ABS控制并不适用于所有制动工况,由此进一步发展衍生出了电子制动力分配系统(Electric Brake force Distribution,EBD)。针对EBD的功能将EBD的工况分为轻制动、强制动和ABS故障,并分别设计控制策略,实现了一种以车轮加速度和滑移率为门...ABS控制并不适用于所有制动工况,由此进一步发展衍生出了电子制动力分配系统(Electric Brake force Distribution,EBD)。针对EBD的功能将EBD的工况分为轻制动、强制动和ABS故障,并分别设计控制策略,实现了一种以车轮加速度和滑移率为门限值的逻辑控制策略。控制策略通过增压、减压和保压调整轮缸制动压力,优先保证制动过程的稳定性,并且在轻制动时注重舒适性,强制动时减缓后轮压力上升速率,ABS故障时EBD代替ABS对后轮进行制动控制。基于车辆动力学仿真软件ve-DYNA的仿真测试和基于ve-DYNA与dSPACE构建的车辆底盘开发平台的硬件在回路测试表明,此EBD控制策略既能防止后轮先于前轮抱死,又能保证制动舒适性和较高的制动效率。展开更多
Fatigue is usually the cause for the cracks identified at bridge elements in service. With an increase in the introduction of corrugated steel web girders in recent highway bridge construction, the understanding of th...Fatigue is usually the cause for the cracks identified at bridge elements in service. With an increase in the introduction of corrugated steel web girders in recent highway bridge construction, the understanding of the fatigue behaviour of welded details in such structures becomes an important issue for the design. The typical welded details were represented as welded joints assembled by longitudinal corrugated plates. All the experiments were performed under fatigue loading using a servo-control testing machine. The test results from the failure mode observation with the aid of infrared thermo-graph technology show that the failure manner of these welded joints is comparable to that of the corrugated steel web beams reported previously. It is indicated from the stiffness degradation analysis that the welded joints with larger corrugation angle have higher stiffness and greater stiffness degradation in the notable stiffness degradation range. It is shown from the test S-N relations based on the free regression and forced regression analyses that there is a good linear dependence between lg(N) and lg(ΔS). It is also demonstrated that the proposed fracture mechanics analytical model is able to give a prediction slightly lower but on the safe side for the mean stresses at 2 million cycles of the test welded joints.展开更多
文摘ABS控制并不适用于所有制动工况,由此进一步发展衍生出了电子制动力分配系统(Electric Brake force Distribution,EBD)。针对EBD的功能将EBD的工况分为轻制动、强制动和ABS故障,并分别设计控制策略,实现了一种以车轮加速度和滑移率为门限值的逻辑控制策略。控制策略通过增压、减压和保压调整轮缸制动压力,优先保证制动过程的稳定性,并且在轻制动时注重舒适性,强制动时减缓后轮压力上升速率,ABS故障时EBD代替ABS对后轮进行制动控制。基于车辆动力学仿真软件ve-DYNA的仿真测试和基于ve-DYNA与dSPACE构建的车辆底盘开发平台的硬件在回路测试表明,此EBD控制策略既能防止后轮先于前轮抱死,又能保证制动舒适性和较高的制动效率。
基金Projects(51308363,11327801)supported by the National Natural Science Foundation of ChinaProject(2013-1792-9-4)supported by the Scientific Research Foundation for the Returned Overseas Chinese ScholarsProject(YJ201307)supported by the Start-up Research Fund for Introduced Talents of Sichuan University,China
文摘Fatigue is usually the cause for the cracks identified at bridge elements in service. With an increase in the introduction of corrugated steel web girders in recent highway bridge construction, the understanding of the fatigue behaviour of welded details in such structures becomes an important issue for the design. The typical welded details were represented as welded joints assembled by longitudinal corrugated plates. All the experiments were performed under fatigue loading using a servo-control testing machine. The test results from the failure mode observation with the aid of infrared thermo-graph technology show that the failure manner of these welded joints is comparable to that of the corrugated steel web beams reported previously. It is indicated from the stiffness degradation analysis that the welded joints with larger corrugation angle have higher stiffness and greater stiffness degradation in the notable stiffness degradation range. It is shown from the test S-N relations based on the free regression and forced regression analyses that there is a good linear dependence between lg(N) and lg(ΔS). It is also demonstrated that the proposed fracture mechanics analytical model is able to give a prediction slightly lower but on the safe side for the mean stresses at 2 million cycles of the test welded joints.
