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Showing papers in "Journal of Dynamic Systems Measurement and Control-transactions of The Asme in 2003"


Journal ArticleDOI
TL;DR: A broad overview of the stability and control of time-delay systems is given in this paper, with a focus on the more recent progress and engineering applications, including practical problems, mathematical descriptions, stability and performance analysis, and feedback control.
Abstract: This paper gives a broad overview of the stability and control of time-delay systems. Emphasis is on the more recent progress and engineering applications. Examples of practical problems, mathematical descriptions, stability and performance analysis, and feedback control are discussed.

599 citations


Journal ArticleDOI
TL;DR: In this article, a new analytic approach to obtain the complete solution for systems of delay differential equations (DDE) based on the concept of Lambert functions is presented, which is in the form of an infinite series of modes written in terms of Lambert function.
Abstract: A new analytic approach to obtain the complete solution for systems of delay differential equations (DDE) based on the concept of Lambert functions is presented. The similarity with the concept of the state transition matrix in linear ordinary differential equations enables the approach to be used for general classes of linear delay differential equations using the matrix form of DDEs. The solution is in the form of an infinite series of modes written in terms of Lambert functions. Stability criteria for the individual modes, free response, and forced response for delay equations in different examples are studied, and the results are presented. The new approach is applied to obtain the stability regions for the individual modes of the linearized chatter problem in turning. The results present a necessary condition to the stability in chatter for the whole system, since it only enables the study of the individual modes, and there are an infinite number of them that contribute to the stability of the system. @DOI: 10.1115/1.1568121#

307 citations


Journal ArticleDOI
TL;DR: In this article, a slip-based method was proposed to estimate the maximum available tire-road friction during braking using data from short braking maneuvers with peak accelerations of 3.9 m/s 2.
Abstract: We develop and test a "slip-based" method to estimate the maximum available tire-road friction during braking. The method is based on the hypothesis that the low-slip, low-μ parts of the slip curve used during normal driving can indicate the maximum tire-road friction coefficient, μ m a x . We find support for this hypothesis in the literature and through experiments. The friction estimation algorithm uses data from short braking maneuvers with peak accelerations of 3.9 m/s 2 to classify the road surface as either dry (μ m a x 1) or lubricated (μ m a x 0.6). Significant measurement noise makes it difficult to detect the subtle effect being measured, leading to a misclassification rate of 20%.

249 citations


Journal ArticleDOI
TL;DR: In this article, the theoretical flow ripple of an external gear pump is derived based upon the flow of incompressible fluid across the changing boundaries of a control volume, and it is shown that the instantaneous length of action within the gear mesh determines the instantaneous flow ripple.
Abstract: In this paper, the theoretical flow ripple of an external gear pump is studied for pumps of similar size using different numbers of teeth on the driving and driven gears. In this work, the flow ripple equation is derived based upon the flow of incompressible fluid across the changing boundaries of a control volume. From this method, it is shown that the instantaneous length of action within the gear mesh determines the instantaneous flow ripple. A numerical and a closed-form approximation are presented for the instantaneous length of action and it is shown that the difference between these two solutions is negligible. Fast Fourier transform analysis is employed for identifying the harmonic frequencies and amplitudes of the flow pulse and these results are compared for 16 different pump designs. In summary, the results of this study show that the driving gear dictates the flow ripple characteristics of the pump while the driven gear dictates the pump size. As a result, it may be advantageous to design an external gear pump with a large number of teeth on the driving gear and a fewer number of teeth on the driven gear This design configuration will tend to reduce both the physical pump size (without reducing the volumetric displacement of the pump) and the amplitude of the flow pulsation, while increasing the natural harmonic frequencies of the machine.

