Alert Belt is a smart wearable notification device that provides vibration along its surface to notify its users with their selected set of messages. For this project, the belt is connected to an ultrasonic sensor on a step motor that monitors the surrounding of the user and vibrates base on the angle of the objects approaching the user.
My goal for this project was to explore the different effects that you can create using simple vibrator motors. It’s straightforward to connect the small vibrator motors to wearable projects, and it is an excellent way to only notify the user without revealing information to other people.
Something that has always been on my mind is the warning systems that are available on cars. Especially when dealing with projects that are very visual base, I feel that vibration would be an excellent replacement using other senses to notify the users with warning signals.
I uploaded the “Blink” example onto the Arduino, examining its performance. I initially placed the disk on the table and tried to hold my finger on top of it, but this limited the movements of the vibration disk and reduced its power. So I decided to place the motors on my body instead. I tried the vibration disks in two different places, my fingertip and my wrist. When it was on my fingertip, I could only sense the vibration at that location, but also it felt too strong and annoyed me after just a few seconds as it was placed right on top of my blood vessel. On the other hand, when I placed it on my wrist, I could feel the vibration around my hand, and it was a much smoother vibration.
I tried changing the frequency of the blink to see at what point do I feel the motors turning off. I only started feeling the motor blinking above 30ms of delay, anything below that it felt as if the motor was continually vibrating.
I then tried running the “Fade” example on the Arduino. I noticed that the analogue value was not directly proportional to the power of the vibration disk. Anything under 60 was just off, and anything higher than 130 was almost full power. In addition, the vibrator’s vibration power increased by more significant steps when it was closer to 60 than when it got to higher values.
For the second experience, I wanted to test the three sensory illusions that we had discussed in the class. I made an array of motors and tried turning them on in order. I was able to get a phi phenomena illusion, where it felts as if something was moving up my skin.
For another test, I placed two motors apart from each other on my hand and turned them on at precisely the same moment to achieve a funnelling illusion. It did really felt as if the whole line between the two vibrators was shaking.
For the third experiment, I installed the Haptic Driver and ran through all the different vibration formats that they had in the library. What I noticed was that for most vibrations were only the power changed I could not feel the difference at all. But the library did include some interesting vibrations which would have be interesting to explore further as a mean of sending different messages.
For the final experiment, I wanted to do something that I have always wanted to do. I had always wondered why they don’t use vibration motors as a mean of alerting in cars, especially for blind spot monitoring or the different new warning systems that have been installed on new vehicles, instead of the extra lights that they keep on adding to the cars.
To explore this topic, I placed an ultrasonic sensor on top of a rotating step motor to scan the user’s environment and set three vibrating disks along a belt to vibrate according to the angle at which objects were approaching the user. I used the funnelling effect to give the user a full sense of 180 degrees of direction with only three vibrating disks.
- Jumper wires
- Arduino Micro
- 3 x Vibrating Disk Motor
- Micro Servo Motor
- Ultrasonic Sensor
The spacing between the different vibration disks is critical when you are trying to achieve a funnelling effect. If they are too far apart, you don’t get the result. Another issue that I found was the exact location of the motors. If they are placed on top of a vein, you feel the vibration throughout your body, but also if you place it too far away from your nerves, you won’t feel the vibration.
How to build a Radar:
The next step would be to build a belt that would house the vibrating disks and test it on the body to see if the relation between the position of the vibration disks and the objects in real life is natural for the mind to understand.