In this study, the integration of two navigation systems Air Data System (ADS) and Global Positioning System (GPS) was aimed. ADS is a widely used navigation system which measures static and total air pressure and the...In this study, the integration of two navigation systems Air Data System (ADS) and Global Positioning System (GPS) was aimed. ADS is a widely used navigation system which measures static and total air pressure and the air temperature. ADS has high sampling frequency and poor accuracy, on the other hand, another navigation system GPS has high accuracy compared to ADS but lower sampling frequency.Kalman Filter is used to integrate and minimize the errors of the two navigation systems. By this integration a navigation system with high sampling frequency and high accuracy is aimed. Another object is to calculate the wind speed with high accuracy.展开更多
Two building factors-a longer thermal lag of more than one hour for building envelops and a lag of indoor radiation to convert into cooling load-have impact on the instantaneous heat input and instantaneous cooling lo...Two building factors-a longer thermal lag of more than one hour for building envelops and a lag of indoor radiation to convert into cooling load-have impact on the instantaneous heat input and instantaneous cooling load.So the two factors should be taken into account when selecting the weather parameters for air-conditioning system design.This paper developed a new statistic method for the rational selection of coincident solar irradiance,dry-bulb and wet-bulb temperatures.The method was applied to historic weather records of 25 years in Hong Kong to generate coincident design weather data.And the results show that traditional design solar irradiance,dry-bulb and wet-bulb temperatures may be significantly overestimated in many conditions,and the design weather data for the three different constructions is not kept constant.展开更多
After the completion of Beijing New Airport, air-rail intermodality will become an important means of internal and external links in Jing-Jin-Ji Region. Jing-Jin-Ji Air-Rail Intermodality System is built and 7 sub-sys...After the completion of Beijing New Airport, air-rail intermodality will become an important means of internal and external links in Jing-Jin-Ji Region. Jing-Jin-Ji Air-Rail Intermodality System is built and 7 sub-systems are divided based on user demand analysis. Refer to the passenger process, the business process of the system is planned and the sub-systems are described using data flow diagram. The system provides theoretical support for the development of air-rail intermodal in Jing-Jin-Ji region.展开更多
