Advanced Control for Applications
ISSN / EISSN : 2578-0727 / 2578-0727
Published by: Wiley-Blackwell (10.1002)
Total articles ≅ 52
Latest articles in this journal
Advanced Control for Applications; https://doi.org/10.1002/adc2.92
A major challenge to develop optimal strategies for allocation of flexible demand towards the smart grid paradigm is the uncertainty associated with the real-time price and electricity demand. This paper presents a regret-based model and a novel iterative algorithm which solves the minimax regret optimization problem. This algorithms exhibits low computational burden compared with traditional linear programming methods and affords iterative convergence through updates of feasible power schedules, thus enabling a scalable parallel implementation for large device populations. Specifically, our approach seeks to minimize the induced worst-case regret over all price scenarios and solves the optimal charging strategy for the electrical devices. The convergence of the method and optimality of the computed solution is justified and some numerical simulations are discussed for the case of a single device operating under different types of price realizations and uncertainty bounds.
Advanced Control for Applications; https://doi.org/10.1002/adc2.90
Research is increasingly shifting from the design and control of single robots towards collaborative methods for multi-robot systems. Particularly interesting are heterogeneous systems since the combination of different capabilities can tackle tasks that are difficult, if not impossible, to perform with a single robot. In this paper we propose a scheme for the control of a novel heterogeneous multi-robot system designed for bricklaying where the use of a single robot is not feasible due to the weight of the payloads to be managed. The proposed solution is based on a crane which cooperates with a lightweight rigid robot. The correct cooperation between the two robotic sub-units poses a series of control challenges that must be studied in the context of cooperative manipulation of an object. In this paper, we first derive the mathematical model of this novel robotic system during the positioning of the block. Then a control law is proposed. The proposed law is based on an ad hoc inverse dynamic control which takes advantage of the over-actuation of the resulting connected system to unload the robotic arm from the weight of the block. A physical CAD-based simulator of the system is used to show the effectiveness of the proposed control law and to show that the proposed architecture allows to position precisely large and heavy blocks while using a relatively small rigid robotic manipulator.
Advanced Control for Applications; https://doi.org/10.1002/adc2.88
Astronomers have to point their telescopes with extreme high precision to their targets on the sky. The early craftsmen, which built their telescope mounts, were masters in mechanics and developed sophisticated axis mechanisms based on clockwork motors for the hour angle. The situation changed with the growth of the size of the optical telescopes, the upcoming of large radio telescopes, the related transition to elevation over azimuth mounts and the introduction of electrical main axes drives. The new telescopes were equipped with gears of high transmission ratios, and the dynamics of the motor control was limited by mechanical resonances between the rotors of the motors and the mass of the telescope structure. Early layout tools for the controllers were lumped mass models for the telescope structure including gear stiffnesses and inertias of rotors and brakes, with the free rotor and locked rotor frequencies as critical characteristics influencing the servo loop performance. Nowadays, static and dynamic analysis is performed with the help of finite element models, and the axes controllers are optimized with end-to-end models. The emergence of large radio telescopes initiated the development of additional compensation methods for environmental influences as temperature and wind on the shape of the reflectors and their pointing to the sky. Additional active elements on the telescope as surface actuators and subreflector positioners, and additional state sensors on the structure allow the identification and compensation of structural deformations. The method is called Flexible Body Control FBC. The increasing size of the optical telescopes initiated the development of new mirror technologies as thin meniscus or segmented mirrors in sizes not feasible with the passive supported thick meniscus mirrors. These mirrors need active elements as shape actuators, segment positioners, and wavefront and edge sensors. The method is called Active Optics AcO. Astronomical observations in the visible are disturbed by atmospheric blur, and the operability is depending of the active compensation of that blur, based on a fast wavefront sensor analyzing an artificial star and an additional fast wavefront corrector. The method is called Adaptive Optics AdO. The following text gives an overview on the historic development of telescope control systems from the viewpoint of the telescope mount and its axes control systems, finally culminating in FBC applications. Actual examples are the large millimeter telescope LMT/GTM in Mexico, the advanced technology solar telescope DKIST in Hawaii, and the airborne telescope of SOFIA, the Stratospheric Observatory for Infrared Astronomy with its base in Palmdale, California. Details of these applications will be described in a second paper.
