ME Seminar Series: A Functional Analysis of Some 4-bar Mechanisms in Vertebrates and Insects with Applications to Robotics
Wednesday, September 5, 2012 - 11:30am to 1:00pm
The talk will present the results of studies of 4-bar mechanisms in living creatures including: the mammalian knee joint, the sling jaw wrasse jaw joint and the bird forearm joint. Kinematic and dynamic models were constructed to analyze and understand the function and performance of the mechanisms. It was found that the 4-bar mechanisms gave sophisticated mechanical functions not present in simple hinge joints. These functions include: high mechanical advantage, variable mechanical advantage, complex optimal pathways, mechanical compliance and optimal actuator location. These case studies from nature show that 4-bar mechanisms are extremely useful devices for achieving high levels of mechanical performance in mechanical joints. Kinematic and dynamic modeling showed that the 4-bar mechanisms exhibited a high degree of optimization. Bio-inspired robotic applications of the mechanisms will be presented. Methods of systems modeling will be briefly discussed. The idea of self-organization is considered very unhelpful because it discourages an understanding of the physics which is driving the high-level systems performance. In contrast, constructal theory is much more helpful because it seeks to understand the physics of the system and give a framework for modeling performance. It also encourages the designer to construct high-level performance criteria for optimizing complex systems.