Object detection
AssigneeMitsubishi Electric Corporation
InventorWieslaw Jerzy Szajnowski
Life of this patent
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Abstract
An object ranging system operates by transmitting alternating up and down frequency sweeps which have randomly distributed slopes as a result of random selection of local frequency peaks and valleys according to predetermined probability tables, and determining the beat frequency obtained when combining the transmitted signal with its reflection from an object.
Claims24
1-23. (canceled)
A method of detecting an object, the method comprising transmitting a varying-frequency signal, detecting the reflection of the signal from the object, and determining the range of the object from the difference between the frequencies of the transmitted signal and its reflection, the signal comprising successive portions each with a frequency extending between a local frequency peak and a local frequency valley, wherein:
- signal portions of increasing frequency alternate with signal portions of decreasing frequency;
- and
- each signal portion extends from a start frequency selected according to the end frequency of the preceding signal portion to an end frequency selected at random from a predetermined set of frequencies each having a corresponding set of probabilities, the selection probabilities for each said frequency being dependent on said start frequency and on the slope direction of the preceding signal portion.
Apparatus as claimed in claim 46, including a random number generator, a comparator arrangement for comparing the output of the random number generator with a plurality of predetermined thresholds, and a selector which selects the end frequency of a signal portion in dependence on the relationship between the random number generator output and the thresholds
An apparatus for detecting an object, the apparatus comprising:
- a transmitter operable to generate and transmit a varying-frequency signal;
- a detector operable to detect the reflection of the signal from the object;
- and
- a processor operable to determine the range of the object from the difference between the frequencies of the transmitted signal and its reflection,
- wherein the varying-frequency signal comprises successive portions each with a frequency extending between a local frequency peak and a local frequency valley with signal portions of increasing frequency alternating with signal portions of decreasing frequency, and each signal portion extends from a start frequency selected according to the end frequency of the preceding signal portion to an end frequency selected at random from a predetermined set of frequencies each having a corresponding set of probabilities, the selection probabilities for each said frequency being dependent on said start frequency and on the slope direction of the preceding signal portion.
Dependencies are inferred from the claim text.