Question 4:
a) Using Figure Q4-1, explain the potential field algorithm for obstacle avoidance. With the potential fields shown in Figure Q4-1, how does one calculate the required force to be applied to the robot at each point (x, y)?
U_target()
U_obstacles
U_x
Target
Figure Q4-1: Potential fields generated by target and obstacles and the resulting overall field.
Figure Q4-2 illustrates the resulting potential fields and the required force to be applied to the robot at each point (x, y) to avoid obstacles. Answer the following questions:
- What do the contours show and what do the numbers on them mean?
- What do the blue vectors show at each point on the map?
- What are the black circles in the middle and the green one on the right side of the image? [6 marks]
b) In Figure Q4-2, if a robot is initially located at either of the red circles, suggest the paths that the robot will follow towards its destination. Hint: You need to redraw Figure Q4-2 on your answer sheet as an XY diagram with the obstacles and the initial and destination points, and then draw the suggested paths.
Explain the rationale behind your suggested paths.