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Showing papers on "Control theory published in 1981"


Journal ArticleDOI
TL;DR: A new conceptually simple approach to controlling compliant motions of a robot manipulator that combines force and torque information with positional data to satisfy simultaneous position and force trajectory constraints specified in a convenient task related coordinate system is presented.
Abstract: A new conceptually simple approach to controlling compliant motions of a robot manipulator is presented. The 'hybrid' technique described combines force and torque information with positional data to satisfy simultaneous position and force trajectory constraints specified in a convenient task related coordinate system. Analysis, simulation, and experiments are used to evaluate the controller's ability to execute trajectories using feedback from a force sensing wrist and from position sensors found in the manipulator joints. The results show that the method achieves stable, accurate control of force and position trajectories for a variety of test conditions.

2,991 citations


Journal ArticleDOI
TL;DR: In this article, the Stanford-JPL hand is described and several architectures for position and force control of this multiloop mechanism are described, including a way of dealing with the internal forces inherent in such systems.
Abstract: Kinematic and control issues are discussed in the context of an articulated, multifinger mechanical hand. Hand designs with particular mobility properties are illustrated, and a definition of accuracy points within manipulator workspace is given. Optimization of tlte physical dimensions of the Stanford-JPL hand is described. Several architectures for position and force control of this multiloop mechanism are described, including a way of dealing with the internal forces inherent in such systems. Preliminary results are shown for the joint torque subsystem used in the hand controller.

737 citations


Journal ArticleDOI
T. Inoue1, Michio Nakano1, T. Kubo, S. Matsumoto, H. Baba 
TL;DR: In this article, a linear feedback control is applied in high accuracy tracking of a periodic reference input by locating the imaginary poles of the controller's transfer function to suit the period of the input.

432 citations


Journal ArticleDOI
TL;DR: A new process-model control system which can yield zero steady-state error and desired transient responses to step disturbances and arbitrary initial conditions is proposed.
Abstract: This paper is concerned with linear systems containing time delay in control. A process-model control which utilizes a mathematical model of the process in the minor feedback loop around the conventional controller to overcome delay is developed. A new process-model control system which can yield zero steady-state error and desired transient responses to step disturbances and arbitrary initial conditions is proposed. The remarkable feature of the proposed system is that the states of the model and the integrator are unobservable in the output of the model. It is shown that this structural property is the key by which the major problems of process-model control can be solved.

428 citations


Book
01 Oct 1981
TL;DR: This paper presents a meta-modelling architecture suitable for linear control system analysis and design and some examples of such systems have been designed and tested in the wild.
Abstract: Linear control system analysis and design , Linear control system analysis and design , کتابخانه دیجیتال جندی شاپور اهواز

326 citations


Patent
23 Oct 1981
TL;DR: In this paper, a numerical control system equipped with a man-machine interface controller (MMC equipment) constructed in the form of a computer is described, where the data are transmitted and received among the NC unit (11), the programmable machine controller (13) and the MAN-machine Interface Controller (14) while they are controlled by the data transmission-reception control unit (15).
Abstract: A numerical control system equipped with a man-machine interface controller (MMC equipment) constructed in the form of a computer. The system comprises an NC unit (11), a programmable machine controller (13) which executes the sequence control relying upon the signals from the NC unit (11) and a machine tool (12), a man-machine interface controller (14) which is equipped at least with a CRT (14d) and a keyboard (14e) and which is constructed in the form of a computer, and a data transmission-reception control unit (15). The data are transmitted and received among the NC unit (11), the programmable machine controller (13) and the man-machine interface controller (14) while they are controlled by the data transmission-reception control unit (15).

290 citations


Journal ArticleDOI
TL;DR: In this article, the results of the research concerned with the problem of induction motor control system synthesis using variable structure systems theory are presented, as well as basic experimental results and problems related to realization of the proposed control algorithms.
Abstract: The results of the research concerned with the problem of induction motor control system synthesis using variable structure systems theory is presented. The procedure of control systems synthesis for the control of position speed and torque is given, as well as basic experimental results and problems related to realization of the proposed control algorithms.