针对先进高性能飞行器对高精度大气数据的测控需求,研发设计了一套适用于亚声速飞行器的嵌入式大气数据传感(flush air data sensing,FADS)系统。该系统首先基于数值建模技术建立了FADS系统模型的压力数据库,并针对建模数据精度及风洞...针对先进高性能飞行器对高精度大气数据的测控需求,研发设计了一套适用于亚声速飞行器的嵌入式大气数据传感(flush air data sensing,FADS)系统。该系统首先基于数值建模技术建立了FADS系统模型的压力数据库,并针对建模数据精度及风洞试验校准数据分析了Ma=0.2~0.4对应的压力误差限;其次,开发了攻角实时解算算法,并集成到工程原理样机中;最后基于风洞试验和飞行试验对FADS系统的实时解算算法及样机进行了系统评估,并通过事后模型算法对攻角进行重新解算以评估攻角实时解算算法的可靠性。结果表明:(1)与机载惯性导航系统等其他独立测试系统解算的数据相比,飞行试验中FADS系统采用的攻角实时解算方法精度整体较好,攻角误差小于1°,在关键段小于0.5°;基于不同模型建立的FADS系统攻角解算方法得到的攻角数值基本一致,证实了开发的实时解算算法的可靠性。(2)基于风洞试验及飞行试验数据对算法误差限的考核结果显示,飞行试验初始阶段实时解算的攻角值产生波动是压力输入波动误差限较大造成的,高空低速时的压力波动幅值大是实时解算攻角值偏差较大的主要原因;建立的FADS系统的攻角解算方法在算法误差限范围内的压力波动对攻角解算值影响较小,但超过算法误差限的压力波动对攻角解算值影响显著。高空低速飞行器FADS系统对测压传感器精度水平及工程实施水平要求较高,在实际工程应用中应尽量保证测压传感器的精度水平。展开更多
针对亚声速飞行器对高精度飞行参数的测控需求,研发了一套亚声速嵌入式大气数据传感(flush air data sensing,FADS)系统,集成工程样机,并通过风洞试验及飞行试验进行系统考核评估。基于计算流体动力学(computational fluid dynamics,CFD...针对亚声速飞行器对高精度飞行参数的测控需求,研发了一套亚声速嵌入式大气数据传感(flush air data sensing,FADS)系统,集成工程样机,并通过风洞试验及飞行试验进行系统考核评估。基于计算流体动力学(computational fluid dynamics,CFD)方法首先建立FADS系统压力数据库,并通过风洞试验考核了模型算法在低亚声速时的误差限;其次,集成融合实时解算算法的FADS工程原理样机;最后通过飞行试验考核了工程样机的工程适用性。结果表明:(1)与机载的其他独立测试系统相比,FADS攻角实时解算精度高,攻角偏差≤1°,关键段攻角偏差≤0.5°;事后重建的攻角数据与飞行试验FADS系统实时解算数据一致,证实FADS实时攻角解算方法可靠;(2)风洞及飞行试验校核数据表明,FADS实时攻角输出数据在飞行试验初始段的波动是由输入压力波动较大导致,特别是在高空低速段,输入压力波动幅值超过算法的误差限,导致实时攻角解算数值波动较大;(3)CFD仿真结果表明,输入压力波动位于算法误差限内对攻角输出精度影响较小,超过算法误差限的压力幅值波动对实时攻角输出精度影响极大。高空低速飞行器FADS系统对压力传感器等硬件精度及工程实现水平要求较高,应尽量保证工程实施精度。展开更多
现代固定翼飞机受头部火控雷达等设备限制,无法在机头驻点附近开设测压孔,缺乏驻点压力会导致常规嵌入式大气数据传感系统测试精度大大下降。针对典型固定翼飞机常用的菱形前体外形,对无驻点压力FADS(Flush Air Data Sensing)系统解算...现代固定翼飞机受头部火控雷达等设备限制,无法在机头驻点附近开设测压孔,缺乏驻点压力会导致常规嵌入式大气数据传感系统测试精度大大下降。针对典型固定翼飞机常用的菱形前体外形,对无驻点压力FADS(Flush Air Data Sensing)系统解算算法及精度进行研究。通过亚跨声速风洞校准试验,获得了测压孔压力分布特性,基于卡尔曼滤波算法构建了无驻点压力FADS技术。通过引入差压数据改进了算法,改进算法实现了部分解耦,提高了解算精度且迭代次数较少,计算量较小。风洞试验结果表明:无驻点压力解算算法可以在外插车次下较好地解算大气参数,其中迎角测量精度为0.33°,侧滑角测量精度为0.30°,静压测量精度为0.67%,马赫数测量精度为0.011。展开更多
文摘In this study, the integration of two navigation systems Air Data System (ADS) and Global Positioning System (GPS) was aimed. ADS is a widely used navigation system which measures static and total air pressure and the air temperature. ADS has high sampling frequency and poor accuracy, on the other hand, another navigation system GPS has high accuracy compared to ADS but lower sampling frequency.Kalman Filter is used to integrate and minimize the errors of the two navigation systems. By this integration a navigation system with high sampling frequency and high accuracy is aimed. Another object is to calculate the wind speed with high accuracy.
文摘Two building factors-a longer thermal lag of more than one hour for building envelops and a lag of indoor radiation to convert into cooling load-have impact on the instantaneous heat input and instantaneous cooling load.So the two factors should be taken into account when selecting the weather parameters for air-conditioning system design.This paper developed a new statistic method for the rational selection of coincident solar irradiance,dry-bulb and wet-bulb temperatures.The method was applied to historic weather records of 25 years in Hong Kong to generate coincident design weather data.And the results show that traditional design solar irradiance,dry-bulb and wet-bulb temperatures may be significantly overestimated in many conditions,and the design weather data for the three different constructions is not kept constant.
