October 27, 2019 · project

Project Proposal

Throughout the past few weeks, I've been thinking over what I'd like my project for this class to be. I've settled on the idea of building a small robot companion, that can be stroked in order to induce purring and contented sounds, with potentially other reactions indicated by LED arrays representing eyes. This fits nicely into one of the project themes, "Artificial Life". By immitating the behavior of a small animal or pet, I want the user to feel calmed when they interact with the robot.

This project has particular meaning to me, as a sufferer of anxiety in certain social environments and situations. I have often turned to fidget toys and to biting my nails to deal with anxiety. Having a small device that reacted to my fidgeting, or more specifically petting and stroking, would hopefully make me feel calm in the same way that petting a cat or dog does. According to Jenkins [1], petting an animal can significantly reduce blood pressure in adults.

This principle is demonstrated well by a device called the Qoobo [2], a small pillow with a tail that wags when you stroke it. I'd like to design something a little bit smaller, and focus on force feedback using a vibration motor (and potentially making use of pulse width modulation to control the speed and intensity of the vibration [3]) and sound from either a speaker, or perhaps even produced by a small motor [4].

Woman holding a pillow with a tail
Qoobo - a cushion with a wagging tail (qoobo.info) [7]

The detection of stroking would be handled by a series of capacitive surfaces, hooked up to a multi-key capacitive touch sensor, like this one from Adafruit [5]. Being an Adafruit product, it has a very well-documented tutorial [6], detailing how to get the output of the sensor displaying to a serial monitor.

The most important aspect of this project is the touch input. If I cannot get the inputs to register in the way I want them to, i.e one after another to follow someone's touch across the surface of the companion robot, then none of the other functions will work. The core output of the robot will be the purring, as I feel it is a key component to making the user feel as if the robot has some sort of life. Purring is a very rhythmic action, hopefully making it easier to replicate than some other functions of pets.

As a member of the audience for this project, I hope it makes me feel calm when I feel the robot companion reacting to my strokes and pets. I want the force feedback and the purring sounds to make the user feel like they aren't alone, and that they have a companion by their side. I'm not neccecarily looking to make the robot 100% lifelike, but just give it the essence of a small pet.

A small robot with a capacitive sensor on one side
Vector - a small robot companion that has a capacitive, strokable back (anki.com) [8]

I feel this is in scope for my current skill level. Having not worked with electronics before, the sensors and inputs I'm looking to use don't require external libraries or particularly complicated fabrication techniques. I feel as if I have a well defined MVP, with decent stretch goals (such as adding LED arrays for eyes), and elements I can work on separately. This will allow me to block out my time accordingly in order to stay on task.

One area of the project I have concern over is the design and fabrication of the robot. I don't have a lot of 3D modelling experience, nor aesthetic design. This will be an aspect I will be looking for particular feedback on during testing.


[1] Jenkins, J. L. (1986) ‘Physiological Effects of Petting a Companion Animal’, Psychological Reports, 58(1), pp. 21–22. doi: 10.2466/pr0.1986.58.1.21.
[2] https://www.youtube.com/watch?v=f2heW910o7c
[3] https://www.precisionmicrodrives.com/content/how-to-drive-a-vibration-motor-with-arduino-and-genuino/
[4] https://www.youtube.com/watch?v=M0un74hBnng
[5] https://www.adafruit.com/product/1982
[6] https://learn.adafruit.com/adafruit-mpr121-12-key-capacitive-touch-sensor-breakout-tutorial/
[7] https://drive.google.com/drive/folders/1eVPZ2k_mzAE-kBsQbh73t0aUAnMry4gZ
[8] https://www.anki.com/en-us/company/press-center.html