A trajectory generator based on vehicle kinematics model was presented and an integrated navigation simulation system was designed.Considering that the tight relation between vehicle motion and topography,a new trajec...A trajectory generator based on vehicle kinematics model was presented and an integrated navigation simulation system was designed.Considering that the tight relation between vehicle motion and topography,a new trajectory generator for vehicle was proposed for more actual simulation.Firstly,a vehicle kinematics model was built based on conversion of attitude vector in different coordinate systems.Then,the principle of common trajectory generators was analyzed.Besides,combining the vehicle kinematics model with the principle of dead reckoning,a new vehicle trajectory generator was presented,which can provide process parameters of carrier anytime and achieve simulation of typical actions of running vehicle.Moreover,IMU(inertial measurement unit) elements were simulated,including accelerometer and gyroscope.After setting up the simulation conditions,the integrated navigation simulation system was verified by final performance test.The result proves the validity and flexibility of this design.展开更多
Roads affect wildlife significantly through direct mortality but also through behavioral change. We explored the ef- fects of unsurfaced sand roads with a low traffic volume on the travelling behavior of gopher tortoi...Roads affect wildlife significantly through direct mortality but also through behavioral change. We explored the ef- fects of unsurfaced sand roads with a low traffic volume on the travelling behavior of gopher tortoises Gopherus polyphemus in scrub habitat in central Florida, as evidenced by the tracks left by tortoises on sand roads. Tortoises （and most other taxa leaving tracks on the roads） did not appear to make use of roads for travel but attempted to cross them, the success of which was influ- enced by the size of the individual. Smaller animals （presumably younger tortoises） were more challenged than larger animals by both sand road widths and depths of vehicle ruts in sand roads. Sand roads may present both physical and physiological challenges to gopher tortoises, particularly to small ones. This research provides further evidence that the negative influence of roads in fragmenting the environment is not limited to vehicle mortality [Current Zoology 61 （4）： 578-585, 2015].展开更多
基金Projects(90820302, 60805027, 61175064) supported by the National Natural Science Foundation of ChinaProject(2011ssxt231) supported by the Master Degree Thesis Innovation Project Foundation of Central South University, China+1 种基金Project(200805330005) supported by the Research Fund for the Doctoral Program of Higher Education, ChinaProject(2011FJ4043) supported by the Academician Foundation of Hunan Province, China
文摘A trajectory generator based on vehicle kinematics model was presented and an integrated navigation simulation system was designed.Considering that the tight relation between vehicle motion and topography,a new trajectory generator for vehicle was proposed for more actual simulation.Firstly,a vehicle kinematics model was built based on conversion of attitude vector in different coordinate systems.Then,the principle of common trajectory generators was analyzed.Besides,combining the vehicle kinematics model with the principle of dead reckoning,a new vehicle trajectory generator was presented,which can provide process parameters of carrier anytime and achieve simulation of typical actions of running vehicle.Moreover,IMU(inertial measurement unit) elements were simulated,including accelerometer and gyroscope.After setting up the simulation conditions,the integrated navigation simulation system was verified by final performance test.The result proves the validity and flexibility of this design.
文摘Roads affect wildlife significantly through direct mortality but also through behavioral change. We explored the ef- fects of unsurfaced sand roads with a low traffic volume on the travelling behavior of gopher tortoises Gopherus polyphemus in scrub habitat in central Florida, as evidenced by the tracks left by tortoises on sand roads. Tortoises （and most other taxa leaving tracks on the roads） did not appear to make use of roads for travel but attempted to cross them, the success of which was influ- enced by the size of the individual. Smaller animals （presumably younger tortoises） were more challenged than larger animals by both sand road widths and depths of vehicle ruts in sand roads. Sand roads may present both physical and physiological challenges to gopher tortoises, particularly to small ones. This research provides further evidence that the negative influence of roads in fragmenting the environment is not limited to vehicle mortality [Current Zoology 61 （4）： 578-585, 2015].
