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2.2.2.3 Planning control module
2.2.2.3.1. Global Navigation Planning
When the user enters the navigation end point, the global navigation planning module will divide the global navigation path into ICA and NCA available segments according to the coverage area of the high-precision map. Realize the division of ICA/NCA functions and automatic de-escalation.
When the self-vehicle does not follow the navigation path (for example, the specified ramp is not used, the intersection does not turn as required), re-planning is triggered, and the global navigation planning module needs to re-plan the navigation path according to the current position of the self-vehicle.
2.2.2.3.2. Driver Behavior Estimation
When the ICA and NCA systems are in the lateral Override state, the driver behavior estimation module
predicts the trajectory of the vehicle according to the current steering wheel angle and the current road topology, and outputs it to the longitudinal planning module for speed planning as the result of lateral planning.
2.2.2.3.3. Horizontal behavior decision
The lateral behavior decision refers to the lane change decision, and the lane change decision is output to the subsequent planning module.
According to the currently activated functions of ICA and NCA, the triggering methods of lane change decision are divided into the following three types: user lever triggers lane change (supported by ICA and NCA), triggers lane change based on navigation of the global navigation planning module (only supported by NCA) and Traffic-triggered lane change based on statistics (only supported by NCA). When the lane change decision is triggered, the ego vehicle starts to prepare for the lane change.
When the system is not triggered by a lane-changing decision, the ego vehicle keeps driving in the current lane. Trigger conditions for lane change decision:
(1) Lever trigger: When the ICA and NCA functions are activated, the user switches the lane lever left or right, and the lane change decision is triggered when the traffic rules allow it. The system starts to search for a suitable merge-in space on the target lane, locks the space, and sends it to the motion planning module. 20s after the trigger for changing lanes, the system cannot find a suitable merge-in space in the target lane, and the lane-changing decision stops triggering.
(2) Navigation trigger: The NCA function is activated, and the off-ramp or intersection to be driven is obtained from the global navigation planning module to determine whether the vehicle needs to change lanes. If the vehicle needs to change lanes, according to the relevant settings confirmed by the system lane change request,
(a) Issue a lane change request or automatically trigger a lane change decision when HWT=(required number of lane changes*30s+5s) from the ramp that needs to be exited. If the required number of lane changes is less than 2, it will prompt or trigger when HWT=65s from the ramp.
(b) Send a lane-changing request or automatically trigger a lane-changing decision when HWT= (required lane-changing times*30s+10s) from the intersection to be passed. If the required number of lane changes is less than 2 times, it will prompt or trigger when HWT=70s from the intersection.
When the lane change request confirmation is turned on, a lane change request is issued for 5s.
i. If the driver does not operate within 5 seconds, the decision to change lanes will be triggered, and the self-vehicle will start searching for a suitable space that can be merged into.
ii. If the driver cancels the request within 5s, the system will no longer prompt the lane change request, and will not issue a lane change decision, so that the ego vehicle stays in the current lane. Waiting for navigation replanning.
iii. If the vehicle is still not in the final target lane when HWT=30s from the ramp or intersection, the system will prompt the driver to take over manually to change lanes.
iv. If the distance from the ramp HWT=5s or the intersection HWT=10s, the self-vehicle cannot change to the final target lane, complete or cancel the current lane change, and the lane-change decision will stop triggering, so that the self-vehicle remains in the current lane. Waiting for navigation replanning.
When the lane change request confirmation is turned off, the system automatically triggers the lane change decision.
i. If the ego vehicle is still not in the final target lane when HWT=30s from the ramp or intersection, the system will prompt the driver to take over manually to change lanes.
ii. If the distance from the ramp HWT=5s or the intersection HWT=10s, the self-vehicle cannot change to the final target lane, complete or cancel the current lane change, and the lane-change decision will stop triggering, so that the self-vehicle remains in the current lane. Waiting for navigation replanning.
Overtaking trigger: HWT > 60s from the road, junction or toll booth, end point of the leading muscle, etc. that need to be driven out. The environment around the car is full
(3) Overtaking trigger: HWT > 60s from the required ramp, intersection or toll station, navigation terminal, etc. The surrounding environment of the self-vehicle meets the following conditions: the average speed of the adjacent lane based on the statistical results for a certain period of time is higher than the following speed of the own vehicle by 5km/h, or the adjacent lane is empty and the following speed of the own vehicle is lower than the current road speed limit of 5km/h . According to the relevant settings of the system lane change request confirmation, a lane change request is issued or a lane change decision is triggered.
When the lane change request confirmation is turned on, the lane change request is issued for 5s.
(a) If the driver does not operate within 5 seconds, the lane change decision is triggered, and the self-vehicle starts to search for a suitable space that can be merged into.
(b) If the driver cancels the request within 5 seconds, the system will no longer prompt the traffic flow to change lanes within 5 minutes, and will not issue a lane change decision.
When the lane change request confirmation is turned off, the system automatically cancels the lane change decision.
Importable space definitions:
(a) Type A space that can be imported
There are no vehicles in the front and rear directions of the target lane. When the target lane is the left lane, 1 forms the lane changing space A; when the target lane is the right lane, 2 forms the lane changing space A.
(b) Class B can be imported into the space
There is no vehicle in front of the traffic flow in the target lane, the leading vehicle in the traffic flow is behind the rear bumper of the own vehicle (as shown in the left lane) or the front bumper of the leading vehicle in the traffic flow exceeds the rear bumper of the own vehicle, and the exceeding distance ll<30m (as shown in the right lane) . The speed of the head of traffic v<= road speed limit +10kph. When the target lane is the left lane, 1 forms the lane changing space B; when the target lane is the right lane, 2 forms the lane changing space B.