Advanced Control for Applications; https://doi.org/10.1002/adc2.86
Advanced Control for Applications; https://doi.org/10.1002/adc2.84
Event-triggered controllers are designed for cyber-physical systems (CPSs) with multiple transmission channels in this paper, including two cases: with and without denial-of-service (DoS) attacks. Through the design of switching controller and the use of linear matrix inequality-based (LMI-based) method, the global exponential stability (GES) of the CPSs with multiple transmission channels in both cases are proved, and the relationship of parameters of DoS frequency and duration with the sampling period is established. An example of UGV (Unmanned Ground Vehicle) under DoS attacks is given to show the effectiveness of the proposed control method.
Published: 27 June 2021
Advanced Control for Applications: Engineering and Industrial Systems; https://doi.org/10.1002/adc2.85
The control scheme for an electric motor drive is generally implemented by involving proportional-integral (PI) controllers in current and speed feedback control loops. A good design of PI controller parameters has always been a challenging task for control system design engineers. This paper describes the D-decomposition method for the design of the parameters of involved DC-link current and speed PI controllers in closed-loop scheme of a pulse width-modulated, current source inverter (CSI)-fed squirrel-cage induction motor drive. The PI controllers ensure the stable operation of CSI-fed induction motor in natural unstable operating region of its torque-slip characteristic. In order to achieve smoother speed tracking performance with minimum overshoot/undershoot, the damping ratio has been pre-specified while designing the PI controller parameters using the D-decomposition method. Simulation results have been presented to confirm the design and have been compared with the results already published.
Published: 18 June 2021
Advanced Control for Applications: Engineering and Industrial Systems; https://doi.org/10.1002/adc2.83
This paper illustrates the control design process, from the requirements determination phase to the vehicle validation phase, as applied to GM’s first two-mode hybrid electric powertrains. Customer requirements are first translated into metrics that must be met with the closed loop control design. Physics based modeling tools developed in-house are utilized to simplify the development of control design and simulation models for the multi-input multi-output hybrid driveline system. Frequency sweep methods and tools are then employed to validate the models and later to verify the control implementation with vehicle tests. Modern control tools are used to develop a multi-input multi-output feedback control design. Finally, vehicle test results show how this design approach is successful in dramatically changing the open loop behavior of the dynamic driveline response, turning an unsalable product into a world class leader in drive quality.
Advanced Control for Applications, Volume 3; https://doi.org/10.1002/adc2.91
Advanced Control for Applications, Volume 3; https://doi.org/10.1002/adc2.89
Extended state observer (ESO) is featured with online estimating both the system's states and the total effect of external disturbance as well as nonlinear uncertain dynamics. The original ESO design, proposed for the cascade-of-integrator system without measurement noise, has been well studied with theoretical foundation and many successful applications. In the last years, multifarious modified ESOs have also been developed to handle many engineering systems captured by the models with general nonlinear structure, time-delay, the noises with stochastic properties, and etc. This paper aims to comprehensively investigate the representative modified ESOs in recent years. Firstly, the ESO's design and tuning law are illustrated for general uncertain systems with multiple control inputs, multiple measured outputs and various uncertainties. The quantitative results regarding the estimation errors of ESO are also presented. Next, the extended state based Kalman typed filters to handle state estimation problem against both stochastic noises and uncertain dynamics are introduced. The consistency, stability and asymptotical optimization of the proposed filters are rigorously shown. Furthermore, some novel designs of ESO to deal with the estimation problem of uncertain nonlinear systems with time-delay and measurement biases are discussed. We believe this overview will be helpful for practioners in applications of recent modified ESOs.