Velocity trajectory generation method, apparatus, and storage medium
View Patent ↗A velocity trajectory generation method and apparatus, and a storage medium are provided. The method includes: setting starting point time, intermediate point time and terminal point time of a velocity trajectory to be generated, wherein the velocity trajectory includes a first velocity sub-trajectory and a second velocity sub-trajectory; generating multiple first velocity sub-trajectories corresponding to a starting point velocity between the starting point time and the intermediate point time, according to the starting point velocity and multiple intermediate point velocities; and generating, for each of the first velocity sub-trajectories, multiple second velocity sub-trajectories between the intermediate point time and the terminal point time according to multiple terminal point velocities. A velocity trajectory which is more in line with a human driving characteristic may be generated, the comfort level of a passenger may be improved, and an algorithm may be simplified.
1. A velocity trajectory generation method, comprising:
setting starting point time, intermediate point time and terminal point time of a velocity trajectory to be generated, wherein the velocity trajectory comprises a velocity of a vehicle running along a path trajectory; wherein the velocity trajectory comprises a first velocity sub-trajectory and a second velocity sub-trajectory;
generating multiple first velocity sub-trajectories corresponding to a starting point velocity between the starting point time and the intermediate point time, according to the starting point velocity and multiple intermediate point velocities; and
generating, for each of the first velocity sub-trajectories, multiple second velocity sub-trajectories between the intermediate point time and the terminal point time according to multiple terminal point velocities;
wherein an acceleration and an acceleration jerk of each of the first velocity sub-trajectories and an acceleration and an acceleration jerk of each of the second velocity sub-trajectories are continuously changed; and intermediate point acceleration jerks and terminal point acceleration jerks are 0.
2. The velocity trajectory generation method according to claim 1 , further comprising:
generating the multiple intermediate point velocities, according to the starting point velocity, a time difference between the starting point time and the intermediate point time, and an acceleration threshold.
3. The velocity trajectory generation method according to claim 2 , wherein the generating the multiple intermediate point velocities, according to the starting point velocity, a time difference between the starting point time and the intermediate point time, and an acceleration threshold comprises:
determining a maximum of the intermediate point velocity according to the starting point velocity and a maximum of the acceleration threshold;
determining a minimum of the intermediate point velocity according to the starting point velocity and a minimum of the acceleration threshold; and
determining multiple intermediate point velocities between the maximum of the intermediate point velocity and the minimum of the intermediate point velocity at a preset sampling velocity interval.
4. The velocity trajectory generation method according to claim 1 , wherein the generating the first velocity sub-trajectory comprises:
generating an Mth-order polynomial function of velocity and time, M being a positive integer greater than 1;
generating multiple sampling points between the starting point time and the intermediate point time at a preset sampling time interval according to the Mth-order polynomial function; and
fitting the multiple sampling points, to obtain a curve representing the first velocity sub-trajectory.
5. The velocity trajectory generation method according to claim 4 , wherein the generating an Mth-order polynomial function of velocity and time comprises:
determining a coefficient of each order of the Mth-order polynomial function according to the starting point time, the starting point velocity, a starting point acceleration, the intermediate point time, the intermediate point velocity, an intermediate point acceleration and an intermediate point acceleration jerk, wherein M is equal to 5.
6. The velocity trajectory generation method according to claim 1 , further comprising:
generating multiple terminal point velocities according to the intermediate point velocity, a time difference between the intermediate point time and the terminal point time, and an acceleration threshold.
7. The velocity trajectory generation method according to claim 6 , wherein the generating multiple terminal point velocities according to a time difference between the intermediate point time and the terminal point time, and an acceleration threshold comprises:
determining a maximum of the terminal point velocity according to the intermediate point velocity and a maximum of the acceleration threshold;
determining a minimum of the terminal point velocity according to the intermediate point velocity and a minimum of the acceleration threshold; and
determining the multiple terminal point velocities between the maximum of the terminal point velocity and the minimum of the terminal point velocity at a preset sampling velocity interval.
8. The velocity trajectory generation method according to claim 1 , wherein the generating the second sub velocity trajectory comprises:
generating an Nth-order polynomial function of velocity and time, N being a positive integer greater than 1;
generating multiple sampling points between the intermediate point time and the terminal point time at a preset time interval according to the Nth-order polynomial function; and
fitting the multiple sampling points, to obtain a curve representing the second velocity sub-trajectory.
9. The velocity trajectory generation method according to claim 8 , wherein the generating an Nth-order polynomial function of velocity and time comprises:
determining a coefficient of each order of the Nth-order polynomial function according to the intermediate point time, the intermediate point velocity, an intermediate point acceleration, the terminal point time, the terminal point velocity, a terminal point acceleration and a terminal point acceleration jerk, wherein N is equal to 5.
