1. Motion control for CNC machine tools, robots and other high-end equipment “brain”

1.1 Motion control system is the core link of efficient operation of high-end equipment such as CNC machine tools and robots

Motion control system is according to the specific motion trajectory requirements, according to the load situation, through the driver, drive to execute the motor to complete the corresponding motion trajectory requirements of the system. Usually includes motion controller, drive, actuator, motion feedback unit and so on. Motion control system is according to the specific motion trajectory requirements, according to the load situation, through the driver, drive to execute the motor to complete the corresponding motion trajectory requirements of the system. Usually includes motion controller, drive, actuator, motion feedback unit and so on.

After years of development, the motion control system is generally based on computer-based digital control. With the support of new technologies such as cloud computing, industrial Internet, and artificial intelligence, the intelligent, flexible, control accuracy and other aspects of the motion control system are rapidly improved.

Motion control system belongs to the national strategic materials, for CNC machine tools, robots and all kinds of high-end equipment of high quality and small operation to the critical importance, the intelligent control of motion system is the core technology in the field of equipment and manufacturing industry, determines the precision and efficiency of equipment.

1.2 Motion controller starts with motion control. General motion controller is divided into PLC controller, embedded controller and PC-based control card

The motion controller consists of four parts: trajectory generator, interpolator, control loop and step generator. Firstly, the trajectory generator calculates the ideal trajectory desired by the task, and the interpolator calculates the next command to be executed by the drive unit according to the actual state of the position or speed feedback unit and the requirements of the trajectory generator, and then gives it to the control loop for precise control. If it is a stepper motor, there is also a step generator, which generates the control phase sequence and pulse step by step according to the control loop control instructions to achieve the purpose of controlling the moving object.

The hardware of motion controller consists of microprocessor (MCU), special chip (ASIC), PC-Based, digital signal processing chip (DSP), programmable logic controller (PLC), multi-core processor and so on. With the progress and perfection of technology, the motion controller has developed from a single chip microcomputer, microprocessor or special chip as the core processor to a general open motion controller with DSP and FPGA as the core processor.

According to the different platform, the general motion controller can be divided into PLC controller, embedded controller and PC-Based control card three categories.

1.3 Motion controller + actuator (drive motor) + sensor constitutes the mainstream motion control system

Servo system is a system that can automatically control mechanical motion according to predetermined requirements, and its role is to make the mechanical displacement (or Angle) of the output accurately track the displacement (or Angle) of the input, so that the output variable accurately follows or reproduces the input variable.

At present, the servo system mainly includes AC servo system, DC servo system and stepping system.

In order to achieve high speed and high precision motion control, the servo system needs to detect parameters such as distance, displacement, speed, acceleration (force), Angle, angular velocity and angular acceleration, and realize closed-loop feedback through real-time monitoring, which needs to be used with the sensor.

Common sensors include grating ruler (linear displacement detection), encoder (angular displacement detection), LiDAR/vision detection (distance detection), resistance strain gauge sensor (torque detection), etc.