Showing papers on "Open-loop controller published in 1982"

Stable model reference adaptive control in the presence of bounded disturbances

Abstract: The adaptive control of a linear time-invariant plant in the presence of bounded disturbances is considered. In addition to the usual assumptions made regarding the plant transfer function, it is also assumed that the high-frequency gain k p of the plant and an upper bound on the magnitude of the controller parameters are known. Under these conditions the adaptive controller suggested assures the boundedness of all signals in the overall system.

Remote control for motor vehicle

Abstract: A remote controller is disclosed for controlling the throttle, brake and steering mechanism of a conventional motor vehicle, with the remote controller being particularly advantageous for use by severely handicapped individuals. The controller includes a remote manipulator which controls a plurality of actuators through interfacing electronics. The remote manipulator is a two-axis joystick which controls a pair of linear actuators and a rotary actuator, with the actuators being powered by electric motors to effect throttle, brake and steering control of a motor vehicle adapted to include the controller. The controller enables the driver to control the adapted vehicle from anywhere in the vehicle with one hand with minimal control force and range of motion. In addition, even though a conventional vehicle is adapted for use with the remote controller, the vehicle may still be operated in the normal manner.

Deadbeat control and tracking of discrete-time systems

Abstract: A new approach for forcing the state of a linear discrete-time system to zero in a minimum number of steps is discussed. The problem is formulated as the solution to a steady-state optimal control problem with no cost on the control. This problem in turn is set up as the solution to an associated eigenvalue problem. No special assumption on the open loop system matrix and/or the ratio of the number of states to controls is required. Stable numerical techniques are presented for solving for the feedback gain. Robust deadbeat tracking is also discussed.

Programmable controller with back-up capability

Abstract: An active programmable controller services I/O racks which contain circuits that interface with sensing devices and operating devices on a machine being controlled. A back-up programmable controller monitors this I/O data to maintain a current I/O image table in its memory. Other status data is coupled to the back-up controller from the active controller through a peer-to-peer communications link. If a malfunction occurs in the active controller, the back-up controller is signaled to switch to the active mode in which it assumes control of the operating devices on the machine being controlled.

Programmable sequence controller and system

Abstract: A programmable sequence controller and a sequence control system including a plurality of such controllers. Each sequence controller includes a program memory for storing a preprogrammed sequence of instructions for controlling a machine or part of a machine in response to the status of the machine or part being controlled. Each controller includes data transfer circuitry for receiving status data from another sequence controller on a common data bus and transmitting its own status data to all of the other sequence controllers on the common data bus. Each sequence controller includes an input-output (I/O) memory and an (I/O) flag memory for storing and keeping track of current status information from each of the plurality of controllers. Thus, each controller can make a control decision based not only on input and output status data from the specific machine or machine part that it controls but also based on the status of the machines or machine parts being controlled by the other sequence controllers linked by the common data bus. The number of sequence controllers linked by the common data line can be increased as necessary to execute increasingly complex control functions.

State-space pole-placing self-tuning regulator using input-output values

Abstract: The paper describes a method for the design of a multivariable self-tuning controller and presents the results of simulations using this controller. The method uses state-space techniques to assign the closed-loop system poles to prespecified locations. The state vector is made up of process input and output values, so that state estimation is unnecessary. Unity closed-loop gain in steady state is ensured by an additional controller term, and offsets are removed by a separate integral action.

Programmable control system for controlling at least two parameters in a predetermined sequence using both analog and digital control signals

Abstract: A method and apparatus for controlling a work function, such as, for example, welding, requiring the control of at least one parameter according to a predetermined sequence, the apparatus including at least one work station where the work function is carried out, a slave controller associated with the work station for controlling the work function, at least one interface operably connected to the slave controller capable of receiving and storing information for a first parameter of the work function and preventing transmission of the parameter information to the slave controller until being probed by the slave controller, and a master controller operably connected to the interface to transmit thereto the parameter information, and the master controller being further operably connected to the slave controller to cause the slave controller to probe the interface to allow transmission of the parameter information to the slave controller. In one embodiment, the information for a second parameter is transmitted from the master controller to the control portion of the slave controller so that such parameter information can be modified, if desired, while the work function is being carried out.

Synthesis of Model Following Servo Controller for Multivariable Linear System

Abstract: This paper considers the model following servo system synthesis method in which optimization techniques like Kreindler are used to design controllers that make the step response of the plant should be kept close to a specified ideal step response of the model. The controller is named model following servo and has several useful characteristics as follows. (1) The controller includes the servo controller to exclude the offset in the presence of the constant disturbances or the parameter perturbations of the plant. (2) The controller for constant reference signals and constant disturbances is treated in this paper, but its generalization to more general reference signals and disturbances can be easily done. (3) The performance of the controller is as good as that of the adaptive model following controllers. (4) The structure of the controller is simpler than that of the adaptive ones. Two examples demonstrated the above mentioned characteristics.

Decoupling of linear multivariable two-dimensional systems via state feedback

Abstract: The paper considers the problem of single-input single-output decoupling of linear multivariable two-dimensional systems. In particular, a method is presented which yields the decoupling state feedback controller matrices, which, when applied to the open-loop system, yield a closed-loop system whose transfer-function matrix is diagonal and nonsingular. This, in effect, simplifies the multi-input multi-output original system to a number of single-input single-output systems. Sufficient conditions are established for the state feedback decoupling problem to have a solution. Two examples are included to illustrate the proposed decoupling method.

