Luca Baglivo, Mariolino De Cecco Mobile Robots Motion Kinematics draft Luca Baglivo, Mariolino De Cecco

Wheel types a) Fixed wheel: One fixed axis, fixed support to robot chassis b) Caster wheel: A fixed axis which can also pivot Image from [Siegwart 2011]

Wheel types c) Swedish wheel or Mecanum Rollers on the wheel circle, mounted with an angle (90°,45°) Holonomic d) Sperical wheel Difficult construction Image from [Siegwart 2011]

Wheel application from the Web Swedish 90° (Omnidirectional ): Honda Ux3 (link 1) Honda Ux3 (link 2) Swedish 45° (Mecanum) : Airtrax Mechanum principle

Kinematic Configurations Image from [Siegwart 2011]

Kinematic Configurations Image from [Siegwart 2011]

Kinematic Configurations Image from [Siegwart 2011]

The 4 swedish wheels Image from [Siegwart 2011]

Tricycle (or car-like) u1 u2 Controls: u1=v1a : velocity of forward wheel [m/s] u2=v2 : steering velocity [rad/s]

Three-wheels Omnidirectional Robot yF u3 yR xR u1 Controls: u1=v1 : velocity of wheel 1 [m/s] u2=v2 : velocity of wheel 2 [m/s] u3=v3 : velocity of wheel 3 [m/s] b d u2 xF

Three-wheels Omnidirectional Robot Exercize: Try to simulate omnidrive performing a circle of radius r while keeping a costant attitude (e.g. 90°) xF yF r

Bibliography Siegwart R., Nourbakhsh I, Scaramuzza D., Introduction to Autonomous Mobile Robots