Research About Feed Servo System Cross-Coupling Adaptive Control Based On CompactRIO

When a CNC machine tool is machining, there are some uncertainties of parameters and disturbances in system’s model due to the weight and material of workpiece and cutting rate are usually variant. Therefore the controller must be robust for such varying conditions. Adaptive control is suitable for that. Besides, to improve the machining precision, it is essential to improve the contour errors, which is the main goal of the cross-coupling control (CCC). In addition to robustness, this research proposes cross-coupling adaptive control(CCAC) by combining above two controllers that could bring a significant improvement of tracking and contour errors.LabVIEW is graphical programming languages and development environment, which is known as the engineer’s language. With the LabVIEW Control Design Toolkit, we can easily and quickly model for the cross coupling servo feed system, analysis and control algorithm design. United States National Instruments launched the CompactRIO is an industrial embedded measurement and control system, which integrated of embedded real-time controller(Real-time), programmable hardware logic(FPGA) and reconfigurable I/O modules. CompactRIO system and LabVIEW development environment can be connected seamlessly, which can be easily accessed the underlying hardware through a graphical development environment. This advantage can greatly shorten the development time.This paper based on the dual-axial servo feed system as the research object, first, build the dual-axial servo feed system using the NI CompactRIO for controller, then modeling the uniaxial servo feed system, which preparing for the controller design. According to the current contour error algorithm, this paper uses a more concise and effective operation logic which used in cross-coupling control, in order to effectively reduce the computation system. Position loop use PID control strategy, based on the PID controller, add cross-coupling controller which make dual-axial combined as one body. In order to reduce the error caused by system model uncertainties and external interference, design a cross-coupling adaptive controller, at then, simulate the system by LabVIEW Control Design and Simulation, compared with the PI controller and cross-coupling controller. The simulation results show that CCAC has a better tracking errors and contour errors in linear contouring, not only has a strong robustness to load disturbances, but also can enhance the rapidity and contour precision. At last, release the control algorithm to the CompactRIO controller.