ECE 470: Introduction to Robotics Homework 4
Question 1.
You are tasked to design the joint control for the manipulator arm analyzed in
Homework 3. Using the control partitioning law, and the formulated dynamics in
Homework 3, fill in the required expression (a)-(d) in the block diagram shown in
Figure 1. (6 Points)
Figure 1.
Question 2.
a) Consider a single-link manipulator arm shown Figure 2.
i) Formulate the dynamic equation factoring coulomb and viscous force acting on the
joint and loading due to gravity. You may assume that viscous and coulomb frictions
result in resisting moment 𝑀𝑣 = 𝑏𝑣𝜃̇ and 𝑀𝑐 = 𝑏𝑐sgn (𝜃̇), respectively. (2 Points)
ii) Draw the control block diagram illustrating the use of control law partitioning for
the non-linearities in the system. (8 Points)
You may assume negligible mass distribution for the link and assumed lumped mass at
the distal time as shown.
b) A DC motor is installed to drive the arm with motor torque 𝜏𝑚 input to a gear
transmission ratio 𝜂. Redraw the control diagram incorporating the dynamics of the
actuator. (4 Points)
Figure 2 (a)-(b).
