| 1. |
- Hostettler, Roland, et al.
(författare)
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Joint Vehicle Trajectory and Model Parameter Estimation using Road Side Sensors
- 2015
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 15:9, s. 5075-5086
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Tidskriftsartikel (refereegranskat)abstract
- This article shows how a particle smoother based system identification method can be applied for estimating the trajectory of road vehicles. As sensors, a combination of an accelerometer measuring the road surface vibrations and a magnetometer measuring magnetic disturbances mounted on the side of the road are considered. First, sensor models describing the measurements of the two sensors are introduced. It is shown that these depend on unknown, static parameters that have to be considered in the estimation. Second, the sensor models are combined with a two-dimensional constant velocity motion model. Third, the system identification algorithm is introduced which iteratively runs a Rao-Blackwellized particle smoother to estimate the vehicle trajectory followed by an expectation-maximization step to estimate the parameters. Finally, the method is applied to both simulation and measurement data. It is found that the method works well in general and some issues when real data is considered are identified as future work.
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| 2. |
- Hostettler, Roland, et al.
(författare)
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Maximum Likelihood Estimation of the Non-Parametric FRF for Pulse-Like Excitations
- 2016
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Ingår i: IEEE Transactions on Automatic Control. - 0018-9286 .- 1558-2523. ; 61:8, s. 2276-2281
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Tidskriftsartikel (refereegranskat)abstract
- This technical note introduces the closed form maximum likelihood estimator for estimating the coefficients of the non-parametric frequency response function from system identification experiments. It is assumed that the experiments consist of repeated pulse excitations and that both the excitation and system response are measured which leads to an error-in-variables setting. Monte Carlo simulations indicate that the estimator achieves efficiency at low signal-to-noise ratios with only few measurements. Comparison with the least-squares estimator shows that better, unbiased results are obtained.
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| 3. |
- Lidström, Viktor, 1991-, et al.
(författare)
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Non-Coherent Acoustic Modulation for Energy Constrained Underwater Platforms
- 2019
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Ingår i: OCEANS 2019 - Marseille, OCEANS Marseille 2019. - : Institute of Electrical and Electronics Engineers Inc..
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Konferensbidrag (refereegranskat)abstract
- With regards to energy constrained Autonomous Underwater Vehicles (AUVs), and difficulties inherent to the acoustic underwater communication channel, a non-coherent method is investigated in order to improve energy consumption and reliability over traditional Frequency Shift Keying (FSK), without increasing the bandwidth. A proposed method of adapting Trellis Coded Modulation (TCM) to constant amplitude Permutated Frequency Shift Keying (PFSK) symbol constellations is evaluated. A system implementation of two PFSK methods is simulated in an Additive White Gaussian Noise channel, and field tested in an underwater channel in the Stockholm archipelago, where a binary FSK reference method is used as a comparison. The main interest is comparing electrical bit energy and bit error rate (BER) for the methods. Time variability of frequency fading, related to wind speed, is also evaluated from the field tests.
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