Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one contro...Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one control method to improve the other. Moreover, many experiments are needed to improve the robustness; therefore, these control methods are underutilized. This paper proposes an integrated control system specially designed for multi-axle vehicles, in which the desired lateral force and yaw moment of vehicles are determined by the sliding mode control algorithm. The output of the sliding mode control is distributed to the suitable wheels based on the abilities and potentials of the two control methods. Moreover, in this method, fewer experiments are needed, and the robustness and simultaneity are both guaranteed. To simplify the optimization system and to improve the computation speed, seven simple optimization subsystems are designed for the determination of control outputs on each wheel. The simulation results show that the proposed controller obviously enhances the stability of multi-axle trucks. The system improves 68% of the safe velocity, and its performance is much better than both di erential braking and active steering. This research proposes an integrated control system that can simultaneously invoke di erential braking and active steering of multi-axle vehicles to fully utilize the abilities and potentials of the two control methods.展开更多
This paper presents the results of field and laboratory tests of railway ballast.Field tests were aimed to study vibrational acceleration of ballast particles and ballast layer stressed state in terms of train traffic...This paper presents the results of field and laboratory tests of railway ballast.Field tests were aimed to study vibrational acceleration of ballast particles and ballast layer stressed state in terms of train traffic with heavy axle loads.The test results are vibrational acceleration and stress values distribution in ballast layer and experimental relationships of vertical and horizontal vibroaccelerations damping in terms of train operation with axle load up to 300 k N.Laboratory stabilometer tests were directed to study the change of ballast strength properties due to vibrodynamic impact and shows that for dynamic loading with 10,25,55 Hz frequencies vibrodynamic impact influences strength properties insignificantly and coincides with the accuracy of test equipment.Stated test results provide references for calculation of ballast and sub-ballast bearing capacity.展开更多
基金National Natural Science Foundation of China(Grant No.51505178)China Postdoctoral Science Foundation(Grant No.2014M561289)
文摘Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one control method to improve the other. Moreover, many experiments are needed to improve the robustness; therefore, these control methods are underutilized. This paper proposes an integrated control system specially designed for multi-axle vehicles, in which the desired lateral force and yaw moment of vehicles are determined by the sliding mode control algorithm. The output of the sliding mode control is distributed to the suitable wheels based on the abilities and potentials of the two control methods. Moreover, in this method, fewer experiments are needed, and the robustness and simultaneity are both guaranteed. To simplify the optimization system and to improve the computation speed, seven simple optimization subsystems are designed for the determination of control outputs on each wheel. The simulation results show that the proposed controller obviously enhances the stability of multi-axle trucks. The system improves 68% of the safe velocity, and its performance is much better than both di erential braking and active steering. This research proposes an integrated control system that can simultaneously invoke di erential braking and active steering of multi-axle vehicles to fully utilize the abilities and potentials of the two control methods.
文摘This paper presents the results of field and laboratory tests of railway ballast.Field tests were aimed to study vibrational acceleration of ballast particles and ballast layer stressed state in terms of train traffic with heavy axle loads.The test results are vibrational acceleration and stress values distribution in ballast layer and experimental relationships of vertical and horizontal vibroaccelerations damping in terms of train operation with axle load up to 300 k N.Laboratory stabilometer tests were directed to study the change of ballast strength properties due to vibrodynamic impact and shows that for dynamic loading with 10,25,55 Hz frequencies vibrodynamic impact influences strength properties insignificantly and coincides with the accuracy of test equipment.Stated test results provide references for calculation of ballast and sub-ballast bearing capacity.
