Benchmarking and Concept Generation Benchmarking a simple joint was great fun! There were tons of great options out there in every possible application except ours. Much of my benchmarking was integrated closely with concept generation. Figure 1 below shows some mind mapping I used to discover possibilities before looking on the internet and in catalogs for benchmarking and concept generation.
Figure 1: Mind Map for Concept Generation
As a team we explored and benchmarked several joint designs. We determined that a simple hinge joint would be the best choice for this application. Below is a list of the joints that were considered. The primary reason for deciding against all of these joint options was primarily their difficulty in manufacturing. We had to attach a sensor and a braking mechanism to each axis in the joint. This meant that we couldn’t just modify “off the shelf parts.”
- Single Prong Fork
- Multiple Prong Fork
- Barrel and Cylinder
- U-Joint
- Ball Joint
Figure 2: U-joint
Listed below are some motion constraint concepts. Some were found in industry in other applications and some originated in the mind mapping exercise:
- Bolt Variations
- Disk Brake
- Pin Lock
- Knuckle Lever
- Break Pads
- C-Clamp
- Gear Mechanism
- Wedge Lever
- Interference Screw
Figure 3: A sketch of the disc brake concept
Most of the sensor benchmarking was done by Dante Bertelli; however, I played a limited role in his benchmarking of possible position sensors to be used in the joint. My work focused on getting the sensor attached and functional. Dante focused on the specifics of computer and user interface.
- Potentiometers
- Gyroscopes
- Optical Encoders
- Force Transducers
Figure 4: Optical Encoder