Saving energy without causing discomfort and without demanding human intervention is the need of the day. It is important to develop sensor systems which not only satisfy user requirements, but also take energy consumption into consideration. In this demo, we present the sensing subsystems of a Smart Academic Environment, based upon the core concept of 'Observability' [1] which -- while satisfying user needs -- helps to reduce the number of sensors required.

A substantial fraction of the energy demand of buildings comes from air-conditioners (ACs), refrigerators, etc., which do not need human interaction for their continuous operations. So long as desirable temperature levels, which we refer to as thermal comfort-bands, are maintained by such background loads, users will not be concerned about when they perform their assigned functions. i.e., when they consume the energy required to function. This paper addresses the problem of maintaining thermal comfort-bands associated with background loads under Peak energy consumption constraint. Based on our empirical observations pertaining to energy consumption profiles of thermal comfort-band maintaining ACs, a) we present a feasibility criterion for maintaining the thermal comfort-band of a given set of background loads under constraints on the peak available power and (b) we propose TCBM, a new algorithm for scheduling such background loads under peak power constraint. In addition to limiting peak power demand, the TCBM algorithm avoids undesirable switching (ON and OFF) of electrical appliances to improve efficiency of the equipment and reduce failures. Results from simulation and real-life implementation demonstrate that our algorithm is superior to the existing work on background load scheduling. We also show how TCBM can adapt to changes in ambient parameters and provide the basis for efficient demand-response systems.

Programmable Controllers (PLC) are being increasingly used in control systems for Nuclear Power Plants. A PLC, qualified for safety applications, is attractive because it saves a lot of time in verification and validation effort as compared to development of embedded control systems. We developed a tool, ST to MISRA-C translator, required for developing application program using Structured Text (ST) in a qualified PLC. The syntax and semantics of ST programming language is defined in the IEC 61131-3 standard. During the development of the translator, we found some issues with ST language syntax and semantics not pointed out by other researchers. These issues are discussed in this paper along with proposed changes in the ST language grammar for its unambiguous parsing.

Use of Programmable Controllers (PLC) in safety-critical applications is gaining importance as a pre-qualified development platform to reduce Verification and Validation (V &V) effort. It has been observed, in practice, that most of the safety-critical functions are fairly simple and is achieved by only a small fraction of a large safety-critical software. This motivates the development of a partitioned operating environment for PLC, so that less critical components of the large safety-critical software can be partitioned from those, which are actually performing safety-critical functions. It will facilitate less rigorous V &V for less critical modules to get necessary approval for safety-critical system from regulatory authorities. This work addresses some issues in a Partitioned-PLC development towards improved schedulability bound, yet offering simplicity in implementation.