Implementation of 3-axis linear interpolation in a FPGA-based 4-axis motion controller

To carry out the motion control of CNC machine and robot, this paper introduces an approach to implement 4-axis motion controller based on Field Programmable Gate Array (FPGA). Starting with introduction to existing excellent 4-axis motion controller MCX314, the fundamental structure of controller is discussed. Since the straight-line motion is a fundamental motion of CNC machine and robot, this paper introduces a linear interpolation method to do approximate straight-line motion within any 3-axis space. As Interpolation calculation of hardware interpolation is implemented by hardware logic circuit such as ASIC or FPGA in the controller, therefore this method can avoid a large amount of complex mathematical calculation, which hints that this controller has high real-time performance. The simulation of straight-line motion within 3D space verifies the effectiveness of the proposed approach.