Comparison of crank based leg mechanism/Intro

in General

This comparison is limited to crank based walking mechanism. This removes a lot of linkages, but makes it easier to compare the mechanisms. Being cranked based, they might be tricky to construct and manufacture, but are easy to operate. All it needs is an engine/motor connected to the crank.

In the literature, crank-based mechanisms can also be found as Single deegre of Freedom (SDOF) mechanism.

Crank based mechanism have some disadvantages. Namely: Usually, stride length and height can not be adjusted. Also, the mechanism must be designed for static walking.

If not noted otherwise, the linkage can also be driven backwards, allowing the robot/mechanism to reverse.

For comparison, all mechanisms are normalized to a stride length of 1.

The simulation run with 10 Deg. per Step, meaning 36 steps per revolution.

First we will compare one leg of each mechanism. Next we will compare how those linkages become a vehicle/robot. Note that not all designs are proven in practice.

The comparison here is mainly based on simulation/calculation as a planar mechanism.

As it is a comparison, the book shall focus on comparing, basic theory as required for comparison. The full discussion on specifics should be done on Wikipedia or Wikibooks. The exception are very simple mechanism that for them shelf are not wikipedia relevant.

The book/article Klann linkage is a companion book, as the Klann Linkages has some complexity, but as of now did not have a good and easy to read (online) articles.

Note that the history of leg mechanism is linked to the history of straight line mechanism.