Research On Several Precise Positioning Problems Of Intelligent Coke Oven

Coke oven is an important production equipment for coke making in metallurgical coking process.Because of the complex operation process and serious environmental pollution,it is urgent to intellectualize the coke oven equipment and process technology.High-precision positioning is the key technology to ensure the automation of intelligent coke oven production.At present,in intelligent coke oven,the most problems of precise positioning are as follows:first,low-dimensional precise positioning in non-personnel areas of coke oven,including fault location of power cables and gas pipelines,gas leakage location detection in coke oven basement,single-point precise positioning of coal hopper and coal tower leak nozzle alignment and cross iron closure of furnace door,and vehicle automation on coke oven track.And Single-dimensional precise positioning problems like location identification of the furnace mouth and walking positioning by the four coke oven vehicles.The second kind,two-dimensional and three-dimensional precise positioning of targets in the coke oven personnel activity area,such as the two-dimensional and three-dimensional precise positioning of the coke oven roof,machine side and side platforms,as well as the personnel,temporary placement equipment,Mobile vehicles in the coke oven side and other areas.Among these positioning problems,the first one is mainly handled by fault analysis method,electromagnetic technology and vehicle address detection technology.However,human activities are random and extensive,the traditional methods of low-dimensional positioning can not deal with this kind of precise positioning problem caused by human activities.In the production of coke oven vehicles,vehicle drivers and on-site staff are obstructed,and the activities of personnel and equipment on the top,side and coke side of the coke oven are difficult to grasp.There is an accident risk that vehicle movement will lead to the extrusion of vehicles and the collision of vehicles.Therefore,this study proposes to use UWB positioning technology to make personnel,vehicles and equipment wear positioning labels to mark.In order to solve the problem of two-dimensional and three-dimensional precise positioning of multi-targets in the production area of intelligent coke oven,the precise positioning of tag-free random equipment and obstacles is carried out by combining with vehicle-borne lidar technology.In this paper,the second type of precision problem in coke oven is studied.UWB positioning technology and lidar technology are used as precise positioning means,focusing on three aspects: positioning model,non-line-of-sight error and positioning algorithm.Firstly,aiming at the problem of precise positioning of field operators and mobile vehicles in intelligent coke ovens,based on the summary and analysis of basic positioning models,a hybrid positioning model based on TDOA ranging and AOA measurement of arrival angle is studied,and a hybrid TDOA/AOA positioning algorithm is proposed.The experimental results proved the model and algorithm can achieve centimeter-level positioning accuracy.Secondly,the problem that the NLOS error of UWB signal is large when coke oven vehicle is running,which leads to the low positioning accuracy of field operators and mobile vehicles is studied.The NLOS error estimation method and NLOS error constraint method of UWB signal are analyzed.A distance correlation probability based NLOS positioning method and a predefined distance error constrained positioning method(LS-SDP)are proposed and applied in WLS.The method and SDP method are improved and realized,and the centimeter level of positioning resolution had been achieved.Thirdly,aiming at the problem of precise positioning of random moving targets in the intelligent production process of coke oven,a mathematical reasoning model of safe distance of coke oven vehicle is proposed,which realizes the centimeter-second precision positioning of random moving targets by lidar scanning.Fourthly,the engineering application schemes of UWB and lidar ranging and positioning based on the above precise positioning method are designed.The test run in Baosteel Phase IV coke oven verifies the engineering application positioning accuracy of the design scheme and meets the design requirements.Finally,the content of this study is summarized,and the prospects for future research are given.