Research Article An Occupancy Based Cyber-Physical System Design for Intelligent Building Automation Kottarathil Eashy Mary Reena, 1 Abraham Theckethil Mathew, 1 and Lillykutty Jacob 2 1 Department of EE, National Institute of Technology, Calicut, India 2 Department of ECE, National Institute of Technology, Calicut, India Correspondence should be addressed to Kottarathil Eashy Mary Reena; maryreenake@gmail.com Received 3 April 2015; Revised 31 July 2015; Accepted 9 August 2015 Academic Editor: Yong Lei Copyright © 2015 Kottarathil Eashy Mary Reena et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Cyber-physical system (CPS) includes the class of Intelligent Building Automation System (IBAS) which increasingly utilizes advanced technologies for long term stability, economy, longevity, and user comfort. However, there are diverse issues associated with wireless interconnection of the sensors, controllers, and power consuming physical end devices. In this paper, a novel architecture of CPS for wireless networked IBAS with priority-based access mechanism is proposed for zones in a large building with dynamically varying occupancy. Priority status of zones based on occupancy is determined using fuzzy inference engine. Nondominated Sorting Genetic Algorithm-II (NSGA-II) is used to solve the optimization problem involving conficting demands of minimizing total energy consumption and maximizing occupant comfort levels in building. An algorithm is proposed for power scheduling in sensor nodes to reduce their energy consumption. Wi-Fi with Elimination-Yield Nonpreemptive Multiple Access (EY-NPMA) scheme is used for assigning priority among nodes for wireless channel access. Controller design techniques are also proposed for ensuring the stability of the closed loop control of IBAS in the presence of packet dropouts due to unreliable network links. 1. Introduction Cyber-physical systems (CPSs) are the system level integra- tions of the computation, networking, and physical dynamics, in which embedded devices such as sensors and actuators are (wirelessly) networked to sense, monitor, and con- trol the physical world [1]. CPSs are expected to have a tremendous impact on many critical sectors (such as energy, manufacturing, healthcare, transportation, and aerospace) of the economy and they transform the way human-to- human, human-to-object, and object-to-object interactions take place in the physical and virtual worlds [2]. Complex cyber-physical systems are compositions of heterogeneous components; they ofen include thermal, electromechanical, chemical, computing, and communication elements with an underlying data network thread for communication and control. Te dynamics of all the networked elements, both cyber and physical, are critical to the performance of the overall system [3]. In energy conservation application of CPS in large scale and comfort critical systems, like Intelligent Building Automation System (IBAS), various physical sys- tems comprise HVAC (heating, ventilation, and air condi- tioning), lighting, elevators, and other electrical subsystems on each foor, which are networked and controlled to achieve the set goal of energy efciency, user comfort, and economic operation [4]. Further, the skyrocketing energy costs and the widely accepted concept of green buildings are driving the adop- tion of Networked Control Systems (NCSs) for building automation so as to use the best technology for the pur- poses mentioned above [5, 6]. NCSs combine low cost and low power devices with embedded processors networked in order to provide intelligent and efcient sensing and actuation over a geographic area [7]. Energy efciency and occupant comfort are two major issues in building control system design as discussed above, and research eforts are needed to develop appropriate communication and control strategies for minimizing the total energy consumed without Hindawi Publishing Corporation Mathematical Problems in Engineering Volume 2015, Article ID 132182, 15 pages http://dx.doi.org/10.1155/2015/132182