1. For the arm with three degrees of freedom shown in the figure, please answer all the

questions below: [4 marks]

yo

L₁

L3

8₂

a) Define all the required coordinate systems associated with each joint based on the DH

method. [y-axis direction is given; you have to assume the other axes directions] (0.5

mark)

b) Derive link parameters based on the answer in a). (DH method!) (0.5 marks)

c) Derive the kinematic equations for ³Ho based on the answer in b). (1.5 marks)

d) Solve the forward kinematics problem using the following input data:

L₁ = 4, L₂ = 2, L3= 1 (m), and Ⓒ = {0₁, 0₂, 03}¹ = {——,——‚— —} assume the numerical

values of the angles less than 90 degrees. (1 mark)

e) Check your result in d) by sketching the robot configuration as a line diagram to

represent robot links. (0.5 marks).