Buongiorno! Divya Shah , , Gio iorgio Metta, Alb lberto Parmig - PowerPoint PPT Presentation

Buongiorno! Divya Shah , , Gio iorgio Metta, Alb lberto Parmig iggiani divya.shah@iit.it 1

Background MEDER, IIT, UDINE GENOVA HOME, MUMBAI 2

Comparison of Workspace Analysis for Different Spherical Parallel Mechanisms IFToMM MEDER 2018

1 Introduction

Decreasing Motive Power STATIC BALANCING MASS RELOCATION Kim and Song; IEEE ICRA; 2013 Kim; IEEE Trans. Robot; 2017 5

SPMs! Agile Eye; Université LAVAL 6

Desired Characteristics 05 Large Range of Motion Higher Payload-to-Weight Over +/- 45 degrees. Ratio Higher payload-to-weight ratio. 01 04 Regular Workspace Simpler Kinematics Higher and consistent mechanism isotropy. Easy to model and control. 02 03 Full Decoupling Independent Yaw and Pitch motions.. 7

2 Modelling & Simulation

Our Approach Mechanism CAD Model Extract Measures Contour Plots Simulation Create conceptual Run kinematic Record and extract Generate workspace design of the simulations spanning platform coordinates and isotropy contours mechanism using CAD the entire actuator and orientation angles against the input tools. range. throughout the actuators. simulation. 9

CAD Models GIMBAL 4-UU 10

CAD Models S5B S6B 11

12 Full Workspace Simulation of 4-UU Mechanism

13 Full Workspace Simulation of S6B Mechanism

3 Analyses

Workspace Analysis ● Platform Position - X,Y,Z Cartesian Coordinates Platform Orientation - Roll, Yaw, Pitch Angles ● 15

16 Workspace Analysis - Position - Gimbal

17 Workspace Analysis - Position - 4-UU

18 Workspace Analysis - Position - S5B

19 Workspace Analysis - Position - S6B

20 Workspace Analysis - Orientation - Gimbal

21 Workspace Analysis - Orientation - 4-UU

22 Workspace Analysis - Orientation - S5B

23 Workspace Analysis - Orientation - S6B

Isotropy Analysis Kim and Khosla; IEEE IROS; 1991 24

25 Isotropy Analysis

Conclusions Warping Parasitic Motion Mechanism behaviours are not Platform posses undesired Roll motion in symmetric, i.e., the plots are not centered case of 4-UU . Central gimbal prevents the with absolute zero. Workspace diverges same for S5B and S6B. towards the extremes. More evident in case of 4-UU . Coupling Anisotropy Pitch and yaw motions of the Mechanisms are not fully isotropic mechanisms are dependent of each throughout the workspace. S6B best with other. Δ ≥ 0.9 . Shah, Metta and Parmiggiani; ASME IDETC; 2018 26

Opening! Post- Doc on “The design of better iCub Hands” alberto.parmiggiani@iit.it 27

Grazie! Any questions? divya.shah@iit.it www.iit.it/people/divya-shah 28

“ FINITO! 29