Route is predefined path (track, road...). It can be made out of lines and curves. It can be imported from file or defined manually. If we define it manually we have four elements we can use:
- Straight – straight line in meters. The direction of straight is the direction in which previous element ends.
- Curve – curve with constant radius in meters and specified arc angle. It starts where previous element ends and goes right if the arc angle is positive or left if its negative.
- Line to – straight line from point where previous element ends to point (X, Y)
- Curve to – a curve with constant radius from point where previous element ends to point (X, Y), the radius is automatically defined with the direction of the previous element ending.
We can see a simple route defined with all the possible elements found in settings. Route starts (where the car is) with a 40 meter straight in the x direction. Straight is followed by a corner with 10 meter radius and 180 degree arc angle in the left. The next straight is defined with ending coordinates. The final corner is defined with the end coordinates, we can see from coordinates that it has a radius of 10 meters and has an arc angle of 180 degrees.
Route visualization (vehicle is positioned on the start)
Complex routes are normally imported. We can record a route with Dewesoft X software, export it to the GoogleEarth .kml format and import it in Polygon. Imported routes can be additionally modified. If we don’t have an origin defined before the route import will set it automatically to the route start. Origin direction (x coordinate) is going to be the same as the start direction of the route.
Import from kml format, imported route in the background
Defined route used for different calculations. Distance from center or edge of the route to the vehicle for example, distance from route start, heading deviation of the vehicle compared to the route. Route position can be either fixed or moving.
Routes are defined by the central path and have a constant width that can be changed in the polygon. If the actual track has large variations in the width we can import each edge of the track as a route on it own.
A full circle that is defined with center, radius and line width. It can be assigned as fixed or as a moving object. It always forms a full circle (if just one part of the circle is needed a route curve should be used instead).
Circle can for example represent a circular lane. The calculated distance between an object and a circle is positive if the object is outside of the circle and negative if it is inside of the circle. The calculated distance is the shortest distance from a circular lane to the object.
If an angle between the circle and the vehicle heading is calculated it represents vehicle’s heading deviation from a circle. If it is zero vehicle heading is the same as a circular lane direction, it is positive if the vehicle points outward of the circle and negative if vehicle heading points inward
Travel radius shows predicted path of the vehicle if steering wheel stays in the same position and all other conditions don't change. It can only be set as »Moving with« the only applicable reference object is a vehicle. Travel radius is calculated from vehicle path in the specified time-frame. The time-frame can be specified from 0.5 to 5 seconds. Travel radius can only be set up with the "Moving with" setting, the master object has to be a vehicle.
The real power of travel radius is shown when it gets frozen on some point. Then the deviations of the real vehicle travel compared to the predicted one can be calculated.
It is used for example in FuSi (Functional safety) tests where first steady drive is performed to get the predicted path (in that stage the travel radius gets frozen) then an error is injected into the vehicle control system and the result of that error can be then measured with distance and angle deviation.
It can also be used in Brake tests to measure lateral deviations from ideal braking line or braking curve if test is performed in curve.
Width is important when we calculate distances to the edges of the travel radius. It is also used for visualization. Calculated distance between an object and travel radius (circle formed by travel radius) is positive if object lays outside of the travel radius and negative if it lays inside of the travel radius. If an angle between the travel radius and the vehicle is calculated it represents vehicle’s heading deviation from the travel radius. If it is positive vehicle's heading points outward of the travel radius and negative if vehicle's heading points inward.
Vehicle with visualized travel radius