Mathematical basis to control your hexapod robot

The purpose is to obtain, by computation, the angular value to affect to each leg joint in order to have the extremity of the leg reaching the required (X, Y and Z) position.
The adequate command can then be set for the three servo-motors of the leg.
Different methods can be used to achieve joint angle computation (trigonometry, matrix, quaternions...). We choose here to present the pure trigonometric method, surely not the optimal in terms of speed, but easier to understand.

Tutorial : using trigonometry to control an hexapod

See pdf tutorial

Implementation

A dynamic link library written in C language includes all the methods introduced in the tutorial and is available for download.
A graphical user interface written in C# is also provided in order to offer rapid testing of all the library methods.

VisualStudio projects

Go further

For the development of more efficient algorithms it is advantageous to use matrix or quaternions for marks or points rotations computation.