235 citations


Journal ArticleDOI
TL;DR: A robust stability test and associated design procedure based on the positivity of operators, assuring global stability when the loop is closed by negative feedback is proposed, and can be extended to nonlinear systems.
Abstract: A robust stability test and associated design procedure based on the positivity of operators is proposed. The test does not rely on modal truncation or high-order truth models of the structure and is independent of the numerical values of the modal data. The stability criterion is applied to the plant (structure) and the controller individually, assuring global stability when the loop is closed by negative feedback. Therefore, design/stability evaluations need only iterate on the low-order controller part of the loop. The method can be extended to nonlinear systems.

207 citations


Journal ArticleDOI
Per-Olof Gutman1
TL;DR: In this paper, the problem of finding stabilizing feedback controllers for continuous bilinear systems, where the controls act additively and multiplicatively simultaneously, is treated and the applicability of the "quadratic" control law of Jacobson [5] and others is extended to the case when the A -matrix has arbitary, eigenvalues under certain conditions.
Abstract: The problem of finding stabilizing feedback controllers for continuous bilinear systems, where the controls act additively and multiplicatively simultaneously, is treated. The applicability of the "quadratic" control law of Jacobson [5] and others is extended to the case when the A -matrix has arbitary, eigenvalues under certain conditions. A class of bilinear systems common among biochemical flow systems is defined: the dyadic bilinear systems. A control scheme, the so-called division controller, for dyadic bilinear systems is suggested. The practicality of the control schemes is demonstrated on the problem of controlling the neutron level in a fission reactor.

142 citations


Journal ArticleDOI
TL;DR: A method is presented for maneuvering a flexible spacecraft from one position to another while leaving an arbitrary number of bending modes inactive at the end of the maneuver, combining standard fixedtime linear quadratic Gaussian regulator control theory with a modal decomposition of a flexible body.
Abstract: A method is presented for maneuvering a flexible spacecraft from one position to another while leaving an arbitrary number of bending modes inactive at the end of the maneuver. The method combines standard fixedtime linear quadratic Gaussian regulator control theory with a modal decomposition of a flexible body. Further features of the method are that it uses minimum control effort and it can be converted to a feedback form to deal with random disturbances and parameter uncertainties. Several examples are given to demonstrate the efficacy of the method, and results from a hardware experiment are presented.

129 citations


Proceedings ArticleDOI
01 Dec 1981
TL;DR: This report presents the first direct adaptive control structure for nonminimum phase systems where controller parameter identification can be posed as a standard linear parameter estimation problem.
Abstract: This report presents the first direct adaptive control structure for nonminimum phase systems where controller parameter identification can be posed as a standard linear parameter estimation problem. In particular a linear equation error model is formulated for estimating both the controller parameters and some additional auxiliary parameters. Although the global stability question is not resolved, the key issue in proving stability is isolated for this scheme, and a simulation study demonstrating the feasibility of this approach is presented.

Journal ArticleDOI
TL;DR: A review of two decades of investigation into one of the fundamental problems of control theory, the discrete linear time invariant time optimal control problem, is presented and two classes of multi-input time optimal controller are considered, one based on system controllability and the other on eigenvalue assignment.


Journal ArticleDOI
D. C. Lee1, R. E. Beaulieu1
TL;DR: In this article, a power system stabilizer based on measurement of unit accelerating power, where the mechanical power component is derived from speed and electrical power signals, is described and techniques to facilitate the implementation of such a controller are discussed and the ability of this type of stabilizer to remove some of the limitations inherent in other stabilizer designs is demonstrated.
Abstract: Further development of a power system stabilizer based on measurement of unit accelerating power, where the mechanical power component is derived from speed and electrical power signals, is described. Techniques to facilitate the implementation of such a controller are discussed and the ability of this type of stabilizer to remove some of the limitations inherent in other stabilizer designs is demonstrated. The design, testing and commissioning of this stabilizers is covered and field experience with it on large fossil-fired and nuclear units is documented.

Patent
10 Apr 1981
TL;DR: In this article, a control system is coupled to control a system for spatially transforming images by separate transformation of each dimension of the image, including a control panel having a three-axis joystick and a set of keys providing function selection and assignment of the joystick to a particular control function, a panel processor coupled to receive and interpret control panel data and a high level controller.
Abstract: A control system is coupled to control a system for spatially transforming images by separate transformation of each dimension of the image. The control system includes a control panel having a three-axis joystick and a set of keys providing function selection and assignment of the joystick to a particular control function, a panel processor coupled to receive and interpret control panel data and a high level controller. The high level controller responds to the operator control information from the panel processor to establish selected image transformation information at selected knot points and communicates to a transformation portion of the transformation system data controlling the transformation of each image field with data for fields between knot points being developed from a cubic spline interpolation between knot points.

