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

Design and control of components-based integrated servo pneumatic drives

On-off traditional pneumatic drives are most widely used in industry offering low-cost, simple but flexible mechanical operation and relatively high power to weight ratio. For a period of decade from mid 1980's to 1990's, some initiatives were made to develop servo pneumatic drives for most sophisticated applications, employing purpose-designed control valves for pneumatic drives and low friction cylinders. However, it is found that the high cost and complex installation have discouraged the manufacturer from applying servo pneumatic drives to industrial usage, making them less favourable in comparison to their electric counterpart. This research aims to develop low-cost servo pneumatic drives which are capable of point-to-point positioning tasks, suitable for applications requiring intermediate performance characteristics. In achieving this objective, a strategy that involves the use of traditional on-off valve, simple control algorithm and distributed field-bus control networks has been adopted, namely, the design and control of Components-based Integrated Pneumatic Drives (CIPDs). Firstly, a new pneumatic actuator servo motion control strategy has been developed. With the new motion control strategy, the processes of positioning a payload can be achieved by opening the control valve only once. Hence, lowspeed on-off pneumatic control valves can be employed in keeping the cost low, a key attraction for employing pneumatic drives. The new servo motion control strategy also provides a way of controlling the load motion speed mechanically. Meanwhile, a new PD-based three-state closed-loop control algorithm also has been developed for the new control scheme. This control algorithm provides a way of adapting traditional PID (Proportional Integral Derivative) control theories for regulating pneumatic drives. Moreover, a deceleration control strategy has been developed so that both high-speed and accurate positioning control can be realised with low cost pneumatic drives. Secondly, the effects of system parameters on the transient response are studied. In assisting the analysis, a second order model is developed to encapsulate the velocity response characteristics of pneumatic drives to a step input signal. Stability analyses for both open loop and closed-loop control have also been carried out for the CIPDs with the newly developed motion control strategy. Thirdly, a distributed control strategy employing Lon Works has been devised and implemented, offering desirable attributes, high re-configurability, low cost and easy in installation and maintenance, etc to keep with the traditional strength for using pneumatic drives. By applying this technology, the CIPDs become standard components in "real" and "virtual" design environments. A remote service strategy for CIPDs using TCP/IP communication protocol has also been developed. Subsequently a range of experimental verifications has been carried out in the research. The experimental study of high-speed motion control indicates that the deceleration control strategy developed in the research can be an effective method in improving the behaviour of high speed CIPDs. The verification of open loop system behaviour of CIPDs shows that the model derived is largely indicative of the likely behaviour for the system considered, and the steady state velocity can be estimated using the Velocity Gain Kv. The evaluation made on a pneumatically driven pick-and-place machine has also confirmed that the system setup, including wiring, tuning, and system reconfiguration can be achieved in relative ease. This pilot study reveals the potential for employing CIPDs in building highly flexible cost effective manufacturing machines. It can thus be concluded that this research has developed successfully a new dimension and knowledge in both theoretical and practical terms in building low-cost servo pneumatic drives, which are capable of point-to-point positioning through employing traditional on-off pneumatic valves and actuators and through their integration with distributed control technology (LonWorks) by adopting a component-based design paradigm

A critical review of cyber-physical security for building automation systems

Modern Building Automation Systems (BASs), as the brain that enables the smartness of a smart building, often require increased connectivity both among system components as well as with outside entities, such as optimized automation via outsourced cloud analytics and increased building-grid integrations. However, increased connectivity and accessibility come with increased cyber security threats. BASs were historically developed as closed environments with limited cyber-security considerations. As a result, BASs in many buildings are vulnerable to cyber-attacks that may cause adverse consequences, such as occupant discomfort, excessive energy usage, and unexpected equipment downtime. Therefore, there is a strong need to advance the state-of-the-art in cyber-physical security for BASs and provide practical solutions for attack mitigation in buildings. However, an inclusive and systematic review of BAS vulnerabilities, potential cyber-attacks with impact assessment, detection & defense approaches, and cyber-secure resilient control strategies is currently lacking in the literature. This review paper fills the gap by providing a comprehensive up-to-date review of cyber-physical security for BASs at three levels in commercial buildings: management level, automation level, and field level. The general BASs vulnerabilities and protocol-specific vulnerabilities for the four dominant BAS protocols are reviewed, followed by a discussion on four attack targets and seven potential attack scenarios. The impact of cyber-attacks on BASs is summarized as signal corruption, signal delaying, and signal blocking. The typical cyber-attack detection and defense approaches are identified at the three levels. Cyber-secure resilient control strategies for BASs under attack are categorized into passive and active resilient control schemes. Open challenges and future opportunities are finally discussed.Comment: 38 pages, 7 figures, 6 tables, submitted to Annual Reviews in Contro

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

NETWORK TRAFFIC CHARACTERIZATION AND INTRUSION DETECTION IN BUILDING AUTOMATION SYSTEMS

The goal of this research was threefold: (1) to learn the operational trends and behaviors of a realworld building automation system (BAS) network for creating building device models to detect anomalous behaviors and attacks, (2) to design a framework for evaluating BA device security from both the device and network perspectives, and (3) to leverage new sources of building automation device documentation for developing robust network security rules for BAS intrusion detection systems (IDSs). These goals were achieved in three phases, first through the detailed longitudinal study and characterization of a real university campus building automation network (BAN) and with the application of machine learning techniques on field level traffic for anomaly detection. Next, through the systematization of literature in the BAS security domain to analyze cross protocol device vulnerabilities, attacks, and defenses for uncovering research gaps as the foundational basis of our proposed BA device security evaluation framework. Then, to evaluate our proposed framework the largest multiprotocol BAS testbed discussed in the literature was built and several side-channel vulnerabilities and software/firmware shortcomings were exposed. Finally, through the development of a semi-automated specification gathering, device documentation extracting, IDS rule generating framework that leveraged PICS files and BIM models.Ph.D

A plug and play framework for an HVAC air handling unit and temperature sensor auto recognition technique

A plug and play framework for an HVAC air handling unit control system is proposed in this study. This is the foundation and the first step towards the plug and play HVAC control system that will eventually lead to self-configuring of HVAC control systems for automatic building controls system set-up, commissioning, more robust HVAC system operations, and automatic detection and repair of potential controls problems. This framework is built on the commercially available smart transducers that are compatible with the IEEE 1451 family of standards, and a data acquisition system that can read and write the smart transducer information. As a proof of concept for the framework, a structural pattern recognition algorithm is developed to automatically recognize temperature sensors in an Air Handling Unit (AHU) at different locations. The algorithm can be a critical part of the self-configuring HVAC control system in establishing a binding list of control system input/output and automated assignment and verification of the binding list. A prototype of the plug and play framework for an AHU was built. Experiments were designed, setup, and tested to automatically recognize eleven different temperature sensors at various AHU locations on two different AHUs. More than one hundred test cases were implemented at various initial conditions, environmental temperatures, and chilled water system configurations, to demonstrate the robustness of the pattern recognition algorithm