Smart mobility homepage localization
Transcript of Smart mobility homepage localization
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2-2-2. Localization
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Output DataComputation
Sensor Data Processing
Velocity Computation
DGPS Data
Processing
Latitude, Longitude
Kalman Filter I
Heading Angle
Conversion
Heading AnglePrediction
Gyroscope Data
Processing
Heading AngleUpdate
Yaw RateHeading Angle
Heading Angle
Heading Angle
Coordinate Conversion(GRS-TM) (X, Y)
Kalman Filter II
PositionConversion
PositionUpdate
PositionPrediction
Velocity (X, Y)(X, Y)Wheel Speed Data
Processing
Flow:
Input Processing • Compensation the
Yaw rate offset • Analyze NMEA proto-
col• Revise OBD II velocity
Prediction• Predict heading angle using in-
tegration the Yaw rate (100Hz)• Predict the position using inte-
gration Velocity (50Hz)
Update• Update GPS heading
angle (10Hz) • Update GPS position
(10Hz)
Output Computation• Transformation Path
planning/tracking coordi-
nate
2-2-2. Localization
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0 0.30.60.91.21.51.82.12.42.7 3 3.33.63.94.24.54.8175
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He
ad
ing
An
gle
(d
eg
ree
)
Time (s)
DGPS B20• 1.5m RMS horizontal error• 10 Hz output rate
< Heading Angle error in low velocity section>
GPSTrue
< GPS error with path curvature >
2-2-2. Localization
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Ave
rage
hea
ding
er-
ror
(deg
ree)
Yaw rate (degree/s)
Dynamic Adjustment of Noise Covariance
Apply a vehicle velocity and yaw rate to noise covariance
– • : Kalman gain • : error covariance at time k• : observation model between the state and the observation• R: measurement noise covariance matrix
– ) + ) +
• , : coefficient• : velocity of vehicle• : yaw rate of vehicle• : threshold of velocity• : threshold of yaw rate
Ave
rage
hea
ding
er-
ror
(deg
ree)
Velocity from wheel speed sensor (m/s)
2-2-2. Localization