i
a
i
−
1
/
mm
α
i
−
1
/
rad
d
i
/
mm
θ
i
/
rad
1
0
0
d
1
0
2
0
0
d
2
θ
2
3
a
2
0
d
3
θ
3
4
a
3
0
d
4
θ
4