# Forward kinematics on Stanford manipulator

I recently had an exam in robotics and one of the questions was about forward kinematics on the Stanford manipulator below.

The DH parameters were given and we were asked to calculate the angular velocity $v_6$. The question mentioned that there was a trick, a shortcut of sorts, so that we would arrive at the answer faster than going through the full forward process, calculating $v_{1-6}$ and $w_{1-6}$ using the all rotation matrices. Does anyone know that trick? Would be really helpful to understand something like that for the resit, when you only have 90min for the whole exam.

Thanks!

• I cannot accurately enter all the equations from my phone, so I’ll point you to a good description of a simpler way to compute the angular velocity of the final link. Read section 6.5 of this course: course.ccs.neu.edu/cs4610/L9/… – SteveO Mar 14 '18 at 0:08