Journal ArticleDOI
TL;DR: The self-tuning control theory is shown to provide a variety of control objectives such as model-reference, optimal Smith prediction and the minimization of a general k-step-ahead cost-function.

Journal ArticleDOI
R.F. Drenick1
01 May 1981

Journal ArticleDOI
TL;DR: In this paper, a simple computer algorithm is presented for on-line estimation of the process parameters in turning, which can be used to solve the stability problem of machining with Adaptive Control Constraint.

Book
01 Aug 1981
TL;DR: The formal framework for interior control is described in this article, where the second order conditions for free-endpoint problems are defined. But the formal framework does not consider the second-order conditions.
Abstract: The formal framework.- Interior controls. Second order conditions.- Free-endpoint problems.

Patent
08 Jun 1981
TL;DR: In this article, an electronic controller is provided to control the energization of an electrical actuator to readjust a valve which controls the flow of a fluid in a controllable process.
Abstract: An electronic controller is provided to control the energization of an electrical actuator to readjust a valve which controls the flow of a fluid in a controllable process. The controller is responsive to two signals, one of which is produced by a process sensor to represent the instantaneous magnitude of a predetermined process parameter and the second of which constitutes a set signal representative of a desired magnitude of the parameter. The signals are compared, and the sense of any resulting error signal is used to control the direction of movement of the actuator while the instantaneous magnitude of the error signal, during a succession of equal time intervals, is used to control the rate of movement of the actuator by controlling the extent of movement of the actuator during each of the time intervals. The actuator is jointly responsive to these two controls and moves in a series of incremental steps, the sizes of which decrease exponentially to match the process loop variable's exponential change with time, as the error signal reduces to zero.

Patent
13 Jul 1981
TL;DR: In this paper, an improved control system for an electric powered vehicle of the type including a D.C. motor drivingly connected to roadway engaging drive wheels is presented, which includes a second storage battery, a manually actuated starting switch for allowing the D.c. motor to be driven by the first battery, the second battery also driving the circulation pump.
Abstract: In a control system for an electric powered vehicle of the type including a D.C. motor drivingly connected to roadway engaging drive wheels, there is provided an improvement. A control system for this type of vehicle has a controller for operating the D.C. drive motor with a voltage having a pre-selected magnitude, a first storage battery supported on the vehicle and having a charging mode and a discharging mode with a voltage rating during both of the modes being generally equal to the pre-selected magnitude, a circulation pump associated with the first storage battery for activating this battery, also driving the circulation pump during the discharge mode of the first storage battery. The improved control system in this type of an environment includes a second storage battery, a manually actuated starting switch for allowing the D.C. motor to be driven by the first storage battery, the second storage battery also driving the circulation pump for limited time after manual actuation of the starter. Also, the improved control system is useable when two pumps are associated with the first storage battery and then includes a control circuit for driving one pump selectively by the second storage battery and an enabling circuit for actuating the drive control by the second storage battery so that the vehicle responds to the second storage battery at least during initial operation.

Journal ArticleDOI
TL;DR: The use of a multivariate autoregressive model for the implementation of a new practical optimal control of a supercritical thermal power plant is discussed and the results clearly demonstrate the advantage of the new controller over the conventional PID controller.

01 Aug 1981
TL;DR: In this paper, a nonlinear programming algorithm is employed to search for the control law design variables that minimize a performance index defined by a weighted sum of mean-square steady-state responses and control inputs.
Abstract: A method of synthesizing reduced-order optimal feedback control laws for a high-order system is developed. A nonlinear programming algorithm is employed to search for the control law design variables that minimize a performance index defined by a weighted sum of mean-square steady-state responses and control inputs. An analogy with the linear quadractic Gaussian solution is utilized to select a set of design variables and their initial values. To improve the stability margins of the system, an input-noise adjustment procedure is used in the design algorithm. The method is applied to the synthesis of an active flutter-suppression control law for a wind tunnel model of an aeroelastic wing. The reduced-order controller is compared with the corresponding full-order controller and found to provide nearly optimal performance. The performance of the present method appeared to be superior to that of two other control law order-reduction methods. It is concluded that by using the present algorithm, nearly optimal low-order control laws with good stability margins can be synthesized.

