提出一种车辆电子稳定性控制系统(electronic stability control system,ESC)补充判据用于定性判定车辆平面运动过程中可能出现的后轴滑移工况.分别研究了二自由度侧向动力学系统方程与考虑纵向加速度因素的三自由度系统方程稳定性判定...提出一种车辆电子稳定性控制系统(electronic stability control system,ESC)补充判据用于定性判定车辆平面运动过程中可能出现的后轴滑移工况.分别研究了二自由度侧向动力学系统方程与考虑纵向加速度因素的三自由度系统方程稳定性判定方法,考虑了车轴切向力与载荷变换对轮胎侧偏特性的综合影响.通过瞬态稳定性分析方法,得到了动力学系统稳定性变化和车辆实际稳定性变化之间可以量化的时域差异关系,基于这种时域差异关系建立了稳定性超前控制方案与理论模型,以理论模型在工况切换瞬态的系统平衡点特性作为控制判据,并且对现有ESC判据应对后轴滑移工况的有效作用时间进行评价.研究表明,特定工况下横摆角速度最大值定义的约束边界与车辆实际稳定性变化边界接近,ESC系统进行控制的时间差有限,超前控制判据理论上可以更早预测车辆运动状态变化.展开更多
Airborne electromagnetic transient method enjoys the advantages of high-efficiency and the high resolution of electromagnetic anomalies,especially suitable for mining detection around goaf areas and deep exploration o...Airborne electromagnetic transient method enjoys the advantages of high-efficiency and the high resolution of electromagnetic anomalies,especially suitable for mining detection around goaf areas and deep exploration of minerals.In this paper,we calculated the full-wave airborne transient electromagnetic data,according to the result of numerical research,the advantage of switch-off time response in electromagnetic detection was proofed via experiments.Firstly,based on the full-wave airborne transient electromagnetic system developed by Jilin University(JLU-ATEMI),we proposed a method to compute the full-waveform electromagnetic(EM)data of 3D model using the FDTD approach and convolution algorithm,and verify the calculation by the response of homogenous half-space.Then,through comparison of switch-off-time response and off-time response,we studied the effect of ramp time on anomaly detection.Finally,we arranged two experimental electromagnetic detection,the results indicated that the switch-off-time response can reveal the shallow target more effectively,and the full-waveform airborne electromagnetic system is an effective technique for shallow target detection.展开更多
文摘提出一种车辆电子稳定性控制系统(electronic stability control system,ESC)补充判据用于定性判定车辆平面运动过程中可能出现的后轴滑移工况.分别研究了二自由度侧向动力学系统方程与考虑纵向加速度因素的三自由度系统方程稳定性判定方法,考虑了车轴切向力与载荷变换对轮胎侧偏特性的综合影响.通过瞬态稳定性分析方法,得到了动力学系统稳定性变化和车辆实际稳定性变化之间可以量化的时域差异关系,基于这种时域差异关系建立了稳定性超前控制方案与理论模型,以理论模型在工况切换瞬态的系统平衡点特性作为控制判据,并且对现有ESC判据应对后轴滑移工况的有效作用时间进行评价.研究表明,特定工况下横摆角速度最大值定义的约束边界与车辆实际稳定性变化边界接近,ESC系统进行控制的时间差有限,超前控制判据理论上可以更早预测车辆运动状态变化.
基金Project(41674109) supported by the National Natural Science Foundation of China
文摘Airborne electromagnetic transient method enjoys the advantages of high-efficiency and the high resolution of electromagnetic anomalies,especially suitable for mining detection around goaf areas and deep exploration of minerals.In this paper,we calculated the full-wave airborne transient electromagnetic data,according to the result of numerical research,the advantage of switch-off time response in electromagnetic detection was proofed via experiments.Firstly,based on the full-wave airborne transient electromagnetic system developed by Jilin University(JLU-ATEMI),we proposed a method to compute the full-waveform electromagnetic(EM)data of 3D model using the FDTD approach and convolution algorithm,and verify the calculation by the response of homogenous half-space.Then,through comparison of switch-off-time response and off-time response,we studied the effect of ramp time on anomaly detection.Finally,we arranged two experimental electromagnetic detection,the results indicated that the switch-off-time response can reveal the shallow target more effectively,and the full-waveform airborne electromagnetic system is an effective technique for shallow target detection.