Electric machine theory for power engineers

Abstract: This is indeed a welcome addition to the set of several exciting introductory books on electromechanical energy conversion devices. It is a well-suited text for an introductory course for electrical engineering students with interest in power systems. The traditional subjects of electric machinery, i.e., transformers, dc machines, induction machines, and synchronous machines, are thoroughly covered without resorting to many complicated electromagnetic field theorems and equations. Many numerical examples demonstrate the theory and principles set forth in the text; the abundance of excellent figures, diagrams, and actual pictures serves to illustrate the important concepts. For the benefit of the students interested in control theory, simple dynamic analyses of several machines, using the sdomain techniques, are presented at the end of selected chapters. The book consists of seven chapters and four appendices. Chapters 1-4 cover transformers, dc machines, three phase system theory, and induction motors, respectively. The chapter on dc machines also contains analog simulation and CSMP programs for descniing the dynamics of a dc machine under different excitations. The remaining chapters are dedicated to synchronous machines. Elementary synchronous machines and measurement of three-phase synchronous devices are topics of Chapters 5 and 7, respectively. Systems considerations of synchronous machines are covered in Chapter 6. Topics such as connection to an infinite bus, excitation systems, parallel operations, dynamic analysis, and swing equations are presented in this chapter. Consistent with the statement at the preface, the author presents material useful to students in control systems. Since stepping motors are used in a variety of control systems application, a section covering the theory, controls, and applications of these motors would have been a valuable addition to the book. The general organization of the book is reasonable in terms of both overall coverage and chapter headings. Each chapter includes a summary, a set of homework problems and a reference list. The text can be used in a two-semester course for electrical engineering students with a major in power systems. However, proper selection of the material in the text allows one to design a onesemester course in electric machine theory.

Robust compensation of optimal control for manipulators

Abstract: In a suboptimally controlled manipulator arm, friction torque variations cause trajectory deviations and performance deterioration. On the other hand, the on-line computation of nonlinear terms in the suboptimal controller is time consuming or requires large memory space when table look-up techniques are used. In order to obtain robustness against variations in open loop dynamics and decrease nonlinear couplings in suboptimal control systems for manipulators with quadratic performance indices, in addition to full state feedback, it is necessary to introduce feedback associated with the derivatives of the state variables. This additional feedback may be implemented as minor compensating loops embedded within the suboptimal controller by analog devices. As an example, torque compensation and acceleration compensation for MIT arm are considered and yield a simple linear controller with improved robustness.

Protective device for controller of internal-combustion engine

Abstract: PURPOSE:To prevent a controller from being subjected to malfunction by preventing the drop of voltage applied to the controller of an internal-combustion engine at the starting of said engine. CONSTITUTION:A control circuit power supply switch 11 is provided between a battery 3 and a regulator 5 for voltage drop, and the voltage dropped by this regulator 5 is applied to the microcomputer 12 of a controller 10 via a reverse- current preventing diode 6 and a backup condenser 7. Further, a non-lock type starting switch 8 is provided on the later stage of the controller power supply switch 11, and connected to the microcomputer 12. The backup condenser 7 having large capacity is charged to a controller driving voltage value through the reverse-current preventing diode 6 until an on-signal is issued from the microcomputer 12 via a relay circuit 13 to a cell motor 2 after turning the control power supply switch 11 on, so that it is possible to obtain a larger voltage value than that capable of driving the controller.

Input and output data transmission system of programmable controller

Abstract: PURPOSE:To simplify the constitution of an input and output data transmission system and to reduce its cost by connecting the limited necessary number of input and output units in series to a controller main body so as to form closed loop with all units through a one series data line. CONSTITUTION:Input units U1 and U32 and output units U2 and U3 are connected respectively independently of the controller body 1. A necessary number of input units and output units are connected between the serial data input terminal SIT and output terminal SOT of the controller body 1 all in a serial loop through the one serial data line 2. Therefore, output data transmission from the controller 1 to the output units U2 and U3 and input data transmission from the input units U1 and U32 to the controller 1 are carried out simultaneously.

Movement controller for machine tool - uses differential counter to compare actual and stored movement signals to control dual step motor assembly

Abstract: A carriage (13) which slides on a fixed frame (12) is driven by a control screw (16) from principal (14) and auxiliary (15) step motors which are mechanically coupled. An incremental sensor (17) produces plses representing movement of the carriage. These pulses pass through a selector (21) to route them to the positive or negative movement cells (C) of a magnetic tape memory (19). A differential counter (27) compares pulses from two further counters (25,26) which receive their inputs from the sensor and memory to drive an amplifier (28) for the auxiliary motor. An amplifier (23) receiving pulses from the memory provides control in open loop by providing step pulses for the principal motor. The closed loop chain (24) provides greater precision by production of the error signal and by driving the auxiliary motor in addition to the principal motor.

Globally stable identification based adaptive control of stable open loop processes

Abstract: This report studies the adaptive control of open loop stable processes, or processes which can be pre-stabilized by fixed compensation. It is shown that by making a simple modification to tradition parameter adaptive control laws, global stability can be assured even if the controller becomes temporarily unstable during adaptation. The results are applicable to a large class of adaptive controllers which estimate parameters from process input-output data.