Showing papers on "Sliding mode control published in 1988"
24 Apr 1988
TL;DR: It is shown that use of the more general class of dynamic nonlinear state-feedback allows solving both the feedback linearization and the input-output decoupling problems.
Abstract: Reference is made to the problem of controlling the dynamic behavior of robots with rigid links but in presence of joint elasticity. It is shown that use of the more general class of dynamic nonlinear state-feedback allows solving both the feedback linearization and the input-output decoupling problems. A constructive procedure for the decoupling and linearizing feedback is given which is based on generalization system inversion and on the properties of the so-called zero-dynamics of the system. A case study of a planar two-link robot with elastic joints is included. The role of dynamic feedback for this class of robots is discussed. >
155 citations
TL;DR: In this article, a geometric approach for the analysis and design of control schemes in bilinear DC-to-DC switch-mode power supplies is presented, where a time scale separation property is used to identify the slow manifold of the average system in which a stable sliding mode trajectory can be locally sustained.
Abstract: Using the theory of variable structure systems (VSSs), a geometric approach is presented for the analysis and design of control schemes in bilinear DC-to-DC switch-mode power supplies. A time scale separation property, which naturally describes desirable transient behavior of the power converter, is used to identify the slow manifold of the average system in which a stable sliding mode trajectory can be locally sustained. It is shown that the geometry associated with the sliding mode control is easy to understand and could be particularly exploited in circuits which are designed to exhibit a time scale separation property. It can be generally shown that sliding modes are locally exhibited on integral manifolds of average models of pulse-width-modulation schemes. Thus, VSS theory provides the designer with an alternative, systematic method of geometric nature for the specification of regulation loops in DC-to-DC power converters, which is equivalent to the traditional pulsewidth modulation design technique in terms of average behavior. >
103 citations
15 Jun 1988
TL;DR: In this paper, a new control method, Time Delay Control (TDC), is proposed for systems with unknown dynamics and unexpected disturbances, which is characterized by a simple estimation technique of the effect of the uncertainties.
Abstract: This paper focuses on the control of systems with unknown dynamics and deals with the class of systems described by ?=f(x,t)+h(x,t)+B(x,t)u+d(t) where h(x,t) and d(t) are unknown dynamics and unexpected disturbances, respectively. A new control method, Time Delay Control (TDC), is proposed for such systems. Under the assumption of accessibility to all the state variables and their derivatives, the TDC is characterized by a simple estimation technique of the effect of the uncertainties. This is accomplished using time delay. The control system's structure, stability and design issues are discussed for linear time-invariant and single-input- single-output systems. Finally, the control performance was evaluated through both simulations and experiments. The theoretical and experimental results indicate that this control method shows excellent robustness properties to unknown dynamics and disturbances.
78 citations
24 Apr 1988
TL;DR: Simulation and experimental results show that the repetitive controller in conjunction with a computed-torque control or a simple proportional-derivative control law achieves good tracking performance when the desired trajectory is periodic and the period is known.
Abstract: The analysis and experimental implementation of a discrete-time repetitive control scheme is presented. The repetitive control structure is designed to be easily implemented on any system without modification to the existing controller. Simulation and experimental results show that the repetitive controller in conjunction with a computed-torque control or a simple proportional-derivative control law achieves good tracking performance when the desired trajectory is periodic and the period is known. >
75 citations
TL;DR: In this article, the authors examined sliding mode control from the perspective of obtaining stable and robust tracking of an arbitrary time-varying reference by a multi-input-output, linear, time-invariant system driven by a certain class of bounded errors, nonlinearities and disturbances.
71 citations
11 Apr 1988
TL;DR: A control system for power conditioning and uninterruptible power supply systems is presented in this article, which is based on the theory of variable-structure systems with sliding mode.
Abstract: A control system for power conditioning and uninterruptible power supply systems is presented. The design is based on the theory of variable-structure systems with sliding mode. Results of an analytical study and digital simulation of both the power and control systems are reported, showing good agreement. The high dynamics and the robustness of the implemented system, indicated by the simulation results, confirm the validity of the control scheme and suggest the possibility of adopting it for three-phase systems, variable frequency supplies, and measuring equipment. >
68 citations
TL;DR: In this paper, the problem of designing a stable sliding mode giving robust performance of a variable structure control system is studied, where a set of specified eigenvalues are assigned to the closed-loop feedback system during the sliding mode.