(c) Class C can be imported into the space
There is no vehicle behind the traffic flow in the target lane, and the trailing car in the traffic flow is located in front of the front bumper of the own vehicle (as shown in the left lane) or the rear bumper of the tailing vehicle in the traffic flow is located behind the front bumper of the own car, and the lagging distance ll<30m (as shown in the right lane ). The speed of the tail car in the traffic flow is v>0kph. When the target lane is the left lane, 1 forms the lane changing space C; when the target lane is the right lane, 2 forms the lane changing space C.
(d) Class D can be imported into the space
The target lane has continuous traffic, and there is space in the traffic. Space length 1>=(current speed of ego vehicle*5s+length of ego vehicle).
The speed of the vehicle ahead in space v>0kph. Space rear vehicle speed - front vehicle speed <= 10kph. The ego car is completely in the space (shown in the left lane), when the space is behind the ego car, the front and rear bars of the space are behind the ego car's front bar distance ll<=30m or when the space is ahead of the ego car, the space rear car front bar is ahead of the ego car rear bar Distance 12<30m. When the target lane is the left lane, 3 forms the lane changing space D; when the target lane is the right lane, 1 and 2 form the lane changing space D.
2.2.2.3.4 Vertical Behavioral Decision-Making
(c) When the confirmed detection result is a yellow light, a wall is added at the stop line; when the traffic light turns green, the virtual wall disappears.
(2) Parking Pole Virtual Wall
(3) Stop card virtual wall
2.2.2.3.5 Horizontal planning
(1) Lane center-keeping planning: When there is no obstacle intrusion or too close to the lane line within the current lane HWT=10s of the self-vehicle, the lane center-keeping planning is carried out so that the self-vehicle travels along the centerline of the current lane.
(2) Lane interior avoidance planning: when there are static obstacles (such as cones, stones, etc.) and dynamic obstacles (vehicles driving under the line, pedestrians, etc.) in the lane where the vehicle is currently located in HWT=10s or laterally away from the lane line When the distance is less than 20cm and the remaining width of the lane allows the vehicle to pass safely (the vehicle will not exceed the lane edge, and the distance between the sides of the vehicle and the lane edge and obstacles is >30cm, which needs to be measured), the lane avoidance plan should be carried out. Keep the ego vehicle in the lane and deviate from the centerline of the lane in the opposite direction to the obstacle to avoid. After the avoidance, the self-vehicle returns to the center of the lane to drive again.
(1) Maintain lane center planning: When receiving the lane change decision instruction and the target lane change space, enter the first stage of lane change. Carry out lane center maintenance planning, so that the ego vehicle travels along the centerline of the current lane until the ego vehicle falls into the center of the target lane-changing space. The ego vehicle completely falls into the lane change space. According to whether there are front and rear vehicles or the status of front and rear vehicles in the lane change space, it is necessary to satisfy the requirement that the front bar distance of the ego vehicle is selected for the lane change space. The HWT of the rear front bumper in the road space is ≥ 3s.
(2) Lane-changing planning: When the ego vehicle falls into the target lane-changing center, enter the second and third phases of lane-changing. Carry out lane-changing planning, so that the vehicle moves laterally along the lane, smoothly changes lanes to the target lane, falls into the target lane-changing space, and drives along the center of the target lane. When the self-vehicle is still in the original lane and does not press the lane line, it belongs to the second stage of lane change; when the self-vehicle crosses the lane line, it belongs to the third stage of lane change. When the ego vehicle completely falls into the lane-changing space and is located in the center of the target lane, it belongs to the fourth stage of lane-changing, and the lane-changing ends. During the lane change process, the lane change space must continue to meet the following conditions.
(a) Class A lane-changing space, meeting the requirements
(b) In category B space for changing lanes, the distance between the rear bumper of the own car and the front bumper of the head car of the target lane is HWT≥2.5s, and TTC≥18s.
(c) Class C lane-changing space, HWT≥1.5s and TTC≥12.5s from the front bumper of the self-vehicle to the rear bumper of the rear vehicle of the target lane.
(d) Class D lane-changing space, the distance between the front bar of the own vehicle and the front and rear bar of the lane-changing space HWT≥1.5s, TTC≥12.5s, the rear bar of the own vehicle
(3) Lane change cancellation plan:
(a) When the self-vehicle is in the first and second lane-changing stages, the self-vehicle has the right of way of the original lane, and when the target lane can change lanes
(b) When the ego vehicle is in the third lane-changing stage, when the lane-changing space of the target lane no longer meets the requirements, the original lane space still satisfies the distance between the rear bar of the ego car and the front bar of the head car of the target lane HWT ≥ 2s and the front bar of the ego car When HWT≥1.5s from the rear bumper of the rear vehicle of the target lane, cancel planning for lane change. During the lane change cancellation process, the original lane space must continue to meet the above requirements.
(4) Lane change takeover plan:
(a) When changing lanes, when the target lane’s space for changing lanes no longer satisfies the conditions, and the space of the original lane no longer meets the requirements, carry out lane changing takeover planning, so that the ego vehicle continues to drive along the current lateral offset, and Request to take over.
(b) When the lane change plan is cancelled, the original lane space no longer meets the requirements, and the lane change takeover plan is carried out so that the ego vehicle continues to drive along the current lateral offset and requests takeover.
2.2.2.3.6. Vertical planning
2.2.2.3.7 Control Module