20.2 Kinematic Analysis
Ideal Motion/Force Profiles
This ideal motion can be better scene for the entire linkage at the bottom of this page with the Full Range of Motion Animation
Subsystem Mobility Calculations
Our mechanism contains 10 links including 4 ternary links (not counting ground), as well as 13 full joints and 0 half joints.
Thus by Gruebler-Kutzbach Equation this mechanism has 1 DOF
Position, Velocity, and Acceleration Analysis of Points and Links of Interest
Forces
F= ma: Force is just directly proportional to the acceleration found above. Since we have not finalized the mass, we do not have a force rating to size our motor.
Interesting Mechanism Features
Probably the most interesting thing about our mechanism is that it’s essentially just three of the links analyzed above in Subsystem Mobility Calculations. The only difference is what part of the rotation a given leg is on a time, which you can see bellow in the Animation of the full linkage for one side. The front and back leg are in sync, but the middle leg is off by about half of a full rotation. The goal of course being to maximize stability.
Also of note is that the third leg doesn’t contain the extra links on top of the moving leg system. Those are there to transfer the momentum to the next leg so motor can spin one, moves the next one, moves the next one.
Additionally, the set of three ternary links are held together by a very small 4 bar mechanism which amplifies the changes in the angle of the bottom links.
Full Range of Motion Animation