings are harmonized based on different criteria such as quantitative measures and handling qualities (HQ) ratings to analyze the developed control laws. Simulation results based on pilot studies for an EC135 in the DLR simulator and an EC225 at ONERA are presented.

Synchronization of fractional-order delayed coupled networks with reaction–diffusion terms and Neumann boundary value conditions

This paper investigates the adaptive pinning strategies for achieving synchronization of fractional-order delayed coupled networks with reaction–diffusion terms and a digraph topology by incorporating Neumann boundary value conditions. By employing the inf–sup method, a novel fractional-order inequality is proved. The classical Poincaré inequality is also extended by utilizing the Hölder inequality. Two types of control laws are developed to achieve synchronization: one with control gains dependent solely on time, and another with control gains dependent on both space and time. For each case, adaptive control laws and synchronization criteria based on matrix inequalities are proposed. Finally, the effectiveness of the synchronization results is demonstrated through two numerical examples.

Design of Aircraft Lateral Control Laws Simulation for Teaching and Learning

This paper studies the design of a simulator to simulate the general behaviour of an aircraft in its lateral motion. The study will be in two parts: the aircraft lateral natural system and the design of the control laws. In the aircraft lateral natural system, all modes will be discussed including the Pure Roll mode, the Dutch Roll mode, and the Spiral mode. In the design of the control laws, two types of control laws were discussed which are the yaw damper and the poles placement method. The result is a complete simulator for aircraft lateral motion which allows the user to simulate and study the lateral characteristic of an aircraft given the desired input. The simulator resulted from this study is suitable to be used for teaching and learning as the changes in parameters yield instantaneous results that can be displayed.

McKean--Vlasov SDEs in Nonlinear Filtering

Various particle filters have been proposed over the last couple of decades with the common feature that the update step is governed by a type of control law. This feature makes them an attractive alternative to traditional sequential Monte Carlo which scales poorly with the state dimension due to weight degeneracy. This article proposes a unifying framework that allows to systematically derive the McKean-Vlasov representations of these filters for the discrete time and continuous time observation case, taking inspiration from the smooth approximation of the data considered in Crisan & Xiong (2010) and Clark & Crisan (2005). We consider three filters that have been proposed in the literature and use this framework to derive It\^{o} representations of their limiting forms as the approximation parameter $\delta \rightarrow 0$. All filters require the solution of a Poisson equation defined on $\mathbb{R}^{d}$, for which existence and uniqueness of solutions can be a non-trivial issue. We additionally establish conditions on the signal-observation system that ensures well-posedness of the weighted Poisson equation arising in one of the filters.

Lyapunov-based unified control method for closed quantum systems

A Lyapunov-based unified control method for closed quantum systems is proposed in this paper for the state transfers from an arbitrary initial state to a desired target state. Especially, the proposed control method can be used in the cases that the free Hamiltonian of the system is not strongly regular, and (or) the control Hamiltonian is not fully connected. Three types of control laws are proposed simultaneously based on the implicit Lyapunov control theory, in which two implicit functions and one Lyapunov function with virtual mechanical quantity are well-designed. The largest invariant set of the quantum control system is investigated, and the convergence of the control system designed is proved. A numerical simulation is implemented in detail to instruct the design procedure and demonstrate the effectiveness of the control method proposed.

Global Stabilization of Fractional-Order Memristor-Based Neural Networks With Time Delay.

This paper addresses the global stabilization of fractional-order memristor-based neural networks (FMNNs) with time delay. The voltage threshold type memristor model is considered, and the FMNNs are represented by fractional-order differential equations with discontinuous right-hand sides. Then, the problem is addressed based on fractional-order differential inclusions and set-valued maps, together with the aid of Lyapunov functions and the comparison principle. Two types of control laws (delayed state feedback control and coupling state feedback control) are designed. Accordingly, two types of stabilization criteria [algebraic form and linear matrix inequality (LMI) form] are established. There are two groups of adjustable parameters included in the delayed state feedback control, which can be selected flexibly to achieve the desired global asymptotic stabilization or global Mittag-Leffler stabilization. Since the existing LMI-based stability analysis techniques for fractional-order systems are not applicable to delayed fractional-order nonlinear systems, a fractional-order differential inequality is established to overcome this difficulty. Based on the coupling state feedback control, some LMI stabilization criteria are developed for the first time with the help of the newly established fractional-order differential inequality. The obtained LMI results provide new insights into the research of delayed fractional-order nonlinear systems. Finally, three numerical examples are presented to illustrate the effectiveness of the proposed theoretical results.

