Determining vehicle load center of mass
Various examples are directed to systems and methods for operating a vehicle comprising a tractor and a trailer attached for pulling behind the tractor. A center-of-mass system may determine a mass of the trailer and a tractor understeer. The center-of-mass system may determine the tractor understeer using steering input data describing a steering angle of the tractor and yaw data describing a yaw of the tractor. The center-of-mass system may determine a load center of mass using the tractor understeer and a mass of the trailer. The center-of-mass system may further determine that the load center of mass transgresses a center-of-mass threshold and send an alert message indicating that the load transgresses the load center-of-mass threshold.
1. A computer-implemented system for controlling a vehicle comprising a tractor and a trailer coupled to the tractor, the system comprising:
at least one processor programmed to perform operations comprising:
obtaining a mass of the trailer;
obtaining a steering response of the tractor;
determining a center-of-mass associated with the trailer based at least in part on the steering response of the tractor and the mass of the trailer;
determining a control input for the tractor, wherein determining the control input is based at least in part on the center-of-mass; and
applying the control input to the tractor.
2. The system of claim 1 , the operations further comprising determining, by the at least one processor, that the center-of-mass fails to satisfy a center-of-mass threshold.
3. The system of claim 2 , the operations further comprising sending an alert message indicating that the center-of-mass fails to satisfy the center-of-mass threshold.
4. The system of claim 3 , wherein the alert message is sent to an output device at a cab of the tractor.
5. The system of claim 3 , wherein the alert message is sent to a remote host system.
6. The system of claim 1 , the operations further comprising determining the steering response based at least in part on steering angle data describing a steering angle of the tractor, and yaw data describing a yaw rate of the tractor.
7. The system of claim 1 , the operations further comprising determining a difference between the center-of-mass and a previous center-of-mass measured at a different time.
8. The system of claim 1 , the operations further comprising determining a distance between the center-of-mass and a rear of the trailer.
9. The system of claim 1 , the operations further comprising determining a distance between the center-of-mass and a front of the trailer.
10. The system of claim 1 , the operations further comprising stopping the vehicle, wherein the stopping of the vehicle comprises the applying of the control input to the tractor.
11. The system of claim 1 , wherein applying the control input to the tractor comprises causing the tractor to reduce a speed of the vehicle.
12. The system of claim 1 , the operations further comprising determining, by the at least one processor, a tractor rear axle force based, at least in part, on the steering response of the tractor, wherein the determining of the center-of-mass also uses the tractor rear axle force.
13. The system of claim 1 , the operations further comprising:
obtaining, by the at least one processor, an engine force applied to the vehicle by an engine of the tractor;
obtaining, by the at least one processor, a gravitational force applied to the vehicle; and
accessing, by the at least one processor, acceleration data describing an acceleration of the vehicle, wherein the mass of the trailer is determined based at least in part on the acceleration, the engine force, and the gravitational force.
14. A method of operating a vehicle comprising a tractor and a trailer coupled to the tractor, the method comprising:
obtaining, by at least one processor, a mass of the trailer;
obtaining, by the at least one processor, a steering response of the tractor;
determining, by the at least one processor, a center-of-mass associated with the trailer based at least in part on the steering response of the tractor and the mass of the trailer;
determining, by the at least one processor, a control input for the tractor, wherein determining the control input is based at least in part on the center-of-mass; and
applying, by the at least one processor, the control input to the tractor.
15. The method of claim 14 , further comprising determining, by the at least one processor, that the center-of-mass fails to satisfy a center-of-mass threshold.
16. The method of claim 14 , further comprising determining the steering response based at least in part on steering angle data describing a steering angle of the tractor, and yaw data describing a yaw rate of the tractor.
17. The method of claim 14 , further comprising stopping the vehicle, wherein the stopping of the vehicle comprises the applying of the control input to the tractor.
18. The method of claim 14 , wherein applying the control input to the tractor comprises causing the tractor to reduce a speed of the vehicle.
19. The method of claim 14 , further comprising determining, by the at least one processor, a tractor rear axle force based, at least in part, on the steering response of the tractor, wherein the determining of the center-of-mass also uses the tractor rear axle force.
20. A computer-readable storage medium comprising instructions thereon that, when executed by at least one processor, causes the at least one processor to perform operations comprising:
obtaining a mass of a trailer attached for pulling behind a tractor;
obtaining a steering response of the tractor;
determining a center-of-mass associated with the trailer based at least in part on the steering response of the tractor and the mass of the trailer;
determining a control input for the tractor, wherein determining the control input is based at least in part on the center-of-mass; and
applying the control input to the tractor.