To Design a Small Pneumatic Actuator Driven Parallel
Link Mechanism forShoulder Prostheses for Daily Living Use 119
Fig. 5. The coordinate system ΣCS 1 and the HumanWorks model.
4.4 Important areas in the working space of the Arm
Two important areas in the working space of the Arm are defined for the analysis and
evaluation of the Arm. One is the area close to the chest and the median sagittal plane, which is
expected to be accessed very frequently during most daily living tasks. This area is the EFAA
defined before, and expressed as ΣEFAA. Another is the area that represents the reachable area
[RA] of the end effector, defined as ΣRA. Geometries of ΣEFAA and ΣRA are illustrated as in Fig. 6.
The volumes of ΣEFAA and ΣRA are set to 12000cm^3 and 75000cm^3 , respectively.
Fig. 6. Geometries of the areas ΣEFAA and ΣRA.