Overview
The ‘Roads Info Sensor’ packages information about the road, locally. This comes from the internal navigation graph. Some post-processing has been applied to the data to produce more meaningful quantities.
The following data is returned:
_Lateral distances to; road centerline, road left edge, road right edge, and their world-space positions, _Local road radius and curvature (κ), _Heading (angle in degrees), _Local road half-width, _Local road polyline (raw, from navigation graph), _Fitted parametric cubic polynomials (fitted to the local polyline), _Some common navigation graph metadata (drivability, speed limit, one-way)
Usage
The roads sensor code is written in Lua code and has an API similar to the other sensors in our suite.
sensorId = extensions.tech_sensors.createRoadsSensor(vid, args)
Args:
vid(int): An id that leads to the vehicle id
GFXUpdateTime(float): How often the roads sensor should update its readings in the simulator (in seconds). This determines how often the user will be able to retrieve a new reading from the sensor.
physicsUpdateTime(float): How often in the simulator’s physics step, we should update the roads sensor readings (in seconds).
Returns: sensorId(int): The unique Id number of this sensor, useful to refer to it hereafter, for example when closing it.
extensions.tech_sensors.setRoadsSensorUpdateTime(sensorId, vid, updateTime)
Args:
sensorId(int): The ID number of the roads sensor.
vid(int): the id number which leads to the vehicle id.
updateTime(float): The new update time for this sensor.
Returns: nil
readings = extensions.tech_sensors.getRoadsSensorReadings(sensorId)
Args:
sensorId(int): The ID number of the roads sensor.
Returns: readings(table): The latest readings from the sensor
The following three functions can be used to send ad-hoc polling requests to a roads sensor. This is for when
we need to first send a request using sendRoadsSensorRequest, then wait for it. We can check it is complete using isVluaRequestComplete
then retrieve it using collectRoadsSensorRequest.
requestId = extensions.tech_sensors.sendRoadsSensorRequest(sensorId, vid)
Args:
sensorId(int): The ID number of the roads sensor.
vid(int): id number that helps get the vehicle id.
Returns: The unique Id number of the ad-hoc sensor polling request which is being sent.
isComplete = extensions.tech_sensors.isVluaRequestComplete(requestId)
Args:
requestId(int): The ID number of the ad-hoc sensor polling request to check on.
Returns: isComplete(bool): True if the ad-hoc polling request has been completed, otherwise false.
data = extensions.tech_sensors.collectRoadsSensorRequest(requestId)
Args:
requestId(int): The ID number of the ad-hoc sensor polling request.
Returns: data(table): The roads sensor readings
extensions.tech_sensors.removeRoadsSensor(vid, sensorId)
Args:
vid(int): The id used to get the vehicle id. sensorId(int): The ID number of the roads sensor to remove.
Returns: nil.
