Design of embedded controller using hybrid systems for integrated building systems

The design of controllers for integrated building systems has been traditionally carried out using basic techniques validated frequently by simulation. However, the demands on occupants’ comfort, safety and energy consumption increase speedily as the current controllers used in buildings are not efficient and enough flexible to be adapted to any changes. To investigate such issues, this paper focuses mainly on the design of embedded control systems for integrated building plants. So therefore, the challenges of modeling embedded controller for building heating system are treated at higher-level of abstraction with the help of sophisticated tools and new development techniques. Particularity, this paper concerns the relevance and reliability of integrating distributed control and building performance simulation environments by run-time coupling, over TCP/IP protocol suite. In addition, this paper involves a case-study with an important setup where the simulated results are obtained within the use of run-time coupling approach

Observations on the desiccation and cracking of clay layers

Waterways and lakes in low-lying delta areas require regular dredging for maintenance. Often these sediments are placed on land, where they are allowed to ripen through a combination of drainage, consolidation and evaporation. When cracks develop during desiccation, the physical response of the soil is affected by changes in the overall strength, stiffness and permeability of the material. To better identify how cracks form and propagate, a series of tests was carried out in a controlled laboratory environment on samples of drying clay slurries under different initial and boundary conditions. The outcomes of this study indicate that the results from laboratory small scale models must be carefully analyzed, as they depend on the area and the thickness of the sample. However, common features from the different tests can be identified, which are mostly related to the intrinsic behavior of the material. For instance, the water content at which cracks initiate depends mostly on the drying rate and not only on the initial water content. Typically for the clayey soil investigated, the cracking water content is well above the shrinkage limit and in some instances even above the liquid limit. Cracks can form anywhere a defect is encountered, but it was observed that they propagate in horizontal directions below the soil surface. On the soil surface they tend to intersect with each other perpendicularly, suggesting that they are dominated by a tensile stress regime. Shear stresses also influence the response, but mainly near the boundaries of the samples, due to the interface friction

Simulation based design environment for multi-agent systems in buildings

With increasing experience and understanding of the behavior of users in buildings, it is very often difficult to properly build a control system that operates in the real world. To explore such a potential, this paper addresses a new approach to building automation systems that utilizes hybrids systems in order to model large scale systems typically arising in multi-agents. In fact hybrid systems are crucial for solving complex problems and for designing real-time controllers that can be used to automatically regulate HVAC (Heating, Ventilation and Air-Conditioning) systems and building components. A statechart formalism is also used for modelling of the entire building system behaviour in the structural analysis paradigm, in order to achieve a comfortable indoor climate while fulfilling operating constraints. Particularity, this paper concerns the relevance and reliability of integrating control and building performance simulation environments by run-time coupling, over TCP/IP protocol suite. In addition, this paper involves a case-study with two important steps; first consists of experiments obtained in TU Delft test-cell, and then simulation results are obtained with the use of run-time coupling approach

Applying advanced control strategies in building performance simulation by using run-time coupling

The use of advanced control technologies and intelligence control in buildings could make the current high performance system much more efficient and reliable. The integration of advanced control strategies in buildings will certainly produce significant results for better building productivity. One way to achieve this aim could be done by developing run-time coupling approach. This paper describes the need for the study and development of better control modeling in building performance simulation by integrating distributed computer programs. To explore control application benefits, the paper also describes the simulation results that would eventually achieve lower energy consumption and higher productivity in buildings. A case-study is presented which illustrates a potential ability of advanced control strategies in buildings. Practically, it shows why and how a run-time coupling approach is more appropriate to achieve better control modeling in building performance simulation

Developing web-services for distributed control and building performance simulation using run-time coupling

This paper reports the final results of a research project, which aims to achieve better control modeling in building performance simulation by integrating distributed computer programs. The paper focus on developing Web-services based SOAP/XML to run-time couple control and building performance simulation. Data exchange via Webservices allows system components to be loosely-coupled, rather than combined into an integrated building control systems. The paper also details an example apllication using this technology to configure a distributed simulation through an open protocol, like BACnet or LonWorks and so on. Particularity, this paper concerns the relevance and reliability of integrating Web-services with run-time coupling of control and building performance simulation environments over TCP/IP protocol suite. In addition, this approach provides a reusable patterns either for other similar projects or for real automated building applications