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Things That Go Bump in the Hall

My next project with the omniwheel is to have it react to bumping into things that it encounters on its journey.  I want to use the HiTechnic Accelerometer to do it, the Mindsensors one is currently being used in another project.

I’ve been racking my brain for about 2 days now, analysing the data from the runs, trying to come up with a generic way to tell the difference between the collisions and the robot’s wheels hitting the grout.  Ideally, I would like to be able to calculate the angle from which the impact came and the amount of force, so that the robot can move away from it at the appropriate speed.

I’ve made a video of two of the test runs I made.  One is on the bare tiles, you can hear the “click” sound when the wheels hit the grout. The other run is on smooth boards on the floor.  The only impact there is the baby gate at the end of the hall.

If anyone knows how to definitively tell the difference between the grout and a similar impact from the side, I am all ears.  I’ve put the two Excel sheets I’ve been working with here: [LINK].  The filter I’ve used is a high-pass filter, controlled by the “alpha” variable.  The offsets for each axis is based on the average values of the first 10 readings.

You can post your suggestions in the comments, I’m all ears!

About Xander

Xander Soldaat is a Software Engineer and former Infrastructure Architect. He loves building and programming robots. He recently had the opportunity to turn his robotics hobby into his profession and has started working for Robomatter, the makers of ROBOTC and Robot Virtual Words.