Sensors, controllers and actuators
Before writing a single line of a program, you need to know what the system is going to measure, what it is going to decide and what it is going to move. Each of the three elements has its own rules, and mixing them up is the cause of many systems that "almost" work.
Sensors: how the system measures the world
Name the three basic components of a control system and explain what each one does using the example of a heating thermostat.
Name the three basic components of a control system and explain what each one does using the example of a heating thermostat.
Classify these components into sensors, actuators, and controller: a light sensor (LDR), a motor, a buzzer, a microcontroller board, a push button, and a servomotor.…
Classify these components into sensors, actuators, and controller: a light sensor (LDR), a motor, a buzzer, a microcontroller board, a push button, and a servomotor. Justify each classification based on what the component does.
The figure shows the chain of a control system, but the central block is missing. State what block this is, what it does, and write the complete chain (with concrete…
The figure shows the chain of a control system, but the central block is missing. State what block this is, what it does, and write the complete chain (with concrete examples for each block) for an automatic garage door.
The controller: the logic that decides
Many of a controller's decisions come down to combining conditions with logical operators: is this true and this other thing as well? Is this true or this other thing? Logic gates are the way to represent and combine those conditions.
Classify these elements as sensors or actuators and justify each decision: microphone, speaker, camera, light bulb, motion sensor, and relay that switches on a motor.
Classify these elements as sensors or actuators and justify each decision: microphone, speaker, camera, light bulb, motion sensor, and relay that switches on a motor.
A smart plant pot waters the plant when the soil is dry. Identify the sensor, controller, and actuator of this system and explain what information passes from one…
A smart plant pot waters the plant when the soil is dry. Identify the sensor, controller, and actuator of this system and explain what information passes from one component to another.
A standard fan runs until you switch it off, but an air conditioner stops and starts by itself to maintain the temperature. Explain the difference between both systems…
A standard fan runs until you switch it off, but an air conditioner stops and starts by itself to maintain the temperature. Explain the difference between both systems using the concept of feedback: which one re-measures the result of its action?
Actuators: how the system acts on the world
A traffic light operates on fixed timings, whether cars pass or not. Does this control system have sensors? What sensor would you add to make it "smart", and how would…
A traffic light operates on fixed timings, whether cars pass or not. Does this control system have sensors? What sensor would you add to make it "smart", and how would that change improve it?
Analyse the full control chain of a push-button pedestrian crossing: what it detects, decides, and actuates at each stage, and explain what happens if the button sensor…
Analyse the full control chain of a push-button pedestrian crossing: what it detects, decides, and actuates at each stage, and explain what happens if the button sensor fails and what failsafe behaviour the system should have.
Design a system that maintains a school greenhouse between $18\ ^\circ\text{C}$ and $25\ ^\circ\text{C}$: select the sensors and actuators and describe the controller's…
Design a system that maintains a school greenhouse between $18\ ^\circ\text{C}$ and $25\ ^\circ\text{C}$: select the sensors and actuators and describe the controller's decision logic using clear rules (if..., then...).