My “nineteenth” attempt to make a four-wheel robot using Lego Mindstorms nxt. All ended in failure as I couldn’t get any of them to turn. This was a kind of articulated tractor-trailer effort, but still no good. I’ve rturned to two wheel / skid-steering for now.
Supposed to be a basic four-wheel platform
CPU: Lego Mindstorms
Sensors / input devices: sonar
Target environment: indoor, carpets and smooth surfaces
how did this one fail? it how did this one fail? it actually looks promising in design but the pivot point might be too far back for it to effectivly turn. You could try putting the motors forward of the wheels and shift the pivot point closer to the wheels as well.
Seemes like a good construction. More pictures please. I’ve also tried to make a robot like that but unsuccessful. Are going to try again and see if it works. Are going to take some ideas from you if it is OK.
How did it fail? When it detected an object ahead, it just carried straight on. Now that I think about it, I think the reason was that I tried to turn like skid steering - ie by reversing one of the wheels. What I should have done was accelerate the other wheel.
Center of gravity The weight of the NXT brick is trying to turn on a point behind the drive wheels, where it might work better if the point is between them. Check out Ben Hur, a lego chariot-like robot that places the twist in between. Weight further behind would resist turning as you’ve seen. Steve Hassenplug has had some other twisty lego robots.
