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1. Introduction
A home appliance control system (HACS) is a system which provides various services to remotely operate on home appliances, such as microwave oven, TV, and garage door etc through remote devices such as mobile phone, desktop and palm-top. This document furnishes the Use Case diagrams, Class diagrams, and Sequence diagrams for the Home Appliance Control System using UML.
2. Project Overview
The Home appliance control system is controlled either by a cell phone or a by palm top or by a PC. They are connected either through wireless application protocol (WAP), the Internet, or intranet. It controls various appliances such as a microwave, TV etc. The HACS system receives commands from remote devices that are manipulated by user. The system in turn dispatch commands to respective appliances that will perform the actions. HACS is responsible for keeping track of the states of the devices. If something goes wrong, it will notify the user by sending messages back to the remote devices as well as emergency department if necessary.
The following picture gives an overview of how this system is going to work.
The system administrator of the HACS system has the ability to add a new appliance or delete an existing one. The system administrator has the ability to add a new remote device and configure it with HACS or delete an existing one when it is not used. Also the system administrator can create an account for a new user or delete existing account if it is no longer used.
3. Functional Requirement
A home appliance control system (HACS) is a system which is controlled by a remote system such as a mobile phone or a palm-top, and at the same time controls, monitors and coordinates home appliances such as air conditioner, microwave oven, garage doors, TV set, VCR, audio controller, indoor/outdoor lights, water sprinkler, home security system, bath tub controller, etc.
In order to activate home appliances and to allow for different ways of cooking, the HACS needs mechanisms for communication between the different devices in the system, and for coordination among the various processes running on such devices.
Note that the HACS needs mechanisms for adapting to different needs of the user as well. For example, when the user is very hungry, the microwave oven may need to respond to the user’s request that it operate maximally to cook the food as fast as it can. For another example, if the user is hungry, tired and may come home late, then the system may be asked to fully cook the meal by the expected arrival time, and periodic warming up every 10 minutes afterwards.
4. Non-Functional Requirement
4.1 Adaptability
The HACS shall be adaptable. Any change is environment shall be detectable, and the HACS shall then be transformable through recognition of the change in HACS needed and the change recognized shall be enacted in the system. The system could be automatically adaptable or manually adaptable. Since speed is of paramount importance for any real-time system, it shall be given a priority comparable to that of the adaptability requirement. This presumably according to the customer needs. Detecting changes in the environment is usually a very time-consuming task, hence hurting speed. Similarly, detection of events could induce significant performance penalty.
4.2 Safety
The HACS shall also be safe. For example, the microwave oven should now blow up or become too hot to touch.
5. Use Case Diagram
Use case diagrams are intended to model the functional requirements of the system. It shows a set of use cases and actors and their relationships. It is always selected to be the start point of software design. The following figure shows the use case diagram of the HACS system from the end user point of view.
5.1 Actors
5.1.1 User
User refers to the person who has an account and a password, can log in on HACS, and operate home appliances remotely by HACS.
5.1.2 Admin
Admin is a kind of user who has special rights, for example Add/Remove Device and Add/Remove Remote System, other than basic operations.
5.1.3 Device
Device refers to computer embedded home appliances that could be added onto HACS, configured, and operated remotely.
5.1.4 TV
TV is a special home appliance that has several operations, such as turn on, turn off, increase volume, decrease volume, and change channel, which can be operated remotely.
5.1.5 Garage door
Garage door is a special home appliance that has operations of opening and closing to be manipulated remotely.
5.1.6 Microwave
Microwave is a special home appliance that has several operations, such as setting command, setting timer, starting, and so on, that can be operated remotely.
5.1.7 Remote System
Remote System refers to system that has wireless connection. It can be added onto HACS system, configured with HACS, and communicate with HACS.
5.1.8 Palm-top
Palm-top is a special remote system.
5.1.9 Cell phone
Cell phone is a special remote system.
5.1.10 Emergency Department
Emergency Department is a public department that can help if there is an emergency happens in the house.
5.1.11 Police Department
Police Department is a special emergency department which will be noticed when there is a break in through garage door.
5.1.12 Fire Department
Fire Department is a special emergency department which will be noticed when there is a fire in the house.
5.2 Use Cases
5.2.1 Operate
The use case Operate is a service provided for the users to operate on the devices that are connected to HACS through remote devices. For example, user can send messages of turning on a TV, starting microwave to cook for five minutes, and so forth to HACS and then HACS will perform the action.
5.2.2 Restart/Redo
The use case Restart/Redo is an extension of the use case Operate. When the HACS could not conduct the command that the user sent, it shall detect and fix the error or restart the device to make it function normally. And the operation will be conducted once more. Besides, the HACS shall inform the user about this exception.
5.2.3 Operate Microwave
The use case Operate Microwave is a service provided for the users to operate on the microwave that is connected to HACS through remote systems. Users can send messages of cooking, defrosting, stopping, etc.
5.2.4 Operate Garage Door
The use case Operate Garage Door is a service provided for the users to operate on the garage door that is connected to HACS through remote systems. Users can send messages of opening and closing it.
5.2.5 Operate TV
The use case Operate TV is a service provided for the users to operate on the TV that is connected to HACS through remote systems. Users can send messages of turning it on, turning it off, increasing the volume, decreasing the volume, and changing channels.
5.2.6 Check/Update Status
The use case Check/Update Status means that the HACS keeps a record of the state of all the connected devices. It keeps updating their states from time to time. When users require the state information of some device through remote systems, the HACS send the latest state of that device to the remote system that requested.
5.2.7 Control
Sometimes the device may malfunction. For example, the microwave may keep cooking for an hour, which is not required by the users. The use case Control means it can detect such malfunctioning by updating the state of the devices, stop it (using operate use case), and inform the user what happened. Another case there might be some emergency happens, for example, a break in through the garage door or fire starts, the HACS shall detect them and notify police department and fire department respectively.
5.2.8 Add/Remove Device
The use case Add/Remove Device is a service for the users to add a device, for example, microwave, TV, and garage door, onto the HACS to be controlled remotely and automatically, as well as remove a device from the HACS that is no longer to be controlled. When a device is connected to HACS, both the HACS and the device are configured in order to collaborate with each other.
5.2.9 Add/Remove Remote System
The use case Add/Remove Remote System is a service for the users to add or remove a remote control system, for example, cell phone and palm-top, onto the HACS, so that the remote system can be used to communicate with the HACS and control the devices