Vehicle control system, method for controlling vehicle, and vehicle
A method for controlling a vehicle and a vehicle control system control a vehicle in one of a motion planning mode and a crash mitigation mode. To switch from the motion planning mode to the crash mitigation mode, both instantaneous and predictive risk evaluation techniques are employed, and a hysteresis band is used to return control from the crash mitigation mode to the motion planning mode. When in the crash mitigation mode, assessments are made as to whether leaving a road boundary or engaging a less severe collision minimize harm in a high-risk environment.
1 . A method for controlling a vehicle, comprising:
determining whether a distance between the vehicle and a collision object is less than a first predetermined distance based on estimated positions of the vehicle and the collision object;
determining whether a time to close encounter between the vehicle and the collision object is less than a first predetermined time to close encounter based on estimated trajectories of the vehicle and the collision object;
determining that the vehicle is operating in a high-risk environment when at least one of:
(i) the distance is less than the first predetermined distance; or
(ii) the time to close encounter is less than the first predetermined time to close encounter;
when the vehicle is determined to be operating in the high-risk environment, controlling the vehicle in a crash mitigation mode by generating vehicle control commands using an occupant comfort parameter within a crash mitigation range of the occupant comfort parameter; and
when the vehicle is not determined to be operating in the high-risk environment, controlling the vehicle in a motion planning mode by generating vehicle control commands using the occupant comfort parameter within a motion planning range, the motion planning range of the occupant comfort parameter being higher than the crash mitigation range of the occupant comfort parameter,
wherein the occupant comfort parameter is used to set an allowable degree of change of acceleration, deceleration, and steering of the vehicle in generating the vehicle control commands, where the allowable degree of change of acceleration, deceleration, and steering of the vehicle is proportionally reduced as the occupant comfort parameter increases, and the allowable degree of change of acceleration, deceleration, and steering of the vehicle is proportionally increased as the occupant comfort parameter decreases.
2 . The method according to claim 1 , further comprising:
estimating a risk of collision with the collision object and increasing the occupant comfort parameter as the risk of collision decreases and decreasing the occupant comfort parameter as the risk of collision increases.
3 . The method according to claim 1 , further comprising:
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment, switching control of the vehicle to the motion planning mode when:
when the vehicle is determined to be operating in the high-risk environment due to the distance being less than the first predetermined difference, the distance changes to be greater than a second predetermined distance, the second predetermined distance being greater than the first predetermined distance;
when the vehicle is determined to be operating in the high-risk environment due to the time to close encounter being less than the first predetermined time to close encounter, the time to close encounter changes to be greater than a second predetermined time to close encounter, the second predetermined time to close encounter being greater than the first predetermined time to close encounter; and
when the vehicle is determined to be operating in the high-risk environment due to the distance being less than the first predetermined difference and due to the time to close encounter being less than the first predetermined time to close encounter, the distance changes to be greater than the second predetermined distance and the time to close encounter changes to be greater than the second predetermined time to close encounter.
4 . The method according to claim 1 , further comprising:
determining positions of a road boundary; and
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimating a risk of collision with the collision object, and
when the risk of collision with the collision object exceeds a predetermined unavoidable collision risk, controlling the vehicle to leave the road boundary to avoid the collision within the road boundary.
5 . The method according to claim 3 , further comprising:
determining positions of a road boundary; and
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimating a risk of collision with the collision object, and
when the risk of collision with the collision object exceeds a predetermined unavoidable collision risk, controlling the vehicle to leave the road boundary to avoid the collision within the road boundary.
6 . The method according to claim 1 , further comprising:
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimating a risk of collision with the collision object and a second collision object, and
when the risk of collision with the collision object exceeds a predetermined unavoidable collision risk, estimating a severity of collision with the collision object and with the second collision object, and controlling the vehicle to collide with the collision object or the second collision object having a lower estimated severity of collision,
wherein the severity of collision is estimated to be higher: as a relative velocity increases between the vehicle and the collision object, and between the vehicle and the second collision object; and when the collision object or the second collision object is identified as a rigid structure.
