As we all know, the servo of the servo motor is composed of three feedback systems: the azimuth loop, the speed loop, and the current loop. The more internal the loop, the more it needs to improve its responsivity. Failure to comply with this criterion will cause errors and vibration. Since the current loop is the innermost loop to ensure its full response, we only need to adjust the azimuth loop and speed loop. The main parameters adjusted are: azimuth loop gain, speed loop gain, and speed integration time constant. Azimuth loop gain is a parameter that determines the followability of the commanded azimuth. It is closely related to the appearance of the workpiece. It is effective only when the driver is operating in the azimuth method. When the servo motor is stopped, adding the azimuth ring share gain can improve the rigidity of the servo motor, that is, the locking force. The response of the servo system depends on the azimuth loop gain. Increasing the azimuth loop gain will improve the azimuth loop response and chip accuracy, while reducing the adjustment time and cycle time. However, the azimuth loop gain is limited by the speed loop characteristics and mechanical characteristics. In order to improve the response, if only the azimuth loop gain is increased, the overall response of the servo system is prone to vibration, so please pay attention to the echo while increasing the speed loop gain. Features: The gain of the azimuth loop is increased, the higher the response is, the shorter the positioning time is.
Vibration and overshoot caused by excessive Adjustment criteria: On the premise of ensuring that the azimuth ring system is stable and that the azimuth is not excessive (overshoot), increase the azimuth ring gain to reduce the amount of azimuth lag. The simple method is to increase the azimuth loop gain until overshoot, and then reduce the azimuth loop gain, that is, the azimuth loop gain with good stiffness, speed loop share gain, speed integration time constant, speed loop share gain, and speed integration time constant. It works during operation (with speed). The size of the speed loop share gain affects the speed of the motor. In order to shorten the adjustment time, it is necessary to increase the speed loop gain and control overtravel or lack of travel. The size of the speed loop integration time constant affects the size of the motor’s steady-state speed error and the stability of the speed loop system. When the servo motor is loaded with a practical load, since the actual load torque and load inertia do not match the default parameter values, the bandwidth of the speed loop will be narrowed. If this is the case, the bandwidth of the speed loop is satisfactory, and there is no motor speed. There is no need to adjust the gain of the speed loop and the integral time constant for phenomena such as chirp or vibration. If the actual load makes the motor operation unstable, trembling or vibration occurs, or the existing speed loop bandwidth is not aspirational, then the speed loop’s share gain and integration time constant need to be adjusted.
The guideline for speed loop parameter adjustment is to ensure that the speed loop system is stable without vibration, so that the speed loop responds fastest and the system operates stably. The simple method is to increase the speed loop’s share gain until the system vibrates, and then lower the speed loop’s share gain a little, which is the speed loop share gain with better stiffness. The integral time constant of the speed loop is a delay factor for the servo system. Therefore, if the setting is too long, the positioning time will be extended to make the response worse. If the inertia is large and the vibration is not increased, the machine will vibrate again. Depending on the situation, the setting is relatively small. Although the error pulse may be closer to 0 during positioning, the time required to reach a stable condition may become longer.的 Guidelines for adjusting the speed loop integration time constant In order to ensure integrated stove motor manufacturers the stable operation of the system, the speed loop integration time constant should be adjusted. The adjustment criterion is that the larger the value of the load inertia converted to the motor shaft and the motor rotor inertia is, the larger the value of the speed loop integration time constant should be.的 To increase the time constant of the speed loop integration, it is necessary to increase the speed loop share gain accordingly to increase the response time of the speed loop. The adjustment of these two parameters is a repetitive process, which requires accurate knowledge and experience of the load.
ZHEJIANGQI