123 citations


Journal ArticleDOI
TL;DR: In this article, an adaptive Posicast controller is proposed to cope with time-delay and parametric uncertainties in the control of combustion control systems, which is shown to be semi-global in the time delay r and to result in asymptotic tracking.
Abstract: The control of physical systems in the presence of time-delays becomes particularly challenging when parametric uncertainties are present. To cope with these ubiquitous uncertainties, we propose an adaptive controller in this paper that can accommodate both a time-delay and parametric uncertainties. The controller includes a) a control architecture that is based on the plant relative degree rather than the plant order, b) an integral implementation of the well known Posicast Controller so as to accommodate unstable plants, c) high-order tuners for parameter adaptation, and d) a Lyapunov-Krasvoskii functional that allows adaptive stabilization. The controller is shown to be semi-global in the time-delay r and to result in asymptotic tracking. The implications of the adaptive controller are explored in the context of combustion control through simulation studies. Robustness properties of the controller are briefly discussed.

113 citations


Journal ArticleDOI
TL;DR: In this article, a new approximate model consisting of a variable gain and a variable time-delay was proposed to describe the hysteresis behavior of a piezoactuator.
Abstract: A new approximate model, which consists of a variable gain and a variable time-delay, is proposed to describe the hysteresis behavior of a piezoactuator. The variable gain is assumed to be a function of the magnitude of the input command, while the time-delay is assumed to be a function of the frequency of the input command. The ranges of these two variable parameters are determined through open loop tests. According to the proposed approximate model, a Smith predictor-based robust H x controller is developed to achieve high-precision tracking control of a piezoactuator. Analytical simulation and experimental results on tracking several types of reference inputs demonstrate that the maximum trucking error can be reduced to be less than 2% of the traveling path by utilising the proposed controller design.

111 citations


Journal ArticleDOI
TL;DR: In this paper, the variable structure filter (VSTF) is proposed for state estimation of a linear system subject to random disturbances and measurement noise, and a proof of stability for the filter is provided.
Abstract: This paper presents a new strategy for state estimation. The strategy may be applied to linear systems and is referred to as the variable structure filter. The filter is considered for discrete-time systems subject to random disturbances and measurement noise. It requires a parametric model and can be formulated to accommodate modeling uncertainties. A proof of stability for the filter is provided. For stability this concept requires a specification of an upper bound for uncertainties, disturbances, and measurement noise. The application of this filter to a third-order linear system is demonstrated.

100 citations


Journal ArticleDOI
TL;DR: In this paper, the asymptotic stability for a class of neutral systems with discrete and distributed multiple time delays is considered, and the resulting stability Criteria are written in the form of spectral radius and linear matrix inequality (LMI).
Abstract: In this paper, the asymptotic stability for a class of neutral systems with discrete and distributed multiple time delays is considered. Discrete-delay-independent and discrete-delay-dependent criteria are proposed to guarantee stability for such systems. The resulting stability Criteria are written in the form of spectral radius and linear matrix inequality (LMI).Some numerical examples are given to illustrate that our obtained results are less conservative.

77 citations


Journal ArticleDOI
TL;DR: In this article, the authors focus on feedback methods for implementing impedance control and reveal the underlying conflict between impedance accuracy and robustness to uncertainties, and propose a novel yet practical method that facilitates robustness while maintaining accurate impedance tracking.
Abstract: Impedance control facilitates the execution of tasks that involve contact with the environment. However task performance depends on the accuracy at which the desired impedance is attained. This paper focuses on feedback methods for implementing impedance control and reveals the underlying conflict between impedance accuracy and robustness to uncertainties. Furthermore, we propose a novel yet practical method that facilitates robustness while maintaining accurate impedance tracking. Eigenvalue analysis and simulation results are presented to demonstrate the accuracy/robustness dilemma and the relative merits of the different methods.

74 citations


Journal ArticleDOI
TL;DR: In this article, the authors describe the design, analysis, and implementation of a vehicle control system using control state information obtained from a carrier phase (CP) differential global positioning system (DGPS) aided inertial navigation system (INS).
Abstract: This paper describes the design, analysis, and implementation of a vehicle control system using control state information obtained from a carrier phase (CP) differential global positioning system (DGPS) aided inertial navigation system (INS). Experimental data from CP DGPS/INS control experiments onboard a PATH 1 vehicle is included. This testing was completed with a magnetometer sensing system onboard and running to provide a ground truth reference for comparison with the CP DGPS/INS. Navigation accuracy has previously been demonstrated at the cm level with the full navigation state updated at 150 Hz. In this article, lateral position control performance is demonstrated during challenging high-speed maneuvers with trajectory tracking accuracy at the decimeter level. During these initial experiments, the control state updated at 30 Hz. Increased trajectory following accuracy is possible, but there is an inherent tradeoff between the tracking accuracy and the ride comfort. This level of performance demonstrates that CP DGPS/ INS technology has the potential to serve as one component of the reliable multisensor centimeter-level position reference system that is necessary for vehicle position control applications, including automated highway systems (AHS).

