Showing papers on "PID controller published in 1985"
TL;DR: In this article, the tracking and disturbance rejection of a class of MIMO nonlinear systems with linear proportional plus integral (PI) compensator was studied. And they showed that a simple PI compensator can be used to yield a stable unity-feedback closed-loop system which asymptotically tracks reference inputs that tend to constant vectors.
Abstract: We study tracking and disturbance rejection of a class of MIMO nonlinear systems with linear proportional plus integral (PI) compensator. Roughly speaking, we show that if the given nonlinear plant is exponentially stable and has a strictly increasing dc steady-state I/O map, then a simple PI compensator can be used to yield a stable unity-feedback closed-loop system which asymptotically tracks reference inputs that tend to constant vectors and asymptotically rejects disturbances that tend to constant vectors.
170 citations
01 May 1985
TL;DR: In this article, a CARIMA plant model in which the noise term is nonstationary is used, and it is shown that good adaptive behavior is then possible both with generalised minimum-variance and pole-placement self-tuning controllers.
Abstract: The CARMA model generally assumed in self-tuning control frequently leads to an offset between the measurement and the desired value when regulating a plant subjected to constant load disturbances about a nonzero set point. The normal ad hoc insertion of an integrator solves the problem but can introduce others (such as convergence difficulties). The solution explored in this paper is to use a CARIMA plant model in which the noise term is nonstationary, and it is shown that good adaptive behaviour is then possible both with generalised minimum-variance and pole-placement self-tuning controllers. The approach produces integral control terms in a natural way, and, for simplified plant models, leads directly to a general PID algorithm.
141 citations
TL;DR: An integrated design procedure for a modified Smith predictor and associated controller for linear time-delay systems having transfer functions of the form k 1, A exp (sT)/B, where A and B are monic polynomials in s of degree n − l and n, respectively, was developed in this paper.
Abstract: An integrated design procedure is developed for a modified Smith predictor and associated controller for linear time-delay systems having transfer functions of the form k 1, A exp (—sT)/B, where A and B are monic polynomials in s of degree n — l and n, respectively. A is Hurwitz and B has a single right-half-plane root at s = λ. For l=1,2,3, an augmented PI controller guarantees asymptotic stability for λT less than an l-dependent limit. The procedure for l = 3 is extended to l = 4 with the introduction of derivative action into the controller. Design arguments are on root locus topology, and on Nyquist analysis applied to an auxiliary system.
109 citations
Patent•
09 Sep 1985
TL;DR: In this paper, a discrete proportional-integral-differential controller, driven from a sampling digital error amplifier, is used to penetrate a quantized duty ratio control signal to provide dynamic output voltage regulation for switching dc-to-dc power converters.
Abstract: A discrete proportional-integral-differential controller, driven from a sampling digital error amplifier, is used to penetrate a quantized duty ratio control signal to provide dynamic output voltage regulation for switching dc-to-dc power converters. The sampling frequency of the digital PID controller is equal to the switching frequency of the power converter, so the digital controller may be used at different switching frequencies without recompensation. Digital techniques are also used to provide output current limiting, soft-start, undervoltage lockout, overvoltage shutdown, and power master-clear indications.
87 citations
01 Sep 1985
TL;DR: An explicit solution for the robot arm controller, optimal in the linear quadratic sense, is obtained and a PID controller with acceleration feedback is proposed which is computationally efficient and robust relative to variations in the dynamic model and external disturbances.
Abstract: An explicit solution for the robot arm controller, optimal in the linear quadratic sense, is obtained. Based on this formulation, a PID controller with acceleration feedback is proposed which is computationally efficient and robust relative to variations in the dynamic model and external disturbances.
78 citations
01 Jul 1985
TL;DR: In both step response and tracking experiments the self-organising controller was found to perform better than a conventional PID controller under similar circumstances, although some tuning was required for the former system.
