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).