In this paper, an actuator fault diagnosis scheme based on the backstepping method is proposed for a class of nonlinear heat equations. The fault diagnosis scheme includes fault detection, fault estimation and time to...In this paper, an actuator fault diagnosis scheme based on the backstepping method is proposed for a class of nonlinear heat equations. The fault diagnosis scheme includes fault detection, fault estimation and time to failure (TTF) prediction. Firstly, we achieve fault detection by comparing the detection residual with a predetermined threshold, where the detection residual is defined as the difference between the observer output and the system measurement output. Then, we estimate the fault function through the fault parameter update law and calculate the TTF using only limited measurements. Finally, the numerical simulation is performed on a nonlinear heat equation to verify the effectiveness of the proposed fault diagnosis scheme.展开更多
The Xianshuihe fault（XSHF） zone, characterized by intense tectonic activity, is located at the southwest boundary of the Bayan Har block, where several major earthquakes have occurred, including the 2008 Wenchuan an...The Xianshuihe fault（XSHF） zone, characterized by intense tectonic activity, is located at the southwest boundary of the Bayan Har block, where several major earthquakes have occurred, including the 2008 Wenchuan and the 2013 Lushan earthquakes. This study analysed underground temperature sequence data for four years at seven measuring points at different depths（maximum depth： 18.9 m） in the southeastern section of the XSHF zone. High-frequency atmospheric noise was removed from the temperature sequences to obtain relatively stable temperature fields and heat fluxes near the measurement points. Our measurements show that the surrounding bedrock at（the seven stations distributed in the fault zone） had heat flux values range from-41.0 to 206 m W/m^2, with a median value of 54.3 m W/m^2. The results indicate a low heat flux in the northern section of DaofuKangting and a relatively high heat flux in the southern section of Kangting, which is consistent with the temperature distributions of the hot springs near the fault. Furthermore, our results suggest that the heat transfer in this field results primarily from stable underground heat conduction. In addition, the underground hydrothermal activity is also an obvious factor controlling the geothermal gradient.展开更多
In this paper,25 new terrestrial heat flow values newly observed along the mid-segment of the Tancheng-Lujiang fault zone are listed.With these geothermal data and 37 other terrestrial heat flow values(previously publ...In this paper,25 new terrestrial heat flow values newly observed along the mid-segment of the Tancheng-Lujiang fault zone are listed.With these geothermal data and 37 other terrestrial heat flow values(previously published),we describe the distribution features of terrestrial heat flows in the area.In this research,the two-dimensional temperature structure from the surface to lithospheric bottom of the Huaibei-Sixian-Jinhu profile is inferred by using the finite-element method and the temperature and heat flow of sedimentary,granitic,and basaltic layers is calculated.展开更多
文摘In this paper, an actuator fault diagnosis scheme based on the backstepping method is proposed for a class of nonlinear heat equations. The fault diagnosis scheme includes fault detection, fault estimation and time to failure (TTF) prediction. Firstly, we achieve fault detection by comparing the detection residual with a predetermined threshold, where the detection residual is defined as the difference between the observer output and the system measurement output. Then, we estimate the fault function through the fault parameter update law and calculate the TTF using only limited measurements. Finally, the numerical simulation is performed on a nonlinear heat equation to verify the effectiveness of the proposed fault diagnosis scheme.
基金supported by the National Natural Science Foundation of China (NSFC) (Grant No.4147408641174084)+2 种基金the CAS/CAFEA international partnership program for creative research teams (KZZD-EW-TZ-19)funded by the Special Fund for Seismic Scientific Research (200808011,2004DIB3J1290)the State Key Laboratory of Earthquake Dynamics,Institute of Geology (LED2009A07)
文摘The Xianshuihe fault（XSHF） zone, characterized by intense tectonic activity, is located at the southwest boundary of the Bayan Har block, where several major earthquakes have occurred, including the 2008 Wenchuan and the 2013 Lushan earthquakes. This study analysed underground temperature sequence data for four years at seven measuring points at different depths（maximum depth： 18.9 m） in the southeastern section of the XSHF zone. High-frequency atmospheric noise was removed from the temperature sequences to obtain relatively stable temperature fields and heat fluxes near the measurement points. Our measurements show that the surrounding bedrock at（the seven stations distributed in the fault zone） had heat flux values range from-41.0 to 206 m W/m^2, with a median value of 54.3 m W/m^2. The results indicate a low heat flux in the northern section of DaofuKangting and a relatively high heat flux in the southern section of Kangting, which is consistent with the temperature distributions of the hot springs near the fault. Furthermore, our results suggest that the heat transfer in this field results primarily from stable underground heat conduction. In addition, the underground hydrothermal activity is also an obvious factor controlling the geothermal gradient.
文摘In this paper,25 new terrestrial heat flow values newly observed along the mid-segment of the Tancheng-Lujiang fault zone are listed.With these geothermal data and 37 other terrestrial heat flow values(previously published),we describe the distribution features of terrestrial heat flows in the area.In this research,the two-dimensional temperature structure from the surface to lithospheric bottom of the Huaibei-Sixian-Jinhu profile is inferred by using the finite-element method and the temperature and heat flow of sedimentary,granitic,and basaltic layers is calculated.
