Introduction
One of the most striking examples of the gulf between human ingenuity and the designs of nature is the great degree of effort and technical knowledge an engineer needs to mimic even the simplest of natural mechanisms. There is perhaps no better example of this fact than the human hand: an assemblage of skin, muscles, tendons, ligaments, cartilage and bone that is capable of remarkably complex and precise motion. Indeed, the evolutionary development of the opposable thumb is what allowed mankind to begin to creating tools and then, some time later, attempt (with great difficulty) to mechanically mimic the very appendages that allowed them to do such a thing in the first place. When looking at the vast majority of robotic hands, one of the first design realities that becomes apparent is the need for many many different actuators to accomplish a product that resembles the real thing. The human hand has 27 degrees of freedom, so it is not hard to see why the amount of actuators required can easily become unwieldy when trying to replicate it. In this conundrum, the simplicity of flesh is lost, and the manufacturing cost can easily become prohibitive. With our project, we aim to explore another path: a robotic hand with as few actuators as possible.
Problem Statement
As part of our goal of minimizing the amount of actuators we use, motors and pistons must be replaced with mechanically interconnected linkages. Even with only one motor, we would like to be able to fully flex and extend our robotic fingers. If time permits, we would also like to animate the wrist.
Additionally, reducing the amount of actuators used is a goal that is intrinsically at odds with the goals of precision and delicacy. There is no purpose in simplifying your design if it cannot, in the end, accomplish its intended function. We would like our product to have the required force to firmly grasp a delicate object such as an egg without using so much force so as to damage the object. As in a real human hand, we want our robotic hand to be able to grasp objects of differing shapes and orientations. To do so, we will need to build in some inherent compliance to our mechanism so that our fingers can close tight around our egg no matter what direction it is oriented in.
Ultimately, the problem we face is to find a middle ground between design simplicity and operational precision.Team Members:
Aaron Kim, Brycen Miller, Philip Bortolotti, Rui Chen
Summary:
We aim to create a robotic hand that, while using as few actuators as possible, is able to safely grasp an egg without breaking it regardless of its orientation
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