10. A velocity trajectory generation apparatus, comprising:
one or more processors; and
a storage device configured to store one or more programs, wherein
the one or more programs, when executed by the one or more processors, cause the one or more processors to:
set starting point time, intermediate point time and terminal point time of a velocity trajectory to be generated, wherein the velocity trajectory comprises a velocity of a vehicle running along a path trajectory; wherein the velocity trajectory comprises a first velocity sub-trajectory and a second velocity sub-trajectory;
configured to generate multiple first velocity sub-trajectory corresponding to a starting point velocity between the starting point time and the intermediate point time, according to the starting point velocity and multiple intermediate point velocities; and
configured to generate, for each of the first velocity sub-trajectories, multiple second velocity sub-trajectories between the intermediate point time and the terminal point time according to multiple terminal point velocities;
wherein an acceleration and an acceleration jerk of each of the first velocity sub-trajectories and an acceleration and an acceleration jerk of each of the second velocity sub-trajectories are continuously changed; and intermediate point acceleration jerks and terminal point acceleration jerks are 0.
11. The velocity trajectory generation apparatus according to claim 10 , wherein the one or more programs, when executed by the one or more processors, cause the one or more processors further to:
generate the multiple intermediate point velocities, according to the starting point velocity, a time difference between the starting point time and the intermediate point time, and an acceleration threshold.
12. The velocity trajectory generation apparatus according to claim 11 , wherein the one or more programs, when executed by the one or more processors, cause the one or more processors further to:
determine a maximum of the intermediate point velocity according to the starting point velocity and a maximum of the acceleration threshold;
determine a minimum of the intermediate point velocity according to the starting point velocity and a minimum of the acceleration threshold; and
determine multiple intermediate point velocities between the maximum of the intermediate point velocity and the minimum of the intermediate point velocity at a preset sampling velocity interval.
13. The velocity trajectory generation apparatus according to claim 10 , wherein the one or more programs, when executed by the one or more processors, cause the one or more processors further to:
generate an Mth-order polynomial function of velocity and time, M being a positive integer greater than 1;
generate multiple sampling points between the starting point time and the intermediate point time at a preset sampling time interval according to the Mth-order polynomial function; and
fit the multiple sampling points, to obtain a curve representing the first velocity sub-trajectory.
14. The velocity trajectory generation apparatus according to claim 13 , wherein the one or more programs, when executed by the one or more processors, cause the one or more processors further to:
determine a coefficient of each order of the Mth-order polynomial function according to the starting point time, the starting point velocity, a starting point acceleration, the intermediate point time, the intermediate point velocity, an intermediate point acceleration and an intermediate point acceleration jerk, wherein M is equal to 5.
15. The velocity trajectory generation apparatus according to claim 10 , wherein the one or more programs, when executed by the one or more processors, cause the one or more processors further to:
generate multiple terminal point velocities according to the intermediate point velocity, a time difference between the intermediate point time and the terminal point time, and an acceleration threshold.
16. The velocity trajectory generation apparatus according to claim 15 , wherein the one or more programs, when executed by the one or more processors, cause the one or more processors further to:
determine a maximum of the terminal point velocity according to the intermediate point velocity and a maximum of the acceleration threshold;
determine a minimum of the terminal point velocity according to the intermediate point velocity and a minimum of the acceleration threshold; and
determine the multiple terminal point velocities between the maximum of the terminal point velocity and the minimum of the terminal point velocity at a preset sampling velocity interval.
17. The velocity trajectory generation apparatus according to claim 10 , wherein the one or more programs, when executed by the one or more processors, cause the one or more processors further to:
generate an Nth-order polynomial function of velocity and time, N being a positive integer greater than 1;
generate multiple sampling points between the intermediate point time and the terminal point time at a preset time interval according to the Nth-order polynomial function; and
fit the multiple sampling points, to obtain a curve representing the second velocity sub-trajectory.
18. The velocity trajectory generation apparatus according to claim 17 , wherein the one or more programs, when executed by the one or more processors, cause the one or more processors further to:
determine a coefficient of each order of the Nth-order polynomial function according to the intermediate point time, the intermediate point velocity, an intermediate point acceleration, the terminal point time, the terminal point velocity, a terminal point acceleration and a terminal point acceleration jerk, wherein N is equal to 5.
19. A non-transitory computer-readable storage medium comprising computer programs stored thereon, wherein the programs, when executed by a processor, cause the processor to:
set starting point time, intermediate point time and terminal point time of a velocity trajectory to be generated, wherein the velocity trajectory comprises a velocity of a vehicle running along a path trajectory; wherein the velocity trajectory comprises a first velocity sub-trajectory and a second velocity sub-trajectory;
generate multiple first velocity sub-trajectories corresponding to a starting point velocity between the starting point time and the intermediate point time, according to the starting point velocity and multiple intermediate point velocities; and
generate, for each of the first velocity sub-trajectories, multiple second velocity sub-trajectories between the intermediate point time and the terminal point time according to multiple terminal point velocities;
wherein an acceleration and an acceleration jerk of each of the first velocity sub-trajectories and an acceleration and an acceleration jerk of each of the second velocity sub-trajectories are continuously changed; and intermediate point acceleration jerks and terminal point acceleration jerks are 0.