Method and device for measuring distance and speed

• US 6,529,794 B1
• Filed: 01/18/2000
• Issued: 03/04/2003
• Est. Priority Date: 08/22/1997
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Storck, Eckhard, Heide, Patric, Vossiek, Martin
• Primary Examiner(s): Von Buhr, Maria N.
• Assistant Examiner(s): Bahta, Kidest
• Application Number:
  US09/463,052
• Time in Patent Office: 1,141 Days
• Field of Search: 700/171, 700/173, 700/177, 700/160, 700/175, 700/39, 700/40, 702/76, 702/142, 702/196, 702/194
• US Class Current: 700/177
• CPC Class Codes: G01S 13/34 using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
• CPC Class Codes: G01S 13/584 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 7/352 Receivers
• CPC Class Codes: G01S 7/356 involving particularities of FFT processing

Abstract

Signals are emitted with a FMCW sensor system, are received after reflection at targets and are processed to form a measured signal whose frequency spectrum is analyzed. Discrete, equidistant samples are stored and are arranged in a double Hankel matrix in the existing sequence. This matrix is diagonalized with a singular value decomposition, and an approximation is identified taking only the “principle values” into consideration, in order to calculate the frequencies and their amplitudes therefrom according to known methods.

Claims

1. A method for distance and speed measurement, comprising the steps of:

emitting signals that propagate in wave form and, after reflection at targets, registering the emitted signals as measured signals, so that said measured signals comprise a frequency modulation that is dependent on a value or values of a quantity or quantities to be measured;

analyzing a frequency spectrum of the measured signals on the basis of a previously defined plurality of measured values; and

the analyzing occurring by the steps of acquiring said plurality of measured values by sampling the measured signal at equidistant time intervals and storing the measured values in a predetermined sequence,

except for equivalent conversions, diagonalizing a data matrix wherein the measured values are chronologically arranged as a double Hankel matrix according to a SVD method,

determining an approximization of the diagonalized data matrix in that diagonal elements are set equal to zero beginning from a predetermined limit or from a limit calculated from a distribution of the diagonal elements, and

calculating frequencies from remaining diagonal elements.

2. The method according to claim 1 wherein in a further step FBLP coefficients a(n) are calculated as a minimum norm solution, and frequencies f_k are calculated from zero settings z_k=exp(2π

·

i·

f_k) of a polynomial $\underset{m=0}{\overset{L}{\sum <br><br>}}<br><br>a<br><br>\left(m\right)<br><br>z^{L-m}.$

3. The method according to claim 1 wherein in a further step, a state transition matrix is calculated for said approximation determination, and frequencies are calculated from eigenvalues Λ

_kk=exp(2π

·

i·

f_k) of a state transition matrix.

4. An apparatus for distance and speed measurement, comprising:

a signal source for generating signals that propagate in wave-shaped fashion;

a sensor unit for emitting signals and receiving signals reflected by targets;

said sensor unit having an editing unit for editing a measured signal, and wherein the sensor unit emits and receives the signals so that a measured signal has time-stable frequencies from which a quantity to be measured or a plurality of quantities to be measured can be identified; and

an evaluation unit for acquiring a previously defined plurality of measured values by sampling the measured signal at equidistant time intervals and storing these in a predetermined sequence,

except for equivalent conversions, diagonalizing a data matrix in which the measured values are chronologically arranged as a double Hankel matrix according to a SVD method,

determining an approximation of the diagonalized data matrix in that diagonal elements are set equal to zero beginning with a predetermined limit or a limit calculated from a distribution of the diagonal elements, and

calculating frequencies from remaining diagonal elements.

5. The apparatus according to claim 4 wherein the sensor unit provides that the measured signal has time-stable frequencies by

a means for frequency modulation of the signals generated by the signal source; and

a mixer means for mixing a received signal with a current transmission signal.

6. The apparatus according to claim 5 wherein the sensor unit provides the measured signal as time-stable frequencies by a means for generating a reference signal by mixing the signal generated by the signal source with a signal that is delayed in time compared