Tracking system and method for characterizing target height using percentage of range bins

1. A method of characterizing height of targets in an environment around a vehicle, comprising:

a) determining a range from a minimum range to a maximum range within which targets will be characterized;

b) transmitting a plurality of signals into the environment such that the signals reflect off the targets in the environment to create a plurality of return signals;

c) for at least one of the targets in the environment, receiving the return signals to determine a track corresponding to said target;

d) for each track, generating a plurality of bins, each bin corresponding to a segment of the range such that the entire range is accounted for, the segments having a gradually increasing size between the minimum range and maximum range;

e) during a cycle, determining a range value and a magnitude value of the received return signals for a selected track of the tracks;

f) determining a plurality of filled bins during the cycle, filled bins indicating that a return signal within the selected track has a range value falling within the segment corresponding to said bin during the cycle; and

g) when the number of filled bins exceeds a set threshold, analyzing the return signals having range values within the segments corresponding to the filled bins to characterize a height of the target corresponding to the selected track, wherein the set threshold of filled bins is between 20 and 30 percent of a total number of bins.

2. The method of claim 1 , further comprising:

h) classifying the target based on the height of the target corresponding to the selected track to generate a target classification.

3. The method of claim 2 , wherein the target classification relates to whether a collision between the target and the vehicle is expected.

4. The method of claim 3 , further comprising:

i) assigning a priority level to each track; and

j) repeating steps e)-h) for a plurality of selected tracks,

wherein, during step e), a scheduler determines the selected track at any given time based on the priority level of the tracks.

5. The method of claim 4 , wherein:

at least one target is associated with a lane of the vehicle and the track corresponding to said target has a relatively high priority level; and

at least one target is associated with a lane separate the lane of the vehicle and the track corresponding to said target has a relatively low priority level.

6. The method of claim 1 , wherein, during step g), analyzing the return signals having range values within the segments corresponding to the filled bins to characterize a height of the target corresponding to the selected track includes:

performing a fast Fourier transform (FFT) on a cumulative averaged product of a magnitude value and a range value of each return signal having a range value falling within the segments corresponding to the filled bins to generate an FFT output.

7. The method of claim 6 , wherein, during step g), analyzing the return signals having range values within the segments corresponding to the filled bins to characterize a height of the target corresponding to the selected track includes:

selecting a peak FFT bin of the filled bins having the greatest FFT output; and

characterizing the height of the target based on the FFT output in the peak FFT bin.

8. The method of claim 1 , wherein, step g) further comprises, identifying at least one empty bin between two surrounding filled bins and filling the empty bin through linear interpolation such that the empty bin becomes a filled bin with a magnitude value between the magnitude values of the return signals corresponding to the surrounding bins.

9. A detection system for characterizing height of targets in an environment around a vehicle, comprising:

a transmitter configured to transmit a plurality of signals into the environment such that the signals reflect off targets in the environment to create return signals;

a receiver configured to receive the return signals; and

a processing module connected to a memory configured to:

for a given cycle, store a range from a minimum range to a maximum range within which targets will be characterized;

determine a selected track corresponding to a target in the environment;

for the selected track, store data related to a plurality of bins, each bin corresponding to a segment of the range such that the entire range is accounted for, the segments having a gradually increasing size between the minimum range and maximum range;

determine a range value and magnitude value of the received signals for the selected track during the cycle;

determine a plurality of filled bins during the cycle, filled bins indicating that a return signal within the selected track has a range value falling within the segment corresponding to said bin; and

when the number of filled bins exceeds a set threshold, analyze the return signals having range values corresponding to the segments the filled bins to characterize a height of the target within the selected track, wherein the set threshold of filled bins is between 20 and 30 percent of a total number of bins.

10. The detection system of claim 9 , wherein the processing module is further configured to classify the target based on the height of the target corresponding to the selected track to generate a target classification.

11. The detection system of claim 10 , wherein the target classification relates to whether a collision between the target and the vehicle is expected.

12. The detection system of claim 11 , wherein the processing module is further configured to:

assign a priority level to each track; and

repeat a plurality of cycles for a plurality of selected tracks,

wherein the detection system further comprises a scheduler configured to determine the selected track at any given time based on the priority level of the tracks.

13. The detection system of claim 12 , wherein:

at least one target is associated with a lane of the vehicle and the scheduler assigns the track corresponding to said target a relatively high priority level; and

at least one target is associated with a lane separate from the lane of the vehicle and the scheduler assigns the track corresponding to said target a relatively low priority level.

14. The detection system of claim 9 , wherein the processing module is further configured to analyze the return signals by:

performing a fast Fourier transform (FFT) on a cumulative averaged product of a magnitude value and a range value of each return signal having a range value falling within the segments corresponding to the filled bins to generate an FFT output.

15. The detection system of claim 14 , wherein the processing module is further configured to analyze the return signals by:

selecting a peak FFT bin of the filled bins having the greatest FFT output; and

characterize the height of the target based on the FFT output in the peak FFT bin.

16. The detection system of claim 9 , wherein the processing module is further configured to:

identify at least one empty bin between two surrounding filled bins and filling the empty bin through linear interpolation such that the empty bin becomes a filled bin with a magnitude value between the magnitude values of the return signals corresponding to the surrounding bins.