Little Friend

Mato can now find the "home" box (Arduino file added in the file area).

There are tasks ahead to make this work well--getting rid of the cardboard box, adjusting the slit and improving the software--but I've made my April goal!

I assembled the beacons and put one on the robot, the other "to be found."

The "to be found" beacon sends out so much signal in all directions (it does that on purpose--for moving targets to find one another) that it was hard to tamp down and directionalize for homing purposes. I put that beacon in a sealed cardboard box with a slit and am now getting some results I can work with.

My software needs some work to make the wheels line up with the sensor detection--that will be a later post.

July 2016

Examine the addition of wifi enabled features--possibly a camera.

Looking to the time frame and materials required, here's my current thinking.

April, 2016

Create ability to find charging station. I will use the Pololu IR Beacon Transceiver Pair and program the bot's Arduino to utilize the information received from the IR beacon. If this fails, my backup system will be to use the Pixy camera (I've done this on another project, but power consumption, lighting and expense put it in the number two position).

May, 2016

Build the charging station and pickup points for the bot. I'm thinking rollers and rails from an O gauge train may work for this.

June, 2016

Add people sensing and "excited to see you" routines. A PIR sensor will be used for human (or animal) detection. This is more tricky than I first thought, since the bot must be still for the "motion detector" to detect motion that is not caused by the bot.

July, 2016

Add stair detection. Some sort of IR detectors will be used for this.

August, 2016

Build a people friendly body, including eyes with servo controlled eyelids.

September, 2016

Build Taco, the people friendly "shell" for the charging station. Taco will have servo controlled eyes that "blink" when Mato passes by.

I'm thinking Mato (short for tomato) will live (charge) in a Taco.

Construction details (at this point in time) can be found here.

Crude preliminary tests have begun! Using (5) 350 farad maxwell ultracapacitors (in series) charged to 12.6 volts; the robot was released to "bump around" in my workroom. From 12.6 volts to 7.3 volts, the robot ran continuously for over 26 minutes. It could still run longer--probably to about 6.5 volts before starving the processor.

Charging at 4.5 amps takes about 90 seconds to go from 7.3 volts to 12.6. The video above starts at about 8.8 volts and goes to 12.6 in roughly 75 seconds.

What have I learned here?

The steel caster wheel is too noisy!

Motor speed and "bumped into something current" need to be adjusted on the fly as the capacitor voltage declines.

The robot doesn't need to run around continuously like a frenetic little puppy.

So . . . twenty minutes of robot socializing followed by 90 seconds of robot rest seems very doable.