Global stabilization of discrete-time multiple integrators with bounded and delayed feedback

This paper investigates the global stabilization problem of discrete-time multiple integrators with bounded and delayed feedback. In the absence of input delay, two classes of nonlinear feedback laws are proposed. The first one consists of parallel connections of saturation functions and the other one consists of nested saturation functions. Some free parameters and the so-called state-dependent saturation functions are introduced into these two types of control laws which can help to improve the transient performance of the closed-loop system. In the presence of input delay, with the aid of a special canonical form, two types of nonlinear control laws are also proposed to achieve global stability of the closed-loop system. Two numerical examples are given to illustrate the effectiveness of the proposed methods.

Quantum genetic sliding mode controller design for depth control of an underwater vehicle

Quantum genetic algorithm (QGA) is an optimization algorithm based on the probability that combines the idea of quantum computing and traditional genetic algorithm. In this paper, a new type of control law is developed for an underwater vehicle along with the desired path. The proposed controller is based on sliding mode control (SMC) in which the reaching law is modified to overcome two challenging problems, chattering, and sensitivity against noise. The disturbance is considered as a set of sinus waves with different frequencies which its parameters are estimated by Particle Swarm Optimization (PSO). Since QGA has some advantages such as fast convergence speed, small population size, and strong global search capabilities, we use QGA to determine the gain of the proposed controller. Finally, the Lyapunov theorem is used to prove that trajectory-tracking error converges to zero. Simulation results show that QGA can converge to the optimal response with a population consist of one chromosome.

Fast Ferry Smoothing Motion via Intelligent PD Controller

A novel type of control law was adopted to reduce the vertical acceleration of a fast ferry as well as the motion sickness incidence suffered by the passengers onboard by means of a submerged T-foil. Considering the system changing characteristics under high disturbances, a model-free approach was adopted. In addition, an upgraded proportional-derivative (PD) controller with correction terms resulting from a fast-online estimation of the system dynamics was designed. The overall controller, known as intelligent PD (i-PD) controller, was tested, and the obtained results were compared with those of a classic PD controller. The controllers were also tested in a changing environment and at different operating velocities. The results confirmed the effectiveness of the i-PD controller to smooth the motions with low computational cost control schemes. Furthermore, thanks to ability of the i-PD controller to continually update the estimated dynamics of the system, it showed a better reduction in both vertical motions and the seasickness level of the passengers with the needed robustness under external disturbances and system changing parameters.

Necessary and Sufficient Conditions For The Stability Of Uncertain Input-Delayed Systems

This paper discusses stability analysis supply chain dynamics using feedback control law structure. The case study concerns the inventory control system which is considered as an input-delay system under uncertainties on customer demands with constraints related to losses of stored products. Due to the lead time of the control law and factors such as the customer demand which is supposed to be unknown, the objective is to define a control law which permits to satisfy the end-customer demand and for which the production system requirements will be completely met. The end customer demand is considered as the external perturbation. To study the stability analysis, two types of control law are proposed, both based on a feedback predictor structure. The necessary and sufficient conditions on the existence of control law are then formulated. The results demonstrate that it possible to improve the performances of the supply chain by choosing optimally the control parameters and the specifications of the production system.

Field Programmable Gate Array Implementation of Active Control Laws for Multi-mode Vibration Damping

A B S T R A C T This paper investigates the possibility and effectiveness of multi-mode vibration control of a plate through real-time FPGA (Field Programmable Gate Array) implementation. This type of embedded system offers true parallel and high throughput computation abilities. The control object is an aluminum panel, clamped to a Perspex box’s upper side. Two types of control laws are studied. The first belongs to non-model based control. This control law is designed to generate active damping within the designed bandwidth. The second control law is model based H-infinity robust control. A system identification process is needed before the controller comes out. Each of the control laws is implemented on a FPGA target, which is powerful enough to achieve high throughput control loop rates. The experimental control results demonstrate that the non-model based control law has sufficient authority to suppress the interesting modes. The model-based robust control law’s control performance is not so positive compared to the previous method. Therefore, it is not recommended for this application.

