There has been an increasing use of modern digital signal processors (DSPs) in industrial control and other applications in the past few years. While courses offered in electrical and computer ...engineering disciplines cover such topics as mobile and digital communication, image and sound encoding and decoding, few courses focus on the use of DSPs in real-time control of electrical machinery and drives. Therefore, there is a growing need in industry for engineers who can perform control design and system integration for various applications in motor control. This paper describes a course on Control of Electrical Machines offered by the School of Industrial Engineering of Barcelona (ETSEIB), Polytechnic University of Catalonia (UPC), Barcelona, Spain. A description of a hands-on laboratory testbed for motor control.
An outline of the course structure, the laboratory setup and the design aspects for implementing modern real-time motor control applications are presented.
Increasing internet connectivity poses an existential threat for cyber-physical systems. Securing these safety-critical systems becomes an important challenge. Cyber-physical systems often comprise ...several control applications that are implemented on shared platforms where both high and low criticality tasks execute together (to reduce cost). Such resource sharing may lead to complex timing behaviors and, in turn, counter-intuitive timing anomalies that can be exploited by adversaries to destabilize a critical control system, resulting in irreversible consequences. We introduce the butterfly attack, a new attack scenario against cyber-physical systems that carefully exploits the sensitivity of control applications with respect to the implementation on the underlying execution platforms. We illustrate the possibility of such attacks using two case-studies from the automotive and avionic domains.
Automatic control applications are real-time systems which pose stringent requirements on precisely time-triggered synchronized actions and constant end-to-end delays in feedback loops which often ...constitute multi-rate systems. Motivated by the apparent gap between computer science and automatic control theory, a set of requirements for real-time implementation of control applications is given. A real-time behavioral model for control applications is then presented and exemplified. Important sources and characteristics of time-variations in distributed computer systems are investigated. This illuminates key execution strategies to ensure the required timing behavior. Implications on design and implementation and directions for further work are discussed.
This paper describes the design of informative system identification experiments for behavioral interventions based on Social Cognitive Theory (SCT); prior work has shown that these can be expressed ...as MIMO dynamical systems. The design methodology relies on identification test monitoring to determine the shortest experimental duration resulting in a model estimate with a prescribed level of accuracy. This is accomplished by generating statistical uncertainty regions that are the result of nonparametric transfer function estimates using periodic (and orthogonal in frequency) multisinusoidal inputs. The procedure is illustrated with an example of a simulated behavioral intervention for promoting physical activity.
This paper presents an agrochemical application system that could be incorporated into existing irrigating center-pivots. The system consisted of a hydraulic circuit with emitters, where the dose was ...individually controlled with variable valve timing. This paper describes the electronic control system, designed to be modular and distributed along the pivot. The main problem solved was the determination of the emitter's absolute displacement to generate their adequate timing control. The paper ends with the test of a low-cost implementation of the complete system under real center-pivot operation.
Fogification of industrial robotic systems Salman, Shaik Mohammed; Struhar, Vaclav; Papadopoulos, Alessandro V. ...
IoT-Fog 2019 - Proceedings of the 2019 Workshop on Fog Computing and the IoT,
04/2019
Conference Proceeding
To meet the demands of future automation systems, the architecture of traditional control systems such as the industrial robotic systems needs to evolve and new architectural paradigms need to be ...investigated. While cloud-based platforms provide services such as computational resources on demand, they do not address the requirements of real-time performance expected by control applications. Fog computing is a promising new architectural paradigm that complements the cloud-based platform by addressing its limitations. In this paper, we analyse the existing robot system architecture and propose a fog-based solution for industrial robotic systems that addresses the needs of future automation systems. We also propose the use of Time-Sensitive Networking (TSN) services for real-time communication and OPC-UA for information modelling within this architecture. Additionally, we discuss the main research challenges associated with the proposed architecture.
The paper presents application of Distributed Model Predictive Control (DMPC) schemes to complex system of Barcelona water distribution network. The dual decomposition of convex optimization problems ...is well known and has been already adopted to DMPC. However, the application of dual based DMPC to truly large scale systems requires efficient algorithms for consensus iterations. The paper treats DMPC with and without centralized coordinator. The non-centralized coordination is based on Nesterov accelerated gradient method and centralized coordination is based on limited memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) method.
This paper presents a very large-scale integration implementation of Galois field arithmetic for high-speed error-control coding applications that is based on the field GF(p/sup m/) with m a small ...integer such as 2 or 3 and p a prime of sufficient value to generate the required field size. In this case, the Galois field arithmetic operations of addition, multiplication, and inversion are based on architectures using blocks that perform integer arithmetic modulo p. These integer arithmetic operations modulo p have previously been implemented with low delay power products through the use of one hot coding and barrel shifters circuits based on transistor arrays. In this paper, the same one hot coding and barrel shifters circuits are used to construct circuits that implement addition, multiplication, and inversion over GF(p/sup m/). The circuits for GF(p/sup m/) addition and multiplication with p/spl ne/2, achieve a lower power-delay product than designs based on GF(2/sup m/). Also, the architecture for GF(p/sup m/) inversion can be efficiently implemented when m=2 or m=3.
Stable and Robust Controller for Induction Motor Drive Fedor, Pavol; Perdukova, Daniela; Kyslan, Karol ...
2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC),
2018-Aug.
Conference Proceeding
The paper deals with the design of a linear stable reference model control structure for continuous nonlinear systems, the stability conditions of which were determined in accordance with the ...Lyapunov theory. This structure is applied in the control of angular speed of an induction motor drive, which, in terms of control, represents a highly nonlinear higher order system. Properties of the proposed control structure were verified by simulation under various AC drive conditions. Comparison of simulation results with those of standard field oriented induction motor control has shown that the proposed control structure is simpler and it can provide comparable dynamic response while ensuring stability, invariance and robustness. The obtained results predict wide applicability of the proposed control structure in technical practice.
Axially moving strips are frequently encountered in industry for various applications. On the one hand, accurate models of transverse displacements of strips are desired for plant design and safety ...or reliability reasons. On the other hand, the models may serve as a basis for model-based controller and observer design. For the latter also, the complexity of the models should be as low as possible. This work focuses on the development of dynamical models of the motion and elastic deformation of axially moving steel strips guided by rolls. For spatial discretization of both in-plane and out-of-plane motion, the Galerkin weighted residual method is employed and the longitudinal direction of the strip is divided into finite elements. A tailored time integration method is implemented and dynamic simulations for different boundary conditions of a strip in a hot dip galvanizing line are carried out and analyzed. The influence of the geometrical nonlinearity on the transversal displacements of the strip is investigated by means of a faulty air cooler. Finally, the affect of the geometrical nonlinearity on the dynamic and static behavior of the steel strip is investigated in more detail.
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