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Wheel odometry statistics

The wheel odometry statistics file allows the user to evaluate the performance of the wheel odometry measurements inputted to the Vision-RTK2 from an auxiliary sensor (e.g., wheel encoder). This file compares the sensor's estimated velocity based on the Fusion engine and the input velocity from each configured sensor (e.g., center, front-left, front-right, rear-left, rear-right). Additionally, the estimated wheel speed factor (i.e., the estimated unit scale of the input measurements) is displayed at the top of each sensor's plot.

In addition, the file presents the estimated velocity from each GNSS receiver for comparison. This information allows for discarding possible failures in the Fusion engine and comparing directly with each receiver's raw GNSS measurements.

Lastly, the file displays the wheel speed convergence and stationary flags, allowing the user to determine how long it took for the wheel odometry values to converge and analyze the performance of the stationary detection block on the platform using the selected operation mode. Please get in touch with support@fixposition.com for further guidance on the matter.


Below is an example of the wheel odometry performance on a slow-moving vehicle with two auxiliary sensors (i.e., rear-left and rear-right encoders). As shown in the figure, there is a high correlation between the input velocity measurements and the estimated velocity of the sensor using the Fusion engine. In addition, the wheelspeed factor for both sensors is virtually the same, indicating that the measurements are correct. Therefore, the user can conclude that the input values are healthy and the Fusion engine can adequately employ them to increase performance in prolonged GNSS outages.

The estimated velocity of the Vision-RTK2 is not in the same reference frame as the input of each auxiliary sensor, which might present some slight deviations between them. This is expected and will be improved soon.

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Comparison between each sensor’s input velocity and the estimated velocity using the Fusion engine.

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Velocity estimation of each GNSS receiver and status flags.

Example HTML:

ws_stats.html

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