Input-output Linearization Approach Research Articles

Design and Analysis of an Input–Output Linearization-Based Trajectory Tracking Controller for Skid-Steering Mobile Robots

This manuscript presents a control law based on the kinematic control concept and the input–output linearization approach. More specifically, the given approach has the structure of a two-loop controller. A rigorous closed-loop system analysis is presented by using known theory on perturbed systems. By assuming that the desired velocity in the body frame is persistently exciting, the uniform bound of the tracking error in earth coordinates is ensured. A simulation study using practical mobile robot parameters shows the viability of the introduced approach. In addition, two known trajectory tracking controllers are simulated in order to compare the performance of the proposed technique. Better tracking accuracy is obtained with the proposed control approach, even if uncertainties in the knowledge of the friction coefficients are presented.

Observer-based type-2 fuzzy approach for robust control and energy management strategy of hybrid energy storage systems

In this paper, an observer-based type-2 fuzzy method is proposed for control and energy management strategy (EMS) of the hybrid energy storage system (HESS) which can be composed of the fuel cell (FC), battery (BA), and supercapacitor (SC). The objective and main contribution of the suggested strategy is to provide: 1) Appropriate tracking performance of power sources by an observer-based control method in the presence of noise and signal ripples. 2) An observer-based composite adaptive type-2 fuzzy (OCAT2F) to approximate the voltage of power sources. 3) A dynamical model of DC-bus to guarantee the stability of closed-loop system. 4) An intelligent EMS. To have a high-power supply, the proposed EMS includes two parts; a type-2 fuzzy logic control rule table (T2FLCRT), and an observer-based robust adaptive fuzzy type-2 fuzzy (ORAT2F). Furthermore, stability analyses of the closed-loop system are provided by the input-output linearization (I-OL) approach and based on the Lyapunov theorem. The simulation results of the proposed control scheme under MATLAB/Simulink indicate that the suggested strategy can provide a suitable control performance, and stability of the whole system is achieved.

Distributed control of linear partial integro-differential equations based on the input-output linearization approach

Distributed control of linear partial integro-differential equations based on the input-output linearization approach

Cooperative Adaptive Cruise Control of Heterogeneous Vehicle Platoons

Abstract Road throughput can be increased by cooperative adaptive cruise control (CACC), which allows vehicles to drive at short inter-vehicle distances without compromising string stability by using wireless inter-vehicle communications. Practical application, however, may involve vehicles with different driveline dynamics, thus forming a heterogeneous platoon. This property potentially requires knowledge of other vehicle’s driveline dynamics for implementation of CACC, which may not be available. As opposed to robust or adaptive approaches, the heterogeneity problem is solved here by revisiting an existing, widely adopted controller for homogeneous strings using an input-output linearization approach. As a result, a class of controllers is obtained which allows for vehicle strings that are heterogeneous with respect to driveline dynamics, without requiring knowledge of these dynamics. Furthermore, it is shown that the new controller represents a class of controllers that encompasses the original homogeneous controller. To illustrate the performance of the new controller, simulations of a heterogeneous platoon are presented and the string stability properties are assessed. From this analysis, it appears that the new controller performs at least as good as the original one, in terms of minimum string-stable time gap, settling time, and maximum jerk.

Nonlinear Controller Design for Tracking Task of a Control Moment Gyroscope Actuator

Control moment gyroscopes (CMG) are widely used as actuators for attitude control of satellites and spacecraft, which requires the controller to fulfill the tracking task of a CMG in a wide operating range, despite its highly coupled nonlinear behavior. A variety of control techniques were proposed for tracking task of the CMG unit, model 750, from Educational Control Products (ECP), but a few accomplished it in a wide operating range, e.g., the linear parameter-varying approach. Another one that may accomplish it is the nonlinear control approach. Therefore, this article proposes a nonlinear controller design based on feedback linearization for the tracking task of the CMG unit in a wide operating range. To cope with a singularity that would appear in the control signal computation, the proposed controller has a cascade structure composed of an outer tracking controller and an inner velocity controller, both based on the input-output linearization approach. The designed controller is validated via numerical simulations and real-time practical experiments.

Variable displacement vane pump, part II: nonlinear volume flow control

Variable displacement vane pumps are one means to provide automotive transmissions with fluid energy. With their ability to adapt volume flow, they have the potential to adjust volume flow according to the specification at hand and thereby to increase energy efficiency. In this paper, a nonlinear volume flow approach for a variable displacement vane pump is suggested based on input–output linearization. A nonlinear observer concept based on high gain state estimation is presented, too. Ultimately, a feedforward linearizing control concept with PI output feedback is discussed as an alternative to the full state feedback input–output linearization approach.

