The current research of direct yaw moment control（DYC） system focus on the design of target yaw moment and the distribution of wheel brake force. The differential braking intervention can effectively improve the lat...The current research of direct yaw moment control（DYC） system focus on the design of target yaw moment and the distribution of wheel brake force. The differential braking intervention can effectively improve the lateral stability of the vehicle, however, the effect of DYC can be improved a step further by applying the control of vehicle longitudinal velocity. In this paper, the relationship between the vehicle longitudinal velocity and lateral stability is studied, and the simulation results show that a decrease of 5 km/h of longitudinal velocity at a particular situation can bring 100° increasing of stable steering upper limit. A critical stable velocity considering the effect of steering and yaw rate measurement is defined to evaluate the risk of losing steer-ability or stability. A novel velocity pre-control method is proposed by using a hierarchical pre-control logic and is integrated with the traditional DYC system. The control algorithm is verified through a hardware in-the-loop simulation system. Double lane change（DLC） test results on both high friction coefficient（μ） and low μ roads show that by using the pre-control method, the steering effort in DLC test can be reduced by 38% and 51% and the peak value of brake pressure control can be reduced by 20% and 12% respectively on high μ and low μ roads, the lateral stability is also improved. This research proposes a novel DYC system with lighter control effort and better control effect.展开更多
The new type of risk management is process management. First, the hazardsources are identified before coal mine accidents occur, and then the pre-control measureand information monitoring method based on classifying t...The new type of risk management is process management. First, the hazardsources are identified before coal mine accidents occur, and then the pre-control measureand information monitoring method based on classifying the hidden hazard sources aregiven. Lastly, the risk pre-alarm and risk control method are confirmed, the managementstandard and management measure are used to eliminate the hidden hazard sources. Inthis study, an evaluation system is built to evaluate the result of risk management.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51275557,51422505)
文摘The current research of direct yaw moment control（DYC） system focus on the design of target yaw moment and the distribution of wheel brake force. The differential braking intervention can effectively improve the lateral stability of the vehicle, however, the effect of DYC can be improved a step further by applying the control of vehicle longitudinal velocity. In this paper, the relationship between the vehicle longitudinal velocity and lateral stability is studied, and the simulation results show that a decrease of 5 km/h of longitudinal velocity at a particular situation can bring 100° increasing of stable steering upper limit. A critical stable velocity considering the effect of steering and yaw rate measurement is defined to evaluate the risk of losing steer-ability or stability. A novel velocity pre-control method is proposed by using a hierarchical pre-control logic and is integrated with the traditional DYC system. The control algorithm is verified through a hardware in-the-loop simulation system. Double lane change（DLC） test results on both high friction coefficient（μ） and low μ roads show that by using the pre-control method, the steering effort in DLC test can be reduced by 38% and 51% and the peak value of brake pressure control can be reduced by 20% and 12% respectively on high μ and low μ roads, the lateral stability is also improved. This research proposes a novel DYC system with lighter control effort and better control effect.
基金Supported by the National Natural Science Foundation of China(70533050)the Eleventh Five-year Science & Technology Support Plan of China(2006BAK03B0703)the Ministry of Education Humanities and Social Science (08JA630083)
文摘The new type of risk management is process management. First, the hazardsources are identified before coal mine accidents occur, and then the pre-control measureand information monitoring method based on classifying the hidden hazard sources aregiven. Lastly, the risk pre-alarm and risk control method are confirmed, the managementstandard and management measure are used to eliminate the hidden hazard sources. Inthis study, an evaluation system is built to evaluate the result of risk management.
