With the development of fast communication technology between ego vehicle and other traffic participants,and automated driving technology,there is a big potential in the improvement of energy efficiency of hybrid elec...With the development of fast communication technology between ego vehicle and other traffic participants,and automated driving technology,there is a big potential in the improvement of energy efficiency of hybrid electric vehicles(HEVs).Moreover,the terrain along the driving route is a non-ignorable factor for energy efficiency of HEV running on the hilly streets.This paper proposes a look-ahead horizon-based optimal energy management strategy to jointly improve the efficiencies of powertrain and vehicle for connected and automated HEVs on the road with slope.Firstly,a rule-based framework is developed to guarantee the success of automated driving in the traffic scenario.Then a constrained optimal control problem is formulated to minimize the fuel consumption and the electricity consumption under the satisfaction of inter-vehicular distance constraint between ego vehicle and preceding vehicle.Both speed planning and torque split of hybrid powertrain are provided by the proposed approach.Moreover,the preceding vehicle speed in the look-ahead horizon is predicted by extreme learning machine with real-time data obtained from communication of vehicle-to-everything.The optimal solution is derived through the Pontryagin’s maximum principle.Finally,to verify the effectiveness of the proposed algorithm,a traffic-in-the-loop powertrain platform with data from real world traffic environment is built.It is found that the fuel economy for the proposed energy management strategy improves in average 17.0%in scenarios of different traffic densities,compared to the energy management strategy without prediction of preceding vehicle speed.展开更多
连接节点的设计是保证木-混凝土混合结构中两种材料协同工作的基础.为研究常用工程木-混凝土螺栓连接节点的力学性能及破坏模式,分别选用正交胶合木(Crosslaminated timber,CLT)-混凝土螺栓连接和云杉-松木-冷杉(Spruce Pine Fir,SPF)...连接节点的设计是保证木-混凝土混合结构中两种材料协同工作的基础.为研究常用工程木-混凝土螺栓连接节点的力学性能及破坏模式,分别选用正交胶合木(Crosslaminated timber,CLT)-混凝土螺栓连接和云杉-松木-冷杉(Spruce Pine Fir,SPF)规格材-混凝土螺栓连接作为试验对象,设计了27组单调加载试验和低周往复加载试验,归纳并对比了两类木-混凝土螺栓连接的典型破坏模式.结果表明:木-混凝土螺栓连接节点承载力大小与螺栓屈服模式相关,CLT-混凝土螺栓连接相较于SPF-混凝土螺栓连接更易发生双铰破坏,且CLT-混凝土螺栓连接具有更好的延性.基于对两类连接力学性能差异的影响机理分析,考虑钢垫板对承载力的影响,并引入CLT等效截面,提出了木-混凝土螺栓连接的承载力力学模型.计算结果与试验结果对比的平均误差为12.18%,表明计算值与试验值吻合良好,可为木-混凝土螺栓连接的设计与应用提供参考.展开更多
为解决反复开挖道路铺设多种管线造成交通拥堵且耗费大量建设成本的难题,提出侧壁出筋叠合板式拼装综合管廊,该管廊具有吊装方便、现场支模少、节点连接可靠、整体性和防水性好等优点。基于ABAQUS大型商用软件,建立水平荷载作用下侧壁...为解决反复开挖道路铺设多种管线造成交通拥堵且耗费大量建设成本的难题,提出侧壁出筋叠合板式拼装综合管廊,该管廊具有吊装方便、现场支模少、节点连接可靠、整体性和防水性好等优点。基于ABAQUS大型商用软件,建立水平荷载作用下侧壁出筋叠合板式拼装综合管廊有限元分析模型。为验证该模型的合理性,开展侧壁出筋叠合板式拼装综合管廊中节点试验,试验结果与有限元分析结果吻合良好。在此基础上,进一步开展叠合板式拼装综合管廊双舱整体结构足尺模型的有限元参数分析,分析参数包括腋角高度和轴压比。分析结果表明:1)双舱整体结构的破坏形态均为弯曲破坏。2)所有试件的峰值承载力在200.5~298.6 k N,层间位移角在1/43~1/27。3)相比于无腋角试件,当腋角高度分别为150 mm和250 mm时,有腋试件的峰值承载力分别提高24.4%和39.7%,峰值侧移分别增加49.3%和60.1%;当轴压比从0增加到0.05、0.10时,有腋试件的峰值承载力分别提升10.3%、19.7%,但峰值侧移分别降低5.2%、18.6%。总体上,侧壁出筋叠合板式拼装综合管廊双舱整体结构具有较大的承载力和较好的变形能力。展开更多
