Design And Implementation Of Localization And Navigation System For Automatic Stacker In Narrow Laneway

With the continuous development of modern logistics technology,the type of warehouse represented by the stereoscopic warehouse plays a more important role in the logistics link.Roadway Stacker localization and navigation system is for stacker localization and navigation control under the stereoscopic warehouse narrow lane environment,which is the key link to achieve fully automatic and flexible work in the stereoscopic warehouse.But the existing localization and navigation system is mainly based on the rail lane stacker.It does not apply to the layout changes of the existing warehouse.The trackless roadway stacker localization and navigation system is mainly based on electromagnetic,QR code,magnetic nails and other methods.Among which electromagnetic cannot obtain the stacker direction information.While the QR code and magnetic nail cannot continuously obtain reliable stacker location information.This thesis designs a roadway stacker localization and navigation system in combination with the reliable positioning,high controlled resolution and environmental robust featured in three-dimensional warehouse in modern enterprises.The system mainly contains stacking layer height detection and positioning and horizontal and vertical localization and navigation,and it achieves practical application in the project.This thesis designs a automatic trackless roadway stacker localization and navigation system in combination with the reliable localization,high controlled resolution and environmental robust featured in automated stereoscopic warehouse control system in modern enterprises.The system contains the height localization and control system which is sensitive to ground flatness,the transverse localization and navigation system which is sensitive to stacker attitude accuracy and the longitudinal localization and navigation system which is sensitive to positioning accuracy,it achieves practical application in the project.First,in view of the characteristics of the stacking layer height detection and localization system which is sensitive to the ground flatness,the traditional laneway stacker generally holds self-built track with less flexibility.This thesis proposes a measurement method which is based on cargo fork followed up stacking layer height by point laser sensor.In the process of palletizing,it gives real-time correction to the shelf height.The experiment shows that the system is robust to the ground flatness,effectively deals with the shelf height of different operating conditions.Second,in allusion to the characteristics of lateral localization and navigation system which is sensitive to stacker attitude accuracy,this thesis proposes the experiment methods of stacker attitude on the basis of point laser sensor.The method collects the lateral deviation of the vehicle in a narrow laneway by point laser sensor,after median average filtering and the attitude analysis process,it gets the real-time position of the stacker.The experiment shows that the method integrates conveniently,detects accurately and has good environmental robustness,but there is a certain measurement noise.So this thesis raises an algorithm based on Kalman filtering algorithm,combining the measurement results with the odometer and the steering angle sensor data,and obtains a more accurate and smooth location output.Due to the smooth attitude change characteristic required by transverse control,it brings stacker speed and attitude angle into the controlling unit.Experiments show that the system can make the stacker stable and controllable in transverse direction on the basis of ensuring the accuracy and robustness of positioning detection.Finally,in allusion to the characteristics of the vertical localization and navigation system which is sensitive to localization accuracy,this thesis proposes the method of stacker location on the basis of long distance point laser sensor by fusing stacker position and local road sign information.The robustness of the system to the environment is improved.And in view of the characteristics of the high precision of vertical control required by the narrow lane automatic stacker,the thesis proposes the rule-based longitudinal velocity and acceleration control algorithm.The experiment shows that the system can achieve the purpose of vertical precision stopping under the premise of maximizing the operation efficiency.