An Intelligent Warehouse Robot Based On Positioning Algorithm By Integrating UWB And Dead Reckoning

With the further implementation of the "Made in China 2025" plan and the vigorous development of the Internet and e-commerce,the scale of the warehousing and logistics industry is continuously expanding.As one of the important tasks for the transformation of China's manufacturing industry,automated warehouse logistics is facing new opportunities and challenges.As an important part of the automated warehouse,warehouse robots are playing an increasingly important role,and it is urgent to improve and innovate its functions continuously.Taking into account the characteristics of chemical drugs that are more sensitive to environmental parameters in an indoor warehouse environment,this paper designs and builds a warehouse environment parameter monitoring platform and intelligent warehouse robot to meet the requirements of real-time accurate monitoring of various areas in the warehouse environment and autonomous drug delivery under abnormal parameters,and ensure the quality and safety of chemical drugs.The warehouse environmental parameter monitoring platform mainly includes the hardware platform and the software system.The hardware part is mainly designed and constructed from the parameter acquisition system,central processing system and transmission system.In the software part,the communication transmission system,data display and warehouse system,and analysis and decision-making system are designed and written.The construction of the intelligent warehouse robot also includes two parts:the hardware system and the software system based on the ROS platform.For the hardware system,it is mainly designed and constructed from the aspects of drive,control,communication,positioning,operation,etc.to meet the needs of robot movement and operation.The ROS platform is designed and constructed from the aspects of development environment,function package configuration and embedded integration to improve robot autonomy and scalability.The positioning accuracy in the indoor environment of the warehouse is an important factor for the intelligent warehouse robot to achieve its functions.Traditional GPS-based outdoor positioning methods cannot meet the accuracy requirements of indoor positioning,and,the cost of construction and reconstruction is relatively large,using the positioning and navigation methods such as rail or electromagnetic in a warehouse environment.At the same time,factors such as non-line-of-sight in the indoor environment of the warehouse also affect positioning accuracy.Therefore,this paper proposes a localization algorithm based on the fusion of the dual-label UWB pose,weighted by square of the logarithm of the residuals,and track estimation.On the one hand,the use of dual tags makes it possible to obtain the calculation of the attitude angle without the need for special antennas.On the other hand,the residuals obtained based on track estimation and UWB positioning reduce the computational complexity and increase the weight of line-of-sight measurement.In this way,the indoor positioning accuracy is improved,and the influence of non-line-of-sight errors is suppressed.The static and dynamic positioning performance of the proposed improved fusion algorithm based on UWB and track estimation are tested in line-of-sight and non-line-of-sight,respectively.At the same time,experiments were carried out during the autonomous delivery and inspection under abnormal environmental parameters,using intelligent warehouse robot in cooperation with warehouse environment parameter monitoring platform.The results show that in static positioning,the root-mean-square error of line-of-sight and non-line-of-sight is less than 10cm,and the maximum yaw angle error does not exceed 0.15rad.Under dynamic positioning,the line-of-sight error is small,the maximum root-mean-square error of non-line-of-sight does not exceed 15cm,and the maximum yaw angle error does not exceed 0.3rad.Therefore the dual-label UWB and track estimation fusion positioning algorithm based on the logarithmic squared weighting of residuals proposed in this paper has good positioning and tracking accuracy,to a certain extent,suppresses the impact of non-line-of-sight errors,and meets the intelligent warehouse robot cooperates with the positioning and navigation needs of the warehouse environment monitoring platform in the warehouse room environment.