381. Curvature Watcher
The curvature watcher provides valuable context for interval-based analysis by detecting and recording instances when the Ego drives on a road with a curvature radius less than or equal to max_radius_large_threshold. It uses the vehicle.get_road_radius() function to get the radius of each map segment. A curve begins when a segment's radius is less than or equal to the max_radius_large_threshold threshold. Subsequent segments are considered part of the same curve as long as their radii do not exceed this threshold. The curve is then categorized based on the minimum radius found within these segments.
The minimum radius is used for categorization because curves typically start and end with a large radius, which does not represent their sharpest point. Users can customize categories by setting the maximum radius for each one; the minimum radius of the next category is then automatically adjusted to be greater than the previous category's minimum.
381.0.1 Start condition
The curvature watcher samples the road radius on each top.w_clk. If the absolute radius is within the range (0..max_radius_large_threshold] meters and the vehicle remains in its lane, a new watcher interval starts and stays active as long as the radius within this range.
381.0.2 End condition
An active curvature interval ends when the absolute radius leaves the range (0..max_radius_large_threshold] meters or when the vehicle leaves its lane. A new interval is emitted whenever the radius re-enters the specified range.
381.1 Plot
381.2 Configuration parameters
The following parameters can be configured to customize the evaluator's behavior.
| Parameter | Type | Description | Default Value |
|---|---|---|---|
max_radius_sharp_threshold |
length | Maximum radius threshold for sharp curves | 150m |
max_radius_medium_threshold |
length | Maximum radius threshold for medium curves | 500m |
max_radius_large_threshold |
length | Maximum radius threshold for large curves | 2000m |
debounce_time_last_curve |
time | Debounce time to delay the interval when the segment road radius is outside the maximum radius threshold | No default |
381.3 Metrics
The following metrics are recorded and tracked by the evaluator.
| Metric item | Unit / Type | Description |
|---|---|---|
avg_velocity |
kph | Speed of vehicle while navigating the curve |
max_lat_acceleration |
mpsps | Maximum lateral acceleration of the vehicle while navigating the curve |
min_curve_radius |
m | Minimum interval curve_radius of the curve |
avg_curve_radius |
m | Average radius of the curve |
curve_category |
enum (sharp, medium, large) |
Category of the curve (sharp, medium, large) |
curve_side |
enum (left, right) |
Side to which the curve turns (left, right) |
381.4 Log and Error Messages
No error messages found.