Methods and systems for lateral control of a vehicle
A computer implemented method for lateral control of a vehicle comprises the following steps carried out by computer hardware components: determining a location error of the vehicle; determining an orientation error of the vehicle; determining a cost function based on the location error and the orientation error using a circular transformation; and processing the cost function in a model predictive controller to control the vehicle laterally.
1. A computer-implemented method for lateral control of a vehicle, the computer-implemented method being carried out by computer hardware components and comprising:
determining a location error of the vehicle;
determining an orientation error of the vehicle;
determining a cost function based on the location error and the orientation error using a circular transformation; and
processing the cost function in a model predictive controller to control the vehicle laterally, wherein:
the cost function includes an integral over an error term,
the error term involves both the location error and the orientation error,
the error term includes a product based on the location error and the orientation error,
the cost function is determined according to equations (a) and (b):
e tr =cos θ e 2 *tan −1 ( d−d ref )+sin θ e 2 *θ e (a)
J=∫ 0 T e tr 2 (b)
θ e represents the orientation error with respect to a reference,
d represents an initial value of a lateral offset from a vehicle sensor input,
d ref represents a reference value that the vehicle should track,
J represents the cost function that needs to be minimized, and
T represents a prediction horizon.
2. The computer-implemented method of claim 1 , wherein the cost function comprises a non-holonomic ellipsoid cost function.
3. The computer-implemented method of claim 1 , wherein the cost function is based on a cosine function.
4. The computer-implemented method of claim 1 , wherein the cost function is based on a sine function.
5. The computer-implemented method of claim 1 , wherein the cost function is based on a tangent function.
6. The computer-implemented method of claim 1 , wherein controlling the vehicle laterally comprises determining the lateral offset of the vehicle.
7. The computer-implemented method of claim 1 , wherein controlling the vehicle laterally comprises determining an optimal steering angle value.
8. A computer system comprising a plurality of computer hardware components configured to carry out instructions including:
determining a location error of a vehicle;
determining an orientation error of the vehicle;
determining a cost function based on the location error and the orientation error using a circular transformation; and
processing the cost function in a model predictive controller to control the vehicle laterally, wherein:
the cost function includes an integral over an error term,
the error term involves both the location error and the orientation error,
the error term includes a product based on the location error and the orientation error,
the cost function is determined according to equations (a) and (b):
e tr =cos θ e 2 *tan −1 ( d−d ref )+sin θ e 2 *θ e (a)
J=∫ 0 T e tr 2 (b)
θ e represents the orientation error with respect to a reference,
d represents an initial value of a lateral offset from a vehicle sensor input,
d ref represents a reference value that the vehicle should track,
J represents the cost function that needs to be minimized, and
T represents a prediction horizon.
9. A vehicle comprising:
the computer system of claim 8 ; and
a sensor configured to determine the location error and/or the orientation error.
10. The vehicle of claim 9 , wherein the sensor comprises at least one of a radar sensor, a lidar sensor, an ultrasound sensor, a camera, or a global navigation satellite system sensor.
11. A non-transitory computer readable medium comprising instructions including:
determining a location error of a vehicle;
determining an orientation error of the vehicle;
determining a cost function based on the location error and the orientation error using a circular transformation; and
processing the cost function in a model predictive controller to control the vehicle laterally, wherein:
the cost function includes an integral over an error term, the error term involves both the location error and the orientation error,
the error term includes a product based on the location error and the orientation error,
the cost function is determined according to equations (a) and (b):
e tr =cos θ e 2 *tan −1 ( d−d ref )+sin θ e 2 *θ e (a)
J=∫ 0 T e tr 2 (b)
θ e represents the orientation error with respect to a reference,
d represents an initial value of a lateral offset from a vehicle sensor input,
d ref represents a reference value that the vehicle should track,
J represents the cost function that needs to be minimized, and
T represents a prediction horizon.