The operating principle of an antilock braking system （ABS） is it compares current value of angular acceleration with the threshold value. The advantage of such system is that enough it has only the angular velocity...The operating principle of an antilock braking system （ABS） is it compares current value of angular acceleration with the threshold value. The advantage of such system is that enough it has only the angular velocity sensors. The disadvantage is successive overshoot, i. e. successive transition from wheels locking mode to wheels rolling mode. So braking mechanism can’ t realize the maximum possible torque in the current road conditions. The idea of increasing the braking effectiveness is the intensity of rising pressure depends on the road conditions. The problem is the torque produced by braking mechanism, current road conditions and the value of traction coefficient is unknown For evaluation of these parameters built and training three neural networks. A simulator of random road condition＇s variation was built to test adequacy of the control unites operation in close to real conditions.展开更多
When a four in-wheel motors drive electric vehicle with a specific wheels mass is running on an uneven road and transient steering occurs in the meantime, the joint action of the large unsprung dynamic load and the ce...When a four in-wheel motors drive electric vehicle with a specific wheels mass is running on an uneven road and transient steering occurs in the meantime, the joint action of the large unsprung dynamic load and the centrifugal force may cause the vehicle to rollover. To avoid the above accident, a rollover prevention control method based on active distribution of the in-wheel motors driving torques is investigated. First, tile rollover evolution process of the four in-wheel motors drive electric vehicle under the described operating condition is analyzed. Next, a multiple degrees of freedom vehicle dynamics model including an uneven road tyre model is established, and the rollover warning threshold is determined according to the load transfer ratio. Then, the hypothesis of the effects of unsprung mass on the vehicle roll stability on a plat road and on an uneven road is verified respectively. Finally, a rollover prevention controller is designed based on the distribution of the four wheels driving torques with sliding mode control, and the control effect is verified by simulations. The conclusion shows that, once the wheels mass does not match road conditions, the large unsprung mass may play a detrimental role on the vehicle roll stability on an uneven road, which is different from the beneficial role of large unsprung mass on the vehicle roll stability on a plat road. With the aforementioned rollover prevention controller, the vehicle rollover, which is caused by the coupling effect between large unsprung dynamic load and suspension potential energy on an uneven road, can be avoided effectively.展开更多
文摘The operating principle of an antilock braking system （ABS） is it compares current value of angular acceleration with the threshold value. The advantage of such system is that enough it has only the angular velocity sensors. The disadvantage is successive overshoot, i. e. successive transition from wheels locking mode to wheels rolling mode. So braking mechanism can’ t realize the maximum possible torque in the current road conditions. The idea of increasing the braking effectiveness is the intensity of rising pressure depends on the road conditions. The problem is the torque produced by braking mechanism, current road conditions and the value of traction coefficient is unknown For evaluation of these parameters built and training three neural networks. A simulator of random road condition＇s variation was built to test adequacy of the control unites operation in close to real conditions.
基金supported by the National Natural Science Foundation of China(Grant Nos.51405259&51775478)
文摘When a four in-wheel motors drive electric vehicle with a specific wheels mass is running on an uneven road and transient steering occurs in the meantime, the joint action of the large unsprung dynamic load and the centrifugal force may cause the vehicle to rollover. To avoid the above accident, a rollover prevention control method based on active distribution of the in-wheel motors driving torques is investigated. First, tile rollover evolution process of the four in-wheel motors drive electric vehicle under the described operating condition is analyzed. Next, a multiple degrees of freedom vehicle dynamics model including an uneven road tyre model is established, and the rollover warning threshold is determined according to the load transfer ratio. Then, the hypothesis of the effects of unsprung mass on the vehicle roll stability on a plat road and on an uneven road is verified respectively. Finally, a rollover prevention controller is designed based on the distribution of the four wheels driving torques with sliding mode control, and the control effect is verified by simulations. The conclusion shows that, once the wheels mass does not match road conditions, the large unsprung mass may play a detrimental role on the vehicle roll stability on an uneven road, which is different from the beneficial role of large unsprung mass on the vehicle roll stability on a plat road. With the aforementioned rollover prevention controller, the vehicle rollover, which is caused by the coupling effect between large unsprung dynamic load and suspension potential energy on an uneven road, can be avoided effectively.
