← Dynamic Systems Engineering Foundations · Semester 1, Week 6
Feedback, Control, and Cybernetics
Theme
A system cannot remain effective without feedback. This week introduces cybernetics as the study of communication, regulation, and control in dynamic systems. Students learn how systems maintain stability, adapt to change, and correct errors through feedback mechanisms. The emphasis is on understanding why feedback is necessary and how it enables learning and adaptation.
Learning Objectives
By the end of this week, students should be able to:
- Explain the purpose of feedback in dynamic systems.
- Distinguish between positive and negative feedback.
- Identify controllers, sensors, and actuators within a system.
- Describe how systems maintain essential variables within acceptable limits.
- Analyze feedback loops in natural, engineered, and social systems.
- Explain why adaptation depends on continuous feedback.
Core Vocabulary
Feedback · Positive Feedback · Negative Feedback · Controller · Sensor · Actuator · Error Signal · Set Point · Regulation · Adaptation · Essential Variable · Cybernetics
Key Concepts
Feedback is information about the current state of a system that is used to influence future behavior. Without feedback, a system cannot determine whether it is achieving its intended purpose.
Positive feedback amplifies change. Examples include population growth, viral social media trends, and financial bubbles. Positive feedback promotes rapid change but can become unstable if not balanced.
Negative feedback reduces error and stabilizes a system. Examples include a thermostat regulating room temperature, cruise control maintaining vehicle speed, and the human body's regulation of temperature. Negative feedback supports stability and reliable performance.
Every dynamic system has variables that must remain within acceptable limits to continue functioning. Students should identify which variables are essential, what disturbances threaten them, and what feedback mechanisms regulate them.
Every feedback system contains: a desired state or goal, sensors that observe the current state, a controller that compares the current state to the desired state, actuators that change system behavior, and feedback that reports the results.
Anchor Example — Thermostat
Anchor Example — Human Learning
Anchor Example — AI Assistant
AI Laboratory
Choose a familiar system and ask the AI to identify: the desired state, sensors, controllers, actuators, feedback loops, and essential variables. Evaluate whether the AI's model is complete and whether any important feedback pathways are missing.
Assignment
Select a dynamic system and document: system purpose, desired state, essential variables, sensors, controllers, actuators, positive feedback loops, negative feedback loops, and potential failure modes if feedback is delayed or absent.
End-of-Week Competency
Students can identify and analyze feedback structures, explain how systems regulate themselves, and recognize the role of cybernetics in adaptation and control.