P13029: Robotic Tiger

MATLAB Simulation

The tiger takeoff and free flight were modeled dynamically and animated, in Matlab. While the modeled design did not end up being used as the final design, the simulation revealed several things that aided in the design of the tiger. The simulation revealed the need for a sequence of muscle group firings as opposed to all muscles actuating at once. When all muscles fire at once, the bottom muscle cannot overcome the reaction forces due to the upper two muscles. The simulation also revealed the need for hard stops at each joint to prevent over extending of each leg segment. Hard stops stop each leg segment at an optimal jump angle of about 45°.

The goal of the simulation was to be able to input muscle forces, link lengths, initial starting positions, and masses of each link/body element, and have the simulation output the tiger's jump distance. However, due to the inability to collect reliable muscle force profile data, we were never able to input accurate muscle forces into the simulation. Furthermore, due to the significant amount of time that was needed for the creation of the simulation, the simulation was started very early in MSD I. However, lessons learned from prototyping in MSD II drastically changed the tiger design from the design used in the simulation, rendering the simulation inaccurate.

MATLAB .m files:

Take Off

Free Flight