System – A set of connected things or parts forming a complex whole, in particular. A set of things working together as parts of a mechanism or an interconnecting network.
Systems can be any size – from microelectromechanical (tiny) to enormous (power generating plants)
Systems engineering – about the whole process of a project
Process
- uncontrolled – settlement pond
Process controls – statistics and engineering discipline that deals with the mechanism, architectures, and algorithms for controlling a process. Some examples of controlled processes are:
- Controlling the temperature of a water stream by controlling the amount of steam added to the shell of a heat exchanger.
- Operating a jacketed reactor isothermally by controlling the mixture of cold water and steam that flows through the jacket of a jacketed reactor.
- Maintaining a set ratio of reactants to be added to a reactor by controlling their flow rates.
- Controlling the height of fluid in a tank to ensure that it does not overflow.
Control systems – control via an embedded system.
How stuff works – System dynamics, the study of the behavior of complex systems
- the behavior of complex systems over time
- internal feedback loops and time delays that affect the behavior of the entire system
- stocks and flows
These elements help describe how even seemingly simple systems display baffling nonlinearity.
Control systems – device, or set of devices, that manages, commands, directs or regulates the behavior of other device(s) or system(s).
- airplane autopilot
- oil refinery
- home heating thermostat
- car engine cooling
There are of course other ways of controlling a system, such as designing it to mechanically self-regulate. While mechanical regulation is definitely a method of controlling a system, it often isn’t lumped in with “control systems”.
- Computers & Information Engineering
- Design Engineering
- Dynamic Systems & Control
- Electronic & Photonic Packaging
- Fluid Power Systems & Technology
- Information Storage & Processing Systems
- Microelectromechanical Systems
Failures in Process Control – Catastrophic failures in process control remind us of the importance of control systems and engineering. Bhopal, India Disaster, Three Mile Island Disaster, Texas City Disaster
Sensors and Actuators
- Control Systems: Measurement devices
- Temperature sensors
- Pressure sensors
- Level sensors
- Flow sensors
- Composition sensors
- pH and viscosity sensors
- Miscellaneous sensors
- Valves: types, kinds, and selection
- Valves: modeling dynamics
modeling systems, analysis
- Simulink
- Modelica – open, free library – model mechanical (1D/3D), electrical (analog, digital, machines), thermal, fluid, control systems and hierarchical state machines.
Engineering ideas
- system components, comparator, controller, plant, sensor, variable, input, output, complexity, behavior, predict, signals, flow
- control effort, measured output, error signal, closed loop system
- proportional control, integral control, and combinations of proportional and integral (plus derivative?) control
- mathematical techniques that involve differential equation solution
- linear system, transfer function
- xogenious
Do it
Here are some challenges for you to work on…
Learn more…
- An Introduction to Control Systems
- Control Systems – open textbook – online, free
- Embedded Control Systems Design – open textbook – online, free
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