An observer-based vaccination control law for an SEIR epidemic model based on feedback linearization techniques for nonlinear systems

This paper presents a vaccination strategy for fighting against the propagation of epidemic diseases. The disease propagation is described by an SEIR (susceptible plus infected plus infectious plus removed populations) epidemic model. The model takes into account the total population amounts as a refrain for the illness transmission since its increase makes the contacts among susceptible and infected more difficult. The vaccination strategy is based on a continuous-time nonlinear control law synthesised via an exact feedback input-output linearization approach. An observer is incorporated into the control scheme to provide online estimates for the susceptible and infected populations in the case when their values are not available from online measurement but they are necessary to implement the control law. The vaccination control is generated based on the information provided by the observer. The control objective is to asymptotically eradicate the infection from the population so that the removed-by-immunity population asymptotically tracks the whole one without precise knowledge of the partial populations. The model positivity, the eradication of the infection under feedback vaccination laws and the stability properties as well as the asymptotic convergence of the estimation errors to zero as time tends to infinity are investigated.

Control of an Autonomous Electric Bicycle with both Steering and Balancer Controls

In this paper, we propose a new cooperation control algorithm for stabilizing and trajectory tracking of an unmanned electric bicycle. The simplified model of the bicycle with the balancer is derived from Lagrangian and non-holonomic constraints with respect to translation and rotation relative to the ground plane. The stabilizing control and trajectory control of an autonomous bicycle are derived independently based on the simplified model. The balancing control is derived based on the output-zeroing controller. The steering and balancer for stabilizing the bicycle are used when the linear velocity is zero or the system starts up. It is shown that a balancing control using both the steering and the balancer has a better performance than conventional ones with only balancer or steering. The trajectory tracking control is derived by an input–output linearization approach to track the path in the ground plane. The steering and the back wheel are used to design the trajectory control. The coupling of the steering between the balancing control and the trajectory control are set by weighting gain. The balancing and the trajectory control have been implemented with the real bicycle by using MATLAB XPC-TARGET. An autonomous electric bicycle can be controlled remotely via a host PC. Numerical simulation and experimental results are shown to verify the effectiveness of the proposed control strategy.

Observer Design for a Class of Multi-input Multi-output Nonlinear Systems Based on Input-output Linearization Approach

The problem of state observer design for a class of multi-input multi-output affine nonlinear systems is investigated.Based on the input-output linearization method,a new approach of state observer design for multi-input multi-output affine nonlinear systems is proposed.Sufficient conditions that guarantee the state observation error to converge to zero asymptotically are obtained.Finally an example is given to show the validity of obtained results.

Modeling and Performance Analysis of the DC/DC Series–Parallel Resonant Converter Operating With Discrete Self-Sustained Phase-Shift Modulation Technique

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A dynamic study of the dc/dc series–parallel resonant converter operating with a discrete self-sustained phase-shift modulation technique is presented. The study includes the synthesis of a suitable averaged large-signal dynamic model and the design of a nonlinear feedback controller based in the input–output linearization approach. The proposed controller and modulation type provide some outstanding features: zero-voltage switching operation for the whole load range, narrowed frequency variation range, fast transient response, and robustness in relation to external parameter variations. Experimental and simulation results are reported to validate the theoretical predictions and confirm the superior performance of the nonlinear controller when it is compared with a conventional linear controller. </para>

APPROXIMATE INPUT-OUTPUT LINEARIZATION OF NONMINIMUM PHASE NONLINEAR SYSTEMS WITH LINEAR UNFORCED DYNAMICS

This paper presents an approximate input-output linearization approach for nonminimum phase nonlinear systems with linear unforced dynamics. A special Byrnes Isidori normal form is introduced, where the internal dynamics are not affected by the inputs up to second order such that the corresponding transformation can be obtained by solving linear equations. After a factorization of the internal dynamics into a stable and into an antistable part a quadratic linear and internally stable input-output behaviour is achieved by state feedback in explicit form.

An Input-Output Linearization Approach to the Control of an n-Body Articulated Vehicle

The problem of path-tracking for an autonomous vehicle composed of a tractor and n−1 trailers with off-axle hitching is considered in this paper. It is shown that an input-output feedback linearization technique can be adopted both in forward and backward maneuvers, leading to the stabilization of the path-tracking offset dynamics about circular paths. The location of the guide-point needs to be selected according to the direction of motion, and, when moving backward, the off-axle distances must be all positive.

