Desirable Properties of a Servomotor in Feedback Control Systems

In feedback control systems, a servomotor is an important component that converts electrical signals into mechanical motion. It plays a crucial role in achieving accurate and precise control of various systems. There are several desirable properties of a servomotor in feedback control systems, but one of them stands out as not being desirable.

A. Fast Response:
One of the key desirable properties of a servomotor is its ability to respond quickly to changes in the control input. A fast response ensures that the motor can quickly track changes in the reference signal and adjust its output accordingly. This property is important in applications where rapid and precise motion control is required.

B. Linear Torque-Speed Characteristic:
Another desirable property of a servomotor is a linear torque-speed characteristic. This means that the torque produced by the motor should be directly proportional to its speed. A linear characteristic allows for more accurate control and better performance of the system. It simplifies the control algorithms and ensures that the motor operates consistently across different speeds.

C. Reversibility:
Reversibility is another important property of a servomotor. It refers to the ability of the motor to rotate in both clockwise and counterclockwise directions. This property enables bidirectional control and allows the motor to perform tasks that require motion in both directions. It is particularly useful in applications such as robotics, where precise and flexible movement is required.

D. Non-linear Relation between Electrical Control System and Rotor Speed:
The property that is not desirable in a servomotor for feedback control systems is a non-linear relation between the electrical control system and rotor speed. In feedback control systems, linearity is generally preferred as it simplifies the control algorithms and ensures predictable and consistent behavior. Non-linearities can introduce complexities and uncertainties in the control system, making it difficult to achieve accurate and precise control.

Non-linearities can be caused by various factors such as friction, saturation, and non-linearities in the motor's magnetic circuit. These non-linearities can lead to inaccuracies and unpredictability in the motor's response, making it challenging to achieve the desired control performance.

In summary, while a servomotor in a feedback control system should have a fast response, linear torque-speed characteristic, and reversibility, a non-linear relation between the electrical control system and rotor speed is not a desirable property as it can introduce complexities and uncertainties in the control system.