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Open-loop controller

About: Open-loop controller is a research topic. Over the lifetime, 16148 publications have been published within this topic receiving 224014 citations. The topic is also known as: non-feedback controller & open-loop control law.


Papers
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Journal Article
TL;DR: A novel adaptive genetic algorithm (AGA) is proposed for the multi-objective optimization design of a fractional PID controller and applies it to the control of an active magnetic bearing (AMB) system.
Abstract: This paper proposes a novel adaptive genetic algorithm (AGA) for the multi-objective optimization design of a fractional PID controller and applies it to the control of an active magnetic bearing (AMB) system. Different from PID controllers with three constants, the fractional PID controller's parameters are composed of proportional constant, integral constant, derivative constant, derivative order and integral order. The fractional PID controller is more flexible and gives the possibility of adjusting more carefully the closed-loop system characteristics. However, its design becomes more complex than that of conventional integer order PID controller. An adaptive genetic algorithm is proposed to design the fractional PID controller. The five parameters of the fractional PID controller are selected as parameters to be determined. The dynamic model of an AMB system for axial motion is also presented. The simulation results of this AMB system show that a fractional PID controller designed via the proposed AGA has good performance.

62 citations

01 Apr 1991
TL;DR: First six-degree-of-freedom, cable-driven controller designed with six revolute joints; contains no prismatic joints, giving advantages of low friction, low inertia, and no backlash.
Abstract: Novel design keeps joints mechanically independent. Force-reflecting hand controller for remote manipulator offers two times work volume of any of its predecessors. Folded into volume half that of its immediate predecessor for storage. First six-degree-of-freedom, cable-driven controller designed with six revolute joints; contains no prismatic joints. Advantages of low friction, low inertia, and no backlash. Intended for use in telerobotic experiments during space flight, controller modified for such terrestrial applications as construction and handling of dangerous (e.g., hot, poisonous, radioactive, or infectious) materials.

62 citations

Journal ArticleDOI
TL;DR: In this paper, the equations of motion of a two-spacecraft formation flying array that uses electromagnets as relative position actuators were analyzed for stability and controllability.
Abstract: In this paper, we consider the equations of motion of a two-spacecraft formation flying array that uses electromagnets as relative position actuators. The relative positions of the spacecraft are controlled by the forces generated between the electromagnets on the two spacecraft, and the attitudes of the spacecraft are controlled using reaction wheels. The nonlinear equations of motion for this system are linearized about a nominal operating trajectory, taken to be a steady-state spin maneuver used for deep-space interferometric observation. The linearized equations are analyzed for stability and controllability. Although the open-loop system proves to be unstable, a controllability analysis indicates that the system is fully controllable with the given suite of actuators, and is therefore stabilizable. An optimal linear feedback controller is then designed, and the closed-loop dynamics are simulated. The simulations demonstrate that the closed-loop system is indeed stable, and that linear control is a very promising technique for electromagnetic formation flight systems, despite the nonlinearity of the dynamics.

62 citations

Journal ArticleDOI
TL;DR: In this article, an artificial intelligence Neuro-Fuzzy (NF) technique was used to design a robust controller to meet the control objectives of a vehicle suspension system, which reduced the discomfort sensed by passengers which arises from road roughness and increased the ride handling associated with the pitching and rolling movements.
Abstract: The main objective of designed the controller for a vehicle suspension system is to reduce the discomfort sensed by passengers which arises from road roughness and to increase the ride handling associated with the pitching and rolling movements. This necessitates a very fast and accurate controller to meet as much control objectives, as possible. Therefore, this paper deals with an artificial intelligence Neuro-Fuzzy (NF) technique to design a robust controller to meet the control objectives. The advantage of this controller is that it can handle the nonlinearities faster than other conventional controllers. The approach of the proposed controller is to minimize the vibrations on each corner of vehicle by supplying control forces to suspension system when travelling on rough road. The other purpose for using the NF controller for vehicle model is to reduce the body inclinations that are made during intensive manoeuvres including braking and cornering. A full vehicle nonlinear active suspension system is introduced and tested. The robustness of the proposed controller is being assessed by comparing with an optimal Fractional Order (FOPID) controller. The results show that the intelligent NF controller has improved the dynamic response measured by decreasing the cost function.

62 citations

Patent
06 Nov 1996
TL;DR: In this paper, a motor driver circuit of an electronic controller for linear cryogenic coolers operates directly from a variable power supply, such as a battery, without the need for the voltage regulator control circuit of the prior art.
Abstract: A highly efficient motor driver circuit of an electronic controller for linear cryogenic coolers operates directly from a variable power supply, such as a battery, without the need for the voltage regulator control circuit of the prior art. Elimination of the prior art voltage regulator ensures a higher efficiency motor driver circuit of the electronic controller. Both open-loop and closed-loop controllers electronically control the motor driver circuit. The open-loop controller protects against temperature sensor failure, and will limit maximum motor power as a function of system ambient temperature. The closed-loop controller regulates the temperature of the cold finger accurately to a preset value, using feedback from a temperature sensor along with a novel pulse-width modulation concept for modifying motor drive waveforms. The motor driver circuit provides the advantages of increased efficiency, operation from a variable power source, tight control of temperature regulation, a fail-safe mode of temperature sensor feedback, and a small envelope space enabling electronic controller mounting internal to the cooler motor/compressor assembly of a linear cryogenic cooler.

62 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202371
2022124
202167
202079
201998
2018155