Input output linearization approach to state observer design for nonlinear system

Presents a state observer for a class of nonlinear systems based on the input output linearization. While the previous result presented state observers for nonlinear systems of full relative degree, we proposed a procedure fur the design of nonlinear state observers which do not require the hypothesis of full relative degree. Assuming that there exists a global state observer for internal dynamics and that some functions are globally Lipschitz, we can design a globally convergent state observer. It is also shown that if the zero dynamics are locally exponentially stable, then there exists a local state observer. An example is given to illustrate the proposed design of nonlinear state observers.

Input-output linearization by velocity-based gain-scheduling

The velocity-based analysis framework provides direct support for divide and conquer design approaches, such as the gain-scheduling control design methodology, whereby the design of a non-linear system is decomposed into the design of an associated family of linear systems. The velocity-based gain-scheduling approach is quite general and directly supports the design of feedback configurations for which the closed-loop dynamics are non-linear. However, the present paper concentrates on the velocity-based design of controllers which, when combined with a non-linear plant, attain linear dynamics. The resulting approach is a direct generalization to non-linear systems of classical frequency-domain pole-zero inversion which is, in many ways, complementary to the Input-Output Linearization approach. In particular the former is dynamic and reduces to open-loop inversion in the linear case whilst the latter is essentially static and utilizes full state feedback.

作業の教示とプログラミング けんに非線形弾性をもつけん駆動システムの制御

The purpose of this paper is to design nonlinear control systems for tendon-driven robotic mechanical systems.Tendon-driven mechanisms are appropriate especially for force-controlled robotic arms as well as robotic hands, because they allow to locate actuators away in the robot bodies and make them small in size and light in weight. In the dynamic aspect of the mechanisms, one of the most important features is the joint stiffness adjustability using the redundancy of actuators and nonlinear elasticity of tendons.A conventional control system for a tendon-driven robotic mechanism is a double looped control system, which consists of an inner loop for tendon force control and an outer loop to generate the desired tendon forces for position and stiffness control. In this control system, the inner loop has to converge to much faster than the outer one does. Thus the inner loop feedback gains become relatively large and the system tends to be vibrative.In this paper, a nonlinear control system that can control the joint angles and the joint stiffness separately is proposed using an exact input-output linearization approach. A necessary and sufficient condition under which we can design such a contoller is given. Classes of tendon-driven robotic mechanisms which satisfy the condition are also investigated. Finally some numerical results will be given to show the efficiency.

Controlling Chaos Using Input–Output Linearization Approach

In this article the input–output linearization approach is used for controlling chaos. It is shown that by using only partial states, the entire chaotic system is stabilizable, provided the zero dynamics is stable. Generally speaking, trajectories of chaotic systems do not grow exponentially and are usually bounded. In particular, for dissipative chaotic systems the stable zero dynamics can always be found. Hence the stabilization as well as tracking periodic signals are possible. The Lorenz system is used to inform the discussion. Simulation results are presented to show the effectiveness of the approach.

Nonlinear Controller Design by Uncovering Linear Dynamics Hidden by Input-Output Linearization

Abstract A great deal of research has addressed the problem of explicitly linearizing the input-output response of a nonlinear system via state feedback. However, this approach can often hide linear dynamics that could be useful for controller design. A controller design methodology is developed based on a coordinate transformation that uncovers the linear dynamics hidden by conventional input-output linearization. This methodology is illustrated via simulation of a CSTR example and it is shown that this controller performance is better than the performance of a standard input-output linearization approach.

Adaptive nonlinear control of a pH neutralization process

An adaptive nonlinear control strategy for a bench-scale pH neutralization system is developed and experimentally evaluated. The pH process exhibits severe nonlinear and time-varying behavior and therefore cannot be adequately controlled with a conventional PI controller. The nonlinear controller design is based on a modified input-output linearization approach which accounts for the implicit output equation in the reaction invariant model. Because the reaction invariants cannot be measured online and the linearized system is unobservable, a nonlinear output feedback controller is developed by combining the input-output linearizing controller with a reduced-order, open-loop observer. The adaptive nonlinear control strategy is obtained by augmenting the non-adaptive controller with an indirect parameter estimation scheme which accounts for unmeasured buffering changes. Experimental tests demonstrate the superior performance of the adaptive nonlinear controller as compared to a non-adaptive nonlinear controller and conventional PI controller.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>