Liquid detection using millimeter-wave radar sensor

A method for detecting a liquid from a moving vehicle, the method comprising:

• generating a 2D radar image of a surface in a field of view of a millimeter-wave radar sensor circuit based on sensed data from N virtual channels generated by the millimeter-wave radar sensor circuit;
• generating a multi-dimensional data structure based on the 2D radar image using a transform function;
• comparing the multi-dimensional data structure with a reference multi-dimensional data structure;
• and
• determining whether liquid is present in the field of view of the millimeter-wave radar sensor circuit based on comparing the multi-dimensional data structure with the reference multi-dimensional data structure.

A vacuum cleaner robot comprising:

• a millimeter-wave radar sensor circuit configured to generate N virtual channels of sensed data, wherein N is an integer number greater than one;
• and
• a processor configured to:
• generate a 2D radar image of a surface in a field of view of the millimeter-wave radar sensor circuit based on sensed data from the N virtual channels of sensed data, wherein the 2D radar image comprises azimuth and range information,
• generate a multi-dimensional data structure based on the 2D radar image using a transform function,
• compare the multi-dimensional data structure with a reference multi-dimensional data structure, and
• determine whether liquid is present in the field of view of the millimeter-wave radar sensor circuit based on comparing the multi-dimensional data structure with the reference multi-dimensional data structure.