US4695156A — Range finding method and apparatus

Claim 1

Independent Claim 246 words

A method for finding the range of a target object, comprising the steps of: (a) viewing the target object from a first perspective, using a camera having a sensor with light-sensitive regions that are disposed in a row having ends, to provide a signal V A (I A ) corresponding to the first perspective, where V A is a voltage proportional to light intensity at a light-sensitive region of the row and I A is an integer corresponding to the distance between the respective light-sensitive region and a predetermined end of the row; (b) viewing the target object from a second perspective, using a camera having a sensor with light-sensitive regions that are disposed in a row having ends, to provide a signal V B (I B ) corresponding to the second perspective, where V B is a voltage proportional to light intensity at a light-sensitive region of the row and I B is an integer corresponding to the distance between the respective light-sensitive region and a predetermined end of the row; (c) finding a disparity function D(I A ) which maps V A (I A ) onto V B (I B ) for every I A in an interval, the interval including a plurality of consecutive integers; (d) using the disparity function D(I A ) to determine the range of the target object at a plurality of points on the target object; and (e) providing electrical signals corresponding to the range to an output device.

Claim 2

Independent Claim 246 words

A method for finding the range of a target object, comprising the steps of: (a) viewing the target object from a first perspective, using a camera having a sensor with light-sensitive regions that are disposed in a row having ends, to provide a signal V A (I A ) corresponding to the first perspective, where V A is a voltage proportional to light intensity at a light-sensitive region of the row and I A is an integer corresponding to the distance between the respective light-sensitive region and a predetermined end of the row; (b) viewing the target object from a second perspective, using a camera having a sensor with light-sensitive regions that are disposed in a row having ends, to provide a signal V B (I B ) corresponding to the second perspective, where V B is a voltage proportional to light intensity at a light-sensitive region of the row and I B is an integer corresponding to the distance between the respective light-sensitive region and a predetermined end of the row; (c) finding a disparity function D(I A ) which maps V A (I A ) onto V B (I B ) for every I A in an interval, the interval including a plurality of consecutive integers; (d) using the disparity function D(I A ) to determine the range of the target object at a plurality of points on the target object; and (e) providing electrical signals corresponding to the range to an output device.

Claim 3

Dependent Claim 145 words

The method of claim 1, wherein step (c) comprises: (f) establishing a disparity matrix in a memory, the disparity matrix having rows corresponding to different values of I B and columns corresponding to different values of I A ; (g) finding a peak in V A (I A ) and a matching peak in V B (I B ); (h) marking the disparity matrix at a row and column corresponding to the I B and I A , respectively, of the peaks in step (g); (i) finding an unmarked column in the disparity matrix where I A differs by one from the column that was marked in the previous step; (j) marking the disparity matrix, in the column found in step (i), at an I B that lies on the disparity function D(I A ); (k) repeating steps (i) and (j) a plurality of times.

Claim 4

Dependent Claim 17 words

The method of claim 2, wherein step (j) comprises finding a relative extremum of a cost functional.

Claim 5

Dependent Claim 37 words

The method of claim 2, wherein step (j) comprises minimizing a cost functional having a term that is a function of the difference between V A (I A ) and V B [I A -D(I A )].

Claim 6

Dependent Claim 43 words

The method of claim 2, wherein step (j) comprises minimizing a cost functional having a term that is a function of the difference between a derivative of V A (I A ) and a derivative of V B [I A -D(I A )].

Claim 7

Dependent Claim 24 words

The method of claim 2, wherein step (j) comprises minimizing a cost functional having a term that is a function of D(I A ).

Claim 8

Dependent Claim 66 words

The method of claim 2, wherein step (j) comprises minimizing a cost functional having a term that is a function of the difference between V A (I A ) and V B [I A -D(I A )], and term that is a function of the difference between a derivative of V A (I A ) and a derivative of V B [I A -D(I A )].

Claim 9

Dependent Claim 75 words

The method of claim 2, wherein step (j) comprises minimizing a cost functional having a term that is a function of the difference between V A (I A ) and V B [I A -D(I A )], a term that is a function of the difference between a derivative of V A (I A ) and a derivative of V[I A -D(I A )], and a term that is a function of D(I A ).

