A 500 kg capacity manipulator may need a force in the horizontal cylinder of around 17 tonnes to push the arms out from minimum radius. Larger machines will need larger forces, so a cylinder is supplied to push with this force. However once the load has reached top dead centre it needs no force for the other half of the horizontal stroke because gravity can do the work.
This means that if the operator stalls the machine against the floor or a conveyor the cylinder force of around 17 tonnes plus the self weight of the manipulator, act together to cause very large stall loads on the machine. This leads to breakages because in certain positions of the machine, the bending moments which these forces cause, are large.
In the diagram it can be seen that all the force from the cylinder is available for doing damage.
But the force still exists because the cylinder knows only to push with a force of 17 tonnes.
So Clansman Dynamics cuts that force to a negligible figure once the manipulator is beyond a certain point in the envelope. The operator is completely unaware of the change of mode. There is no loss in performance.
But Selective Force Limitation gives a 40% reduction in the forces that act to destroy the manipulator (and conveyors, monorails, etc.).