| With the development of society,many large warehouses are faced with material security issues.Traditional warehouse security requires fixed installations of infrared cameras and other security devices at all corners.However,large warehouses are lined with shelves,and the shelves and goods are easy to block the camera line of sight.The security inspection mobile robot,which combines mobile robots and cameras,can monitor the warehouse all-weather and in all directions without dead angles,and can carry out key inspections in local areas.Even in the future,it can automatically check inventory to achieve a safe and intelligent warehouse management.So it is of great practical significance to study mobile robots for warehouse inspection.Existing warehouse inspection mobile robots are mainly suitable for internal inspection of a single warehouse.With the continuous development of the warehousing industry,there is an urgent need for a mobile robot that can inspect multiple warehouses with high efficiency.This inspection robot needs to adapt not only to the indoor walking environment of multiple warehouses,but also to the outdoor walking environment between warehouses.Therefore,in this environment,it is difficult for a single navigation method to complete the needs of mobile robots inspecting multiple warehouses.For the operation environment of multi-warehouse inspection,this paper studies the key technologies of combined positioning and navigation of mobile robots with cross-warehouse inspection capabilities,and provides a reliable inspection mobile platform.The specific research content is as follows:For the unstructured road inside and outside of warehouse,a mobile robot structure with good adaptability to the ground is designed,and the key components are simulated and analyzed based on the finite element to verify the reliability of the structure and materials.The differential wheel kinematics model and error model are researched,and the pose estimation of the mobile robot in the world coordinate system is completed.Based on the kinematics simulation,it analyzes the driving stability on unstructured road and verifies the rationality of the mechanical system.For the inspection and operation environment of the warehouse area,the mobile robot combined positioning system is studied.Based on Kalman data fusion algorithm,the data fusion between the encoder and the angle sensor is completed,the angle data fusion accuracy of 0.1°/s is achieved,and the inertial navigation method of the mobile robot is completed.Aiming at the problem that the single magnetic nail positioning mobile robot cannot correct the angle error in time and accurately,a dual magnetic nail absolute positioning mobile robot model is proposed.Aiming at the interference magnetic signals in some areas in the warehouse,based on the image processing technology and skeleton algorithm,more accurate ribbon path deviation data was extracted.The same model of correcting cumulative error of inertial navigation as the dual magnetic nail positioning is established,and the absolute positioning of the mobile robot in the world coordinate system by region is completed.According to the characteristics of the indoor and outdoor environment of the warehouse area and the nonlinear and time-varying characteristics of the mobile robot system,the path correction method of the mobile robot is designed based on the fuzzy control algorithm.Through a unified external absolute positioning error correction model,the inertial navigation accumulation error is corrected every control cycle.And it combines with PID algorithm to complete the mobile robot path correction.Based on the STM32 interrupt priority mechanism,the mobile robot path tracking and navigation task management is completed.It realizes the tracking and navigation of mobile robots under complex road conditions.An experimental platform for cross-warehouse inspection of mobile robots was built,and important performances such as positioning and navigation accuracy,speed,obstacle crossing,and obstacle avoidance were tested through experiments.The test results showed that the overall navigation accuracy of the mobile robot is within ±5mm/±3° on the unstructured road,and the rest of performance meets the inspection requirements. |
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