The advantages of stepper motors include high positioning accuracy, simple control, and relatively low price. Stepper motors can be precisely positioned based on pulse signals, making them suitable for applications requiring high precision and low speed, such as printing presses and plotters. Furthermore, their relatively low price makes them suitable for use in situations where budget is limited.
The advantages of servo motors include a wide speed range, fast response, high precision, and strong load capacity. Servo motors achieve precise position, speed, and torque control through feedback control, making them suitable for high-speed, high-precision motion control, such as in machine tools, automated production lines, and robots. Furthermore, servo motors possess strong load capacity and response speed, enabling them to adapt to relatively complex control requirements.
Therefore, the choice of motor depends on the specific application and requirements. If high precision, low speed operation is required and cost is limited, a stepper motor can be chosen; if high speed, high precision, fast response, and high control accuracy are required, a servo motor can be chosen.
Stepper motors and servo motors are two different types of electric motors, and their main differences lie in their working principles, control methods, and performance characteristics.
The working principles are different: stepper motors achieve precise stepping motion of the rotor by sequentially exciting each phase winding in the stator, while servo motors achieve high-precision motion by precisely controlling the rotor position, speed, and acceleration.
The control methods differ: Stepper motors have a relatively simple control method, requiring only the control of the excitation signal to the stator windings, which can be achieved using controllers such as microcontrollers and PLCs. Servo motors, on the other hand, require a more complex control system to achieve high-precision position, speed, and acceleration control, typically necessitating the use of specialized servo controllers and encoders.
The performance characteristics differ: Stepper motors typically have high torque and low speed, enabling precise positioning control, but their accuracy and speed range are relatively narrow. Servo motors, on the other hand, can achieve higher precision, speed, and acceleration, and are widely used in high-precision applications such as robotics and automated equipment.
Stepper motors and servo motors have different low-frequency characteristics: One drawback of stepper systems is the inherent resonance point. The SR series stepper driver automatically calculates this resonance point and adjusts the control algorithm accordingly to suppress resonance, greatly improving mid-frequency stability and resulting in greater torque output and superior high-speed performance. Servo motors operate very smoothly, without vibration even at low speeds. AC servo systems have resonance suppression capabilities, compensating for insufficient mechanical rigidity, and incorporate frequency response time (FFT) to detect mechanical resonance points, facilitating system adjustments.
Operating performance differs: Stepper motors are generally open-loop controlled, which can lead to step loss or stalling when the starting frequency is too high or the load is too heavy. Therefore, it is necessary to handle the speed issue or add an encoder for closed-loop control when using them. See what a closed-loop stepper motor is. Servo motors, on the other hand, use closed-loop control, which is easier to control and does not have the problem of step loss.
The two motors differ in speed and overload capacity: Stepper motors are prone to low-frequency vibrations at low speeds, so damping techniques are typically used to overcome this, such as adding dampers to the motor or using microstepping technology in the driver. Servo motors, on the other hand, do not exhibit this problem; their closed-loop control characteristics ensure excellent performance at high speeds. Their torque-frequency characteristics also differ; generally, the rated speed of a servo motor is higher than that of a stepper motor. The output torque of a stepper motor decreases as the speed increases, while a servo motor provides constant torque output. Therefore, stepper motors generally lack overload capacity, while AC servo motors have a stronger overload capacity.
In general, stepper motors and servo motors have their own advantages and disadvantages in different application scenarios, and the appropriate motor type should be selected according to the specific application requirements.
