Theme
Apart from the class deliverable, our main intention was to inspire young children so that they pursue engineering in college and as a career. To catch their attention we used a speed racer theme( popular cartoon)
Walker presentation
The walker was interesting in its design because it was not a traditional Theo-Jansen or Klann mechanism. We finalized the design of the walking mechanism through trial and error, particularly by experimenting with the SAM software.
When we tested our walker mechanism, we were cautiously optimistic about its performance, so we had used a 1:1 gear ratio between the motor gear and the gear on the drivetrain shaft.
However, owing to delrin’s elasticity under loading, we noticed that our walker, despite its fast movements, was able to hold itself and even able to traverse both concrete and grass without any significant mechanical wear and tear. This was confirmed on the day of the competition when we tested our walker against 31 other walkers.
Automaton presentation
The automaton was also unique in the fact that our group utilized two 4-bar linkages that had movement instead of just one. The automaton had the moving arm motion and the leg moving as well. The leg moved a lot faster than the arm due to the shear proximity to the motor gear and the inefficiency of the belt connecting the two gears of the linkages. The automaton works well with the walkers uneasy motion since it models a mountain biker and the mountainous regions are bumpy.
PVA and DFA- by hand
PVA
DFA
Method of instantaneous centers
It is seen that there are two ways to find the foot velocity: Method of instantaneous centers and comprehensive analysis. However the method of instantaneous requires less calculations but more needs to be sketched out it could take more time and be less accurate
PVA and DFA IN Matlab and SAM
From the plots below it can be seen that the vertical step height for each step is around 5 cm which enabled the walker to climb over small rocks or change in elevation. Additionally the almost 1:1 gear ratio enabled a velocity of 4 cm/rotation and as the motor spins around 100 Revolutions/second, the walker was able to cover around 10cm/sec ( due to the lack of traction). This enabled our walker to complete the task of covering 15 m in 2 mins
