Assignment 2

Fall 2013--Assignment 2--Due at start of Class 3 on September 17th

Requisite variety of a first-order feedback, automatic system (diagram)

As with the last assignment, identify a system that includes automatic feedback

• The system should nor rely on a person to close the feedback loop.
• You may use the same system you used in the last assignment

Then, determine if the system has requisite variety; explain your judgement.

If your system does not have RV, suggest how to modify it to achieve RV.

If you system does have RV, broaden its goals and extend the system to achieve RV for the new goal. (You might think of this as 'improving' a product.)

Create a diagram of the system (on a single 8.5 x 11 inch page).

• Identify the specific components of the system and their functions (e.g. sensor, comparator, actuator, disturbance, response, etc.)
• Include the range, resolution, and frequency of the sensor(s) and actuator(s)
• Represent the relationships between components visually
• Title the system
• Include your name, the date, and assignment number

In addition to the questions from the last assignment sheet, your diagram should help its audience answer these questions:

• In what ways might the system fail? (The type of possible disturbances)
• What is the relation of the system's goal to the range, resolution, and frequency of its sensor and actuator?
• Is there a mismatch? If so, where? How should it be corrected?
• If there is no mismatch, suggest how the system might be 'improved' by adding sensing and acting in another dimension. (For example, a thermostat/furnace system might be improved by adding an air conditioner or humidifier/dehumidifier thus contributing to a higher-level goal of comfort.)
• Describe how your new dimension makes sense in the system (how it serves the same higher-level goal as the dimensions in the original system).

The ability to answer these questions from the model helps ensure that you understand the concept of RV and can apply it to a given system. 

Please make two printouts, one to use during class, and one to hand in. Please also place a copy of the assignment in the dropbox folder marked 'Assignment 2' BEFORE class begins.