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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 ArticleDOI
TL;DR: In this article, the authors presented the modelling and design steps of a discrete time recursive repetitive controller (RC) used in a grid-connected photovoltaic (PV) system.
Abstract: This study presents the modelling and design steps of a discrete time recursive repetitive controller (RC) to be used in a grid-connected photovoltaic (PV) system It is shown that the linear synchronous reference frame proportional-integral controller, originally designed to control the converter's output currents, may have its effectiveness compromised because of non-linearities in the system components A RC is introduced as an alternative to overcome this drawback and improve the system's output currents The performance of the designed hybrid controller is tested, under both steady-state and transient operations, for variations on the power generated by a 30 kWp PV power plant Experimental results obtained from the operation of the PV system connected to a distribution network, without output passive filters, only through a transformer that operates in a non-linear region are presented The results are used to evaluate the performance of the proposed compensation method and to validate the designed hybrid controller

55 citations

Patent
10 Nov 2005
TL;DR: A versatile controller as mentioned in this paper is a controller that can be used as either a stand-alone controller in a relatively small process plant or as one of numerous controllers in a distributed process control system depending on the needs of the process plant.
Abstract: A versatile controller that can be used as either a stand-alone controller in a relatively small process plant or as one of numerous controllers in a distributed process control system depending on the needs of the process plant includes a processor adapted to be programmed to execute one or more programming routines and a memory, such as a non-volatile memory, coupled to the processor and adapted to store the one or more programming routines to be executed on the processor. The versatile controller also includes a plurality of field device input/output ports communicatively connected to the processor, a configuration communication port connected to the processor and to the memory to enable the controller to be configured with the programming routines and a second communication port which enables a user interface to be intermittently connected to the controller to view information stored within the controller memory. When used in a distributed process control system, the controller platform may be used as a remote input/output device and the ports of this remote input/output device may be logically mapped to controllers within the distributed process control system in a manner that is different than the physical connection between such controllers and the remote input/output device.

55 citations

Journal ArticleDOI
TL;DR: In this paper, a modified adaptive controller is proposed for high performance tracking applications, such as robotics, actuation and manipulation, where the rotor position and/or the speed of the dc motor is forced to follow preselected tracks, even when the load condition varies.
Abstract: This paper presents a novel application of a modified adaptive controller to a dc motor for high performance tracking applications, such as robotics, actuation and manipulation. By the proposed technique, the rotor position and/or the speed of the dc motor is forced to follow preselected tracks, even when the load condition varies. An algorithm based on Minimum Variance Self Tuning control is developed for this purpose. The adaptive controller is effective even in the presence of external disturbances, provided that the system exhibits minimum phase characteristics. The effectiveness of the controller is demonstrated by using a general purpose nonlinear simulation software. The simplicity of the algorithm and the promising test results prove that this proposed controller is very effective in high performance tracking applications.

55 citations

Journal ArticleDOI
TL;DR: In this paper, a successful implementation of a fuzzy logic controller structure for switch-mode power-stage dc-dc converters was presented and evaluated experimentally for variable supply voltages and load resistance variations.
Abstract: This paper presents a successful implementation of a fuzzy logic controller structure for switch-mode power-stage dc-dc converters and evaluates experimentally its sensitivity for variable supply voltages and load resistance variations. The optimum topology of the controller structure is determined using experimental tests. An advanced test-bed system is used to evaluate the robustness capacities of the controller under varying loading conditions and input voltage variations. The experiment is performed using a low-cost microcontroller PIC16F877 to verify the design performance over a wide range of operating conditions. The controller shows very interesting tracking features and is able to cope with load changes and input voltage variations. The proposed controller structure is general and can be directly applied to any dc-dc converter topologies. The fuzzy controller structure is compared experimentally with the existing proportional-integral control used in industry. It yields a better dynamic performance without overshoot

55 citations

Patent
08 May 2000
TL;DR: In this paper, the authors present a controller that monitors activity of components within the controller which require access to a local memory, and then decreases a clocking frequency for a memory interface to the local memory when the monitoring indicates that reduced amounts of activity are present.
Abstract: A controller (or controller chip) providing reduced power consumption without impacting performance is disclosed. The controller monitors activity of components within the controller which require access to a local memory, and then decreases a clocking frequency for a memory interface to the local memory when the monitoring indicates that reduced amounts of activity are present. Following such a decrease in the clocking frequency, when increased amounts of activity are detected, the clocking frequency is increased for high performance operation. The controller thus tailors the clocking frequency for the memory interface in accordance with the amount of activity of these components that require access to the local memory so that overall less power is used by the controller yet the performance is essentially not hindered. In one embodiment, the controller is a graphics controller, as such controllers require access to local memories.

55 citations


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