The Design Of Mobile Robot Navigation System Based On FPGA

With the steady progress in science and technology, the mobile robot’s research realmand application range is constantly expanding. People need mobile robot to get environmentand itself status by sensors, to realize moving to the object autonomously in the environmentwhere having obstacle. Consequently, the navigation technology of mobile robot has becomethe key technology of intellectualized mobile robot. Design a small volume, low power, highreliability navigation system for mobile robot has engineering significance and marketprospects.Besides, Field-Programmable Gate Array technology as an advanced embedded systemsSolution, with its powerful capability of data processing and software-hardware collaborativedesign concept, has more and more applied in mobile robot navigation system. This articleuse self-designed four-wheel differential driven mobile robot as research object, designedmobile robot navigation system based on FPGA. Main contents are below:First, researched navigation sensors such as odometer, GPS, electric compass andAccelerometers’ advantages and disadvantages, analyzed the work principles of navigationsensors. Established the kinematics model of four-wheel differential driven mobile robot, andgiven its carriage output equation in two dimensions and three dimensions. Elaborated thetechnology of FPGA’s work principles, design concept and design flow process. Give the totalscheme of mobile robot software-hardware design.This article designed the mechanical structure of four-wheel differential driven mobilerobot. Under the system’s actual demand, chosen DE2Board based on EP2C35serial FPGAchip as the navigation computer, chosen MSP430F449as the distance data processing chip.Finished the chip selected and circuit designed of navigation unit, obstacle avoidance unit,and motor driver unit. The design used modular construction, connected by interface board. Inorder to facilitate the system debug, this article designed wireless communications moduleand LCD module.Finished design of SOPC system based on FPGA; including custom the NIOS Ⅱembedded soft core processer, add the custom PWM IP core. For reduce the system’s cost,this article used hard ware design language to programmed photoelectric encoder’s datareceive module and GPS data receive module. For increase the system’s process speed,researched the single float precision operation’s basic principle. Realized the single floatprecision matrix operations’ harden implementation in FPGA. At last, this article gave each navigation sensors’ error model, designed odometer/GPS/electric compass combined navigation system’s kalman filter, gave mobile robot’s surcospeculation algorithm in complex road surface conditions, programmed the task program ofgathering odometer information, multi-point solute electric compass course angle, GPScoordinates conversion, and obstacles to measure distances. Realized every task’s fairscheduling in uc/OS-Ⅱ embedded operating system. Validate the mobile robot’s navigationsystem by navigation experiment and obstacle avoidance experiment, and analysis ofexperiment report.