Group 4

The purpose of this assignment was to create a physical model of a Smart Home. To this end we were supposed to use phidgets. The Smart Home should be designed to meet the needs of elderly persons, but we got to choose a specific target group ourselves.

The assignment also included writing code to control the phidgets in the Smart Home, create a mobile client from which a doctor or relative should be able to follow the behavior of the elderly person living in the Smart Home.

To present the results of the assignment a homepage should be created containing an introduction to the Smart Home, specifications for the system created, pictures of the physical model and a video describing how the Smart Home works.

Target group
Elderly people with bad memory (Alzheimer's disease) and other health problems, living alone.

Target group’s needs
The environment needs to be able to remind the users about important things, e.g. if someone left the cooking plate on or to lock the door at night. Since the user group consists of elderly people, they need things to be simple to use and understand, and as much as possible should be done automatically by the system.

We are also aware of falls and other accidents are acting as important factor of injury or death among target group.

Ideas for designs
Our model will cover whole house/flat with focus is on the bathroom, and we have the idea that you should be able to choose an exact temperature and amount of water you want to fill the bathtub with, since the water in a bathtub often gets too hot or too cold. When the bathtub is filled and ready the users will be notified through a LED-screen and a sound indicating that the bathtub is ready.

Another idea was to make sure that an alarm goes off if the user fall asleep in the bathtub and starts to drown, sensors detecting motion, vibrations and maybe the water level (since the water level will rise if you put your head under water along the rest of your body) can be used to determine if the user is about to drown. If the alarm goes on, the bathtub will empty itself and a doctor will be notified.

Other ideas include doors that open when a user wearing a RFID-tag approaches and lights that automatically turns of when the user is not home or if the user is asleep. Motion sensors and RFID-tags can be used to determine of the user is home. Motions sensors, along with weight sensors in the bed and a clock can determine of the user is asleep (not entirely though, the user may be in bed watching TV or something).

Contextual Information
Contextual information useful in our design includes if the user is asleep or awake, if the user is in the bathtub or not and if the user is drowning or not. The design must also know if the user is home or away. Somehow the design must also know if things have been forgotten or left on on purpose. Perhaps you want to leave the lights on when you leave home.

Components & materials required

RFID-tags and sensors for the doors.

Motion detectors in all rooms.

Temperature and vibration sensors in the bathtub.

Sliders for choosing water temperature and the amount of water in the bathtub.

LED-display to display messages.

Our Smart Home consists of a door that opens automatically for the person wearing the right RFID-tag. The RFID-tag is placed in the house owners’ shoes or cloths (in our case, the shoes) so that it’s harder to forget or lose. A green light beside the door turns on if a person with the right RFID-tag approaches the door, if someone with another RFID-tag approaches, a red light turns on.

The bathtub in our Smart Home is controlled by a lever and a rotator, making the user able to adjust precisely how much water should be in the tub and what temperature the water should have. When adjustments are set, the user presses a touch sensor and the bathtub fills up automatically. The amount of water and the temperature of the water can be seen on a LCD-screen above the bathtub. The LCD-screen also notifies when the bathtub is filling up with water and when it’s ready.

In the bedroom there is a motion sensor, and in the bed there is a pressure sensor. Together this two sensors can tell if someone is lying still in the bed for a longer amount of time, and thus conclude that the person is sleeping. If the sensors detect this, lights in all rooms, the LCD-screen and the stove will turn of automatically.

The bed has a vibration sensor which can be used to turn off or on the lights (and turn of the stove and LCD-screen). To activate it you just clap hard on the side of the bed. When the sensors register that the user is in the bed for a longer period of time, the mobile client will know that the user is sleeping or at leas lying in the bed. The same goes for the bathtub.

Knut comes home, opens the door with the RFID-key. He then wants to take a bath.
He chooses the temperature and the amount of water he wants and the bathtub automatically adjusts to his choice. He use the touch sensor to start the water to fill up, when it's ready Knut is informed by a LCD-display. He goes inside and baths, but after a while he falls asleep and starts to drown. An alarm goes off to wake him and the bathtub empties itself on water, for safety reasons. Knut’s doctor is contacted, but after a while Knut is okey so he informs the doctor by pushing a button. Then he goes to bed and  the lights  turn of automatically. When he wakes up in the morning the lights turns on and the system makes him coffee.

We had a lot of ideas for our Smart Home, but when we started building it we realized that some of the functions were not possible to implement in a physical model. We wanted the bathtub to be able to tell if someone was drowning in it, but since we didn’t have an actual bathtub with actual waters, or waterproof sensors, we were not able to implement this.

Because of the lack of sensors we also didn’t have lights and motion sensors in every room, which would have made us able to tell is someone was in that room or not. Could you do that you could also turn off or on the lights automatically if someone enters or exits a room.

Our system can never be absolutely certain that a person that lies in the bed is sleeping or just resting for a moment, so sometimes it will shut of the bathtub or the stove when it shouldn't have. This could perhaps be fixed with a timer based on the users sleeping habits, or a function that checks the amount of time it has been between the user turning on e.g. the stove and going to bed.

Another problem we didn’t solve was how the bathtub should be able to tell if the person is drowning or not. We didn’t try to implement this in the physical model, for reasons previously mentioned, but even with unlimited sensors we weren’t certain how to do it. Perhaps measure the water level when the person is in the bath with his/hers head above the water and compare it to what the level would be if the users head was under water.