Digital System Control for Three-Degrees of Freedom Mechanical Arm with FPGA

Abstract

This work has as objective to show the design process and implementation of three-degrees of freedom mechanical arm, controlled by a digital system, described under VHDL, and implemented into a FPGA (field programmable gate array). The digital system for control is designed through the interconnection of circuits and functional blocks. The FPGA terminals are used to control the sequences of three stepper motors and this way to achieve the movement of the three-degrees of freedom arm, the interface stage among the control and the motors, is developed with a power electronic circuit based on transistors. This design proposal is a didactic model that seeks to illustrate the stages of the design and, mainly, the digital system for control the movements of the mechanical arm. For this case,the mechanical design of the arm does not depend on a specific trajectory, it is a free trajectory and user can decide, trough the FPGA interface, the mechanical arm movement. The mechanical arm proposal does not have the capacity to exercise big forces, not to lift big weight, but rather it seeks to be an easy construction model and accessible for everyone, since it can be built until with recycled material, just as it was made in this case, for educational purposes.