Proceedings ArticleDOI
01 Jun 1981
TL;DR: In this article, a survey of the instabilities of switching voltage regulators with different types of current-mode controllers (including LC3 or constant-hysteresis; MC2 or constant frequency and constant off-time versions) is presented.
Abstract: A survey of the instabilities of switching voltage regulators with different types of current-mode controllers (including LC3 or constant-hysteresis; MC2 or constant-frequency and constant off-time versions) is presented. Apart from the well-known open-loop oscillation of the constant frequency regulator above 50% duty ratio, other instabilities can also arise by increasing the ac loop-gain. At the constant-hysteresis controller the operating frequency changes, at the other types continuously or hysteretically arising subharmonic oscillation appears. These phenomena can be analysed by taking into account the effect of the amplified and fed-back ripple voltage to the operation of the current comparator. Calculations were accomplished in order to establish maximum usable ac gains for the three basic power converter topologies (buck, boost and buck-boost) and for the above mentioned controllers. Experiments were also carried out for several particular power circuit and controller combinations showing close correspondence to theoretical results.

Journal ArticleDOI
TL;DR: Papers on optimal control theory, reviewed in Referativnyi Zhurnal "Matematika" during 1971-1975, are surveyed in this paper, where a survey of control theory is presented.
Abstract: Papers on optimal, control theory, reviewed in Referativnyi Zhurnal “Matematika” during 1971–1975, are surveyed.

Journal ArticleDOI
TL;DR: In this paper, the design of MRAC for achieving independent tracking and regulation objectives with a unique equilibrium point in the controller parameter space is presented, where the stability of the system and boundness of various variables do not require any positivity condition.
Abstract: The design of MRAC for achieving independent tracking and regulation objectives with a unique equilibrium point in the controller parameter space is presented. The corresponding schemes can use either an explicit reference model or an implicit reference model. The design is done from a stability point of view by extending an appropriate control configuration used for the case of known plant parameters. The result of the design is a simple control scheme using a linear constant feedforward controller and a non-linear feedback controller. The stability of the system and boundness of various variables do not require any positivity condition. The performances of the control structure in tracking and regulation are evaluated by simulations.

Patent
13 Apr 1981
TL;DR: In this article, a combined mode program-panel controller is proposed for a distributed industrial process control system that allows a system operator to configure the overall system architecture to control the sequential operation of the entire system or a sub-portion thereof.
Abstract: A combined mode program-panel controller method for a distributed industrial process control system permits a system operator to configure the overall system architecture to control the sequential operation of the entire system or a sub-portion thereof. The program-panel controller includes a first user accessible graphic program by which the system architecture can be symbolically reconfigured and a second user accessible instruction set program by which the operating parameters of the so-configured system or a sub-portion thereof may be altered.

Journal ArticleDOI
TL;DR: The controller described in this paper is designed for multivariable plants with constant, unknown parameters and operates on-line with the a priori information about the time delay.

Journal ArticleDOI
TL;DR: In this article, the dead-beat control of linear periodic discrete-time systems subject to periodic disturbances is studied and necessary and sufficient conditions are given for the existence of a linear periodic controller such that both output deadbeat control under periodic disturbances, and state dead-beast control under no disturbance, are performed.
Abstract: In this paper the dead-beat control of linear periodic discrete-time systems subject to periodic disturbances is studied. Necessary and sufficient conditions are given for the existence of a linear periodic controller such that both output dead-beat control under periodic disturbances, and state dead-beat control under no disturbance, are performed. Moreover synthesis procedures of the controller, as well as of state dead-beat observers, are given, which can be applied also to a class of bilinear systems.

Proceedings ArticleDOI
01 Dec 1981
TL;DR: In this paper, a new approach to the position and velocity control of a manipulator by using the adaptive (self-tuning) controllers is presented. But the adaptive controller is designed on the basis of the difference equation model, and a chosen performance criterion.
Abstract: This paper presents a new approach to the position and velocity control of a manipulator by using the adaptive (self-tuning) controllers. The complicated model of a manipulator system is modeled by a set of time varying difference equations. The parameters of the system are determined by an on-line recursive algorithm based on the least squares error criterion. An adaptive controller is designed on the basis of the difference equation model, and a chosen performance criterion. The controllers are calculated on-line using the model with the estimated values of system parameters. Simulation results are presented to demonstrate the applicability of the approach to the control of a manipulator.