Table 1.

D-H parameters for the 7 DOFs arm model.

Link	DOF	αi	ai	θi	di	Type	Offset
1	Sh X	π/2	0	π/2	0	P	0
2	Sh Y	π/2	0	π/2	0	P	0
3	Sh Z	π/2	0	π/2	0	P	0
4	Sh adduction	π/2	0	0	0	R	−π/2
5	Sh flexion	π/2	0	0	0	R	π/2
6	Sh external rotation	π/2	0	0	LU	R	π
7	El flexion	0	LF	0	0	R	π/2

Sh, shoulder; El, elbow; L_F, forearm link length; L_U, upper arm link length; P is for prismatic joints and R is for revolute joints.