5. 5
D-H Algorithm
1. Number the joints from 1 to n starting
from the base and ending with tool
yaw, pitch and roll in that order
2. Assign a right handed orthogonal
coordinate frame L0 (x0y0z0) to the base
such that z0 axis is aligned with the
axis of base joint (J1). Set k=1
6. 6
3. Assign zk to the axis of joint
(k+1)
4. Locate the origin of Lk at the
intersection of zk and zk-1. If they
do not intersect, use the
intersection of zk with the
common normal between
zk and zk-1
7. 7
5. Select xk to be orthogonal to both
zk and zk-1. If zk and zk-1 are
parallel, point xk away from zk-1
6. Select yk to form a right handec
cordinate frame Lk
7. Set the origin of Ln at the tool
tip.
8. 8
8. Align zk along the approach
vector, yk along the sliding vector
and xk along the normal vector of
the tool.
11. 11
Link Length ak
It is the distance to be covered by zk-1
along xk axis so as to intersect zk.
Link Twist Angle αk
It is the angle by which zk-1 should
be rotated about xk axis so as to
make it parallel to zk.
13. 13
Joint Distance dk
It is the translation required along zk-1 axis
so that xk-1 intersects xk.
Joint Angle θk
It is the rotation about zk-1 axis
required to make xk-1 parallel to
xk.