Abstract: The problem of designing a stable sliding mode giving robust performance of a variable structure control system is studied. A set of specified eigenvalues is assigned to the closed-loop feedback system during the sliding mode. The design philosophy seeks to build on the known robustness and invariance properties associated with the use of discontinuous (or continuous) non-linear controls, by assigning the eigenvectors associated with the sliding-mode eigenvalues in a manner that leads to a robust control scheme. A previously developed canonical form for the hyperplane design problem is again employed. The design technique centres on a recently published eigenvalue assignment algorithm, and is illustrated by the inclusion of an example.
65 citations
63 citations
07 Dec 1988
TL;DR: The problem of simultaneous motion and force control of a constrained robot manipulator is studied and the system stability, in particular the force control stability, is theoretically analyzed.
Abstract: The problem of simultaneous motion and force control of a constrained robot manipulator is studied. It is recognized that the degrees of freedom of the manipulator are reduced in the presence of constraints. A dynamic model suitable for motion and force control is derived. Both motion and force control loops are exactly linearized and decoupled by using a dynamic nonlinear state feedback and a nonlinear state transformation. Separate inputs are designated for control of the end effector motion and the constraint force. The system stability, in particular the force control stability, is theoretically analyzed. The application of the proposed control method to redundant manipulators is discussed. >
62 citations
TL;DR: In this article, general relationships are established among variable structure control strategies and pulsewidth modulated control schemes leading to sliding modes in non-linear systems, and the results are applied to the design of a sliding regime for the regulation of DC-to-DC switchmode power converters exhibiting a slow integral manifold due to time-scale separation properties among input and output circuits.
Abstract: In this article, general relationships are established among variable structure control strategies and pulse-width modulated control schemes leading to sliding modes in non-linear systems. The results are applied to the design of a sliding regime for the regulation of DC-to-DC switchmode power converters exhibiting a slow integral manifold due to time-scale separation properties among input and output circuits.
43 citations
TL;DR: In this article, a new force control method was proposed which may be thought as logically derived from compliance control and impedance control for which only a reference position is usually assigned, and the attractive feature of the proposed control is that it also allows for a reference force to be assigned.
Journal Article•
TL;DR: A decentralized model reference adaptive approach using a variable-structure sliding model control has been developed for the vibration suppression of large flexible structures.
Abstract: A decentralized model reference adaptive approach using a variable-structure sliding model control has been developed for the vibration suppression of large flexible structures. Local models are derived based upon the desired damping and response time in a model-following scheme, and variable structure controllers are then designed which employ colocated angular rate and position feedback. Numerical simulations have been performed using NASA's flexible grid experimental apparatus.
TL;DR: In this article, a method to design a servomechanism by using sliding mode control is proposed, which is applied to an augmented system in which an integrator is added.
Abstract: A method to design a servomechanism by using sliding mode control is proposed. Sliding mode control is applied to an augmented system in which an integrator is added. The input-output relation of this servomechanism is described by a transfer function of which the poles can arbitrarily be assigned in a sliding mode. The results are further extended to realize a servomechanism of type l. The advantageous properties of sliding mode control to parameter variations and disturbances also hold in this servomechanism. Examples are given to illustrate the effectiveness of the proposed design method.
07 Dec 1988
TL;DR: In this paper, an estimation-based adaptive controller with corrective terms for more general families than robot arms is proposed, assuming some structural properties, they obtain global convergence under far less restrictive growth assumptions than previously.
Abstract: The authors consider how to make a nonlinear control law adaptive. Assuming that the uncertainties interfere linearly, they answer this question for a certain class of systems. In particular, they propose an estimation-based adaptive controller with corrective terms for more general families than robot arms. Assuming some structural properties, they obtain global convergence under far less restrictive growth assumptions than previously. >
31 Oct 1988
TL;DR: The authors discuss ongoing work in the design of an advanced AUV control system designed using sliding mode control and is being prepared for at sea testing onboard the Martin Marietta AUV testbed in early 1989.
Abstract: The authors discuss ongoing work in the design of an advanced AUV control system. They focus on the application of a nonlinear control technique known as sliding mode control (SMC) to an AUV testbed being developed at Martin Marietta. It is noted that AUVs present challenges in the area of dynamic closed loop control. AUV control systems must be able to robustly control movement of all angles of attack or sideslip, adapt to changing mission payloads and dynamics, and provide a tolerance to control element failures. SMC provides a theoretical framework for the design of controllers that can meet these requirements. The AUV control system has been designed using SMC and is being prepared for at sea testing onboard the Martin Marietta AUV testbed in early 1989. >
15 Jun 1988
TL;DR: This paper presents a new approach, based on the theory of variable structure systems and sliding mode, for the analysis and control design for robotic systems subject to task constraints.
Abstract: Many robotic maipulator tasks involve arm motions which are constrained by the task geometry. This paper presents a new approach, based on the theory of variable structure systems and sliding mode, for the analysis and control design for robotic systems subject to task constraints.