Consensus and formation control on [formula omitted] for switching topologies

This paper addresses the consensus problem and the formation problem on SE(3) in multi-agent systems with directed and switching interconnection topologies. Several control laws are introduced for the consensus problem. By a simple transformation, it is shown that the proposed control laws can be used for the formation problem. The design is first conducted on the kinematic level, where the velocities are the control laws. Then, for rigid bodies in space, the design is conducted on the dynamic level, where the torques and the forces are the control laws. On the kinematic level, first two control laws are introduced that explicitly use Euclidean transformations, then separate control laws are defined for the rotations and the translations. In the special case of purely rotational motion, the consensus problem is referred to as consensus onSO(3) or attitude synchronization. In this problem, for a broad class of local representations or parameterizations of SO(3), including the Axis–Angle Representation, the Rodrigues Parameters and the Modified Rodrigues Parameters, two types of control laws are presented that look structurally the same for any choice of local representation. For these two control laws we provide conditions on the initial rotations and the connectivity of the graph such that the system reaches consensus on SO(3). Among the contributions of this paper, there are conditions for when exponential rate of convergence occurs. A theorem is provided showing that for any choice of local representation for the rotations, there is a change of coordinates such that the transformed system has a well known structure.

A comparative study of game mechanics and control laws for an adaptive physiological game

We present an adaptive biofeedback game that aims to maintain the player’s arousal by modifying game difficulty in response to the player’s physiological state, as measured with wearable sensors. Our approach models the interaction between human physiology and game difficulty during gameplay as a control problem, where game difficulty is the system input and player arousal its output. We validate the approach on a car-racing game with real-time adaptive game mechanics. Specifically, we use (1) car speed, road visibility, and steering jitter as three mechanisms to manipulate game difficulty, (2) electrodermal activity as physiological correlate of arousal, and (3) two types of control law: proportional (P) control, and proportional-integral-derivative (PID) control. We also propose quantitative measures to characterize the effectiveness of these game adaptations and controllers in manipulating the player’s arousal. Experimental trials with 25 subjects in both open-loop (no feedback) and closed-loop (negative feedback) conditions show statistically significant differences in effectiveness among the three game mechanics and also between the two control laws. Specifically, manipulating car speed provides higher control of arousal levels than changing road visibility or vehicle steering. Our results also confirm that PID control leads to lower error and reduced oscillations in the closed-loop response compared to proportional-only control. Finally, we discuss the theoretical and practical implications of our approach.

On output regulation in state-constrained systems: An application to polyhedral case

This paper deals with the problem of output regulation using the state feedback control laws for a class of nonsmooth dynamical systems where the state is constrained to evolve within some convex set. The formalism of differential inclusions (DIs) is used to describe the system dynamics and the derivation of the state feedback law is based on the internal model principle. We study two types of control laws: firstly, a static control is designed assuming that the entire states of the plant and the exosystem are available for feedback; In the second case, only the error to be regulated is available for feedback and a dynamic compensator is designed. The analyses are based on using the properties of the normal cones associated with convex sets to study the well-posedness (existence and uniqueness of solutions) and the stability of the closed-loop system. As an application, we design a discontinuous controller which guarantees the viability of a predefined polyhedral subset of the state space using the formulation of linear complementarity systems.

A MATLAB toolkit for composite nonlinear feedback control — improving transient response in tracking control

We present in this article a MATLAB toolkit with a user-friendly graphical interface for composite nonlinear feedback control system design. The toolkit can be utilized to design a fast and smooth tracking controller for a class of linear systems and nonlinear systems with actuator and other nonlinearities as well as with external disturbances. The parameters of the controller can be tuned easily on the user panel or autotuned by the toolkit. The toolkit is capable of displaying both time-domain and frequency-domain responses on its main panel and generating three different types of control laws, namely, the state feedback, the full-order measurement feedback and the reduced-order measurement feedback controllers. The usage and design procedure of the toolkit are illustrated by practical examples on a rotational/translational actuator (RTAC) system and a hard disk drive servo system. The toolkit can be utilized to design servo systems that deal with point-and-shoot fast targeting.

