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misc:investigations:lps-precision [2017-03-23 17:43] kristoffer |
misc:investigations:lps-precision [2017-07-07 09:29] arnaud [The results] |
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These measurements are in no way meant to be a specification of the system properties of the Loco Positioning system, but are intended to give an indication of the performance. | These measurements are in no way meant to be a specification of the system properties of the Loco Positioning system, but are intended to give an indication of the performance. | ||
+ | |||
+ | ===== Multiple measurements in reference system ===== | ||
==== The reference system ==== | ==== The reference system ==== | ||
- | The reference system is based on the indoor explorer bundle: one Crazyflie with a Loco Positioning Deck and six Loco Positioning Anchors. See the [[doc: | + | The reference system is based on the indoor explorer bundle: one Crazyflie with a Loco Positioning Deck and six Loco Positioning Anchors. See the [[doc: |
All measurements were done in the Two way ranging mode. | All measurements were done in the Two way ranging mode. | ||
==== The results ==== | ==== The results ==== | ||
- | ^ Physical position ^^^ Average estimated position ^^^ Std deviation | + | ^ Physical position ^^^ Average estimated position |
- | ^ X ^ Y ^ Z ^ X ^ Y ^ Z ^ X ^ Y ^ Z ^ | + | ^ X ^ Y ^ Z ^ X ^ Err ^ Y ^ Err ^ Z ^ Err ^ X ^ Y ^ Z ^ |
- | ^ 1.62 ^ 3.15 ^ -0.15 ^ 1.66 ^ 3.18 ^ 0.29 ^ 0.014 ^ 0.0097 | + | | 1.62 | 3.15 | -0.15 | 1.66 |0.04 | 3.18 |0.03 | 0.29 |0.44 | 0.014 |
- | ^ 2.95 ^ 0.00 ^ -0.15 ^ 2.80 ^ 0.12 ^ 0.16 ^ 0.0072 | + | | 2.95 | 0.00 | -0.15 | 2.80 |-0.15| |
- | ^ 1.62 ^ 3.15 ^ 1.44 ^ 1.56 ^ 3.02 ^ 1.37 ^ 0.020 ^ 0.0066 | + | | 1.62 | 3.15 | 1.44 |
- | ^ 1.62 ^ 4.80 ^ 1.44 ^ 1.67 ^ 4.64 ^ 1.40 ^ 0.013 ^ 0.0093 | + | | 1.62 | 4.80 | 1.44 |
+ | |||
+ | [[https:// | ||
+ | ===== Measurement of accuracy and noise of 3D estimate and ranges ===== | ||
+ | |||
+ | ==== Setup ==== | ||
+ | |||
+ | The system is setup with 6 anchors and one Crazyflie ranging in two-way-ranging mode. The Crazyflie in static position without movement. | ||
+ | |||
+ | === Positions === | ||
+ | |||
+ | ^ Anchor ^ X ^ Y ^ Z ^ | ||
+ | | 0 | 3.01 | 0.57 | 2.5 | | ||
+ | | 1 | 3.01 | 2.63 | 2.5 | | ||
+ | | 2 | 6.53 | 2.27 | 2.84 | | ||
+ | | 3 | 6.53 | 0.51 | 2.84 | | ||
+ | | 4 | 2.91 | 0.86 | 0.16 | | ||
+ | | 5 | 6.95 | 2.32 | 0.16 | | ||
+ | |||
+ | Crazyflie: (x,y,z) = (5.00, 1.50, 0.76) | ||
+ | |||
+ | === Measurements === | ||
+ | |||
+ | * Kalman filter 3D estimated position: https:// | ||
+ | * Raw range measurement (not taken at the same time as the kalman estimate): https:// | ||
+ | |||
+ | === Analysis === | ||
+ | |||
+ | == Estimated position == | ||
+ | |||
+ | ^ Physical position ^^^ Average estimated position ^^^^^^ Std-dev of estimated position ^^^ Average error ^ | ||
+ | ^ X ^ Y ^ Z ^ X ^ Err ^ Y ^ Err ^ Z ^ Err ^ X ^ Y ^ Z ^ distance ^ | ||
+ | | 5.00 | 1.50 | 0.76 | 4.96 | 0.017 | 1.60 | 0.041 | -0.096 | -0.213 | 0.017 | 0.018 | 0.015 | 0.237 | | ||
+ | |||
+ | == Raw range measurements == | ||
+ | |||
+ | Physical distances from Crazyflie to anchors are calculated from positions of anchors and the Crazyflie. | ||
+ | |||
+ | Average and standard deviations are calculated on all data, including outliers. | ||
+ | |||
+ | The main part of the error should be caused by the antenna delay, expected to be the same for all anchors. | ||
+ | ^ ^ Physical ^ Raw range measurements ^^^ | ||
+ | ^ Anchor ^ Distance ^ Average ^ Std dev ^ Err ^ | ||
+ | | 0 | 2.80 | 2.46 | 0.025 | 0.34 | | ||
+ | | 1 | 2.87 | 2.58 | 0.006 | 0.30 | | ||
+ | | 2 | 2.69 | 2.30 | 0.002 | 0.40 | | ||
+ | | 3 | 2.77 | 2.55 | 0.017 | 0.22 | | ||
+ | | 4 | 2.27 | 1.97 | 0.041 | 0.29 | | ||
+ | | 5 | 2.20 | 1.90 | 0.008 | 0.30 | | ||
+ | == Histogram over raw range measurements == | ||
+ | {{: |