Conclusion

During this project we have encountered some problems and solved them. Based on these experiences the following points seem helpful:

• Always think about the role of friction in your mechanism
  When we simulate the kinematics of our design, we don’t see how the friction can affect.
  In our design, we needed friction to avoid looseness. On the other hand too much friction could make the motion difficult. Nuts and pin clips provided the enough friction for us.
• Use the appropriate laser cutter for your material
  There is a high probability that the wood burns without being cut if low power laser cutter be used many times on it. We used high power one with only one path for the wood and it worked well.
• Bolts length
  The proper bolt length should be considered in the design stage of project.
• Simulation
  The Simulink toolbox of MATLAB is a great tool for simulating the mechanisms. The links and joints properties are defined through blocks. The MATLAB would find and solve the equations itself. We used Simulink in our project to find the ankle velocity given a crank velocity and also the required motor torque.
• Miscellaneous
  • The toggle points can cause the mechanism not to have a smooth motion.
  • The moving mechanism can make noise when working especially due to friction or not well engagement of links.

In sum the process of our project consists of optimization, simulation, parts design, prototyping and manufacturing the final model. Optimization provided the appropriate link lengths for the purpose of generating the Gait motion. Simulation helped us visualize the motion of whole mechanism, find the proper velocity, obtain the necessary motor torque. The design of parts including the mechanism, the base structure, and the power transferring system were accomplished by SolidWorks. Prototyping revealed some issues that are hard to be seen during design process. The final model was manufactured on the basis of our design while removing the issues of our prototype.