Feedback control is defined as a control that uses which elements to set the manipulated variable?

Feedback control is defined as a control that uses which elements to set the manipulated variable?

• A. The sensor reading and the setpoint
• B. Only the setpoint without sensing
• C. Only the sensor reading with no setpoint
• D. Random disturbances to adjust the variable

Answer: (A)

In feedback control, the controller determines the manipulated variable by comparing where you want the process to be with what the process actually is. The setpoint provides the target value, and the sensor reading gives the actual measured value. The difference between these two—often called the error—drives the controller to adjust the manipulated variable to reduce that error. This uses negative feedback to reject disturbances and keep the process at the desired level. Without the setpoint there’s no target to aim for, and without the sensor reading there’s no way to know how far off you are. Random disturbances aren’t a deliberate source for setting the manipulated variable; they are factors the controller tries to compensate for. So the correct idea is that both the sensor reading and the setpoint are used to set the manipulated variable.

In feedback control, the controller determines the manipulated variable by comparing where you want the process to be with what the process actually is. The setpoint provides the target value, and the sensor reading gives the actual measured value. The difference between these two—often called the error—drives the controller to adjust the manipulated variable to reduce that error. This uses negative feedback to reject disturbances and keep the process at the desired level. Without the setpoint there’s no target to aim for, and without the sensor reading there’s no way to know how far off you are. Random disturbances aren’t a deliberate source for setting the manipulated variable; they are factors the controller tries to compensate for. So the correct idea is that both the sensor reading and the setpoint are used to set the manipulated variable.