69 citations


Journal ArticleDOI
TL;DR: Output tracking in causal nonlinear systems with an output time delay is considered using sliding mode control to reduce the problem to that of the tracking of the output reference profile given by an exogenous system in a causal non-minimum phase system without delay.
Abstract: Output tracking in causal nonlinear systems with an output time delay is considered using sliding mode control. The problem is reduced to that of the tracking of the output reference profile given by an exogenous system in a causal non-minimum phase system without delay, where the delay is being replaced by its Pade' approximation. The non-minimum phase output-tracking problem is transformed to a corresponding state tracking problem. Bounded state tracking profiles are generated by equations of the stable system center A sliding mode control algorithm is developed. A numerical example demonstrates the effectiveness of the sliding mode control design.

Journal ArticleDOI
TL;DR: In this article, a nonlinear harmonic disturbance observer for nonlinear systems subject to harmonics is designed and stability of the proposed observer is established using passivity approach and a systematic procedure to choose the nonlinear gain function in the observer is proposed.
Abstract: A nonlinear harmonic disturbance observer for nonlinear systems subject to harmonics is designed and stability of the proposed observer is established using passivity approach. A systematic procedure to choose the nonlinear gain function in the observer is proposed. The proposed nonlinear disturbance observer can be integrated with a linear/nonlinear controller to improve its disturbance attenuation ability for nonlinear systems under harmonics.

Journal ArticleDOI
TL;DR: Two control strategies (based on wave variables and a time forward observer), bandwidth issues, and some related programming details are focused on.
Abstract: This article focuses on Internet-based real time control, such as remote bilateral teleoperation. In such applications, it is required that the control loop be closed through a time delayed network. This paper focuses on two control strategies (based on wave variables and a time forward observer), bandwidth issues, and some related programming details. Experimental results of bilateral teleoperation via the Internet between Atlanta and Tokyo are given. The system used is a two-degree-of-freedom haptic interface, bilaterally coupled to a simulation (implemented on a windows NT based computer) of a similar system.

Journal ArticleDOI
TL;DR: In this article, the Direct Method for linear time invariant, time delayed systems (LTI-TDS) is revisited in this work considering the degenerate system dynamics, and the principal strengths and enabling novelties of the method are reviewed along with its structured steps involved for assessing the stability.
Abstract: A recent stability analysis, the Direct Method, for linear time invariant, time delayed systems (LTI-TDS) is revisited in this work considering the degenerate system dynamics. The principal strengths and enabling novelties of the method are reviewed along with its structured steps involved for assessing the stability. Uncommon in the literature, the Direct Method can handle large dimensional systems (e.g., larger than two) very comfortably. It returns an explicit formula for the exact stability posture of the system for a given time delay, as such it reveals the possible detached stability pockets throughout the time delay axis. Both retarded and neutral classes of LTI-TDS are considered in this work. The main contribution here is to demonstrate the ability of the Direct Method in tackling degenerate cases. Along with the analytical arguments, example case studies are provided for a group of degeneracies. It is shown that the new method is capable of resolving them without any difficulty.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a control strategy to stop the load dead in a finite time by learning from the previously unknown dynamic response in the first part of the motion exactly how to terminate the motion.
Abstract: Rest to rest movement of a crane's swinging load, at the bottom end of a cable, by moving a speed-limited gantry trolley at the top, involves resolving the apparently conflicting demands of exact load positioning and active swing damping. If system parameters are unknown beforehand, best existing strategies offer only asymptotic solutions. The proposed control strategy stops the load dead, exactly on target, in a finite time. It is robust and self-adapting. Using mechanical wave concepts, the gantry controller "learns" from the previously unknown dynamic response in the first part of the motion exactly how to terminate the motion. All results are verified numerically.

