I. Networked Motion Controller
The application of motion control in the fields of robotics and CNC machine tools is more complex than its application in specialized machines, because the latter have simpler motion patterns and are often referred to as general motion control (GMC).
With the development of industrial field network bus technology, network-based motion controllers have seen tremendous growth and are beginning to be applied in multi-axis synchronous control. An increasing number of traditional systems that rely on mechanical axis synchronization are adopting network motion controllers for motor axis control, which reduces system maintenance and increases system flexibility.
Due to the unique market demands in my country, other specialized motion control systems will become increasingly common. Examples include dedicated motion controllers for image servo control and force servo control. Customizing motion controllers to meet specific user application requirements will become a major trend in the market.
A typical motion control system mainly consists of moving parts, transmission mechanisms, actuators, drivers, and a motion controller. The motion commands for the entire system are provided by the motion controller, making it the core of the entire motion control system. Users must utilize the standard functions provided by general-purpose motion controllers for secondary development, applying the relevant functions of the motion controller according to the process conditions of their application system to develop an application system that integrates their own process characteristics and industry experience. Simultaneously, users need to understand the other components constituting the motion control system and ensure the integrity of the mechanical system to integrate a high-quality motion control system. From the perspective of my country's economic development, the application and market of general-purpose motion controllers are only just beginning. Compared with developed countries in the United States and Europe, my country's government investment in motion controller technology development is minimal, and a unified product standard has not been established in this field. Higher education institutions have not kept pace, failing to cultivate a large number of talents capable of developing and applying motion controllers. The biggest difficulty encountered in market promotion is the lack of application engineers among domestic system integrators and equipment manufacturers. This hinders the application of motion controllers and increases the difficulty of after-sales technical support. Therefore, rapidly cultivating a large number of motion controller development and application talents is key to accelerating the new technological and industrial revolution.
II. Methods of controlling servo motors with motion controllers
In this section, we'll mainly understand how motion controllers control servo motors. Specifically, motion controllers typically control servo motors using two command methods:
1. Digital Pulse
This method is similar to the control method of stepper motors. The motion controller sends pulse command signals of the type "pulse/direction" or "CW/CCW" to the servo driver; the servo driver operates in position control mode, and the position closed loop is completed by the servo driver. Most Japanese and domestic servo products adopt this mode. Its advantages are simple system debugging and less susceptibility to interference, but its disadvantage is that the servo system response is slightly slower.
2. Analog signal
Another approach is analog signals. In this method, the motion control system sends an analog voltage command of +/-10V to the servo driver, while simultaneously receiving position feedback signals from position detection elements such as motor encoders or linear encoders. The servo driver operates in speed control mode, and the position closed loop is completed by the motion controller. Most servo products from Europe and America adopt this operating mode. Its advantage is fast servo response, but its disadvantage is that it is more sensitive to field interference and the debugging is slightly more complex.
