Smart building's benefits range from improving comfort of occupant, increased productivity, reduction in energy consumption and operating costs, lower CO2 emission, to improved life cycle of utilities, efficient operation of building systems, etc. [65]. Hence, modern building owners are turning towards smart buildings. However, the current smart buildings mostly are not capable of achieving the objectives they are designed for and they can improve a lot better [22]. Therefore, a new technology called, Internet of Things, or IoT, is combined with the smart buildings to improve their performance [23]. IoT is the inter-networking of things embedded with electronics, software, sensors, actuators, and network connectivity to collect and exchange data, and things in this definition is anything and everything around us and even ourselves. Using this technology, e.g. a door can be a thing and can sense how many people have passed it's sensor to enter a space and let the lighting system know to prepare appropriate amount of light, or the HVAC (Heating Ventilation Air Conditioning) system to provide desirable temperature. IoT will provide a lot of useful information that before that accessibility to it was impossible, e.g., condition of water pipes in winter, which helps avoiding damages like frozen or broken pipes. However, despite all the benefits, IoT suffers from being vulnerable to cyber attacks. Examples have been provided later in Chapter 1.
In this project among building systems, HVAC system is chosen to be automated with a new control method called MPC (Model Predictive Control). This method is fast, very energy efficient and has a lower than 0.001 rate of error for regulating the space temperature to any temperature that the occupants desire according to the results of this project. Furthermore, a PID (Proportional–Integral–Derivative) controller has been designed for the HVAC system that in the exact same cases MPC shows a much better performance. To design controllers for HVAC system and set the temperature to the desired value a method to automate balancing the heat flow should be found, therefore a thermal model of building should be available that using this model, the amount of heat, flowing in and out of a space in the building disregarding the external weather would be known to estimate. To automate the HVAC system using the programming languages like MATLAB, there is a need to convert the thermal model of the building to a mathematical model. This mathematical model is unique for each building depending on how many floors it has, how wide it is, and what materials have been used to construct the building. This process is needs a lot of effort and time even for buildings with 2 floors and 2 rooms on each floor and at the end the engineer might have done it with error. In this project you will see a software that will do the conversion of thermal model of buildings in any size to their mathematical model automatically, which helps improving the HVAC controllers to set temperature to the value occupants desire and avoid errors and time loss which is put both into calculations and troubleshooting.
In addition, a test environment has been designed and constructed as a cyber physical system that allows us to test the IoT- enabled control systems before implementing them on real buildings, observe the performance, and decide if the system is satisfying or not. Also, all cyber threats can be explored and the solutions to those attacks can be evaluated. Even for the systems that are already out there, there is an opportunity to be assessed on this testbed and if there is any vulnerability in case of cyber security, solutions would be evaluated and help the existing systems improve. / Master of Science / Buildings function as shelters more than any thing else, and this has allowed humans to use it as a space to store important things like private and important information. Therefore, this space should be safe and secure from any vulnerabilities for occupants and their information. Smart buildings, have made a great difference in increasing the comfort level of occupants, but they haven’t been greatly successful achieving their objectives [50]. Therefore, a new technology called, Internet of Things, or IoT, is combined with the smart buildings to improve their performance [23]. IoT is the inter-networking of things embedded with electronics, software, sensors, actuators, and network connectivity to collect and exchange data, and things in this definition is anything and everything around us and even ourselves. Internet of Things (IoT) has helped improving the smart buildings and getting a considerable amount of energy efficiency [27]. But adding Internet of Things has added a network of things connected to internet, which gives the cyber hackers an opportunity to hack the buildings, and get access to the information stored inside the building or put even occupants lives in danger. Therefore, in this thesis the following items have been contributed:
• Designing and programming a novel control system for HVAC system of the buildings (Model Predictive Control): This is a new method to control HVAC system of buildings and in comparison with the methods available in the market, it is the most energy efficient, it is faster, and it has a lower error rate in following the desired temperature of the occupants.
• Design and construction of IoT- enabled smart building testbed: Since cyber attacks make buildings vulnerable, the author believes it is better to build a test environment to simulate the buildings and the control methods that are used inside the buildings, and try to evaluate performance of the control methods before implementing them on real buildings. Also, by installing IoT sensors inside the test environment, the engineers can perform some cyber attack tests, and also evaluate the solutions for each attack on the testbed.
• Design and program a software to convert thermal model of buildings to mathematical model : In designing a new control method for HVAC system of buildings, the first required information is the thermal model of the buildings. Eventually, there is a need to program. Thus, the thermal model should be converted to a mathematical model. However, there is a heavy manual calculation behind it that is really overwhelming, tiring, with a high possibility of error, and time-consuming even for a very small sized building. Therefore, automating this process in terms of a software that takes the information of thermal model of buildings as an input and giving the output of the mathematical model of building is a considerable achievement.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/85579 |
| Date | 29 October 2018 |
| Creators | Amanzadeh, Leila |
| Contributors | Electrical Engineering, Gerdes, Ryan M., Yu, Guoqiang, Chantem, Thidapat |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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