Range extension with segmentation

#The subject disclosure relates to radar systems and, in particular, to a system and method for operating a radar system to detect objects outside of a stated range limit of the radar system.

#Vehicular radar systems can be used to detect an object within an environment of the vehicle by reflecting an electromagnetic wave off of the object and recording a time-of-flight required for the electromagnetic wave to return to the radar system. Various radar systems use a linear frequency modulated signal to probe the environment. These radar systems have a maximum range that is a function of a slope of the linear frequency modulated signal and a sampling rate of the radar system. There is a need to be able to determine the range of objects, even when the objects are outside of the range of the radar system.

#In one exemplary embodiment, a method of extending a range of a radar system is disclosed. A reference signal is transmitted from the radar system. An echo signal is received at the radar system in response to reflection of the transmitted reference signal from an object located at a distance outside of a range limit of the radar system, wherein the range limit indicates a frequency sampling range. A frequency peak is generated for the object from the received echo signal, wherein the frequency peak lies outside of the frequency sampling range. The frequency peak is shifted to within the frequency sampling range. The range of the object is determined using the frequency-shifted peak.

#Other features, advantages and details appear, by way of example only, in the following detailed description, the detailed description referring to the drawings in which:

#FIG. 1 shows an autonomous vehicle in an illustrative embodiment;

#FIG. 2 shows a schematic diagram of the radar system of FIG. 1 in various embodiments;

#The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

#In accordance with an exemplary embodiment, FIG. 1 shows an autonomous vehicle 10. In an exemplary embodiment, the autonomous vehicle 10 is a so-called Level Four or Level Five automation system. A Level Four system indicates “high automation”, referring to the driving mode-specific performance by an automated driving system of all aspects of the dynamic driving task, even if a human driver does not respond appropriately to a request to intervene. A Level Five system indicates “full automation”, referring to the full-time performance by an automated driving system of all aspects of the dynamic driving task under all roadway and environmental conditions that can be managed by a human driver.

#The autonomous vehicle 10 generally includes at least a navigation system 20, a propulsion system 22, a transmission system 24, a steering system 26, a brake system 28, a sensor system 30, an actuator system 32, and a controller 34. The navigation system 20 determines a trajectory plan for automated driving of the autonomous vehicle 10. The propulsion system 22 provides power for creating a motive force for the autonomous vehicle 10 and may, in various embodiments, include an internal combustion engine, an electric machine such as a traction motor, and/or a fuel cell propulsion system. The transmission system 24 is configured to transmit power from the propulsion system 22 to wheels 16 and 18 of the autonomous vehicle 10 according to selectable speed ratios. The steering system 26 influences a position of the wheels 16 and 18. While depicted as including a steering wheel 27 for illustrative purposes, in some embodiments contemplated within the scope of the present disclosure, the steering system 26 may not include a steering wheel 27. The brake system 28 is configured to provide braking torque to the wheels 16 and 18.