Lect 7 Flashcards
How to move in an uneven terrain? (engebeli arazi)
Suspension required to maintain contact
Bigger wheels for bigger wheels, but they need greater torques
What is shrimp robot?
It can climb high terrains without having bigger wheels thanks to the parallel bogie. It can climb obstacles bigger than its wheels
Why we need 2 coordinate frames as World reference frame and robot reference frame?
Our goal is to find “"”correct transformation””” between the world reference frame and robot reference frame. If the robot perceives an obstacle we want to map this obstacle.
1)World reference frame:
Our reference frame in real world. We want to choose a point and we want to know how our robot is moving wrt this point
2)Robot Reference Frame:
The actuation and perception happens in this frame
What is 1 DOF 2 DOF 3 DOF and 6DOF
1 DOF: a rigid body translate or rotate a 1 dimensional path
2 DOF: a rigidy body either translate or rotate in 2 directions (train)
3 DOF : Rigid body translating or rotation along 2 D plane 2 translations+1 rotation
6 DOF : Rigid body translating or rotation in 3D volume 3 rotations+3 translations
What is a differential drive?
Two motors for each wheel. Steering is achieved by setting different speeds on each wheel.
Not the movement of wheels but the body is steering.
Two wheels same speed : straight motion
Two wheels opposite speed: rotation on spot
other combinations: motion in “"”circular arcs”””
Non holonomic robot examples?
Rack and pinion Differential drive Synchrodrive Skid steer all these robots have 2 motors but have 3 degrees of movement freedom.
