State + relational control
1
i
j
k
𝒬°
OPERATOR
scalar / identity
rotation basis
rotation basis
rotation basis
q = a + bi + cj + dk
Quaternion = orientation state · 𝒬° ≠ fifth component
Two rails + moving belt
L
R
S = R − L
0.00
−1
+1
ξ
Q
= 2(x − L)/(R − L) − 1 ∈ [−1,+1]
Rails = bounds · belt = channel · width = scale
▶ Play
Scale width
100%
Joystick coordinate ξ
Q
0.00
q
state
·
𝒬°
operator
·
ξQ
control coordinate
·
wᵢ
pressures / weights
·
Δq
orientation change