Application Of Multi-axis Servo System Based On Fieldbus

Due to the simple structure, easy to expand, digital communications, and low cost, fieldbus has been widely used in industrial automation. Meanwhile for the good stability, fast response, high precision, servo system is applied to various devices require high precision. With the appearance of digital servo driver, fieldbus is used in servo system to make the system be simple, be easy to expand and achieve multi-axis synchronous control. In this paper, it has designed two multi-axis servo systems based on CAN bus or Ether CAT bus to drive control of different institutions.Firstly, this article introduces the details of the CAN bus. Then outlines the overall design door drive system based on CAN bus, including control system electrical design and hardware selection. After confirming the requirements of the system, the PLC-based program is designed with the S-type trajectory and biaxial synchronization algorithm. When the system is completed, the main door was tested, trajectory planning and biaxial synchronous control meet the requirement.Then, this paper introduces a 6DOF parallel platform system based on Ether CAT bus. The 6DOF platform system is used to simulate the movement of a ship in the sea, to test the performance of shipboard equipment. After the designing of electrical control system, the hardware is select. Then the paper built the kinematic model of platform to study the pros and cons of the solution for the position and orientation. According to the customer demand, we design the mechanical structure, establish a simplified model of the platform structure to analyses the stress, verify the safety of mechanical design and provide a reference for motor selection. Then understanding Ether CAT bus and its application in motion control, we use the VC++ and Twin CAT to program. The program introduces the electronic cam to solve the problem of multi synchronization and trajectory planning, to implement the capacity of simulation irregular trajectory.When the 6DOF platform system is completed, a high-precision gyroscopes is settled on it, do a rotate position accuracy testing, sum up correction function. After soft correction, the test result prove that the absolute error of rotational degrees is in ±0.0052°, and relative error is in 0.026%. Through the simulation of ship trajectory, comparing the target trajectory with trajectory result from motor encoders,the dynamic tracking error in the translational degrees of freedom is within ± 0.04 mm, in the rotational degrees of freedom is within ± 0.006 °.