| With the continuous development of the chemical industry,the frequency of fire and explosion accidents in chemical plants is increasing year by year.Such accidents are characterized by high suddenness,high danger in the post-disaster environment and high complexity of the rescue process,which makes rescue work extremely difficult.Therefore,the use of robotic equipment to replace rescue personnel into chemical plants to carry out rescue activities has become an important trend.To address the problem of difficult robot rescue positioning in chemical rescue scenarios,it is necessary to find suitable technical means to improve robot positioning accuracy,and this paper selects ultra-wideband(UWB)positioning technology with high penetrating power and high temporal resolution as the research object.The main research contents as well as innovative work in this paper include the following aspects.To address the problem that UWB is susceptible to the influence of the base station deployment method and that the values fluctuate greatly when the TOA-based least squares positioning algorithm is used to solve for the tag coordinates,this paper first chooses to optimize the TOA-based positioning method: in the first step,the Gaussian Newton method is used to solve for the 3D coordinates of the tag,and in the second step,the coordinates are combined with Kalman filtering for optimization.Then the optimal base station deployment scheme for indoor localization in a simulated chemical plant gas leakage scenario is explored.Finally,physical experiments are designed to verify the effectiveness of the improved positioning base station deployment method by using Gaussian Newton algorithm for localization under two base station deployment methods in the first step.In the second step,the least squares positioning algorithm,Gaussian Newton method,and the algorithm after fused Kalman filter are compared for positioning under this base station deployment method.The experimental results show that the optimized algorithm based on TOA positioning method can effectively improve the positioning accuracy and reduce the situation of large fluctuation of values.To address the problem that the range accuracy of UWB is seriously reduced due to the presence of smoke and obstacles in the chemical plant,and the positioning accuracy cannot be improved by simply improving the positioning algorithm of UWB,this paper chooses to add IMU sensors,fuses UWB and IMU for positioning,establishes the navigation models of two combined methods of loose combination and tight combination,and designs simulation experiments to verify the positioning performance of the two combined methods of UWB and IMU.The simulation experiments are designed to verify the positioning performance of both UWB and IMU combinations.The results show that UWB and IMU fusion positioning can effectively compensate for the short-term positioning data jitter and signal loss problems of UWB positioning system by taking advantage of IMU independent positioning.Moreover,the tight combination of positioning reduces the errors generated when the information of individual systems is solved,and the fusion of positioning information is more thorough than the loose combination,resulting in higher positioning accuracy.By analyzing the simulation results of tight-combination and loose-combination localization,the more optimal tight-combination localization method is selected for real environment experiments.After testing the good UWB and IMU positioning performance,the UWB and IMU fusion positioning algorithm and the UWB alone positioning algorithm are positioned in indoor ideal environment and indoor complex environment respectively under the improved base station layout scheme.The final experiment verifies that the UWB and IMU tight combination positioning algorithm has higher positioning accuracy,better stability and more adaptability compared with the UWB positioning algorithm alone.It has certain engineering practice significance. |