为平抑微源半桥变流器串联星型结构微电网HCSY-MG(half-bridge converter series Y-connection micro-grids)并网系统中微源出力的波动,保证各相直流侧电压之和相等,与并网电流三相平衡,提出1种基于改进近端策略优化PPO(proximal policy...为平抑微源半桥变流器串联星型结构微电网HCSY-MG(half-bridge converter series Y-connection micro-grids)并网系统中微源出力的波动,保证各相直流侧电压之和相等,与并网电流三相平衡,提出1种基于改进近端策略优化PPO(proximal policy optimization)的分布式混合储能系统HESS(hybrid energy storage system)充、放电优化控制策略。在考虑HCSY-MG系统并网电流与分布式HESS特性的条件下,确定影响并网电流的主要系统变量,以及HESS接入系统的最佳拓扑结构。然后结合串联系统的特点,将分布式HESS的充、放电问题转换为深度强化学习的Markov决策过程。同时针对PPO算法中熵损失权重难以确定的问题,提出1种改进的PPO算法,兼顾智能体的收敛性和探索性。最后以某新能源发电基地的典型运行数据为算例,验证所提控制策略的可行性和有效性。展开更多
文摘With the development of fast communication technology between ego vehicle and other traffic participants,and automated driving technology,there is a big potential in the improvement of energy efficiency of hybrid electric vehicles(HEVs).Moreover,the terrain along the driving route is a non-ignorable factor for energy efficiency of HEV running on the hilly streets.This paper proposes a look-ahead horizon-based optimal energy management strategy to jointly improve the efficiencies of powertrain and vehicle for connected and automated HEVs on the road with slope.Firstly,a rule-based framework is developed to guarantee the success of automated driving in the traffic scenario.Then a constrained optimal control problem is formulated to minimize the fuel consumption and the electricity consumption under the satisfaction of inter-vehicular distance constraint between ego vehicle and preceding vehicle.Both speed planning and torque split of hybrid powertrain are provided by the proposed approach.Moreover,the preceding vehicle speed in the look-ahead horizon is predicted by extreme learning machine with real-time data obtained from communication of vehicle-to-everything.The optimal solution is derived through the Pontryagin’s maximum principle.Finally,to verify the effectiveness of the proposed algorithm,a traffic-in-the-loop powertrain platform with data from real world traffic environment is built.It is found that the fuel economy for the proposed energy management strategy improves in average 17.0%in scenarios of different traffic densities,compared to the energy management strategy without prediction of preceding vehicle speed.
文摘连接节点的设计是保证木-混凝土混合结构中两种材料协同工作的基础.为研究常用工程木-混凝土螺栓连接节点的力学性能及破坏模式,分别选用正交胶合木(Crosslaminated timber,CLT)-混凝土螺栓连接和云杉-松木-冷杉(Spruce Pine Fir,SPF)规格材-混凝土螺栓连接作为试验对象,设计了27组单调加载试验和低周往复加载试验,归纳并对比了两类木-混凝土螺栓连接的典型破坏模式.结果表明:木-混凝土螺栓连接节点承载力大小与螺栓屈服模式相关,CLT-混凝土螺栓连接相较于SPF-混凝土螺栓连接更易发生双铰破坏,且CLT-混凝土螺栓连接具有更好的延性.基于对两类连接力学性能差异的影响机理分析,考虑钢垫板对承载力的影响,并引入CLT等效截面,提出了木-混凝土螺栓连接的承载力力学模型.计算结果与试验结果对比的平均误差为12.18%,表明计算值与试验值吻合良好,可为木-混凝土螺栓连接的设计与应用提供参考.
文摘为解决反复开挖道路铺设多种管线造成交通拥堵且耗费大量建设成本的难题,提出侧壁出筋叠合板式拼装综合管廊,该管廊具有吊装方便、现场支模少、节点连接可靠、整体性和防水性好等优点。基于ABAQUS大型商用软件,建立水平荷载作用下侧壁出筋叠合板式拼装综合管廊有限元分析模型。为验证该模型的合理性,开展侧壁出筋叠合板式拼装综合管廊中节点试验,试验结果与有限元分析结果吻合良好。在此基础上,进一步开展叠合板式拼装综合管廊双舱整体结构足尺模型的有限元参数分析,分析参数包括腋角高度和轴压比。分析结果表明:1)双舱整体结构的破坏形态均为弯曲破坏。2)所有试件的峰值承载力在200.5~298.6 k N,层间位移角在1/43~1/27。3)相比于无腋角试件,当腋角高度分别为150 mm和250 mm时,有腋试件的峰值承载力分别提高24.4%和39.7%,峰值侧移分别增加49.3%和60.1%;当轴压比从0增加到0.05、0.10时,有腋试件的峰值承载力分别提升10.3%、19.7%,但峰值侧移分别降低5.2%、18.6%。总体上,侧壁出筋叠合板式拼装综合管廊双舱整体结构具有较大的承载力和较好的变形能力。
文摘为平抑微源半桥变流器串联星型结构微电网HCSY-MG(half-bridge converter series Y-connection micro-grids)并网系统中微源出力的波动,保证各相直流侧电压之和相等,与并网电流三相平衡,提出1种基于改进近端策略优化PPO(proximal policy optimization)的分布式混合储能系统HESS(hybrid energy storage system)充、放电优化控制策略。在考虑HCSY-MG系统并网电流与分布式HESS特性的条件下,确定影响并网电流的主要系统变量,以及HESS接入系统的最佳拓扑结构。然后结合串联系统的特点,将分布式HESS的充、放电问题转换为深度强化学习的Markov决策过程。同时针对PPO算法中熵损失权重难以确定的问题,提出1种改进的PPO算法,兼顾智能体的收敛性和探索性。最后以某新能源发电基地的典型运行数据为算例,验证所提控制策略的可行性和有效性。