Abstract: The paper reports results of the practical application of the self-organising controller to the simultaneous control of two interacting joints of a robot. The rationale for its use and the architecture of this heuristic fuzzy rule-based dynamic control approach are outlined. This shows it to be a relatively simple intelligent knowledge-based system capable of both learning and displaying a variable nonlinear input/output relationship. In both step response and tracking experiments the self-organising controller was found to perform better than a conventional PID controller under similar circumstances, although some tuning was required for the former system.
62 citations
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TL;DR: A fuzzy supervisor for a conventional PID controller the knowledge of an expert in tuning the parameters of the PID controller is applied and a performance index is formulated, which matches the requirements in real applications better than the integral criteria generally used.
Abstract: A fuzzy supervisor for a conventional PID controller is described. In the design of the supervisor the knowledge of an expert in tuning the parameters of the PID controller is applied. Moreover, a performance index is formulated, which matches the requirements in real applications better than the integral criteria generally used. In a simulation set-up system performances of the PID controller with and without the fuzzy supervisor are compared for different values of the parameters of the process to be controlled.
51 citations
TL;DR: Techniques for approximate determination of the dominant poles are derived, as well as design methods based on these formulas which are shown to be suitable for automatic tuning of PID controllers.
42 citations
19 Jun 1985
TL;DR: In this paper, the tracking and disturbance rejection of a class of MIMO nonlinear systems with linear proportional plus integral (PI) compensator was studied. And they showed that a simple PI compensator can be used to yield a stable unity-feedback closed-loop system which asymptotically tracks reference inputs that tend to constant vectors.
Abstract: We study tracking and disturbance rejection of a class of MIMO nonlinear systems with linear proportional plus integral (PI) compensator. Roughly speaking, we show that if the given nonlinear plant is exponentially stable and has a strictly increasing dc steady-state I/O map, then a simple PI compensator can be used to yield a stable unity-feedback closed-loop system which asymptotically tracks reference inputs that tend to constant vectors and asymptotically rejects disturbances that tend to constant vectors.
42 citations
TL;DR: In this article, a globally stable adaptive predictive control system (APCS) is evaluated by application to a simulated PVC batch reactor, run under APCS control with the objective of either temperature setpoint tracking or constant reaction rate.
Abstract: A globally stable adaptive predictive control system (APCS) is evaluated by application to a simulated PVC batch reactor. The reactor is run under APCS control with the objective of either temperature setpoint tracking or constant reaction rate. The batch nature of this system makes it possible to learn about the physical problem from successive runs. This knowledge is incorporated into the control strategy to improve the performance of the reactor. The problem of excessive manipulation of the control variable has been recognized and resolved by using control weighting. Performance of the adaptive technique is compared with previous results using self-tuning and PID control of the same reactor. APCS provides good, robust control despite the nonlinear dynamics of the system.
41 citations
TL;DR: In this article, a roll/yaw attitude control of a bias momentum stabilized flexible spacecraft is presented, where a transition controller has been designed to meet the pointing requirements during the transition from the stationkeeping mode to the normal mode.
Abstract: Roll/yaw attitude control of a bias momentum stabilized flexible spacecraft is presented. The roll/yaw normal controller with a nonminimum phase control logic is shown to be very insensitive to the structural mode uncertainty. However, if this controller is switched on at the termination of a thruster-controlled stationkeeping maneuver, it cannot provide sufficient nutation damping by itself to guarantee that the initial transients will remain within specifications. Consequently, a roll/yaw transition controller has been designed to meet the pointing requirements during the transition from the stationkeeping mode to the normal mode. The new transition controller design requires consideration of the solar array flexibility because a control logic, designed to stabilize the nutation mode neglecting the solar array flexibility, could destabilize the solar array flexible mode.
TL;DR: A thorough analysis of the water flow and water level control problems arising in several industrial systems is provided using classical and sampled data linear control theory.
Patent•
07 Jan 1985
TL;DR: In this article, the authors proposed to improve follow-up characteristics and eliminate vibration by having computed an integral value in PID operation according to operating conditions of the prime mover at the time when the feedback control is stopped and adapting the integrated value to be used as the initial value of the integral term in the PID operation when the slip controlling is started.
