16-311 Homework 3

Learning Objectives

1. Connect sensing and odometry concepts from Lab 3.
2. Reinforce basic controls.
3. Expand control themes to follow a path.
4. Practice making block diagrams.

Background

See the Lab 3 page for information on odometry.

Pure pursuit is one method of tracking a path. This Technical Report by Craig Coulter summarizes this approach. This MATLAB documentation also provides helpful diagrams and information.

Block diagrams are used to summarize parts of a controlled system. There are established rules for simplifying block diagrams, but we will stick to relatively simple systems in this class. Common blocks include "Plant", which is the overall system, and "Controller" which would be where the PID, LQR, etc. is implemented. Arrows represent the transmission of information from one block to another.

Control can be "open loop", where there is no feedback to the system or "closed loop", where there is feedback. "Feedback" refers to information obtained by the robot that is measured after an action is taken and used to inform the next action.

Arrows can be split to indicate that the value is used in multiple places. Summing/difference points represent places where values are added or subtracted.

Homework Requirements

The specifications for Homework are presented in the following document.

Homework 3 Handout

Extensions

The course Sensing and Sensors (16-722) provides in depth information about types of sensors and strategies for using them.

If you are interested in more complicated block diagrams, this resource provides a good summary of combination rules.