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Some common sense of servo motor, servo feeder manufacturers online


Release time:

2024-02-04

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Servo feeder manufacturers believe that the stepper motor is a discrete motion device, which is intrinsically linked to modern digital control technology. At present, the stepper motor is widely used in the domestic digital control system. With the advent of all-digital servo systems, servo motors are increasingly used in digital control systems. In order to adapt to the development trend of digital control, motion control systems mostly use stepper motor or all-digital servo motor as the executive motor. Although they are similar in control (pulse sequence and direction signal), they are very different in performance and application.

  Servo feederManufacturers believe that the stepper motor is a discrete motion device, and modern digital control technology has an intrinsic link. At present, the stepper motor is widely used in the domestic digital control system. With the advent of all-digital servo systems, servo motors are increasingly used in digital control systems. In order to adapt to the development trend of digital control, motion control systems mostly use stepper motor or all-digital servo motor as the executive motor. Although they are similar in control (pulse sequence and direction signal), they are very different in performance and application.

(1) control accuracy is different

Servo feeder manufacturers believe that the rotary encoder at the rear end of the motor shaft ensures the control accuracy of the motor. For the motor with standard 2500 line encoder, the pulse equivalent of the motor is 360/10000=0.036 due to the quadruple frequency technology adopted in the servo driver. For the motor with 17-bit encoder, the motor rotates once for every 217=131072 pulses received by the driver, I .e. the pulse equivalent is 360/131072=9.89 seconds. It is 1/655 of the pulse equivalent of a stepper motor with a step angle of 1.8.

(2) The moment frequency characteristics are different.

Servo feeder manufacturers believe that the output torque of the stepping motor decreases with the increase of the speed, and will drop sharply at a higher speed, so its limit working speed is generally 300~600 r/min. The servo motor is a constant torque output, that is, it can output rated torque within its rated speed range (usually 2000 r/min or 3000 r/min), and constant power output above the rated speed.

(3) Different low-frequency characteristics.

Servo feeder manufacturers believe that stepper motors are prone to low-frequency vibration at low speeds. The vibration frequency is related to the load condition and the performance of the driver. It is generally believed that the vibration frequency is half of the no-load take-off frequency of the motor. This low-frequency vibration phenomenon is determined by the working principle of the stepper motor, which is very unfavorable to the normal operation of the machine. When the stepper motor works at low speed, damping technology should generally be used to overcome the low-frequency vibration phenomenon, such as adding a damper on the motor or using subdivision technology on the drive.

Servo feeder manufacturers believe that the servo motor runs very smoothly, even at low speeds, there will be no vibration. The servo system has a resonance suppression function, which can make up for the lack of mechanical rigidity. The system has a frequency analysis function (FFT), which can detect the resonance point of the machine and facilitate system adjustment.

(4) different operating performance.

Servo feeder manufacturers believe that the control of stepping motor is open-loop control. If the starting frequency is too high or the load is too large, it is easy to lose step or stall, and if the speed is too high, it is easy to overshoot. Therefore, in order to ensure its control accuracy, it is necessary to deal with the problem of speed increase and speed reduction. The servo system is closed-loop control. The driver can directly sample the feedback signal of the motor encoder, and form a position loop and a speed loop inside, so that the stepper motor will not lose step or overshoot, and the control performance is more reliable.

(5) different speed response performance.

Servo feeder manufacturers believe that it takes 200 to 400 milliseconds for the stepper motor to accelerate from rest to working speed (usually several hundred revolutions per minute). The acceleration performance of the servo system is good. The servo motor accelerates from a standstill to a rated speed of 3000RPM in only a few milliseconds, and can be used in control situations that require fast start-stop.