Abstract: PURPOSE:To improve follow-up characteristics and eliminate vibration, by having computed an integral value in the PID operation according to operating conditions of the prime mover at the time when the feedback control is stopped and adapting the integrated value to be used as the initial value of the integral term in the PID operation at the time when the slip controlling is started CONSTITUTION:A prime mover a is connected with operating condition monitor means (g) and slip controlling means (f) is connected with feedback control stopping detector means (h) And, outputs from the monitor means (g) and detector means (h) are applied to a PID operational means (e) Integral term initial value computing means (i) for computing an integral value in the PID operation in accordance with the operating conditions of the prime mover at the time when the feedback control is stopped and adapting the integrated value to be used as the initial value of the integral term in the PID operation is properly connected Thus, at the time the slip controlling is started, the value obtained in the PID operation will not largely deviate from the value corresponding to the desired value Consequently, the follow-up characteristics can be improved and vibrations can be prevented
[...]
TL;DR: In this article, a reformulation of the adaptive pole-placement controller such that subject to some conditions and restrictions, it has the structure of a digital PID controller is presented.
Abstract: Conventional PID controllers are used commonly in industry. However, under various circumstances, such as changing process conditions, the PID loop does not necessarily perform in an `optimal' manner, and retuning may then be required. This paper presents a reformulation of the adaptive pole-placement controller such that subject to some conditions and restrictions, it has the structure of a digital PID controller. Various properties of this adaptive PID controller are described and illustrated by simulation examples.
Journal Article•
TL;DR: In this paper, the authors describe a control laboratory and a sequence of experiments performed in the basic automatic control courses at the Lund Institute of Technology (LIT), based on level control of two cascaded tanks.
Abstract: Laboratory experiments offer one way to introduce more realism into the education of automatic control. This paper describes a control laboratory and a sequence of experiments performed in the basic automatic control courses at Lund Institute of Technology. The laboratory is based on level control of two cascaded tanks. An Apple II computer is used to implement control laws and to provide graphics and computer-aided instruction. Four laboratory experiments of successively increasing complexity are performed. They include empirical experimentation with PI and PID control, modeling and parameter fitting, design, implementation, and tuning of PID control, antiwindup, autotuning, selector control, state feedback, Kalman filtering, and output feedback.
TL;DR: In this article, the adaptive internal model control (IMC) and the adaptive parameter identification technique by the model refernece adaptive system (MRAS) are newly combined, and the combined one is called the adaptive IMC (AIMC).
TL;DR: A very simple class of adaptive PID regulators, where the the method is based on the explicit identification of the process and a design equation is used ensuring 5% overshoot in the step response.
TL;DR: In this paper, simple pseudo-steady state relations between the hydraulic and nozzle pressures of an injection molding machine were presented and verified experimentally, and a simulation study was performed to evaluate the performance of simple controllers using dynamic models developed for the hydraulic pressure.
Abstract: Simple pseudo-steady state relations between the hydraulic and nozzle pressures of an injection molding machine were presented and verified experimentally. A simulation study was performed to evaluate the performance of simple controllers using dynamic models developed for the hydraulic and nozzle pressures. The controllers chosen were the discrete proportional, proportional-integral (PI), and proportional-integral-derivative (PID) types, tuned according to the ITAE criterion. The control of hydraulic pressure simulation showed that the PI controller had the best overall performance, whereas the result of nozzle pressure control loop simulation showed that the PID controller performance was better than that of the PI controller. All the controllers, in both loops, gave responses that were about an order of magnitude more rapid than the open loop response.
19 Jun 1985
TL;DR: A mathematical model for predicting dynamics between the feedrate and cutting force in the lathe cutting process is derived by combinations of a parameter identification technique and geometrical consideration for chip thickness time variation as mentioned in this paper.
