Algorithm 1.

UKF&GPR for Grip Force Estimation

Train GPR with training data (X,Y)

Calculate sigma points χt−1 = {χt−1,i},i = 0, ⋯, 2L of X* according to Eqn. 4

Pt|t−1 = Pt−1 + Qt

for i = 0, ⋯,2L do

Calculate γt−1,i = GP(χt−1,i)

end for

$Y_{\ast }={\displaystyle {\sum }_{i=0}^{2L}{W}_i^m{\gamma }_i}$

$P_t={\displaystyle {\sum }_{i=0}^{2L}{W}_i^c\left({\gamma }_i-Y_{\ast }\right){\left({\gamma }_i-Y_{\ast }\right)}^T}$