Tesla has outlined improvements to its Autopilot self-driving software, with the new ‘Version 8’ to channel a heavier focus on radar detection.
As reported last month, the radar fitted to all Teslas since October 2014 will be of more use to the Autopilot system thanks to “more advanced signal processing” following the upgrade.
Tesla said the radar was initially designed to support the on-board camera system with safety features including semi-autonomous driving.
But the carmaker has had a rethink - saying “we now believe [the radar] can be used as a primary control sensor without requiring the camera to confirm visual image recognition”.
Version 8 of Autopilot uses the same hardware, but Tesla says it unlocks access to six times as many radar objects, gaining more information per object.
Using this information, the radar system is able to create a 3D ‘picture’ of its surroundings with new data gathered every tenth of a second. Such a frequency allows the system to decipher between moving and stationary objects and the dangers each object may present.
Tesla has outlined several challenges faced by its tech team and the Autopilot system in the ‘real world’. For example, a discarded soft-drink can with the concave base facing the vehicle could previously have confused the radar into thinking it was much larger - and therefore, posing a much greater hazard to the vehicle’s occupants.
This could have caused a vehicle to brake heavily, but Tesla has invested much effort into ensuring the system can recognise ‘false alarms’.
Advantages of radar over a camera-based system include its ability to see through fog, rain, snow and dust, but Tesla says people appear “partially translucent” to the radar system.
Tesla plans to uses its existing owners to further advance the Autopilot system by gathering and storing GPS data related to objects that the radar may perceive to be a hazard. The carmaker uses the example of overhead signage (example pictured below) or an overpass, which may seem like a solid metal object if the radar detects it on approach over a crest.
If several Tesla drivers can pass by or ‘through’ a perceived hazard without incident, the GPS point will be added to the ‘safe’ list.
Should a collision appear unlikely, but the data for a particular point is lacking, the system may choose to begin gradual braking - ramping up to full emergency braking if a collision would otherwise seem 99.99 percent likely.
“The net effect of this, combined with the fact that radar sees through most visual obscuration, is that the car should almost always hit the brakes correctly even if a UFO were to land on the freeway in zero visibility conditions,” Tesla said in a blog post.
“Taking this one step further, a Tesla will also be able to bounce the radar signal under a vehicle in front - using the radar pulse signature and photon time of flight to distinguish the signal - and still brake even when trailing a car that is opaque to both vision and radar. The car in front might hit the UFO in dense fog, but the Tesla will not.”
Other updates to Autopilot for Version 8 include (with a special mention for the final point):
- TACC braking maximum ramp rate increased and latency reduced by a factor of five
- Now controls for two cars ahead using radar echo, improving cut-out response and reaction time to otherwise-invisible heavy braking events
- Will take highway exit if indicator on (8.0) or if nav system active (8.1). Available in the United States initially
- Car offsets in lane when overtaking a slower vehicle driving close to its lane edge
- Interface alerts are much more prominent, including flashing white border on instrument panel
- Improved cut-in detection using blinker on vehicle ahead
- Reduced likelihood of overtaking in right lane in Europe
- Improved auto lane change availability
- Car will not allow reengagement of Autosteer until parked if user ignores repeated warnings
- Automatic braking will now amplify user braking in emergencies
- In manual mode, alerts driver if about to leave the road and no torque on steering wheel has been detected since Autosteer was deactivated
- With further data gathering, car will activate Autosteer to avoid collision when probability around 100 percent
- Curve speed adaptation now uses fleet-learned roadway curvature
- "Approximately 200 small enhancements that aren't worth a bullet point"
Tesla owners can expect Autopilot Version 8 to be rolled out globally within the next few weeks.