# 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}= x

^{2}+ h

^{2 }---- ① and, when ∠OLD = 0° then ∠OE'B = 0° so, z-y = h

^{ }---- ② (As a matter of fact, yz = x

^{2}is true, too. ∠OLD = ∠OE'B is always true.) ① is (h+2y)

^{2}= x

^{2}+ h

^{2 }-----→ y is given.