Wednesday, June 26, 2019

Event Detection Considerations for Autonomous Vehicles (OEDR -- part 2)

Object and Event Detection and Recognition (OEDR) also involves making predictions about what might happen next. Is that pedestrian waiting for a bus? or about to walk out into the crosswalk right in front of my car? Did you think of all of these aspects?
The infamous Pittsburgh Left. The first vehicle at a red light
will (sometimes) turn left when the light turns to green.

Some factors to consider when deciding what events and behaviors your system needs to predict include:

  • Determining expected behaviors of other objects, which might involve a probability distribution and is likely to be based on object classification.
  • Normal or reasonably expected movements by objects in the environment.
  • Unexpected, incorrect, or exceptional movement of other vehicles, obstacles, people, or other objects in the environment.
  • Failure to move by other objects which are reasonably expected to move.
  • Operator interactions prior to, during, and post autonomy engagement including: supervising driver alertness monitoring, informing occupants, interaction with local or remote operator locations, mode selection and enablement, operator takeover, operator cancellation or redirect, operator status feedback, operator intervention latency, single operator supervision of multiple systems (multi-tasking), operator handoff, loss of operator ability to interact with vehicle.
  • Human interactions including: human commands (civilians performing traffic direction, police pull-over, passenger distress), normal human interactions (pedestrian crossing, passenger entry/egress), common human rule-breaking (crossing mid-block when far from an intersection, speeding, rubbernecking, use of parking chairs, distracted walking), abnormal human interactions (defiant jaywalking, attacks on vehicle, attempted carjacking), and humans who are not able to follow rules (children, impaired adults).
  • Non-human interactions including: animal interaction (flocks/herds, pets, dangerous wildlife, protected wildlife) and delivery robots.

Is there anything we missed?   (Previous post had the "objects" part of OEDR.)

(This is an excerpt of Koopman, P. & Fratrik, F., "How many operational design domains, objects, and events?" SafeAI 2019, AAAI, Jan 27, 2019.)

Wednesday, June 19, 2019

Object Detection Considerations for Autonomous Vehicles (OEDR -- part 1)

Object and Event Detection and Recognition (OEDR) involves having an autonomous vehicle detect and classify various types of objects so that it can plan a response. Detection is only the first step; you need to also be able to classify the obstacle to predict what might happen next. Pedestrians tend to walk into the roadway. Bushes, not so much. Did you think of all of these aspects?
Q: Why did the Mr. Rogers-saurus cross the street?
A: Trick question; he doesn't actually move because he is part of the Pittsburgh Dinosaur Parade.

Some factors to consider when deciding what objects your system needs to detect and recognize include:
  • Ability to detect and identify (e.g. classify) all relevant objects in the environment.
  • Processing and thresholding of sensor data to avoid both false positives (e.g., bouncing drink can, steel bridge joint, steel road construction cover plate, roadside sign, dust cloud, falling leaves) and false negatives (e.g., highly publicized partially automated vehicle collisions with stationary vehicles)
  • Characterizing the likely operational parameters of other road users (e.g., braking capability of leading and following vehicle, or whether another vehicle is behaving erratically enough that there is a likely control fault.)
  • Permanent obstacles such as structures, curbs, median dividers, guard rails, trees, bridges, tunnels, berms, ditches, roadside and overhanging signage.
  • Temporary obstacles such as transient keep-out zones, spills, floods, water-filled potholes, landslides, washed out bridges, overhanging vegetation, and downed power lines. (For practical purposes, “temporary” might mean obstacles not included on maps, with some vehicle having to be the first vehicle to detect an obstacle for placement even on a dynamic map.)
  • People, including cooperative people, uncooperative people, malicious behaviors, and people who are unaware of the operation of the autonomous system.
  • At-risk populations which might be unable, incapable, or exempt from following established rules and norms, such as children as well as injured, ability-impaired, or under-the-influence people.
  • Other cooperative and uncooperative human-driven and autonomous vehicles.
  • Other road users including special purpose vehicles, temporary structures, street dining, street festivals, parades, motorcades, funeral processions, farm equipment, construction crews, draft animals, farm animals, and endangered species.
  • Other non-stationary objects including uncontrolled moving objects, falling objects, wind-blown objects, in-traffic cargo spills, and low-flying aircraft.
Is there anything we missed?   (Next post will have the "events" part of OEDR.)

(This is an excerpt of Koopman, P. & Fratrik, F., "How many operational design domains, objects, and events?" SafeAI 2019, AAAI, Jan 27, 2019.)

Wednesday, June 12, 2019

Operational Design Domain (ODD) for Autonomous Systems

The Operational Design Domain (ODD) is the set of environmental conditions that an autonomous system is designed to work in. Typically an ODD is thought of as some sort of geo-fencing plus a obvious weather conditions (rain, snow, sun). But, it's a lot more than that. Did you think of all of these?

Canton Avenue, the unofficial steepest street in the world, is less than 4 miles from downtown Pittsburgh.
Note cobblestone on the top half and the sidewalk stairs.  Cars slide (sometimes backwards) down the street in winter.
Geo-fencing is more complicated than drawing a circle around a city center.
Characterizing the system operational environment should include at least the following:

  • Operational terrain, and associated location-dependent characteristics (e.g., slope, camber, curvature, banking, coefficient of friction, road roughness, air density) including immediate vehicle surroundings and projected vehicle path. It is important to note that dramatic changes can occur in relatively short distances.
  • Environmental and weather conditions such as surface temperature, air temperature, wind, visibility, precipitation, icing, lighting, glare, electromagnetic interference, clutter, vibration, and other types of sensor noise.
  • Operational infrastructure, such as availability and placement of operational surfacing, navigation aids (e.g., beacons, lane markings, augmented signage), traffic management devices (e.g., traffic lights, right of way signage, vehicle running lights), keep-out zones, special road use rules (e.g., time-dependent lane direction changes) and vehicle-to-infrastructure availability.
  • Rules of engagement and expectations for interaction with the environment and other aspects of the operational state space, including traffic laws, social norms, and customary signaling and negotiation procedures with other agents (both autonomous and human, including explicit signaling as well as implicit signaling via vehicle motion control).
  • Considerations for deployment to multiple regions/countries (e.g., blue stop signs, “right turn keep moving” stop sign modifiers, horizontal vs. vertical traffic signal orientation, side-of-road changes).
  • Communication modes, bandwidth, latency, stability, availability, reliability, including both machine-to-machine communications and human interaction.
  • Availability and freshness of infrastructure characterization data such as level of mapping detail and identification of temporary deviations from baseline data (e.g., construction zones, traffic jams, temporary traffic rules such as for hurricane evacuation).
  • Expected distributions of operational state space elements, including which elements are considered rare but in-scope (e.g. toll booths, police traffic stops), and which are considered outside the region of the state space in which the system is intended to operate.

Special attention should be paid to ODD aspects that are relevant to inherent equipment limitations, such as the minimum illumination required by cameras.

Are there any other aspects of ODD we missed?

(This is an excerpt of Koopman, P. & Fratrik, F., "How many operational design domains, objects, and events?" SafeAI 2019, AAAI, Jan 27, 2019.)