Control
Control
Control is the process of managing and directing the behaviour or operation of a system so that it achieves a desired outcome. Control ensures that a system does what it is supposed to do, when it is supposed to do it, and within safe and efficient limits.
What does control mean?
Control involves: - deciding what needs to be controlled in order for the system to operate safely and effectively - setting targets or limits using clearly defined parameters - making adjustments when the system deviates from what is expected
A system without control may still work, but it will be unpredictable, inefficient, or unsafe for its purpose.
Depending on your system will depend what kind of controls you need. For example, an automated dog door should not need any user interaction once it is operating, but the system will need to control itself to open and close as needed. On the other hand, an air-conditioning system needs to allow user control to set the mode, and desired temperature.
What can be controlled in a system?
Common things that require control include:
- temperature
- speed
- position
- angles
- force or torque
- voltage or current
- timing and sequence of actions
Not every part of a system needs control.
Control through parameters and calibration
Parameters
Parameters are values the system is designed to aim for or stay within. This could include maximum speed, maximum load on a DC motor, target angle, or targe speed. The parameters are individual to your system.
Calibration
Calibration is the process of adjusting a system so that its measurements and responses are accurate.
For example, when using an LDR you might find you are constantly adjusting the high and low values within your code. Using potentiometers to adjust those values allows you to step away from the code, and then provide calibration settings to the user.
Microphone modules have mini potentiometers on them to allow calibration of the sensitivity of the microphone.
Your system will have its own parameters that require calibration. You can create a control panel that uses switches and dials to set different parameters within your microcontroller, rather than going back and forth from your code.
Monitoring system performance
For control to work, the system must monitor itself.
Monitoring can be done using a range of different components, such as sensors, switches, timers, and logic.
Monitoring allows the system to determine whether it is behaving as expected, whether adjustments are needed, or whether a fault has occurred.
You can provide feedback to the user using speakers or lights.