This paper presents the development ofa PNS （Pedestrian Navigation System）, which utilizes accelerometer, gyroscope and magnetometer data to enable accurate positioning. Therefore, the sensor basics as well as the m...This paper presents the development ofa PNS （Pedestrian Navigation System）, which utilizes accelerometer, gyroscope and magnetometer data to enable accurate positioning. Therefore, the sensor basics as well as the mathematics regarding reference frames and coordinate transformations are introduced initially. Particular focus is given to quaternions, since they provide a performance-effective means to execute rotations. In great detail the two distinct approaches for a PNS are introduced, i.e. INS （inertial navigation systems） and PDR （pedestrian dead reckoning）. For each, a comparison of state-of-the-art techniques is presented. Special attention is paid to orientation estimation and stance phase detection. Our system combines the most promising techniques and describes improvements, whose usefulness becomes obvious in our experiments. We have applied our PNS in five different test scenarios. For the most complex rectangular-shaped use case, we achieve on average error of 1.66% with regard to the total travelled distance, which is superior to other recent PNS utilizing comparable sensors.展开更多
This work presents modelling aspects of automatic gain control （AGC） loops based on linear-in-dB variable gain amplifiers （VGAs）. In these loops, the VGA control voltage is also an excellent received signal streng...This work presents modelling aspects of automatic gain control （AGC） loops based on linear-in-dB variable gain amplifiers （VGAs）. In these loops, the VGA control voltage is also an excellent received signal strength indicator （RSSI）. The VGA gain is however nonlinearly related to the control voltage. Moreover, VGAs and detectors undergo nonlinear compression under high input amplitudes during settling transients. The main contribution in this work is a proposed nonlinear model based on simple and readily available components from the ＂analogLib＂ and ＂functional＂ libraries in CADENCE design environment -making it very easy and fast to build and simulate-that captures the nonlinear effects of AGC loops. The model is capable of verifying the AGC loop stability and capturing the loop dynamics with high accuracy compared to time consuming circuit level simulations. This provides insights into system level parameters such as AGC loop bandwidth, phase margin, settling time as well as estimating the AGC range and RSSI voltage vs. input power. Measurement results from a fabricated AGC prototype are in good agreement with simulation and modelling results thus validating the proposed modelling approach.展开更多
文摘This paper presents the development ofa PNS （Pedestrian Navigation System）, which utilizes accelerometer, gyroscope and magnetometer data to enable accurate positioning. Therefore, the sensor basics as well as the mathematics regarding reference frames and coordinate transformations are introduced initially. Particular focus is given to quaternions, since they provide a performance-effective means to execute rotations. In great detail the two distinct approaches for a PNS are introduced, i.e. INS （inertial navigation systems） and PDR （pedestrian dead reckoning）. For each, a comparison of state-of-the-art techniques is presented. Special attention is paid to orientation estimation and stance phase detection. Our system combines the most promising techniques and describes improvements, whose usefulness becomes obvious in our experiments. We have applied our PNS in five different test scenarios. For the most complex rectangular-shaped use case, we achieve on average error of 1.66% with regard to the total travelled distance, which is superior to other recent PNS utilizing comparable sensors.
文摘This work presents modelling aspects of automatic gain control （AGC） loops based on linear-in-dB variable gain amplifiers （VGAs）. In these loops, the VGA control voltage is also an excellent received signal strength indicator （RSSI）. The VGA gain is however nonlinearly related to the control voltage. Moreover, VGAs and detectors undergo nonlinear compression under high input amplitudes during settling transients. The main contribution in this work is a proposed nonlinear model based on simple and readily available components from the ＂analogLib＂ and ＂functional＂ libraries in CADENCE design environment -making it very easy and fast to build and simulate-that captures the nonlinear effects of AGC loops. The model is capable of verifying the AGC loop stability and capturing the loop dynamics with high accuracy compared to time consuming circuit level simulations. This provides insights into system level parameters such as AGC loop bandwidth, phase margin, settling time as well as estimating the AGC range and RSSI voltage vs. input power. Measurement results from a fabricated AGC prototype are in good agreement with simulation and modelling results thus validating the proposed modelling approach.
