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.

Control software updating technique for a network apparatus

Abstract: A network apparatus has first and second controllers that are coupled via communication channel, and is coupled to a network by the first controller. In order to update the firmware of this first controller, the first controller obtains update data for updating via the network and transfers the obtained data to the second controller. The second controller stores the update data transferred from the first controller in a storage device incorporated in the second controller. After the entirety of the update data has been stored in the storage device by the second controller, the second controller transfers the update data to the first controller. The first controller updates the firmware for the first controller using the update data transferred from the second controller.

Real-Time Implementation and Hardware Testing of a Hybrid Vehicle Energy Management Controller Based on Stochastic Dynamic Programming

Abstract: An energy management controller based on shortest path stochastic dynamic programming (SP-SDP) is implemented and tested in a prototype vehicle. The controller simultaneously optimizes fuel economy and powertrain activity, namely gear shifts and engine on–off events. Previous work reported on the controller's design and its extensive simulation-based evaluation. This paper focuses on implementation of the controller algorithm in hardware. Practical issues concerning real-time computability, driver perception, and command timing are highlighted and addressed. The SP-SDP controllers are shown to run in real-time, gracefully handle variations in engine start and gear-shift-completion times, and operate in a manner that is transparent to the driver. A hardware problem with the test vehicle restricted its maximum engine torque, which prevented a reliable fuel economy assessment of the SP-SDP controller. The data that were collected indicated that SP-SDP controllers could be straightforwardly designed to operate at different points of the fuel economy tradeoff curve and that their fuel economy may equal or exceed that of a baseline industrial controller designed for the vehicle.

A rule-based adaptive PID controller

Abstract: The authors describe a functioning expert controller implemented with industrial programmable logic controller technology. In its present state the controller implements an adaptive PID (proportional, integral, and derivative) algorithm based on rule-based logical modules. The controller does not presume a model for the system. It detects several features of the current system response to a step input change and uses a pattern matching procedure to adjust the PID parameters to reshape the system output response. >

Microcomputer implementation of optimal algorithms for closed-loop control of hybrid stepper motor drives

Abstract: This paper discusses optimal algorithms for closed-loop control of hybrid stepper motor drives and their microprocessor implementation. The torque characteristics and the optimal control angle of hybrid stepper motor drives with added series resistance and reluctant stepper motor drives have been described in detail in the literature. The specific contribution of the paper to this field of research consists of the analysis of the torque characteristics and the optimal control angle of hybrid stepper motor drives with a chopper amplifier and current controller. Analytical expressions for the average torque and the optimal control angle of a two-phase hybrid stepper motor with chopper amplifier and current controller have been developed. An actual hybrid stepper motor drive and the microcontroller-based implementation of the suboptimal and exact optimal control algorithms have been described. The experimental results obtained by positioning a two-phase hybrid stepper motor drive with chopper amplifier, phase current controller, and incremental encoder suggested that the derived optimal control algorithm provided maximum acceleration and minimum positioning time of the hybrid stepper motor drive.

Linear parameter-varying modelling and control of an offshore wind turbine with constrained information

Abstract: This study deals with linear parameter-varying modelling and output-feedback H ∞ control design for an offshore wind turbine. The controller is designed with consideration that not all the information in the feedback loop will be used. This constraint is incorporated into the design procedure. Constrained information means that a special zero-non-zero pattern is forced upon the gain matrix. The constrained controller is obtained based on parameter-dependent Lyapunov functions and formulated in terms of linear-matrix inequalities. Since the functions are dependent on the wind speed and accurate wind speed measurements are rarely available in practice, an extended Kalman filter is used to estimate the wind speed. The controller is designed in such a way that it should maintain its stability and performance even if one of the sensors in the feedback loop should malfunction. The control objectives are to mitigate oscillations in the structure and drivetrain, to smoothen power/torque output in addition to keep the closed-loop system stable. This should be achieved by means of individual blade pitch. A traditional procedure for designing a controller for such a system is to choose an operating point and assume it works in a suitable way under the influence of turbulent wind. In this study, the wind turbine model is obtained from the software fatigue, aerodynamic, structural and turbulence (FAST). To design the controller, the model is linearised about several operating points. The degrees of freedom in the linearised model are chosen according to the controller objectives. The linear models are valid within the span of operating points. Finally, the controller is tested on the fully non-linear system under the influence of turbulent wind and a scenario where one of the sensors in the feedback loop is malfunctioning. The closed-loop response of the presented controller is compared to the closed-loop response of the baseline controller included in the FAST package along with a controller designed based on a single linearised model.