METHOD FOR AUTOMATIC MOVEMENT CONTROLLING OF A VEHICLE

Abstract

In a method for automatic movement controlling of a vehicle, at least one trajectory is determined on the basis of environmental and driving state data, and driving state quantities are subsequently calculated for an upcoming time period, using a mathematical vehicle model, taking the trajectory as a basis.

Claims

1. A method for the automatic movement controlling of a vehicle, comprising: determining at least one trajectory based on environmental data and driving state data; after the determining, calculating driving state quantities for an upcoming time period using a mathematical vehicle model, taking the trajectory as a basis; and ascertaining an evaluation criterion for the trajectory from the calculated driving state quantities of the upcoming time period.

2. The method as recited in claim 1, wherein based on the environmental data and the driving state data, a plurality of trajectories are determined, and one of the plurality of trajectories is subsequently selected using the mathematical vehicle model.

3. The method as recited in claim 1, wherein a modified trajectory is ascertained using the mathematical vehicle model.

4. The method as recited in claim 1, further comprising: providing, to at least one vehicle unit, at least one of: (i) the calculated driving state quantities of the upcoming time period, and (ii) a modified trajectory.

5. The method as recited in claim 4, wherein the vehicle unit includes at least one actuator that influences the driving state, which actuator is controlled based on at least one of: the calculated driving state quantities of the upcoming time period, and (ii) the modified trajectory.

6. The method as recited in claim 5, wherein at least one of a longitudinal, a transverse, and a vertical dynamic behavior of the vehicle is capable of being influenced via the actuator.

7. The method as recited in claim 1, wherein at least one trajectory is determined continuously on the basis of environmental data and driving state data, and driving state quantities are subsequently calculated for an upcoming time period, using the mathematical vehicle model, taking the trajectory as a basis.

8. The method as recited in claim 1, wherein a simulation is carried out using the mathematical vehicle model over the overall time period that the vehicle would require to travel the trajectory.

9. A control device for automatic movement controlling of a vehicle, the control device configured to: determine at least one trajectory based on environmental data and driving state data; after the determination, calculate driving state quantities for an upcoming time period using a mathematical vehicle model, taking the trajectory as a basis; and ascertain an evaluation criterion for the trajectory from the calculated driving state quantities of the upcoming time period.

10. A driver assistance system in a vehicle, comprising: a control device for automatic movement controlling of a vehicle, the control device configured to (i) determine at least one trajectory based on environmental data and driving state data, (ii) after the determination, calculate driving state quantities for an upcoming time period using a mathematical vehicle model, taking the trajectory as a basis, and (iii) ascertain an evaluation criterion for the trajectory from the calculated driving state quantities of the upcoming time period.

11. A vehicle having a driver assistance system, the driver assistance system comprising: a control device for automatic movement controlling of a vehicle, the control device configured to (i) determine at least one trajectory based on environmental data and driving state data, (ii) after the determination, calculate driving state quantities for an upcoming time period using a mathematical vehicle model, taking the trajectory as a basis, and (iii) ascertain an evaluation criterion for the trajectory from the calculated driving state quantities of the upcoming time period.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 shows, in a top view, a vehicle on a roadway that describes a curve.

[0026] FIG. 2 shows the vehicle in various positions along a trajectory through the curve;

[0027] FIG. 3 shows a representation corresponding to FIG. 2, but with a modified trajectory that the vehicle departs from;

[0028] FIG. 4 shows a further representation having a modified trajectory that the vehicle follows.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0029] In the Figures, identical parts are provided with identical reference characters.

[0030] FIG. 1 shows a roadway 1 that describes a curve; a vehicle 2 is shown at the beginning of the curve. Vehicle 2 is situated on the right side of roadway 1, which is divided by center line 3. FIG. 1 shows an initial situation of vehicle 2 at the beginning of the curve at time to. For an automated driving function, in a control device of vehicle 2, starting from the current driving state and the course of the roadway, which is acquired using an environmental sensor system and/or a navigation system including a position determination system in the vehicle, a trajectory is ascertained along which vehicle 2 is to travel through the curve of roadway 1, in partly or completely automatic fashion.

[0031] Trajectory 4 is shown in FIG. 2. In FIG. 2, vehicle 2 is shown at various time intervals ?t, and is correspondingly shown at various positions on trajectory 4. Trajectory 4 extends on the right side of the roadway at least approximately centrically between center line 3 and the right edge of roadway 1. Trajectory 3 includes the movement path for vehicle 2 through the curve of roadway 1, but in addition the trajectory can also contain information concerning speed, acceleration, and, if warranted, the jerk in the vehicle longitudinal direction, vehicle transverse direction, and/or vehicle vertical direction.

[0032] Trajectory 4 is determined in the control device in the vehicle, and driving state quantities that result during travel of the vehicle model along trajectory 4 are subsequently calculated for the upcoming time period, using a mathematical vehicle model also stored in the control device. In this way, the travel of the vehicle along trajectory 4 is predictively simulated in the vehicle model, and from this there result driving state quantities at various times of vehicle 2 along trajectory 4, or at various positions of trajectory 4.

[0033] These driving state quantities calculated ahead of time can be used as the basis for determining an evaluation criterion with which trajectory 4 is evaluated. On the basis of the evaluation criterion, it can be decided whether the trajectory can be traveled, with regard to various considerations such as vehicle safety or driving comfort, or whether the trajectory has to be modified or a changeover has to be made to an alternative trajectory.

[0034] FIG. 3 shows the situation in which vehicle 2, due to its speed and/or external circumstances, such as a reduced friction value, cannot completely follow trajectory 4 through the curve. Approximately in the center of the curve, vehicle 2 departs from the trajectory and moves radially outward, in the direction towards the outer edge of the roadway. This driving behavior of vehicle 2 can be simulated ahead of time in the mathematical vehicle model, whereupon the trajectory according to FIG. 3 is rejected, and instead a changeover is made to a modified or alternative trajectory according to FIG. 4.

[0035] The trajectory according to FIG. 4 is a modification of the trajectory of FIG. 3, and is realized such that vehicle 2 can follow trajectory 4 over the entire course of the curve under the given circumstances, or given the current or predicted vehicle speed. FIG. 4 is also a simulation made ahead of time. Correspondingly, before reaching a critical point on the trajectory a modified trajectory along which the vehicle is actually moving can still be taken as a basis. For partly automatic or fully automatic driving through the curve along trajectory 4, actuators in various vehicle units are correspondingly controlled, in particular in the brake system, in the steering system, and in the drive unit.

[0036] During the actual traveling through the curve along trajectory 4, tests can be continuously carried out at time-discrete intervals. Here, starting from the current driving state and the current position of the vehicle, a new trajectory is continuously determined that, immediately subsequently, is used as a basis for a simulation in the mathematical vehicle model, from which, as described above, driving state quantities are determined and an evaluation criterion for the newly calculated trajectory is ascertained. If the evaluation criterion is within a defined specification, then the newly calculated trajectory, which may also agree with the previously calculated trajectory, can continue to be used. If, in contrast, the evaluation criterion is outside defined limits, the newly calculated trajectory must be modified or rejected, as described above. Only if the trajectory in the simulation results in acceptable driving state quantities can the newly calculated trajectory be used as a basis for the controlling of the actuators in the vehicle.