Journal ArticleDOI
TL;DR: The paper presents the optimal nonlinear filter for quadratic state and linear observation equations confused with white Gaussian disturbances and the general scheme for obtaining the optimal filter in case of polynomial state andlinear observation equations is announced.
Abstract: The paper presents the optimal nonlinear filter for quadratic state and linear observation equations confused with white Gaussian disturbances, The general scheme for obtaining the optimal filter in case of polynomial state and linear observation equations is announced.

Journal ArticleDOI
TL;DR: In this article, the Strutt-Ince chart of the damped Mathieu equation and the Hsu-Bhatt-Vyshnegradskii chart were combined to describe the intriguing stability properties of an important class of delayed oscillatory systems subjected to parametric excitation.
Abstract: In the space of the system parameters, the stability charts are determined for the delayed and damped Mathieu equation defined as ?(t)+κ?(t)+(δ+ω cos t)x(t)=bx(t-2π). This stability chart makes the connection between the Strutt-Ince chart of the damped Mathieu equation and the Hsu-Bhatt-Vyshnegradskii chart of the autonomous second order delay-differential equation. The combined charts describe the intriguing stability properties of an important class of delayed oscillatory systems subjected to parametric excitation.

Journal ArticleDOI
TL;DR: In this paper, a semi-active seat suspension with an electrorheological (ER) fluid damper is presented, and the governing equations of motion are derived by treating the driver mass as a parameter uncertainty.
Abstract: This paper presents a semi-active seat suspension with an electrorheological (ER) fluid damper A cylindrical ER seat damper is devised on the basis of a Bingham model of an arabic gum-based ER fluid and its field-dependent damping characteristics are empirically evaluated. A semi-active seat suspension is then constructed, and the governing equations of motion are derived by treating the driver mass as a parameter uncertainty. A sliding mode controller, which has inherent robustness to system uncertainties, is formulated to attenuate seat vibration due to external excitations. The controller is then experimentally realized, and controlled responses are presented in both time and frequency domains. In addition, a full-car model consisting of primary, cabin, and seat suspensions is established, and a hardware-in-the-loop simulation is undertaken to demonstrate a practical feasibility of the proposed seat suspension system showing ride comfort quality under various road conditions.

Journal ArticleDOI
TL;DR: In this article, the role of active dancers in attenuation of web tension disturbances in a web process line is investigated, and three types of control designs are investigated for the active dancer system: a proportional-integral-derivative controller, an internal model based controller, and a linear quadratic optimal controller.
Abstract: This paper investigates the role of active dancers in attenuation of web tension disturbances in a web process line. A general structure of the active dancer is considered; governing equations for web spans upstream and downstream to the dancer roller are developed. A structural limitation that facilitates efficient design of the active dancer system for web tension disturbance attenuation is derived and discussed based on the developed model. An open-architecture experimental web platform is developed for conducting real-time control experiments using the active dancer system. The active dancer system model is experimentally identified using the standard system identification techniques available in literature. Three types of control designs were investigated for the active dancer system: a proportional-integral-derivative controller, an internal model based controller, and a linear quadratic optimal controller. Data collected from a series of experiments using the three control designs validate the usefulness of the active dancers in attenuating web tension disturbances in a web process line. A representative sample of the experimental data is presented and discussed.

Journal ArticleDOI
TL;DR: In this article, a dynamic mathematical model of a free-piston diesel engine and a control oriented dynamic analysis leading to a piston motion control structure are presented, and a full scale test cylinder is included and show feasibility of the suggested control approach.
Abstract: Free-piston diesel engines are characterized by freely moving pistons without any crankshaft or camshaft connected to the pistons This allows a compact and efficient engine design, but requires automatic control of the piston motion This paper present a dynamic mathematical model of a free-piston diesel engine, and a control oriented dynamic analysis leading to a piston motion control structure Experimental results using a full scale test cylinder are included and show feasibility of the suggested control approach

Journal ArticleDOI
TL;DR: In this article, the authors examined the kinematics and control of a Load Haul Dump Vehicle used in underground mining operations and developed an autonomous guidance strategy based on a linear, state-space, mathematical model of the vehicle.
Abstract: This paper examines the kinematics and control of a Load Haul Dump Vehicle used in underground mining operations. The aim of the work is to develop an autonomous guidance strategy. A linear, state-space, mathematical model of the vehicle is derived purely from geometric consideration of the vehicle and its desired path. Autonomous regulation of the vehicle is shown to be theoretically feasible using state variable feedback of displacement, heading, and curvature error. A relationship between stability and vehicle speed is derived. This expression forms the basis of an adaptive tuning strategy, which optimizes the vehicle's dynamic response.

