This paper presents a multi-antenna GPS based system developed for local continuous deformation monitoring. Due to a large number of points that needs to be monitored, the standard approaches of using permanent GPS re...This paper presents a multi-antenna GPS based system developed for local continuous deformation monitoring. Due to a large number of points that needs to be monitored, the standard approaches of using permanent GPS receiver arrays will cause high cost. It eventually becomes the limiting factor for large-scale use of GPS in these application areas. Multi-antenna GPS system allows a number of GPS antennas to be linked to one GPS receiver by a specially designed electronic component, i. e. the so-called GPS multi-antenna switch (GMS), The receiver takes data sequentially from each of the antennas attached to the receiver. A distinctive advantage of the approach is that one GPS receiver can be used to monitor more than one point. The cost per monitored point (i. e. the expenses of hardware) is therefore significantly reduced.展开更多
By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is b...By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is based on the cyclic redundancy check( CRC) of the messages in the subframes 2 and 3. The simulation results show that average number of iterations of the proposed strategy is less than that of the standard ET strategy,with nearly no degradation in decoding performance. Besides,the proposed ET strategy can be efficiently implemented in a sequential or parallel manner. Thus,the proposed ET strategy is attractive for practical purposes.展开更多
The geometrical product specifications and verification(GPS)system is an engineering tool for product development and manufacture.The new GPS standard system is necessary,as companies are rapidly moving ahead with new...The geometrical product specifications and verification(GPS)system is an engineering tool for product development and manufacture.The new GPS standard system is necessary,as companies are rapidly moving ahead with new technologies,new manufacturing processes,new materials and visionary products in an environment of international outsourcing.The GPS system takes the complete life cycle of a product from function requirements,design,manufacturing to verification into account.The matrix framework of the new GPS is masterplanned under one main line and two kinds of correlation.The main line is based on specifications concerning the whole production process.And two kinds of correlation are the expanded uncertainties and duality principle-based operators.They are two important tools for manufacture production and there are other concepts and definitions proposed in the new GPS that differ from the traditional geometrical standards.The paper discusses the improved GPS system about its background,characteristics,framework and some important concepts,which will present a clear and impressive standard system for the digital manufacture.展开更多
To realize the data synchronization between the inertial measurement unit （IMU） and the global positioning system （GPS）, the synchronization technology in the IMU/GPS integrated measurement system of vehicle motio...To realize the data synchronization between the inertial measurement unit （IMU） and the global positioning system （GPS）, the synchronization technology in the IMU/GPS integrated measurement system of vehicle motion parameters is studied. According to the characteristics of the output signals of the IMU and the GPS, without the IMU synchronization signal, the synchronization circuit based on CPLD is designed and developed, which need not alter the configurations of the IMU and GPS. Experiments of measuring vehicle motion parameters, which rely on the synchronization circuit to realize IMU/GPS data synchronization, are made. The driving routes in experiments comprise a curve and a straight line. Experimental results show that the designed circuit can accurately measure the synchronization time difference and the IMU period, and can effectively solve the data synchronization in IMU/GPS integration. Furthermore, the IMU/GPS integrated measurement system based on the synchronization circuit can measure and calculate many vehicle motion parameters in high frequency mode.展开更多
基金Supported by the National Natural Science Foundation of China(No. 49771062), by a grant forUniversity Key Teacher of China, an
文摘This paper presents a multi-antenna GPS based system developed for local continuous deformation monitoring. Due to a large number of points that needs to be monitored, the standard approaches of using permanent GPS receiver arrays will cause high cost. It eventually becomes the limiting factor for large-scale use of GPS in these application areas. Multi-antenna GPS system allows a number of GPS antennas to be linked to one GPS receiver by a specially designed electronic component, i. e. the so-called GPS multi-antenna switch (GMS), The receiver takes data sequentially from each of the antennas attached to the receiver. A distinctive advantage of the approach is that one GPS receiver can be used to monitor more than one point. The cost per monitored point (i. e. the expenses of hardware) is therefore significantly reduced.
基金Sponsored by the National Natural Science Foundation of China(Grant No.61271423)
文摘By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is based on the cyclic redundancy check( CRC) of the messages in the subframes 2 and 3. The simulation results show that average number of iterations of the proposed strategy is less than that of the standard ET strategy,with nearly no degradation in decoding performance. Besides,the proposed ET strategy can be efficiently implemented in a sequential or parallel manner. Thus,the proposed ET strategy is attractive for practical purposes.
基金supported by the Postdoctoral Foundation of Huazhong University of Science and Technology(HUST).
文摘The geometrical product specifications and verification(GPS)system is an engineering tool for product development and manufacture.The new GPS standard system is necessary,as companies are rapidly moving ahead with new technologies,new manufacturing processes,new materials and visionary products in an environment of international outsourcing.The GPS system takes the complete life cycle of a product from function requirements,design,manufacturing to verification into account.The matrix framework of the new GPS is masterplanned under one main line and two kinds of correlation.The main line is based on specifications concerning the whole production process.And two kinds of correlation are the expanded uncertainties and duality principle-based operators.They are two important tools for manufacture production and there are other concepts and definitions proposed in the new GPS that differ from the traditional geometrical standards.The paper discusses the improved GPS system about its background,characteristics,framework and some important concepts,which will present a clear and impressive standard system for the digital manufacture.
文摘To realize the data synchronization between the inertial measurement unit （IMU） and the global positioning system （GPS）, the synchronization technology in the IMU/GPS integrated measurement system of vehicle motion parameters is studied. According to the characteristics of the output signals of the IMU and the GPS, without the IMU synchronization signal, the synchronization circuit based on CPLD is designed and developed, which need not alter the configurations of the IMU and GPS. Experiments of measuring vehicle motion parameters, which rely on the synchronization circuit to realize IMU/GPS data synchronization, are made. The driving routes in experiments comprise a curve and a straight line. Experimental results show that the designed circuit can accurately measure the synchronization time difference and the IMU period, and can effectively solve the data synchronization in IMU/GPS integration. Furthermore, the IMU/GPS integrated measurement system based on the synchronization circuit can measure and calculate many vehicle motion parameters in high frequency mode.
