Formal (temporal logic) interpretation of DARPA Urban Challenge rules and task descriptions

[vraman]

Formalize the rules from the 2007 DUC, such that they may be used to evaluate submissions in the second domain.

[vraman]

Summary of rules:

• mission defined by an ordered series of checkpoints in a complex route network.
• 5 minutes to process a mission description before attempting the course
• traffic laws and conventions
• context-dependent speed limits
• safe-following distance when approaching other vehicles from behind in a traffic lane
• safe check-and-go behavior when pulling around a stopped vehicle, pulling out of parking spot, moving through intersections, and in situations where collision is possible.
• stay on the road and in a legal and appropriate travel lane while en route, including around sharp turns, through intersections, and while passing.
• stop signs
• change lanes safely when legal and appropriate, such as when passing a vehicle or entering an opposing traffic lane to pass a stopped vehicle
• must not pass other vehicles queued at an intersection
• merge safely with traffic moving in one or more lanes after stopping at an intersection
• pull across one lane of moving traffic to merge with moving traffic in the opposing lane
• stop safely within 1 meter of the stop line at a stop sign intersection and proceed without excessive delay (less than 10 seconds) according to intersection precedence rules
• proper queue behavior at an intersection, including stopping at a safe distance from other vehicles and stop-and-go procession to the stop line without excessive delay
• navigate toward a destination
• fixed obstacles such as parked vehicles and moving obstacles including other vehicles
• pull into and back out of a specified parking space in a parking lot
• three-point turning maneuvers to effect a U-turn
• re-plan and execute the route to a destination if the primary route is blocked or impassable.

Details:

• Safety E-stop brings the vehicle traveling at 20 mph to a smooth, controlled, and complete rolling stop in less than 20 meters after E-stop activation
• Preparation for run: Vehicle is in autonomous mode and ready to begin run less than 5 minutes after receipt of the Mission Data File (MDF) from DARPA.
• Mission start: Vehicle follows checkpoints in the DARPA MDF starting at any location in the route network.
• Checkpoints: Vehicle front bumper passes over each checkpoint in the MDF in the correct lane or spot and in the correct sequence.
• Stay in lane: Vehicle remains entirely in travel lane at all times except when performing a legal traffic maneuver such as a left turn or maneuvering to avoid an obstacle.
• Speed limits: Vehicle speed conforms to minimum and maximum limits.
• Excess delay: Vehicle exhibits less than 10 seconds of excess delay on route as judged by DARPA.
• Collisions: Vehicle acts to avoid collisions and near-collisions at all times, as judged by DARPA.
• Stop line: Vehicle stops so front bumper is within 1 meter of stop line at intersection.
• Vehicle Separation: Vehicle maintains a minimum standoff of 1-meter on the sides and rear from all obstacles and vehicles in all areas. In safety areas, vehicle maintains a minimum forward vehicle separation equal to 2-meters. In travel areas, vehicle maintains a minimum forward vehicle separation of one vehicle length for every 10 miles-per-hour of speed, one vehicle length minimum.
• Leaving lane to pass: Vehicle maintains a forward vehicle separation of one vehicle length when leaving lane to initiate a passing maneuver in a travel area.
• Returning to lane after pass: Vehicle returns to travel lane between one and four vehicle lengths when completing a passing maneuver.
• U-Turn: Vehicle exhibits ability to perform a U-turn on a 9 meter wide road within a 30-meter road length.
• Intersection precedence: Vehicle respects precedence order at intersections and does not proceed out of turn.
• Minimum following distance: When following a moving traffic-vehicle, autonomous vehicle maintains the required forward vehicle separation distance.
• Queueing: Vehicle exhibits correct stop-and-go queueing behavior in a line of stopped vehicles, always maintaining a minimum spacing equal to the forward vehicle separation distance and a maximum spacing of two vehicle lengths.
• Parking lot: Vehicle exhibits correct parking lot behavior and demonstrates the ability to pull forward into and reverse out of a specified parking spot.
• Dynamic re-planning: Vehicle exhibits behaviors necessary to achieve objective checkpoints when roads are blocked.
• Road following: Vehicle navigates roads with sparse waypoints and stays in travel lane through road-following by sensing berms or road edges, or by any other sensorbased technique.
• GPS outage: Vehicle does not exhibit excess delay or leave travel lane due to intermittent loss of navigation signals such as GPS.
• Merge: Vehicle always merges into moving traffic when there is a delay of 10 seconds or more before the arrival of the next traffic-vehicle. Vehicle may pull into a gap of less than 10 seconds when conditions permit.
• Vehicle separation during merge: Vehicle merges between two vehicles into a lane of moving traffic. Vehicle maintains the forward vehicle separation distance to the leading vehicle, and the trailing vehicle does not slow or stop.
• Left turn: Vehicle always completes a left turn across a lane carrying oncoming traffic when there is a delay of 10 seconds or more before the passing of the next on-coming vehicle. Vehicle may complete turn when the delay is less than 10 seconds when conditions permit.
• Vehicle separation during left turn: Vehicle makes a left turn across a lane of oncoming traffic while preserving forward vehicle separation distances to vehicles in its lane. Vehicle must maintain a two vehicle minimum safety separation from oncoming traffic, without causing oncoming traffic to slow or stop.
• Emergency braking: Vehicle comes to a complete and safe stop to avoid collision when a moving obstacle suddenly moves into the travel lane.
• Defensive driving: Vehicle performs defensive driving maneuvers to avoid impending head-on collision and maintains the required forward vehicle separation distance.
• Traffic jam: When encountering a partially-blocked intersection, vehicle maneuvers to make forward progress and avoids collisions.
• Specific definitions needed for
  • Lane Boundaries * Checkpoints * Passing * Safe following * Stop sign intersections * Merging into moving traffic * Traffic circles * Left turns * Zones and parking

[slivingston]

Why is the item about GPS outage italicized?

[vraman]

Because it may not be applicable to our challenge. I suggest we focus on
the case of reliable sensing for this year.
On 22 Feb 2016 5:33 a.m., "Scott C. Livingston" [email protected]
wrote:

Why is the item about GPS outage italicized?

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[slivingston]

For posterity, the source file is http://archive.darpa.mil/grandchallenge/docs/Urban_Challenge_Rules_102707.pdf

[slivingston]

Additional rules and guidelines are available at http://archive.darpa.mil/grandchallenge/rules.html

Additional resources including examples are available at http://archive.darpa.mil/grandchallenge/resources.html. In particular,

• final event RNDF
• final event sample MDF