TL;DR: In this article, a multivariable sliding mode controller based on the equations of motion of an unmanned aircraft or remotely piloted vehicle (RPV) is described and an emphasis on robust eigenstructure assignment is given.
Abstract: The design of a multivariable sliding mode controller based on the equations of motion of an unmanned aircraft or remotely piloted vehicle (RPV) is described and an emphasis on robust eigenstructure assignment is given. The linear and nonlinear model responses are compared when subjected to the same variable-structure control design. The ability of the controller to cope with uncertain parameter variations is investigated as a problem of robustness assessment. It is shown that after sliding has commenced, the response of the objective system is tracked by the corresponding nonlinear or perturbed system. A measure of sensitivity is defined as the proximity of the actual system modal structure and response to that of the designed objective. The nonlinear system with variable-structure controller is also shown to be robust in the sense that this objective response is always recovered after a disturbance or parameter variation.
07 Dec 1988
TL;DR: In this article, a globally asymptotically stable VS-MRAC for plants of arbitrary relative degree is presented, which requires only input/output measurements and is free of differentiators.
Abstract: For pt.I. see Tech. Rep. RT-01/87, COPPE/UFRJ-EE (1987). A globally asymptotically stable VS-MRAC was proposed in part I for plants with relative degree one. A VS-MRAC for plants of arbitrary relative degree is presented here. The controller requires only input/output measurements and is free of differentiators. The VS-MRAC, for relative degree >or=2, explicitly requires the equivalent controls associated with certain sliding modes. In the ideal case where these equivalent controls are perfectly measurable, global asymptotic stability of the closed-loop system and exponential convergence of the output error are demonstrated. Stability is preserved in the presence of bounded input disturbances, and asymptotic tracking is shown to be possible even in this case. >
07 Dec 1988
TL;DR: The authors study the tracking and disturbance rejection problem of a class of time-invariant nonlinear systems which are linear equivalent to controllable linear systems by using a nonlinear feedback control and a slowly varying integral control.
Abstract: The authors study the tracking and disturbance rejection problem of a class of time-invariant nonlinear systems which are linear equivalent to controllable linear systems By using a nonlinear feedback control and a slowly varying integral control, the closed-loop system asymptotically tracks a reference input and rejects disturbances which are both unknown and slowly varying The integral manifold concept is used to design a nonlinear controller >
07 Dec 1988
TL;DR: Simulation results are presented to show that precise large rotational maneuvers can be performed using the attitude controller and the elastic mode stabilizer in spite of the uncertainty in the system.
Abstract: The authors present a control system design for large-angle rotational maneuvers of a spacecraft-beam-tip body (an antenna or a reflector) configuration. It is assumed that an unknown but bounded disturbance torque is acting on the spacecraft. A sliding mode attitude control law is derived for the slewing of the space vehicle. This slewing control law requires only attitude error and its derivative for feedback and does not need any information on the elastic motion of the system. For the damping of the elastic motion, a stabilizer is designed separately based on the asymptotically decoupled system describing the elastic deflections in two orthogonal planes. Simulation results are presented to show that precise large rotational maneuvers can be performed using the attitude controller and the elastic mode stabilizer in spite of the uncertainty in the system. >
02 Oct 1988
TL;DR: A novel methodology which is convenient for the design of optimal sliding-mode control for an asynchronous machine drive is developed, and the optimal synthesis is directly related to the desired system specifications in the time domain without the necessity of solving the Riccati equation or complicated matrix equations.
Abstract: A novel methodology which is convenient for the design of optimal sliding-mode control for an asynchronous machine drive is developed. A suitable model of the induction machine control system, incorporating the counter-EMF (electromotive force) under field orientation, is presented. Analytic solutions for the optimal switching vector C, and the feedback matrix, L in unit-vector sliding-mode control are obtained. The optimal synthesis is directly related to the desired system specifications in the time domain without the necessity of solving the Riccati equation or complicated matrix equations. This greatly simplifies the conventional complicated design procedure and improves the design quality. Simulation and experimental results verify the optimal design. >
13 Apr 1988
TL;DR: In this paper, a second order linear system sliding controller is proposed to eliminate the reaching phase and associated problems of load sensitivity and high demanded torque, and the chattering usually present in the sliding phase also disappears with the new control law.
