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

2. 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]

3. 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]

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

5. Kinematic
Configurations
Image from [Siegwart 2011]

6. Kinematic
Configurations
Image from [Siegwart 2011]

7. Kinematic
Configurations
Image from [Siegwart 2011]

8. The 4 swedish wheels
Image from [Siegwart 2011]

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

10. Three-wheels Omnidirectional RobotyF 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

11. 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

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