Servo motors are typically employed in closed-loop position control; for example let us consider the following application, where the angular position of the output shaft is intended to follow the reference voltage (ϴref).
The potentiometer mounted on the output shaft provides a feedback voltage proportional to the actual position of the output shaft. The voltage from this potentiometer must be a linear function of angle, and must not vary with temperature; else the accuracy of the system will be affected.
The feedback voltage – representing the actual angle of the shaft, is subtracted from the reference voltage – representing the desired position and the resulting position error signal is amplified and used to drive the motor so as to rotate the output shaft in the desired direction. When the output shaft reaches the target position, the position error becomes zero, no voltage is applied to the motor, and the output shaft remains at rest. Any effort to physically move the output shaft from its target position immediately creates a position error and a restoring torque is applied by the motor.
Related: How Servo Motors are used in Process Control
The tachometer feedback is used in addition to the main position feedback to help improve the dynamic performance of the system.
Vision Sensors A vision sensor is basically a TV camera connected to a computer, usually…
Sampling Systems The Purpose of Sampling Systems The objective of a sampling system is to…
The major limitation of a conventional feedback control system is that the correction for disturbances…
Electromagnetic Compatibility (EMC) is one of the key factors of consideration in the design, construction,…
This category of AC drives that is often referred to as “Variable Frequency Inverters” is…
Analog systems are normally based on low voltages and as a result, they are vulnerable…
