US 8,410,978 B2Granted

Shape measurement instrument and shape measurement method

AssigneePanasonic Corporation

InventorsHiroyuki Sakai, Takeshi Fukuda, Takuya Sakamoto, Toru Sato

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Abstract

A shape measurement instrument includes a plurality of transmitters 1 to 4 which radiate signals having different waveforms or phases, receivers 31 to 34 which receive signals reflected from an object O, correlation units 41 to 44 which obtain correlation waveforms between waveforms of the signals received by the receivers 31 to 34, and the signal radiated by a transmitter radiating the received signal of the transmitters 1 to 4, and a shape estimation unit 5 which extracts a quasi-wavefront based on the correlation waveforms obtained by the correlation units 41 to 44 and estimates a shape of the object O based on a relationship between the quasi-wavefront and the object O. As a result, a period of time required to measure an object shape can be significantly reduced.

Claims16

Dependent claims

A shape measurement instrument comprising:

a plurality of transmitters configured to generate signals expressed as an orthogonal function system or a quasi-orthogonal function system, and radiate the signals having different waveforms or phases;
a receiver configured to receive the signal reflected from a target object;
a correlation unit configured to obtain a correlation waveform of a waveform of the signal received by the receiver and the signal radiated by the transmitter radiating the received signal of the plurality of transmitters;
and
a shape estimation unit configured to extract a quasi-wavefront based on a plurality of the correlation waveforms obtained by the correlation unit, and estimate a shape of the target object based on a relationship between the quasi-wavefront and the shape of the target object,
wherein the transmitter has a transmitting antenna configured to transmit the signal,
the receiver has a receiving antenna configured to receive the signal, the receiving antenna being provided at a location different from that of the transmitting antenna,
the location of the transmitting antenna is (2X, 0) and the location of the receiving antenna is (0, 0), a location of a scattering point on a boundary of the target object which contacts an ellipse whose focuses are (2X, 0) and (0, 0) and whose major axis has a length of 2Y is (x, y), and a derivative dY/dX is Y′,
the shape estimation unit converts a location relationship (X, Y) between a time delay and the location of the transmitting antenna to the location (x, y) of the scattering point by:
x
=
(
X
2
+
Y
2
)
⁢
Y
.
-
2
⁢
XY
X
⁢
Y
.
-
Y
⁢
⁢
y
=

Y
2
-
X
2
Y
-
X
⁢
Y
.

⁢
1
-
Y
.
2
(
Expression
⁢
⁢
16
)
thereby estimating the shape of the target object.

58 more elements

A method for measuring a shape using a shape measurement instrument including a plurality of transmitters, a receiver configured to receive a signal reflected from a target object, a correlation unit, and a shape estimation unit, the method comprising the steps of:

(a) radiating signals having different waveforms or phases expressed as an orthogonal function system or a quasi-orthogonal function system by the plurality of transmitters;
(b) receiving the signals reflected from the target object by the receiver;
(c) obtaining a correlation waveform of a waveform of the signal received by the receiver and the signal radiated by the transmitter radiating the received signal of the plurality of transmitters, by the correlation unit;
(d) obtaining extremums of the correlation waveform by the shape estimation unit;
(e) connecting adjacent ones of the extremums to generate a quasi-wavefront by the shape estimation unit;
(f) extracting a true quasi-wavefront from the quasi-wavefront by the shape estimation unit;
and
(g) estimating a shape of the target object from the true quasi-wavefront by the shape estimation unit,
wherein the plurality of transmitters each have a transmitting antenna configured to transmit the signal,
the receiver has a receiving antenna configured to receive the signal, the receiving antenna being provided at a location different from that of the transmitting antenna,
the location of the transmitting antenna is (2X, 0) and the location of the receiving antenna is (0, 0), a location of a scattering point on a boundary of the target object which contacts an ellipse whose focuses are (2X, 0) and (0, 0) and whose major axis has a length of 2Y is (x, y), and a derivative dY/dX is Y′,
in step (g), the following expression:
x
=
(
X
2
+
Y
2
)
⁢
Y
.
-
2
⁢
XY
X
⁢
Y
.
-
Y
⁢
⁢
y
=

Y
2
-
X
2
Y
-
X
⁢
Y
.

⁢
1
-
Y
.
2
(
Expression
⁢
⁢
16
)
is used to estimate the shape of the target object.

61 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/597,875Filed 17 Apr 2008
Priority: JP 2007-11910127 Apr 2007
Published: US 2010/0127916 A127 May 2010
Granted: 2 Apr 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01S 13/89
Radar or analogous systems specially adapted for specific applications: for mapping or imaging
G01S 13/003
Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose…:…
G01S 13/288
Using coded pulses: phase modulated
G01S 13/878
Combinations of radar systems, e.g. primary radar and secondary radar: combination of several spaced transmitters or receivers of known location…