Servo motor: 6 key parameters for servo drive selection
2022-05-28
Servo motor: 6 key parameters for servo drive selection
A servo system is a feedback control system used to accurately follow or reproduce a process. The servo system is an automatic control system that enables the output controlled quantities such as the position, orientation, and state of the object to follow any changes in the input target (or given value). Its main task is to amplify, transform and regulate the power according to the requirements of the control command, so that the torque, speed and position control of the drive device is very flexible and convenient.
The servo driver is a part of the servo system and is used to control the servo motor. Its function is similar to that of the inverter acting on the ordinary AC motor. It is mainly used in high-precision positioning systems. Generally, the servo motor is controlled by three methods of position, speed and torque to achieve high-precision positioning of the transmission system. It is currently a high-end product of transmission technology.
Selecting a suitable servo driver needs to consider various aspects, which are mainly selected according to the requirements of the system. Before selecting the type, first analyze the following system requirements, such as size, power supply, power, control method, etc., to set the direction for the selection. . Let's take a look at various parameters of the servo drive.
1. Continuous current, peak current;
2. Power supply voltage, control part supply voltage;
3. Supported motor types and feedback types;
4. Control mode, form of accepting commands;
5. Communication protocol
6. Digital IO
Based on this information, we can roughly select the servo driver that matches the motor. In addition, pay attention to the working environment, temperature and humidity conditions, whether the installation is the right size, etc.
The selection of the driver is not only considering whether the driver matches the motor, but also the control method. The servo drive has three control modes: position, speed and torque mode. Torque mode and speed can be set by external analog input or communication command, while position mode determines the speed and length of motion through the frequency and number of pulses. In torque mode, the motor outputs a fixed torque and cannot control the position and speed. Position mode has very strict control of speed and position, and is generally used for positioning devices. According to the needs of the system and the type of upper control, the appropriate control method can be selected.
Now servo drives are becoming more and more intelligent, not only supporting various types of servo motors, but also compatible with various types of feedback, can receive analog, PWM, pulse + direction and software commands, communication supports CANopen, Ethercat, etc. Provides three-loop control and commutation functions, and intelligent one-key tuning, etc. It is very convenient to use and has high control precision, which greatly improves the performance of the system and saves a lot of time for developers.