7 . The method according to claim 3 , further comprising:
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimating a risk of collision with the collision object and a second collision object, and
when the risk of collision with the collision object exceeds a predetermined unavoidable collision risk, estimating a severity of collision with the collision object and with the second collision object, and controlling the vehicle to collide with the collision object or the second collision object having a lower estimated severity of collision,
wherein the severity of collision is estimated to be higher: as a relative velocity increases between the vehicle and the collision object, and between the vehicle and the second collision object; and when the collision object or the second collision object is identified as a rigid structure.
8 . The method according to claim 1 , further comprising:
determining positions of a road boundary; and
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimating a risk of collision with the collision object and a second collision object, and
when the risk of collision with the collision object and the second collision object exceeds a predetermined unavoidable collision risk, controlling the vehicle to leave the road boundary to avoid the collision within the road boundary when leaving the road boundary would avoid collision with the collision object and the second collision object, and
when the risk of collision with the collision object and the second collision object exceeds the predetermined unavoidable collision risk, estimating a severity of collision with the collision object and with the second collision object, and controlling the vehicle to collide with the collision object or the second collision object having a lower estimated severity of collision,
wherein the severity of collision is estimated to be higher: as a relative velocity increases between the vehicle and the collision object, and between the vehicle and the second collision object; and when the collision object or the second collision object is identified as a rigid structure.
9 . The method according to claim 3 , further comprising:
determining positions of a road boundary; and
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimating a risk of collision with the collision object and a second collision object, and
when the risk of collision with the collision object and the second collision object exceeds a predetermined unavoidable collision risk, controlling the vehicle to leave the road boundary to avoid the collision within the road boundary when leaving the road boundary would avoid collision with the collision object and the second collision object, and
when the risk of collision with the collision object and the second collision object exceeds the predetermined unavoidable collision risk, estimating a severity of collision with the collision object and with the second collision object, and controlling the vehicle to collide with the collision object or the second collision object having a lower estimated severity of collision,
wherein the severity of collision is estimated to be higher: as a relative velocity increases between the vehicle and the collision object, and between the vehicle and the second collision object; and when the collision object or the second collision object is identified as a rigid structure.
10 . A vehicle control system provided in a vehicle, comprising a vehicle electronic control unit in communication with a vehicle sensor system and a vehicle actuator system, the electronic control unit being programmed to:
estimate a distance between the vehicle and a collision object based on input from the vehicle sensor system;
estimate trajectories of the vehicle and the collision object based on input from the vehicle sensor system;
determine a time to close encounter between the vehicle and the collision object based on the estimated trajectories;
determine whether the distance is less than a first predetermined distance;
determine whether the time to close encounter is less than a first predetermined time to close encounter;
determine that the vehicle is operating in a high-risk environment when at least one of:
(i) the distance is less than the first predetermined distance; or
(ii) the time to close encounter is less than the first predetermined time to close encounter;
when the vehicle is determined to be operating in the high-risk environment, controlling the vehicle actuator system to control the vehicle in a crash mitigation mode by generating vehicle control commands using an occupant comfort parameter within a crash mitigation range of the occupant comfort parameter; and
when the vehicle is not determined to be operating in the high-risk environment, controlling the vehicle actuator system to control the vehicle in a motion planning mode by generating vehicle control commands using the occupant comfort parameter within a motion planning range of the occupant comfort parameter, the motion planning range of the occupant comfort parameter being higher than the crash mitigation range of the occupant comfort parameter,
wherein the occupant comfort parameter is used to set an allowable degree of change of acceleration, deceleration, and steering of the vehicle in generating the vehicle control commands, where the allowable degree of change of acceleration, deceleration, and steering of the vehicle is proportionally reduced as the occupant comfort parameter increases, and the allowable degree of change of acceleration, deceleration, and steering of the vehicle is proportionally increased as the occupant comfort parameter decreases.
11 . The vehicle control system according to claim 10 , wherein the electronic control unit is further programmed to:
estimate a risk of collision with the collision object and increase the occupant comfort parameter as the risk of collision decreases and decrease the occupant comfort parameter as the risk of collision increases.