Abstract: A mathematical model for predicting dynamics between the feedrate and cutting force in the lathe cutting process is derived by combinations of a parameter identification technique and geometrical consideration for chip thickness time variation. The model prediction of transient responses is in good agreement with the experimental results. The model is used for tuning a PI controller for regulating the cutting force as well as to show performance limitations of the conventional PI controller. A simple adaptive control scheme which makes use of the model structure is proposed. Experimental results from laboratory evaluation of the proposed controllers are presented.
TL;DR: In this paper, the effects of the eddy currents in the conductive components, such as the first wall, blanket, shield and coil vacuum chamber, on the vertical position control in tokamak reactors are presented.
01 Mar 1985
TL;DR: An optimal control formulation for robotic manipulators is proposed and the Computed Torque Control, Resolved Acceleration Control, and a PID End Point Control are derived as special cases of this formulation.
Abstract: An optimal control formulation for robotic manipulators is proposed in this paper. The Computed Torque Control, Resolved Acceleration Control, and a PID End Point Control are derived as special cases of this formulation. Torque and acceleration feedback are adopted to eliminate the on-line calculations of feed forward components in the above control algorithms, and to increase robustness of the control system. This controller can be implemented approximately without torque sensors and accelerometers. The resulting control system is proved to be bounded input bounded state stable. Simulation results on both the Scheinman MIT and PUMA 600 arms are presented.
19 Jun 1985
TL;DR: This paper describes a simple self-tuning-procedure for PI- and PID-controllers, which is based on discrete parameter estimation and application of slightly modified Ziegler-Nichols tuning-rules.
Abstract: Microprocessor-based tuning aids and self-tuning-methods for conventional PID-controllers are an important subject to industrial users. Some of the existing techniques use simple pattern-recognition, some use expensive optimization procedures. This paper describes a simple self-tuning-procedure for PI- and PID-controllers, which is based on discrete parameter estimation and application of slightly modified Ziegler-Nichols tuning-rules. Controller tuning has been simplified to the choice of the desired over-shoot of the PID-controlled closed loop system. The method is easy to implement in microprocessors and allows quick online-tuning of PID-controllers. Simulation results and a comparison with controllers tuned by an optimization procedure are presented.
Patent•
26 Aug 1985
TL;DR: In this article, a comparison circuit indicating PID operation depending on an output temperature is proposed to decrease the overshoot of an output by providing a comparison circuits indicating PID operations depending on the output temperature, and the comparison circuit stops a PID circuit, drives a heater energyzing circuit and continues to energize a heater.
Abstract: PURPOSE:To decrease the overshoot of an output by providing a comparison circuit indicating PID operation depending on an output temperature. CONSTITUTION:When an output of a temperature detector 2 is smaller than an output of a threshold value generating circuit 7, the comparison circuit 6 stops a PID circuit 3, drives a heater energyzing circuit 4 so as to continue to energize a heater 5. When an output of a temperature detector 2 exceeds an output of the threshold value circuit 7, the energyzing of the heater 5 is stopped through the heater energyzing circuit 4 so as to drive the PID circuit 3. The PID circuit 3 performs PID operation from the point of time and drives the heater energyzing circuit 4 so that the temperature of the heater 5 is coincident with an object value.
19 Jun 1985
TL;DR: In this article, a novel method for automatically tuning PID controllers is presented, which is intended for use of distributed instrumentation and computer control systems in two Canadian pulp mills, where closed-loop identification of the process and tuning constants of the regulator are found by optimization.
Abstract: A novel method for automatically tuning Proportional-Integral-Derivative (PID) controllers is presented. After closed-loop identification of the process, the tuning constants of the regulator are found by optimization. The representation of the closed-loop system by a series of Laguerre functions is seen as the key to the robustness of the method. The method is intended for use of distributed instrumentation and computer control systems. It was implemented on such systems in two Canadian pulp mills. Successful tests were Performed on several loops in both plants. Results are presented and discussed.
01 Dec 1985
TL;DR: A multivariable self-tuning PID (SPID) controller is introduced to robot manipulator control and it is shown that the structure is simple, eliminates interactions quite well, and is easy to implement.
