In order to enhance the accuracy and overcome the limitation of representing the vehicular velocity with non driving wheel speed signals, which is commonly used in researching on automotive dynamic control systems at...In order to enhance the accuracy and overcome the limitation of representing the vehicular velocity with non driving wheel speed signals, which is commonly used in researching on automotive dynamic control systems at present, the dynamic and kinematics models of running vehicles and wheels are established. The concept that expresses vehicle velocity using only the driving wheel speed information with adjustable weight factors is described and an algorithm is proposed. A Matlab program with the algorithm embedded is made to simulate the vehicle’s accelerating under different road conditions, and it’s simulation results coincide well with the experimental results, which demonstrates the validity of the algorithm.展开更多
Good understanding of relationship between parameters of vehicle, terrain and interaction at the interface is required to develop effective navigation and motion control algorithms for autonomous wheeled mobile robots...Good understanding of relationship between parameters of vehicle, terrain and interaction at the interface is required to develop effective navigation and motion control algorithms for autonomous wheeled mobile robots （AWMR） in rough terrain. A model and analysis of relationship among wheel slippage （S）, rotation angle （0）, sinkage （z） and wheel radius （r） are presented. It is found that wheel rotation angle, sinkage and radius have some influence on wheel slippage. A multi-objective optimization problem with slippage as utility function was formulated and solved in MATLAB. The results reveal the optimal values of wheel-terrain parameters required to achieve optimum slippage on dry sandy terrain. A method of slippage estimation for a five-wheeled mobile robot was presented through comparing the odometric measurements of the powered wheels with those of the fifth non-powered wheel. The experimental result shows that this method is feasible and can be used for online slippage estimation in a sandy terrain.展开更多
On lunar exploration missions, the rovers which can move and explore directly are considered by various agency like NASA （National Aeronautics and Space Administration）, JAXA （Japan Aerospace Exploration Agency）, ...On lunar exploration missions, the rovers which can move and explore directly are considered by various agency like NASA （National Aeronautics and Space Administration）, JAXA （Japan Aerospace Exploration Agency）, ESA （European Space Agency）. Lunar rovers are required to move on rough terrains such as craters and rear cliffs where it is scientifically very important to explore. However, there is a problem that the rovers have possibility of stack because of the lunar surface is covered with loose soil named Regolith. Therefore, this paper investigates a mechanism of kinetic behavior between the wheels of the exploration rovers and loose soil. And then, this paper proposed a flexible wheel to solve like that problems. The flexible wheel has the surface which can be changed flexibly toward rough terrain. Running experiments on loose soil which imitated regolith were carried out to observe the traversability of the flexible wheel using slip ratio. Traversality of flexible wheel was better than the circular rigid wheel. The authors believe that stress distribution is important. The stress distribution of the flexible wheels is horizontally long and stress value is small. However, the stress distribution can be changed by loaded more weight. Therefore, the relationship between the stress and the running performance was considered using this differential stress distribution. In experiments, the authors used the flexible wheel with simple structure （3 limbs）. From these considerations, the relationship between the stress of the flexible wheel and the running performance was described.展开更多
文摘In order to enhance the accuracy and overcome the limitation of representing the vehicular velocity with non driving wheel speed signals, which is commonly used in researching on automotive dynamic control systems at present, the dynamic and kinematics models of running vehicles and wheels are established. The concept that expresses vehicle velocity using only the driving wheel speed information with adjustable weight factors is described and an algorithm is proposed. A Matlab program with the algorithm embedded is made to simulate the vehicle’s accelerating under different road conditions, and it’s simulation results coincide well with the experimental results, which demonstrates the validity of the algorithm.
基金Project(60775060) supported by the National Natural Science Foundation of ChinaProject(F200801) supported by the Natural Science Foundation of Heilongjiang Province,China+1 种基金Project(200802171053,20102304110006) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject(2012RFXXG059) supported by Harbin Science and Technology Innovation Talents Special Fund,China
文摘Good understanding of relationship between parameters of vehicle, terrain and interaction at the interface is required to develop effective navigation and motion control algorithms for autonomous wheeled mobile robots （AWMR） in rough terrain. A model and analysis of relationship among wheel slippage （S）, rotation angle （0）, sinkage （z） and wheel radius （r） are presented. It is found that wheel rotation angle, sinkage and radius have some influence on wheel slippage. A multi-objective optimization problem with slippage as utility function was formulated and solved in MATLAB. The results reveal the optimal values of wheel-terrain parameters required to achieve optimum slippage on dry sandy terrain. A method of slippage estimation for a five-wheeled mobile robot was presented through comparing the odometric measurements of the powered wheels with those of the fifth non-powered wheel. The experimental result shows that this method is feasible and can be used for online slippage estimation in a sandy terrain.
文摘On lunar exploration missions, the rovers which can move and explore directly are considered by various agency like NASA （National Aeronautics and Space Administration）, JAXA （Japan Aerospace Exploration Agency）, ESA （European Space Agency）. Lunar rovers are required to move on rough terrains such as craters and rear cliffs where it is scientifically very important to explore. However, there is a problem that the rovers have possibility of stack because of the lunar surface is covered with loose soil named Regolith. Therefore, this paper investigates a mechanism of kinetic behavior between the wheels of the exploration rovers and loose soil. And then, this paper proposed a flexible wheel to solve like that problems. The flexible wheel has the surface which can be changed flexibly toward rough terrain. Running experiments on loose soil which imitated regolith were carried out to observe the traversability of the flexible wheel using slip ratio. Traversality of flexible wheel was better than the circular rigid wheel. The authors believe that stress distribution is important. The stress distribution of the flexible wheels is horizontally long and stress value is small. However, the stress distribution can be changed by loaded more weight. Therefore, the relationship between the stress and the running performance was considered using this differential stress distribution. In experiments, the authors used the flexible wheel with simple structure （3 limbs）. From these considerations, the relationship between the stress of the flexible wheel and the running performance was described.
