A hexapod is a spatial movement machine with six drive elements.
A hexapod (hexa (greek): six , pod (greek): foot) is a special form of a parallel kinematic machine that has six legs. The typical construction of the hexapod allows mobility in all six degrees of freedom (three translational and three rotational). Due to the parallel arrangement of the drives, hexapods have a better payload to deadweight ratio compared to serial robots.
The first hexapod is said to have been built in the 1950s.
Advantages:
- High dynamics and low moving masses. This results in high accelerations and final speeds (rapid traverse) and a correspondingly faster workpiece machining or manipulation.
- Positioning accuracy is basically better with a parallel kinematics system, since position errors of the axes do not accumulate.
- High mobility. The degree of freedom of the tool or the tool holder reaches almost spherical 5-sides. However, traditional machines with serial kinematics today achieve a comparably high degree of freedom with the simultaneous use of pivoting tool heads and rotating clamping tables.
Disadvantages:
- The spatial clamping of the hexapod construction results in a limited mobility. For the same reason, a hexapod construction in machine tools requires a comparatively larger footprint.
- The lower mass of the construction requires a much higher susceptibility to vibration, which is generally very undesirable, especially during machining (roughness).
- Design-related sensitivity or a correspondingly high wear of the usually very expensive feed modules.
References
- Wiki page (german)