A brief review of research in agricultural vehicle guidance technologies is presented.The authors propose the conceptual framework of an agricultural vehicle autonomous guidance system,and then analyze its device char...A brief review of research in agricultural vehicle guidance technologies is presented.The authors propose the conceptual framework of an agricultural vehicle autonomous guidance system,and then analyze its device characteristics.This paper introduces navigation sensors,computational methods,navigation planners and steering controllers.Sensors include global positioning systems(GPS),machine vision,dead-reckoning sensors,laser-based sensors,inertial sensors and geomagnetic direction sensors.Computational methods for sensor information are used to extract features and fuse data.Planners generate movement information to supply control algorithms.Actuators transform guidance information into changes in position and direction.A number of prototype guidance systems have been developed but have not yet proceeded to commercialization.GPS and machine vision fused together or one fused with another auxiliary technology is becoming the trend development for agricultural vehicle guidance systems.Application of new popular robotic technologies will augment the realization of agricultural vehicle automation in the future.展开更多
The morphing technology of hypersonic vehicle improved the flight performance by changing aerodynamic characteristics with shape deformations,but the design of guidance and control system with morphing laws remained t...The morphing technology of hypersonic vehicle improved the flight performance by changing aerodynamic characteristics with shape deformations,but the design of guidance and control system with morphing laws remained to be explored.An Integrated of Guidance,Control and Morphing(IGCM)method for Hypersonic Morphing Vehicle(HMV)was developed in this paper.The IGCM method contributed to an effective solution of morphing characteristic to improve flight performance and reject the disturbance for guidance and control system caused by the morphing system for HMV in gliding phase.The IGCM models were established based on the motion models and aerodynamic models of the variable span vehicle.Then the IGCM method was designed by adaptive block dynamic surface back-stepping method with stability proof.The parallel controlled simulations’results showed the effectiveness in accomplishing the flight mission of IGCM method in glide phase with smaller terminal errors.The velocity loss of HMV was reduced by 32.8%which inferred less flight time and larger terminal flight velocity than invariable span vehicle.Under the condition of large deviations of aerodynamic parameters and atmospheric density,the robustness of IGCM method with variable span was verified.展开更多
文摘A brief review of research in agricultural vehicle guidance technologies is presented.The authors propose the conceptual framework of an agricultural vehicle autonomous guidance system,and then analyze its device characteristics.This paper introduces navigation sensors,computational methods,navigation planners and steering controllers.Sensors include global positioning systems(GPS),machine vision,dead-reckoning sensors,laser-based sensors,inertial sensors and geomagnetic direction sensors.Computational methods for sensor information are used to extract features and fuse data.Planners generate movement information to supply control algorithms.Actuators transform guidance information into changes in position and direction.A number of prototype guidance systems have been developed but have not yet proceeded to commercialization.GPS and machine vision fused together or one fused with another auxiliary technology is becoming the trend development for agricultural vehicle guidance systems.Application of new popular robotic technologies will augment the realization of agricultural vehicle automation in the future.
文摘The morphing technology of hypersonic vehicle improved the flight performance by changing aerodynamic characteristics with shape deformations,but the design of guidance and control system with morphing laws remained to be explored.An Integrated of Guidance,Control and Morphing(IGCM)method for Hypersonic Morphing Vehicle(HMV)was developed in this paper.The IGCM method contributed to an effective solution of morphing characteristic to improve flight performance and reject the disturbance for guidance and control system caused by the morphing system for HMV in gliding phase.The IGCM models were established based on the motion models and aerodynamic models of the variable span vehicle.Then the IGCM method was designed by adaptive block dynamic surface back-stepping method with stability proof.The parallel controlled simulations’results showed the effectiveness in accomplishing the flight mission of IGCM method in glide phase with smaller terminal errors.The velocity loss of HMV was reduced by 32.8%which inferred less flight time and larger terminal flight velocity than invariable span vehicle.Under the condition of large deviations of aerodynamic parameters and atmospheric density,the robustness of IGCM method with variable span was verified.