12 . The vehicle control system according to claim 10 , wherein the electronic control unit is further programmed to:
while controlling the vehicle actuator system in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment, switching control of the vehicle actuator system to the motion planning mode when:
when the vehicle is determined to be operating in the high-risk environment due to the distance being less than the first predetermined difference, the distance changes to be greater than a second predetermined distance, the second predetermined distance being greater than the first predetermined distance;
when the vehicle is determined to be operating in the high-risk environment due to the time to close encounter being less than the first predetermined time to close encounter, the time to close encounter changes to be greater than a second predetermined time to close encounter, the second predetermined time to close encounter being greater than the first predetermined time to close encounter; and
when the vehicle is determined to be operating in the high-risk environment due to the distance being less than the first predetermined difference and due to the time to close encounter being less than the first predetermined time to close encounter, the distance changes to be greater than the second predetermined distance and the time to close encounter changes to be greater than the second predetermined time to close encounter.
13 . The vehicle control system according to claim 10 , wherein the electronic control unit is further programmed to:
determine positions of a road boundary based on input from the vehicle sensor system; and
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimate a risk of collision with the collision object based on input from the vehicle sensor system, and
when the risk of collision with the collision object exceeds a predetermined unavoidable collision risk, control the vehicle actuator system to cause the vehicle to leave the road boundary to avoid the collision within the road boundary.
14 . The vehicle control system according to claim 12 , wherein the electronic control unit is further programmed to:
determine positions of a road boundary based on input from the vehicle sensor system; and
while controlling the vehicle actuator system in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimate a risk of collision with the collision object based on input from the vehicle sensor system, and
when the risk of collision with the collision object exceeds a predetermined unavoidable collision risk, control the vehicle actuator system to cause the vehicle to leave the road boundary to avoid the collision within the road boundary.
15 . The vehicle control system according to claim 10 , wherein the electronic control unit is further programmed to:
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimate a risk of collision with the collision object and a second collision object based on input from the vehicle sensor system, and
when the risk of collision with the collision object exceeds a predetermined unavoidable collision risk, estimate a severity of collision with the collision object and with the second collision object based on input from the vehicle sensor system, and control the vehicle actuator system to cause the vehicle to collide with the collision object or the second collision object having a lower estimated severity of collision,
wherein the severity of collision is estimated to be higher: as a relative velocity increases between the vehicle and the collision object, and between the vehicle and the second collision object; and when the collision object or the second collision object is identified as a rigid structure.
16 . The vehicle control system according to claim 12 , wherein the electronic control unit is further programmed to:
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimate a risk of collision with the collision object and a second collision object based on input from the vehicle sensor system, and
when the risk of collision with the collision object exceeds a predetermined unavoidable collision risk, estimate a severity of collision with the collision object and with the second collision object based on input from the vehicle sensor system, and control the vehicle actuator system to cause the vehicle to collide with the collision object or the second collision object having a lower estimated severity of collision,
wherein the severity of collision is estimated to be higher: as a relative velocity increases between the vehicle and the collision object, and between the vehicle and the second collision object; and when the collision object or the second collision object is identified as a rigid structure.
17 . The vehicle control system according to claim 10 , wherein the electronic control unit is further programmed to:
determine positions of a road boundary based on input from the vehicle sensor system; and
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimate a risk of collision with the collision object and a second collision object based on input from the vehicle sensor system, and
when the risk of collision with the collision object and the second collision object exceeds a predetermined unavoidable collision risk, controlling the vehicle actuator system to cause the vehicle to leave the road boundary to avoid the collision within the road boundary when leaving the road boundary would avoid collision with the collision object and the second collision object, and
when the risk of collision with the collision object and the second collision object exceeds the predetermined unavoidable collision risk, estimate a severity of collision with the collision object and with the second collision object based on input from the vehicle sensor system, and control the vehicle actuator system to cause the vehicle to collide with the collision object or the second collision object having a lower estimated severity of collision,
wherein the severity of collision is estimated to be higher: as a relative velocity increases between the vehicle and the collision object, and between the vehicle and the second collision object; and when the collision object or the second collision object is identified as a rigid structure.
