Week 3: Open Loop and Closed Loop Control Systems Flashcards
(13 cards)
What is a control system
A control system is a set of subsystems and processes assembled together for the purpose of achieving a desired response with a desired performance given a specified input
What are the classifications of Industrial control
What they control: motion, process
What is the function of a motion control system
It controls the physical motion or position of an object
What is the function of a process control system
It regulates one or more variables of a process
What are the four main components of a feedback control system
The process, the feedback loop, the summing point, and the control device
What is the input into a control system
This is the desired value or setpoint for the system’s output. It represents what we want the system to achieve
What is the function of the error detector summing point
It compares the input signal with the feedback signal
What is the error signal
It represents the difference between the input and output from the summing point
What is the function of a controller in a control system
The controller processes the error signal according to a specific control algorithm and generates an actuating signal that drives the plant in the way that reduces the error signal to zero or minimum acceptable value
Give examples of closed loop control system
Analyse the setpoint, sensor and actuator in a level control in a tank
Setpoint: desired level in a tank; Sensor: level sensor providing the feedback signal; Actuator: control valve regulating the flow of liquid
Analyse the setpoint, sensor and actuator in a position control of a robot
Setpoint: desired position of robotic arm; Sensor: linear or angular sensors providing feedback of the actual position; Actuator: servomotor
Where are open loop control systems unsuitable
For applications where precise control is required or when disturbances in the process can significantly impact the output
