A06B-0075-B003 FANUC AC SERVO MDL BiS 8/3000

Servo drivers are high-end products of modern transmission technology, widely used in automation equipment such as industrial robots and CNC machining centers. Especially the servo driver used to control AC permanent magnet synchronous motors has become a research hotspot at home and abroad. The current design of AC servo drives generally adopts vector control based closed-loop control algorithms for current, speed, and position. The rationality of the speed closed-loop design in this algorithm plays a crucial role in the entire servo control system, especially in the performance of speed control.
Servo drives, also known as “servo controllers” or “servo amplifiers,” are a type of controller used to control servo motors. Their function is similar to that of a frequency converter acting on ordinary AC motors, and they are a part of servo systems. They are mainly used in high-precision positioning systems. Generally, servo motors are controlled through three methods: position, speed, and torque to achieve high-precision positioning of the transmission system. Currently, it is a high-end product in transmission technology.
In the servo drive speed closed-loop, the real-time speed measurement accuracy of the motor rotor is crucial for improving the dynamic and static characteristics of the speed control of the speed loop. To find a balance between measurement accuracy and system cost, incremental photoelectric encoders are generally used as speed sensors, and the corresponding commonly used speed measurement method is the M/T speed measurement method. Although the M/T speed measurement method has certain measurement accuracy and a wide measurement range, it has inherent drawbacks, mainly including: 1) at least one complete code disk pulse must be detected within the speed measurement cycle, which limits the minimum measurable speed; 2) The timer switches of the two control systems used for speed measurement are difficult to strictly maintain synchronization, and speed measurement accuracy cannot be guaranteed in measurement scenarios with significant speed changes. Therefore, the traditional speed loop design scheme using this speed measurement method is difficult to improve the speed following and control performance of the servo driver.

A06B-0075-B003