Design Of Position And Attitude Monitoring System For Large Front Shovel Excavator

In order to solve various problems caused by traditional large-scale mining excavators relying on manual operation,unmanned intelligent large-scale mining excavators have begun to develop.The premise for the unmanned excavator to work normally is to use a high-precision position and attitude monitoring system to monitor the position and attitude of the excavator in real time,and the high-precision position and attitude monitoring information can not only help the excavator achieve a higher full bucket rate,but also help excavators unload more safely.The research object of the position and attitude monitoring system in China is mainly limited to the front-end working mechanism of the excavator.Usually,only the position and attitude of the bucket in the excavator’s local coordinate system during the excavation process is considered,and the position and attitude of the slewing platform,the chassis and the mining truck is not considered.This kind of position and attitude monitoring system cannot provide data support for the completely unmanned operation of excavators such as walking and unloading.Therefore,this thesis designs a set of high-precision position and attitude monitoring system,which can not only completely monitor the position and attitude of each working position of the excavator and mining truck,but also has strong portability and can be applied to most types of front shovel excavator.In this thesis,after analyzing the mechanical structure and working mode of the large mining front shovel excavator,the overall position and attitude monitoring scheme of the excavator and the mining truck is designed,which can monitor Coordinates and attitude angles of the center of the slewing platform,the center of the chassis,the bucket tip and the mining truck bucket center in the global space Cartesian coordinate system.According to the position and attitude monitoring scheme of the excavator and the mining truck,the hardware system is built,and the model selection of the main equipment such as GPS receiver,IMU,and wireless data transmission radio is carried out,and the connection scheme and data output method of the hardware equipment are determined.After the hardware system is built,the software program is written in the computer using the C++ programming language,including the communication module,the data analysis module,the coordinate conversion module and the data output module.After the design of the position and attitude monitoring system is completed,the position and attitude monitoring errors during the excavator’s walking,digging and rotary unloading process are analyzed in detail.Finally,the position and attitude monitoring system is installed on a 1:5scaled prototype of a large mining front shovel excavator to conduct static position and attitude monitoring,walking,digging and rotary unloading experiments,and the experimental results are analyzed.The experimental results of static position and attitude monitoring show that the maximum error of excavator and mining truck position monitoring is 9.484 cm,the maximum error of yaw angle monitoring is 0.5°,and the maximum error of roll angle and pitch angle monitoring is0.4°.The static position monitoring data is highly accurate.The results of the walking experiment show that the maximum error of the monitoring of the center position of the excavator chassis is 8.976 cm,the dynamic position monitoring data is highly accurate,and the actual walking route of the excavator can accurately fit the planned optimal walking path.The excavation experiment results show that the average full bucket rate of the bucket after multiple excavations is 85%,which is 15% higher than the average 70% full bucket rate of manual operation.The excavator can ensure good excavation efficiency.The results of the rotary unloading experiment show that when the unloading is completed within 5s and the rotation angle is 135°,the variable speed control of the rotary motor reduces the maximum position monitoring lag error of the shovel tip by 75% when it reaches the target unloading position,and the excavator can safely and accurately unload at the target discharge location.