Design
|
follower body
The most significant consideration in designing the follower body was the torque capabilities of servos which were within our price range. To determine the torque required, we conducted both a static analysis and a dynamic analysis. For both, the worst-case scenario of a fully extended load was considered, and the link moments of inertia and masses were also rounded to provide the most cautious conditions.
From this analysis, we elected to use servos capable of delivering 15 lb-in of torque. Additionally, we added a counterweight to the back of the shoulder to assist the servo at that joint.
The base of the follower is attached to a turn table to provide torso rotation. There are servos at the shoulder, elbow, and wrist to provide bending at thsoe three joints. Additional degrees of freedom are obtained at the wrist and gripper. Our design had an emphasis on simplicity and ease of manufacturing; all linkages were water jetted with only smaller revisions (including bushings and shop collars) manufactured manually in the machine shop. |