semi-circle move

[andreahmed]

Hi, i wanna my robot to move around a semi-circle , how can i do this ? and what tools should i've and what's the algorithm for it ?

[Steve Joblin]

I assume your robot is a "two wheel drive with a center caster" design?  If so, just drive one wheel faster than the other... the greater the difference between the speed of the two wheels will control the "tightness" of the arc.

[andreahmed]

Hi , yea same design but there are two casters in the front , but as you know PWM will depend on battery and i dont want to depend on that ... also i want an accurate curve ... how do i do that ? would an equation of the circle help also how much an encoder can help in that ?

thanks

[Steel_monkey]

Encoder should solve the problem. I am using muse wheels-middle buttons from widely used Genius mice as driving wheels for my robot (sounds lol). And 10 sectors per turn is enough to realise stable feedback and maintain constan speed. However, number of sectors should be chosen from desirable speed.

[Admin]

 

http://www.societyofrobots.com/programming_differentialdrive.shtml

http://www.societyofrobots.com/sensors_encoder.shtml