Journal ArticleDOI
TL;DR: In this article, the authors address the problem of the determination of regions of stability for linear systems with delayed inputs and subject to input saturation through anti-windup strategies and propose delay dependent results.
Abstract: This paper addresses the problem of the determination of regions of stability for linear systems with delayed inputs and subject to input saturation through anti-windup strategies. Differently of the most anti-windup techniques, where the design of the anti-windup loop is introduced with the objective of minimizing the performance degradation, we are particularly interested in the synthesis of anti-windup gains in order to guarantee the stability of the closed-loop system for regions of admissible initial states as large as possible. With this aim, due to the presence of delay in the input we propose delay dependent results.

Journal ArticleDOI
TL;DR: In this article, the authors developed an active control strategy for railway vehicles with independently rotating wheels, which does not require basic guidance measurements (e.g., wheel-rail deflection and angle of attack) that are expensive and impractical to implement.
Abstract: This paper presents the development of an active control strategy for railway vehicles with independently rotating wheels. The proposed control scheme is intuitively formulated with a simple control structure and adaptiveto vehicle speed. It does not require basic guidance measurements (e.g., wheel-rail deflection and angle of attack) that are expensive and impractical to implement. Speed sensors are used to measure the relative rotational speed of the two wheels on a same axle and sensors are also used to measure the relative yaw velocity of the wheelset and the body it is connected. Both curving performance and passenger ride comfort of the actively controlled vehicle are compared with that of a typical passive vehicle and an optimal control scheme.

Journal ArticleDOI
TL;DR: In this paper, a combined observer is synthesized to estimate plant uncertainties and disturbances, which enables robust state estimation for uncertain dynamical systems and simultaneously, provides full-stateto the perturbation observer under output feedback conditions.
Abstract: A combined observer is synthesized bv unifying the conventional linear state estimator and the perturbation observer to estimate plant uncertainties and disturbances. It enables robust state estimation for uncertain dynamical systems and simultaneously, provides full-stateto the perturbation observer under output feedback conditions. The proposed combined observer is very practical since it is given as a recursive discrete-time form with minimal tuning parameters, and it requires no knowledge of the plant uncertainty. A coupled estimation error dynamics is derived, and the related technical issues such as stability and noise sensitivity are addressed. The combined observer setting is also extended to stochastic systems, and the discrete Kalman filter is reformulated by including the perturbation estimate update process. Numerical examples and experimental results validate the proposed schemes.

Journal ArticleDOI
TL;DR: In this paper, a fault tolerant control (FTC) strategy to compensate for the degrading effects of fluid leakage across a faulty actuator piston seal in an electrohydraulic positioning system is presented.
Abstract: The development of a fault tolerant control (FTC) strategy to compensate for the degrading effects of fluid leakage across a faulty actuator piston seal in an electrohydraulic positioning system is presented. Due to relatively large variations in the dynamics of the plant, accomplishing the FTC task with a single controller requires a compensator of relatively high gain. Hence, the problem is first reformulated by discretizing the desired range of fault tolerance into a number of distinct levels. Next, a set of low gain local controllers is synthesized via quantitative feedback theory, such that the resulting closed-loop systems all conform to a priori defined performance specifications. Each controller is designed to compensate for a specific level of leakage. A simple switching algorithm is then employed to determine the appropriate control action by scaling each controller's output based upon an estimate of the leakage level. Experimental results illustrate the ability of the designed FTC scheme to compensate for the degrading effect of the leakage fault.

