FPGA-Realization of a Multi-Axis Motion Controller

A multi-axis motion controller based on FPGA technology is developed in this paper. Firstly, a multi-axis motion system is presented and the servo controller design is described. Secondly, an Altera FPGA (Field Programmable Gate Arrays) chip and an embedded soft-core Nios II processor are applied to develop the multi-axis motion controller. The proposed FPGA-based multi-axis motion control IC has two modules. The first module is an embedded soft-core Nios II processor which is used to realize the motion trajectory planning by software. The second module is presented to realize the multi- axis position/speed/current controllers by hardware. In the second module, two approaches are proposed which one is individual-axis isolated design approach and another is multi- axis module design approach. In the latter, it will collect multiple CCCT (Current vector controller and coordination transformations) circuits or multiple position/speed controller circuits into one circuit; therefore it can substantially reduce hardware resource usage in FPGA. Thirdly, VHDL (VHSIC Hardware Description Language) is applied to describe the overall multi-axis controller behavior. Finally, to verify the effectiveness and correctness of the proposed multi-axis motion control IP, a three-axis XYZ table is constructed and some experimental results are presented.