Objectives:
- Explore the individual control of multiple appendages into a coordinated assembly
- Understand the importance of central pattern generators in structuring stereotyped activities
- Consider the patterns of neural activity that underly motor behaviors
The Department of Defense has hired you as a consultant to help in the development of a biomimetic, ambulatory, under-water robot. The basic design hopes to implement some of the functionality of a design that has proven its success over millions of years - decapod crayfish which utilize 4 pairs of walking legs. Your job is to develop software that controls the walking legs in various modes, including fast and slow forward walking, backward walking, turning left or turning right. As in the real animal, each walking leg of the robot is controlled by two thin-film plastic actuators (the muscles): one that elevates the leg, and one that depresses it. In this lab exercise, please first characterize the modes of walking in crayfish, and then design an artificial neural pattern across the eight legs that will allow your programmers to implement these behaviors in the robot's software.
Exercise 1:
Characterize the movements of legs in walking behavior of crayfish (Orconectes rusticus). Specifically note at what point in time and for what duration each leg bears weight. Do you observe coordination of a leg with its closest neighbor on the same side? Is there coordination across all legs of one side? Is there coordination of leg movements between sides? Record this information on the Handout for Exercise 1 for various modes of locomotion: