· Devices: All the devices within the green frame would be the physical context.

Obviously the appliances form one basic block in the kitchen; their contribution to the context will be informing about their status (for example, temperature in the case of the fridge, washing program in the washing machine, etc. ) and execute actions (for example, change temperature reference, stop operation, etc.).

 

Diverse sensors are usually used for context awareness tasks; specific selection depends on the application. We propose some sensors already usual inside the kitchen (temperature, fire, smoke, flooding) and other not so used in this scenario:

·         door sensors for detecting when the user opens/closes a cupboard or drawer.

·         illumination sensor to detect when the user forgets the light on .

·         presence sensor to detect when the user enters the kitchen.

 

We have also considered RFID readers for identifying clothes and food. The use of RFID and EPC can provide useful information about what is in the washing machine or fridge, what does the user want to eat or have just bought, etc. Food information is useful to inform the user about the food that is missing, which food is going to go out of date, which food the user may eat, etc. Cloth information is helpful to determine which washing programme fits best with clothes the user has introduced in the washing machine.

· USER INTERFACES: yellow frame is the human-machine interface (HMI) that manages user interaction.

HMI devices must be easy of use and must be available for any kind of user, having the capability of change the interface according with the user profiles. They must have good communications interface, but they do not need a powerful processing neither storage capacity.

 

There are many different types of clients that can be used to managing the system: the mobile devices (PDAs, smart phones, wearable devices, ultra-mobile PCs, touch screens, etc.) which means the user can carry them around the house and be able to monitor the house appliances wherever he or she is; the fixed devices (computer or digital TV) will be used as a centralized control and finally the embedded devices which can be control panels implanted in each of the actual appliances. After a study of the state-of-art in the actual market about the technical specifications of potential clients, it was decided that suitable user controls for the system will be:

 

·         Digital TV plus remote controller (elderly people accept it and know how to use basic functions). Central intelligence could send “HMI output” through a S-video or digital signal and receive “User information” through an infrared remote control.

 

·         As a portable device, there are many devices of this type but thinking in low cost and enough process and storage capacities, the best option could be a touch screen device with a dock, middle way between a tablet PC and a PDA; something similar to Nokia N800.

· e-SERVANT: Inside the red frame we have the intelligence of the system; what is been called e-servant.

E-servant is aware of the context and user enhancing the intelligence of the white goods and providing new functions:

 

·         With or without user cooperation, it facilitates the use of the appliances, adapting the systems to the disabilities or preferences of the user.

 

·         It analyzes all the data gathered to extract relevant information that could be useful for user’s carer and/or relatives to evaluate the person’s quality of life. It is able to detect behaviour changes, loss of abilities (memory problems, oblivions, etc.) of the user.

 

·         In the case of conflict or emergency it can send a warning message to a remote care centre that can immediately send a social worker to help “in situ” the users.

 

E-servant will also be the coordinator with whom all the other systems communicate. In order to have an invisible system for the user, different blocks use the most appropriate way of communicating, and e-servant has to implement them all

 

·         We use power line communication (PLC) over the main wires to get the status of appliances and to control them. PLC is the best option for white goods because all have to be mains powered and there are European standards being promoted on this line. Moreover there is no configuration needed to install a new appliance.

 

·         We use wireless sensor networks to enrol all the sensors in the kitchen and also to get RFID data from the readers. Many protocols exist on these field, so far we are using ZigBee because it is becoming a de-facto standard in home environments.

 

·         Communication with the interfaces is used through standard communication protocols such as Bluetooth or WiFi. The main reason for this is that the communication established can be considered between computers that already include this kind of communication ability.

 

·         Finally, communication outside of the house (information to the social services or families, information about possible technical alarms, information about maintenance needed, etc.) is also done using standard protocols such as DSL or WiFi

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