Hart's A-frame walker
- Author:
- asifsound
Hart's A-frame linkage biped application.
Exact straight line. big stride.
■ Variation
Chebyshev linkage's bar ratio is fixed. But, above Hart's A-frame ratio is more variable.
ex. Very long stride leg is easy.
Bar length calcuration is easy.
if you want height = h, stride = x, ----- other bars are function(h, x)
i.e. BH=h, OL=LD=0.5 x,
so, then if OE'=y, E'B=z, solve next eq. ① & ②.
when ∠OLD = 180° then ∠OE'B = 180°
(y+z)2 = x2 + h2 ---- ①
and, when ∠OLD = 0° then ∠OE'B = 0°
so, z-y = h ---- ②
(As a matter of fact, yz = x2 is true, too. ∠OLD = ∠OE'B is always true.)
① is (h+2y)2 = x2 + h2 -----→ y is given.