Journal ArticleDOI
TL;DR: In this paper, an analytical study of the response of a simple Coriolis meter subjected to external mechanical vibrations and corresponding finite element studies of three commercially available meters is presented, which shows that vibrations produce additional components in the meter sensor signals but that these components are only at the frequency of the vibrations.
Abstract: An analytical study of the response of a simple Coriolis meter subjected to external mechanical vibrations and corresponding finite element studies of three commercially available meters are presented. These show that vibrations produce additional components in the meter sensor signals but that these components are only at the frequency of the vibrations. The results show that errors reported in vibration experiments, using any frequency except the meter drive frequency, are due to failure of the determination of the phase difference between the sensor signals. The results also show that external vibrations at the meter drive frequency produce a meter error regardless of the phase detection algorithm.

Journal ArticleDOI
TL;DR: In this article, an integrated procedure is proposed in designing the closed-loop discrete-time sliding mode controller using the reaching law method, and the results on an experimental test setup are verified on a stag driven by a linear motor.
Abstract: The closed-loop transfer function of a plant controlled with a classical feedback contra ler, depends on the dynamics of the plant. Since most feedforward tracking controllers a designed based on this closed-loop transferfunction, they are not robust against pla model uncertainties. Sliding-mode controllers have the property that when the system on the switching line, the closed-loop behavior is independent of the plant dynamics. As result, it can be expected that a feedforward control design based on this closed-loop behavior is robust against plant model uncertainties. This paper studies this feed forward robustness issue in detail and verifies the results on an experimental test setup: a stag driven by a linear motor An integrated procedure is proposed in designing the closed loop discrete-time sliding mode controller using the reaching law method.

Journal ArticleDOI
TL;DR: In this paper, a model of sound propagation in a duct, for the purpose of active noise control, is presented, with non-constant acoustic load impedance at the one end, and a coupled disturbance loudspeaker model at the other end.
Abstract: This paper presents a model of sound propagation in a duct, for the purpose of active noise control. A physical model generally different from those explored in much of the literature is derived, with non-constant acoustic load impedance at the one end, and a coupled disturbance loudspeaker model at the other end. Experimental results are presented which validate the derived transfer function.

Journal ArticleDOI
TL;DR: In this paper, a nonlinear comprehensive model has been developed to study the train derailment and hunting in severe braking conditions, which includes nonlinear springs and dampers of primary and secondary suspensions, dry friction between different parts such as car body and side bearers, centerplate parts, wheelset bearings and bogie frames, and also clearances and mechanical stops.
Abstract: A nonlinear comprehensive model has been developed in this paper to study the train derailment and hunting in severe braking conditions. The train consists of cars each having 40 dof, connected to each other by couplers and buffers. The car model is nonlinear and three-dimensional and includes nonlinear springs and dampers of primary and secondary suspensions, dry friction between different parts such as car body and side bearers, center-plate parts, wheelset bearings and bogie frames, and also clearances and mechanical stops. Nonlinearities of wheel and rail profiles, pressure build-up delay in brake circuit, and nonlinearities of connecting parts have also been included in the model. A complete set of equations has been derived for the train. The equations are solved numerically for different car weight configurations when severe brake is applied. Derailment coefficient is determined for several train make-ups and tendency of the wheels towards derailment is investigated. Optimum configuration of cars in a light-heavy set, and critical derailment velocity can be determined to minimize the tendency of train derailment. The results are in excellent agreement with the field experience.

Journal ArticleDOI
TL;DR: In this article, a control design methodology that provides a prescribed degree of stability robustness for plants characterized by discontinuous (i.e., switching) dynamics is presented. But the approach is specifically targeted at pneumatically actuated servo systems that are controlled by solenoid valves and do not incorporate pressure sensors.
Abstract: This paper presents a control design methodology that provides a prescribed degree of stability robustness for plants characterized by discontinuous (i.e., switching) dynamics. The proposed control methodology transforms a discontinuous switching model into a linear continuous equivalent model, so that loop-shaping methods may be utilized to provide a prescribed degree of stability robustness. The approach is specifically targeted at pneumatically actuated servo systems that are controlled by solenoid valves and do not incorporate pressure sensors. Experimental demonstration of the approach validates model equivalence and demonstrates good tracking performance.