Semi-active MR dampers for seismic control of structures

Magnotorheological (MR) dampers have been demonstrated to be more effective in reducing the structural response due to earthquakes using only a small amount of external power. The performance of MR damper depends upon type of control law used and the damper force is directly depends on the input command voltage. The purpose of this study is to evaluate the effectiveness of input command voltage on MR damper system against recently proposed control laws under different earthquakes. The magnitude of control force increases with the increase in the input command voltage of MR damper, however for the different damper locations and configurations maximum command voltage to the current driver may not always effective in reducing the structural responses. To investigate the effective performance of the MR dampers, different control algorithms with multiple MR damper locations are considered in this study. A phenomenological model of a shear- mode MR damper, based on a Bouc–Wen element, is employed in the analysis of the controlled building. The control algorithms are tested on a five-story framed building and parametric study on variation in the input command voltage is conducted for different real earthquake ground motions. The numerically evaluated optimum parametric values are considered for the analysis of the different damper locations in the building in order to reduce the displacement, acceleration and the base shear of the building. It is shown numerically that the performance of the MR damper has a great potential in suppressing structural vibrations over a wide range of seismic inputs by selecting appropriate optimum input command voltages.

Nonlinear path-following control of an AUV

A new type of control law is developed to steer an autonomous underwater vehicle (AUV) along a desired path. The methodology adopted for path-following deals explicitly with vehicle dynamics. Furthermore, it overcomes stringent initial condition constraints that are present in a number of path-following control strategies described in the literature. Controller design builds on Lyapunov theory and backstepping techniques. The resulting nonlinear feedback control law yields convergence of the path-following error trajectory to zero. Simulation results illustrate the performance of the control system proposed.

COOPERATIVE ATTITUDE SYNCHRONIZATION IN SATELLITE SWARMS: A CONSENSUS APPROACH

The present paper considers the problem of autonomous synchronization of attitudes in a swarm of spacecraft. Building upon our recent results on consensus on manifolds, we model the spacecraft as particles on SO(3) and drive these particles to a common point in SO(3). Unlike the Euler angle or quaternion descriptions, this model suffers no singularities nor double-points. Our approach is fully cooperative and autonomous: we use no leader nor external reference. We present two types of control laws, in terms of applied control torques, that globally drive the swarm towards attitude synchronization: one that requires tree-like or all-to-all inter-satellite communication (most efficient) and one that works with nearly arbitrary communication (most robust).

Nonsingular path following control of a unicycle in the presence of parametric modelling uncertainties

AbstractA new type of control law is derived to steer the dynamic model of a wheeled robot of unicycle type along a desired path. The methodology adopted for path following control deals explicitly with vehicle dynamics and plant parameter uncertainty. Furthermore, it overcomes stringent initial condition constraints that are present in a number of path following control strategies described in the literature. This is done by controlling explicitly the rate of progression of a ‘virtual target’ to be tracked along the path, thus bypassing the problems that arise when the position of the virtual target is simply defined by the projection of the actual vehicle on that path. In the paper, a nonlinear adaptive control law is derived that yields convergence of the (closed‐loop system) path following error trajectories to zero. Controller design relies on Lyapunov theory and backstepping techniques. Simulation results illustrate the performance of the control system proposed. Copyright © 2006 John Wiley & Sons, Ltd.

Iterative learning control scheme for manipulators including actuator dynamics

This paper presents the iterative learning control for the industrial robot manipulators including actuator dynamics. Motivated by human learning, the basic idea of iterative learning control is to use information from previous execution of a trial in order to improve performance from trial to trial. This is an advantage, when accurate model of the system is not available as friction and actuator dynamics, though present in the system, are not modeled to reduce the computational complexity. In this paper different aspects of ILC including the design schemes and control algorithms are covered. The learning control scheme comprises two types of control laws: a linear feedback law and a feed-forward control law. In the feedback loop, the fixed gain PD controller provides stability of the system and keeps its state errors within uniform bounds. In the feed-forward path, a learning control rule/strategy is exploited to track the entire span of a reference input over a sequence of iterations. Algorithms are verified through detailed simulation results on a two DOF robot manipulator.