Friday, 4 October 2013

Inmoov elbow

In a effort to get more out off the inmoov arm I have made some mod these mods are still experimental looking at the NASA robonaut the shoulders rotate back and give almost 270 degrees of rotation by pulling the shoulder back it makes it easer to drive around, tucking the arm up and being able to lock them in place which will help with the bounce when going over small gaps . Part 2 of the mod requires the elbow to move more than 90 degrees I was never a fan of the old thread design having broken a few also I need feed back using a motor and pulleys I'm able to get the required movement and using the same motor controller as the rest of the arm also helps keep it simple. Todo move the motor lower  to increase the up angle  and smaller motor this one is only at 1/3 power and speed.

Thursday, 3 October 2013


The improved base is now fitted and working well the rear castors will need to be replace as they don't turn freely. After generating a new map, Navigation works but I haven't tuned it yet out of the box localization is within 200mm after a 10meter loop
with a couple of loops. Encouraged by this I made a launch file to start all the systems
on Robbie with the plan to do a endurance test in the near future something involving a roving patrol and charging the batteries when required. Driving Robbie
around the lounge room and kitchen there is only 10 cm of gap between the walls
and the shoulders. Instead of controlling the motors using a RPM method I now use
distance per timing frame the main advantage is both wheels move the same distance making it easier for navigation. In the video Robbie is driving under remote control I need to work on the movie making skills. The next step is navigation runs.
After repeated test of the arm the original part are staring to fail some due to problems I had when I first started printing (poor quality ) and other while adjusting the new motors the plastic parts tend to break when the joint PID controller oscillates or travels too far to fast.