Ascertaining an indicator for the drive-over capability of an object
In a method for ascertaining whether a target object can be driven over by the controlled motor vehicle, with the aid of frequency-modulated radar signals of a radar sensor, amplitude ratios between received radar signals reflected from the target object are utilized, the received radar signals corresponding to signals which have been transmitted in different frequency ranges. Based on the amplitude ratios, an occurrence of interference between (i) a first radar signal propagation path between the radar sensor and the target object and (ii) a second propagation path with additional reflection from a road is detected, and based on the detection of an occurrence of interference it is ascertained whether the object can be driven over.
1. A method for ascertaining a capability of a controlled vehicle to drive over a target object, the method comprising:
transmitting multiple frequency-modulated radar signals in different frequency ranges from a radar sensor of the controlled vehicle;
determining amplitude ratios between received radar signals reflected from the target object, the received radar signals corresponding to the radar signals transmitted in different frequency ranges;
detecting, based on the determined amplitude ratios, an occurrence of interference between (i) a first radar signal propagation path between the radar sensor and the target object, and (ii) a second, indirect propagation path between the radar sensor and the target object, the second propagation path including an additional reflection from a road; and
ascertaining, based on the detection of the occurrence of interference, an indicator for the capability of the controlled vehicle to drive over the target object.
2. The method as recited in claim 1 , wherein an occurrence of destructive interference between the first propagation path and the second propagation path is detected.
3. The method as recited in claim 2 , wherein the occurrence of interference between the first and second propagation paths is detected based on a progression of amplitude ratios ascertained for a range of distances between the radar sensor and the object.
4. The method as recited in claim 1 , wherein the radar signals transmitted in different frequency ranges are each frequency-modulated with the aid of a respective frequency ramp, the mid-frequencies of the frequency ramps being different.
5. The method as recited in claim 4 , wherein the different frequency ranges in which the radar signals are transmitted do not overlap.
6. The method as recited in claim 5 , wherein the radar signals transmitted in the different frequency ranges are component radar signals of a comprehensive radar signal, and wherein the comprehensive radar signal is modulated with the aid of a frequency ramp extending over the chronological progression of the individual component radar signals.
7. The method as recited in claim 4 , wherein the occurrence of interference is detected based on a degree of deviations of the amplitude ratios relative to a mean value over a range of distances between the radar sensor and the target object.
8. The method as recited in claim 4 , wherein in the step of ascertaining the indicator for the capability of the controlled vehicle to drive over the target object, the indicator has at least one first state if the occurrence of the interference is detected, and a second state if a non-occurrence of the interference is detected.
9. The method as recited in claim 4 , wherein information regarding a height of the target object is ascertained based on (i) the detection of an occurrence of interference and (ii) at least one value of the distance between the radar sensor and the target object at which the interference occurs.
10. The method as recited in claim 4 , wherein the indicator for the capability of the controlled vehicle to drive over the target object is ascertained based on the detection of an occurrence of interference and at least one of (i) a value of the distance between the radar sensor and the target object, and (ii) at least one parameter characterizing a signal transmission quality of the propagation path between the radar sensor and the target object.
11. A device for ascertaining an indicator for a capability of a controlled vehicle to drive over a target object, comprising:
a radar sensor transmitting multiple frequency-modulated radar signals in different frequency ranges;
a unit for determining amplitude ratios between the multiple radar signals reflected from the target object and received by the radar sensor;
a detection unit configured to detect, based on the determined amplitude ratios, an occurrence of interference between (i) a first, direct propagation path for the radar signal between the radar sensor and the target object, and (ii) a second, indirect propagation path for the radar signal between the radar sensor and the target object, the second propagation path including an additional reflection from a road; and
an assessment unit configured to ascertain, based on the detection of an occurrence of interference by the detection unit, the indicator for the capability of the controlled vehicle to drive over the target object.