Agilis, a fast and smooth moving omniwheel NXT robot.
About this creation
Agilis is the most agile NXT robot. It features a triangular frame and three powered omniwheels from Rotacaster. Each wheel is driven by a NXT motor via a gear train. This gear train can be configured to have a 1:2 or 1:3.333 gear ratio. This gives Agilis a top speed of 60 or 99 cm/sec.
Agilis has advanced software for motion control. It is able to make complex movements like driving in a straight line while rotating. It is also able to make smooth transitions between different movements. I created some video's that show the abilities of this robot. Thanks to the advanced motion control the movements of Agilis are also very precise. Tests show that Agilis is able to return within 6 cm of its starting position after driving a 16 meter course.
A close up of the gear train configured with a 1:2 gear ratio.
Video showing some of the complex movements Agilis can make. A move is made up of two independent parts, a movement in the XY-plane and a rotation around the Z-axis. By combining these two components one can create almost any move one can think of. Like driving in a straight line (XY-plane) while rotating (Z-axis).
Video showing Agilis equiped with some dLights from DexterIndistries. There are three lights, one pointing to each of the wheels. The color of each light is related to the speed of the corresponding wheel.
Video showing action blending. This is a technique for making smooth transitions between motions. With action blending consecutive moves, or actions, are mixed into each other just like a dee-jay mixes misic tracks. As a result there are no more sudden accelerations, this makes the movements much smoother and also increases the accuracy of the movements.
I explain motion control in more detail in several blog posts on my blog. The explanation starts withthis post.