Motions of a Hexapod Robot

The Stewart–Gough or Hexapod platform consists of six extensible legs connecting a fixed base to a movable platform. The platform is capable of moving with six degrees of freedom, three translational and three rotational. The Inverse Problem in robotics, calculating the actuator coordinates (leg lengths) for a given platform orientation, is straightforward in this situation. Simple geometry is all that is needed to express the rotation and translation matrices. In a nutshell, the nominal platform coordinates of the legs are rotated and translated by the desired values. Then the leg lengths are calculated by simply taking the norm of the difference between the base and platform coordinates for each leg. This Demonstration uses homogeneous coordinates to combine the rotations and the translations into a single matrix operation.