18 . The vehicle control system according to claim 12 , wherein the electronic control unit is further programmed to:
determine positions of a road boundary based on input from the vehicle sensor system; and
while controlling the vehicle in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment,
estimate a risk of collision with the collision object and a second collision object based on input from the vehicle sensor system, and
when the risk of collision with the collision object and the second collision object exceeds a predetermined unavoidable collision risk, controlling the vehicle actuator system to cause the vehicle to leave the road boundary to avoid the collision within the road boundary when leaving the road boundary would avoid collision with the collision object and the second collision object, and
when the risk of collision with the collision object and the second collision object exceeds the predetermined unavoidable collision risk, estimate a severity of collision with the collision object and with the second collision object based on input from the vehicle sensor system, and control the vehicle actuator system to cause the vehicle to collide with the collision object or the second collision object having a lower estimated severity of collision,
wherein the severity of collision is estimated to be higher: as a relative velocity increases between the vehicle and the collision object, and between the vehicle and the second collision object; and when the collision object or the second collision object is identified as a rigid structure.
19 . A vehicle, comprising:
a vehicle sensor system;
a vehicle actuator system; and
a vehicle electronic control unit in communication with the vehicle sensor system and the vehicle actuator system, the electronic control unit being programmed to:
estimate a distance between the vehicle and a collision object based on input from the vehicle sensor system;
estimate trajectories of the vehicle and the collision object based on input from the vehicle sensor system;
determine a time to close encounter between the vehicle and the collision object based on the estimated trajectories;
determine whether the distance is less than a first predetermined distance;
determine whether the time to close encounter is less than a first predetermined time to close encounter;
determine that the vehicle is operating in a high-risk environment when at least one of:
(i) the distance is less than the first predetermined distance; or
(ii) the time to close encounter is less than the first predetermined time to close encounter;
when the vehicle is determined to be operating in the high-risk environment, controlling the vehicle actuator system to control the vehicle in a crash mitigation mode by generating vehicle control commands using an occupant comfort parameter within a crash mitigation range of the occupant comfort parameter; and
when the vehicle is not determined to be operating in the high-risk environment, controlling the vehicle actuator system to control the vehicle in a motion planning mode by generating vehicle control commands using the occupant comfort parameter within a motion planning range of the occupant comfort parameter, the motion planning range of the occupant comfort parameter being higher than the crash mitigation range of the occupant comfort parameter,
wherein the occupant comfort parameter is used to set an allowable degree of change of acceleration, deceleration, and steering of the vehicle in generating the vehicle control commands, where the allowable degree of change of acceleration, deceleration, and steering of the vehicle is proportionally reduced as the occupant comfort parameter increases, and the allowable degree of change of acceleration, deceleration, and steering of the vehicle is proportionally increased as the occupant comfort parameter decreases.
20 . The vehicle according to claim 19 , wherein the electronic control unit is further programmed to:
while controlling the vehicle actuator system in the crash mitigation mode after the vehicle is determined to be operating in the high-risk environment, switching control of the vehicle actuator system to the motion planning mode when:
when the vehicle is determined to be operating in the high-risk environment due to the distance being less than the first predetermined difference, the distance changes to be greater than a second predetermined distance, the second predetermined distance being greater than the first predetermined distance;
when the vehicle is determined to be operating in the high-risk environment due to the time to close encounter being less than the first predetermined time to close encounter, the time to close encounter changes to be greater than a second predetermined time to close encounter, the second predetermined time to close encounter being greater than the first predetermined time to close encounter; and
when the vehicle is determined to be operating in the high-risk environment due to the distance being less than the first predetermined difference and due to the time to close encounter being less than the first predetermined time to close encounter, the distance changes to be greater than the second predetermined distance and the time to close encounter changes to be greater than the second predetermined time to close encounter.