Abstract: A multivariable self-tuning PID (SPID) controller is introduced to robot manipulator control. The control structure is simple, eliminates interactions quite well, and is easy to implement.
Patent•
26 Jul 1985
TL;DR: In this article, an allowable range expanding means consisting of a limiter variable part 25 and a timer mechanism 26 is provided to suppress a variation of the number of revolution by providing an allowable ranging expanding means for expanding an allowable ranges of the set number of revolutions as a prescribed time elapses.
Abstract: PURPOSE: To suppress a variation of the number of revolution by providing an allowable range expanding means for expanding an allowable range of the set number of revolution as a prescribed time elapses. CONSTITUTION: A control object 20 of a self-tuning regulator controller 21 consists of a system containing a diesel main engine 22 and a PID speed governor 23, and the controller 21 inputs the main engine speed K being a plant output, the set number of revolution T being a plant input, and the target number of revolution M, and estimates and determines successively an unknown parameter of the main engine 22 by an identification method, and sends out a set signal T'. In this case, an allowable range expanding means 24 consisting of a limiter variable part 25 and a timer mechanism 26 is provided. As a result, with respect to the set number of revolution speed T' which is sent out of the controller 21, its allowable range is narrowed when starting an adaptive control, and it is expanded stepwise as time elapses. In this way, the magnitude of an input amplitude limit of the set number of revolution T' is increased gradually. COPYRIGHT: (C)1987,JPO&Japio
Patent•
09 Dec 1985
TL;DR: In this paper, the deviation of the fed-back response output value of a process from a target value is inputted to a PID controller 2, and the controller 2 outputs an operation signal to an operation part of the process 1 in accordance with PID adjustment rules.
Abstract: PURPOSE: To improve the process control and to reduce the energy and the labor by comparing an absolute deviation area, which is obtained when at least one of process gain, dead time, and time constant system parameters is changed, with preceding that and repeating this comparison to optimize the control. CONSTITUTION: The deviation of the fed-back response output value of a process 1 from a target value is inputted to a PID controller 2, and the controller 2 outputs an operation signal to an operation part of the process 1 in accordance with PID adjustment rules. A controller output U and a process variable (y) which are inputted to and outputted from the process 1 are temporarily stored in a data storage part 3. These data are sent to an identifying part 10, and the part 10 obtains the absolute deviation area of the process variable for the change of at least one of dead time, process gain, and time constant system parameters in a process transfer function and compares this area with preceding that, and the obtained value is used as the initial value to repeatedly change parameters if it is smaller than preceding value, but the obtained value is fixed and is sent to the controller 2 if it is larger than preceding value. COPYRIGHT: (C)1987,JPO&Japio
Patent•
24 Sep 1985
TL;DR: In this article, the authors presented a method to attain the optimum temperature control by changing the set temperature set by a temperature setter by manual or automatic program control to call it out of a storage device and calculate a temperature by a called control parameter.
Abstract: PURPOSE: To attain the optimum temperature control by changing the set temperature set by a temperature setter by the manual or program control to call it out of a storage device and calculating a temperature by a called control parameter CONSTITUTION: A desired heating temperature T 1 is set by a temperature setter 16 and the setting signals are sent to a temperature controller 18 and a storage device 14 The storage device 14 decides the area of the temperature T 1 and delivers the proportion, integration and differentiation PID constants P 1 , I 1 and D 1 corresponding to said temperature area to the controller 18 The controller 18 gives the PID control to the output of a heater 20 based on the contents P 1 , I 1 and D 1 given from the storage 14 as well as the setting signal sent from the setter 16 so that an object is set at the temperature T 1 When the heating temperature T 2 of the object is changed, the set temperature of the setter 16 is changed by the manual or automatic program control Thus the setting signals are given to both the controller 18 and the storage device 14 and the area of the set temperature is decided Then the corresponding PID is delivered to the controller 18 In such a way, the automatic temperature control is possible with high accuracy COPYRIGHT: (C)1987,JPO&Japio