Motion Graphs
Background: My goal is to create a robust suspension analysis tool for bicycles. Similar to Linkage X3, the program is able to take a series of vectors defining the suspension mechanism and derive responses (e.g. leverage ratio, wheel path, AS, AR, etc.)
Coding method: I am using Matlab. The code is simple - I store rotation angles for each rigid body and use initial conditions to calculate a position on any body at any point in travel.
Several examples are plotted below. I automatically generate these animations in After Effects using .csv outputs from Matlab. The full capabilities of the current tool are shown in the first image below. The Matlab/After Effects workflow produces automatically scaled graphs, animations, and a correct linkage visualization.
DW-link is a 4-bar mechanism with a short upper and lower rotating link.
VPP is a 4-bar mechanism with long, counter-rotating links. Commonly used by Santa Cruz.
CBF is a 4-bar mechanism with two long-ish links that co-rotate. This mechanism seems to be somewhere between DW-link and VPP.
ABP is a 4-bar mechanism where the lower link is the entire chain stay. The swingarm and lower link share a pivot at the rear axle. The axle path is the same as a single-pivot, but the upper linkage enables specific suspension tuning.
Horst link is a 4-bar mechanism with a long lower link. This is a very popular style.
Linkage driven single pivot. The single pivot location defines the wheel path and most kinematics. The shock linkage determines the shock response.