文摘After the completion of Beijing New Airport, air-rail intermodality will become an important means of internal and external links in Jing-Jin-Ji Region. Jing-Jin-Ji Air-Rail Intermodality System is built and 7 sub-systems are divided based on user demand analysis. Refer to the passenger process, the business process of the system is planned and the sub-systems are described using data flow diagram. The system provides theoretical support for the development of air-rail intermodal in Jing-Jin-Ji region.
文摘针对先进高性能飞行器对高精度大气数据的测控需求,研发设计了一套适用于亚声速飞行器的嵌入式大气数据传感(flush air data sensing,FADS)系统。该系统首先基于数值建模技术建立了FADS系统模型的压力数据库,并针对建模数据精度及风洞试验校准数据分析了Ma=0.2~0.4对应的压力误差限;其次,开发了攻角实时解算算法,并集成到工程原理样机中;最后基于风洞试验和飞行试验对FADS系统的实时解算算法及样机进行了系统评估,并通过事后模型算法对攻角进行重新解算以评估攻角实时解算算法的可靠性。结果表明:(1)与机载惯性导航系统等其他独立测试系统解算的数据相比,飞行试验中FADS系统采用的攻角实时解算方法精度整体较好,攻角误差小于1°,在关键段小于0.5°;基于不同模型建立的FADS系统攻角解算方法得到的攻角数值基本一致,证实了开发的实时解算算法的可靠性。(2)基于风洞试验及飞行试验数据对算法误差限的考核结果显示,飞行试验初始阶段实时解算的攻角值产生波动是压力输入波动误差限较大造成的,高空低速时的压力波动幅值大是实时解算攻角值偏差较大的主要原因;建立的FADS系统的攻角解算方法在算法误差限范围内的压力波动对攻角解算值影响较小,但超过算法误差限的压力波动对攻角解算值影响显著。高空低速飞行器FADS系统对测压传感器精度水平及工程实施水平要求较高,在实际工程应用中应尽量保证测压传感器的精度水平。
文摘针对亚声速飞行器对高精度飞行参数的测控需求,研发了一套亚声速嵌入式大气数据传感(flush air data sensing,FADS)系统,集成工程样机,并通过风洞试验及飞行试验进行系统考核评估。基于计算流体动力学(computational fluid dynamics,CFD)方法首先建立FADS系统压力数据库,并通过风洞试验考核了模型算法在低亚声速时的误差限;其次,集成融合实时解算算法的FADS工程原理样机;最后通过飞行试验考核了工程样机的工程适用性。结果表明:(1)与机载的其他独立测试系统相比,FADS攻角实时解算精度高,攻角偏差≤1°,关键段攻角偏差≤0.5°;事后重建的攻角数据与飞行试验FADS系统实时解算数据一致,证实FADS实时攻角解算方法可靠;(2)风洞及飞行试验校核数据表明,FADS实时攻角输出数据在飞行试验初始段的波动是由输入压力波动较大导致,特别是在高空低速段,输入压力波动幅值超过算法的误差限,导致实时攻角解算数值波动较大;(3)CFD仿真结果表明,输入压力波动位于算法误差限内对攻角输出精度影响较小,超过算法误差限的压力幅值波动对实时攻角输出精度影响极大。高空低速飞行器FADS系统对压力传感器等硬件精度及工程实现水平要求较高,应尽量保证工程实施精度。
文摘现代固定翼飞机受头部火控雷达等设备限制,无法在机头驻点附近开设测压孔,缺乏驻点压力会导致常规嵌入式大气数据传感系统测试精度大大下降。针对典型固定翼飞机常用的菱形前体外形,对无驻点压力FADS(Flush Air Data Sensing)系统解算算法及精度进行研究。通过亚跨声速风洞校准试验,获得了测压孔压力分布特性,基于卡尔曼滤波算法构建了无驻点压力FADS技术。通过引入差压数据改进了算法,改进算法实现了部分解耦,提高了解算精度且迭代次数较少,计算量较小。风洞试验结果表明:无驻点压力解算算法可以在外插车次下较好地解算大气参数,其中迎角测量精度为0.33°,侧滑角测量精度为0.30°,静压测量精度为0.67%,马赫数测量精度为0.011。
