Hexapod as a 6dof platform

The omnidirectional, 3dof each leg, hexapod programmed as a 6dof platform; the platform being the robot body. Actually only 2degrees of freedom of only 3 legs are required so there is a lot of redundancy in the robot since there are 18 degrees of freedom in the complete robot. Interestingly, a walking hexapod can be thought of as a mobile Stewart platform

Compact in-line design

This robot was a one-off design that used 3dof legs and all electronics and microcomputers (7 x Basic Stamp2SX) hidden in the central tubular body. This body was CNC machined from solid aluminium alloy bar such that the wall thickness was machined down to only 1mm thickness resulting in a lightweight stiff and strong structure on which to mount the legs.

Tracking robots

Research into tracking and stalking of a robot by another robot. These robots are early 2dof leg hexapods that are in need of adjustment since they are walking with a limp. 2dof leg robots are not omnidirectional and are similar to tracked tank vehicles. They can turn but the leg tips slip on the ground. These robots were later abandoned in favour of 3dof leg robots which are omnidirectional.

Behaviour patterns for omnidirectional hexapod

Clips showing a sample of the behaviour patterns possible with the omnidirectional hexapod. Note that the computer architecture facilitating these patterns consists of 7 Basic Stamp2SX microcomputers that use only 16-bit integers and no trigonometrical functions other than to use integer multiplication, division, addition and subtraction. Specialised low complexity algorithms have been developed to solve complex inverse kinematics equations in less than 20msec.

Latest Hexapod, circular design

Great care has been taken with this latest design. For example, (i) 60 ball bearing races are used for the leg and tendon joints to give low friction, long life, extremely low maintenance and high repeatability, (ii) legs have low mass with hollowed out “bones”, high stiffness and low polar moment of inertia brought about by careful design, CNC precision machining, and use of aluminium alloy, Delrin plastic and carbon fibre materials.

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