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IB DP Computer Science — A1 Computer fundamentals — Operating systems and control systems | HL | A1.3.7
📋 What You Will Learn
- Apply a four-question framework to analyse any control system: what is sensed, what decides, what acts, what is fed back
- Explain how control systems work in everyday applications: thermostats, washing machines, automatic doors, home security
- Explain infrastructure-scale control: traffic signals, elevators and irrigation systems
- Explain the sense–decide–act loop of an autonomous vehicle and why it is a demanding closed loop
- Construct and trace a realistic control algorithm (soil-moisture irrigation with hysteresis)
🌍 Why This Matters Between waking up and reaching school you probably pass through a dozen control loops — the boiler thermostat, the fridge, a lift, several sets of traffic lights, an automatic door. Exam questions hand you one of these systems and ask you to take it apart; this note gives you the method.
A Framework for Analysing Any Control System
Every application in this note yields to the same four questions. Answer them in order and the explanation writes itself.
- 1. Input — what is sensed? Name the sensors and the physical quantities they measure.
- 2. Process — what