The mobile loading arm(MLA)system is one of the most important mechanical equipments in the petrochemical industry consisting of rigid pipelines and rotating elbows.This paper researches the problems of dynamical mode...The mobile loading arm(MLA)system is one of the most important mechanical equipments in the petrochemical industry consisting of rigid pipelines and rotating elbows.This paper researches the problems of dynamical modelling and tracking control.At first,an MLA dynamic model is built by using Euler-Lagrange function.And then,an adaptive third-order fixed time sliding mode(FDTSM)tracking controller with chattering free is represented,which enables the MLA system to dock with the vehicle tank mouth.In this paper,a new double-layer third-order fixed time sliding mode controller is first proposed to address the tracking problem in model-based MLA systems with known parameters.Moreover,considering the presence of modeling uncertainty and external disturbances,a nerual network adaptive FDTSM controller is designed to ensure that the close-loop system state tracking error converges to a bounded region around zero within a fixed time.Further,the stability of the close-loop system is proven by using the Lyapunov stability theorem.Simulation results illustrate the validaty of the controller.展开更多
Ensuring food security has become a global challenge owing to climate change and population growth.High-throughput phenotyping can effectively drive crop genetic enhancement,which can potentially solve food crisis.Phe...Ensuring food security has become a global challenge owing to climate change and population growth.High-throughput phenotyping can effectively drive crop genetic enhancement,which can potentially solve food crisis.Phenotyping robot is an essential part of crop ground phenotyping information monitoring,although there are challenges such as the inability to adjust the fixed track width,poor load capacity of the detection robotic arm,and inability to fuse information in real-time.This study reports a phenotyping robot with a gantry-style chassis featuring an adjustable wheeltrack(1400-1600 mm)to adapt to different row spacing arrangements and reduced damage,and function effectively in both dry field and paddy field environments.A six-degree-of-freedom sensor gimbal with high payload capacity is also developed to enable precise height(1016-2096 mm)and angle ad-justments.Additionally,this study introduces an enhanced method for data acquisition from multiple imaging sensors through registration and fusion using Zhang's calibration and feature point extraction algorithm,calcu-lating a homography matrix for high-throughput data collection at fixed positions and heights.The experimental validation results demonstrate that the RMSE of the registration algorithm does not exceed 3 pixels.The gimbal data strongly correlated with that of a handheld instrument data(r^(2)>0.90).The robot is practical,reliable,and fully functional,offering a solid theoretical foundation and equipment support for high-throughput phenotyping.展开更多
基金supported by the Beijing University of Posts and Telecommunications(BUPT)Excellent Ph.D.Students Foundation under Grant No.CX2020116。
文摘The mobile loading arm(MLA)system is one of the most important mechanical equipments in the petrochemical industry consisting of rigid pipelines and rotating elbows.This paper researches the problems of dynamical modelling and tracking control.At first,an MLA dynamic model is built by using Euler-Lagrange function.And then,an adaptive third-order fixed time sliding mode(FDTSM)tracking controller with chattering free is represented,which enables the MLA system to dock with the vehicle tank mouth.In this paper,a new double-layer third-order fixed time sliding mode controller is first proposed to address the tracking problem in model-based MLA systems with known parameters.Moreover,considering the presence of modeling uncertainty and external disturbances,a nerual network adaptive FDTSM controller is designed to ensure that the close-loop system state tracking error converges to a bounded region around zero within a fixed time.Further,the stability of the close-loop system is proven by using the Lyapunov stability theorem.Simulation results illustrate the validaty of the controller.
基金The work was supported by the National Key Research and Development Program of China(Grant No.2021YFD2000101).
文摘Ensuring food security has become a global challenge owing to climate change and population growth.High-throughput phenotyping can effectively drive crop genetic enhancement,which can potentially solve food crisis.Phenotyping robot is an essential part of crop ground phenotyping information monitoring,although there are challenges such as the inability to adjust the fixed track width,poor load capacity of the detection robotic arm,and inability to fuse information in real-time.This study reports a phenotyping robot with a gantry-style chassis featuring an adjustable wheeltrack(1400-1600 mm)to adapt to different row spacing arrangements and reduced damage,and function effectively in both dry field and paddy field environments.A six-degree-of-freedom sensor gimbal with high payload capacity is also developed to enable precise height(1016-2096 mm)and angle ad-justments.Additionally,this study introduces an enhanced method for data acquisition from multiple imaging sensors through registration and fusion using Zhang's calibration and feature point extraction algorithm,calcu-lating a homography matrix for high-throughput data collection at fixed positions and heights.The experimental validation results demonstrate that the RMSE of the registration algorithm does not exceed 3 pixels.The gimbal data strongly correlated with that of a handheld instrument data(r^(2)>0.90).The robot is practical,reliable,and fully functional,offering a solid theoretical foundation and equipment support for high-throughput phenotyping.