Abstract: A new sliding controller is proposed. Second order linear system sliding curves eliminate the reaching phase and consequently and associated problems of load sensitivity and high demanded torque. Moreover, the chattering usually present in the sliding phase also disappears with the new control law. Simulation results show a negligible coupling between axes, thus enabling an easier and more efficient controller adjustment. It is also shown that the controller parameter set can be easily adjusted, and there is a large set of possible quasi-optimal values. This is of utmost importance, when one thinks of the industrial applications of this type of algorithms. Experiments were developed based on the position control problem. Nevertheless, generalization to the trajectory tracking problem is trivial. In either case the controller computational requirements are low, thus well adapted to today's microprocessor based digital control technology. >
TL;DR: In this article, the motion of a linear controlled system from any initial state to a given final state is considered when there are geometric constraints on the control functions, and sufficient conditions are obtained, under which this control law solves the problem in finite time.
11 Apr 1988
TL;DR: In this paper, a variable-structure-systems approach is presented for controlling DC machine position, speed, or current, where the introduction of sliding mode leads to good dynamic and steady-state behavior of the overall system.
Abstract: A system based on the variable-structure-systems approach is presented for controlling DC machine position, speed, or current. The introduction of sliding mode leads to good dynamic and steady-state behavior of the overall system. A method for switching function estimation that is based on control error and armature current information is proposed. An external torque observer is constructed. Simulation and experimental results show that the system motion is predicted well by theoretical analysis. >
15 Jun 1988
TL;DR: In this paper, a variable structure control (VSC) law is derived such that the output variable asymptotically tracks a given output trajectory in spite of the uncertainty in the system.
Abstract: This paper considers control of a class of uncertain nonlinear systems which can be decoupled by state variable feedback. A variable structure control (VSC) law is derived such that in the closed-loop system the output variable asymptotically tracks a given output trajectory in spite of the uncertainty in the system. Based on this result, a control law is derived for the attitude control of an orbiting spacecraft in the presence of uncertainty using reaction jets. The controlled outputs are the three Euler angles which describe the orientation of the spacecraft relative to an orbital frame. Simulation results are presented to show that in the closed-loop system precise attitude control is accomplished in spite of the uncertainty in the system.
TL;DR: In this article, a continuous self-adaptive scalar control law is developed from a straightforward modification of sliding variable structure system theory, which needs no parameter identification and exhibits invariance to a class of parameter variations.
Abstract: A new continuous self-adaptive scalar control law is developed from a straightforward modification of ‘sliding’ variable structure system theory. The controller needs no parameter identification and exhibits invariance to a class of parameter variations. The continuous controller identifies certain null spaces in the state space associated with the derivatives of the switching function defined for the variable structure system and adapts itself and the time-varying switching hyperplane accordingly. The justification of the scheme and the stability of the method are highlighted. Comparisons are drawn with a previously defined discontinuous self-adaptive controller based on variable structure system theory. The general results are illustrated through the simulation of second- and third-order systems.
02 Oct 1988
TL;DR: The novel design technique is shown to have identical results to that based on the minimization of the quadratic performance index with a suitable weighting matrix, which is insensitive to variations in system parameters and load disturbance.
Abstract: Two analytic solutions for the optimal switching vector for a third-order system are obtained. The tedious computation associated with the conventional trial and error selection of the weighting matrix and numerical solution of the Riccati equation in optimal control problems can be avoided. The novel design technique is shown to have identical results to that based on the minimization of the quadratic performance index with a suitable weighting matrix. Substantial improvement in performance over that reported in the literature is achieved. The performance obtained is insensitive to variations in system parameters and load disturbance. >
24 Oct 1988
15 Sep 1988-JSME international journal. Series 3, Vibration, control engineering, engineering for industry
TL;DR: In this paper, a modeling of bending-torsion coupled vibrations of flexible structures, such as solar battery arrays, and a control method based on this model are presented, where the center of flexure does not coincide with the centroid in the cross section.
Abstract: This paper describes a modeling of bending-torsion coupled vibrations of flexible structures, such as solar battery arrays, and a control method based on this model. The bending-torsion coupled vibrations are modeled by the unconstrained mode method in the case that the center of flexure does not coincide with the centroid in the cross section. The system and the observation equations of this system are derived after the modal decomposition. Considering the state feedback control system with the state estimator, we elucidate the effect of the coupling terms in this system. Furthermore, a control method to deal with noise contamination of the sensors is also shown. Finally, some simulation results of the bending-torsion coupled vibration control are presented.
24 Oct 1988
TL;DR: Selftuning control, sliding mode control and adaptive control are experimentally applied to the control of a direct drive motor system and give satisfactory results for the variation of parameters.
Abstract: Since direct drive motors have not reduction gears, they are largely affected by the change of load. This causes parameter's changes in dynamic models, and the conventional time-invariant control system could not have desirable responses. T o cope with the problem, selftuning control, sliding mode control and adaptive control are experimentally applied to the control of a direct drive motor system. They give satisfactory results for the variation of parameters.