Claim 10

Dependent Claim 23 words

The method of claim 8, wherein the cost functional is ##EQU5## where k 1 , k 2 , and k 3 are constants.

Claim 11

Dependent Claim 32 words

The method of claim 8, further comprising the step of marking the disparity matrix with constraints after step (h) and marking the disparity matrix with constraints after each repetition of step (i).

Claim 12

Dependent Claim 12 words

The method of claim 10, wherein the constraints include a line-of-sight constraint.

Claim 13

Dependent Claim 13 words

The method of claim 10, wherein the constraints include a convex surface constraint.

Claim 14

Dependent Claim 76 words

The method of claim 8, wherein step (a) is conducted using a first camera having a first sensor with light sensitive regions that are disposed in a plurality of first rows, wherein step (b) is conducted using a second camera having a second sensor with light sensitive regions that are disposed in a plurality of second rows, and further comprising the step of repeating steps (f) through (k) for a plurality of first and second rows.

Claim 15

Dependent Claim 76 words

The method of claim 2, wherein step (a) is conducted using a first camera having a first sensor with light sensitive regions that are disposed in a plurality of first rows, wherein step (b) is conducted using a second camera having a second sensor with light sensitive regions that are disposed in a plurality of second rows, and further comprising the step of repeating steps (f) through (k) for a plurality of first and second rows.

Claim 16

Dependent Claim 32 words

The method of claim 2, further comprising the step of marking the disparity matrix with constraints after step (h) and marking the disparity matrix with constraints after each repetition of step (i).

Claim 17

Dependent Claim 147 words

The method of claim 1, wherein step (a) is conducted using a first camera having a first sensor with light sensitive regions that are disposed in a first row, wherein step (b) is conducted using a second camera having a second sensor with light sensitive regions that are disposed in a second row, wherein the first and second cameras are identical and further include lens means for focusing light on the respective sensor, the sensors being disposed in a plane, and wherein step (d) comprises the step of solving, for a plurality of I A , the equation ##EQU6## where Z c is the range, b is half the center-to-center distance between the sensors, f is the focal length of the lens means, I max is the number of light sensitive regions in a row, and L x is the distance between the ends of a row.

Claim 18

Dependent Claim 72 words

The method of claim 16, wherein step (c) comprises finding the relative extremum of a cost functional having a term that is a function of the difference between V A (I A ) and V B [I A -D(I A )], and having a term that is a function of the difference between a derivative of V A (I A ) and a derivative of V B [I A -D(I A )].

Claim 19

Dependent Claim 72 words

The method of claim 1, wherein step (c) comprises finding the relative extremum of a cost functional having a term that is a function of the difference between V A (I A ) and V B [I A -D(I A )], and having a term that is a function of the difference between a derivative of V A (I A ) and a derivative of V B [I A -D(I A 0].

Claim 20

Independent Claim 251 words

An apparatus for finding the range of a target object, comprising: a first camera directed toward the target object to view the target object from a first perspective, the first camera having a first sensor with light-sensitive regions that are disposed in a first row having ends, the first camera providing a signal V A (I A ), where V A is a voltage proportional to light intensity at a light-sensitive region of the first row and I A is an integer corresponding to the distance between the respective light-sensitive region and a predetermined end of the first row; a second camera directed toward the target object to view the target object from a second perspective, the second camera having a second sensor with light-sensitive regions that are disposed in a second row having ends, the second camera providing a signal V B (I B ), where V B is a voltage proportional to light intensity at a light-sensitive region of the second row and I B is an integer corresponding to the distance between the respective light-sensitive region and a predetermined end of the second row; and means for finding a disparity function D(I A ) which maps V A (I A ) onto V B (I B ) for every I A in an interval, the interval including a plurality of consecutive integers, and for using the disparity function D(I A ) to determine the range of the target object at a plurality of points on the target object.

Claim 21

Independent Claim 251 words

An apparatus for finding the range of a target object, comprising: a first camera directed toward the target object to view the target object from a first perspective, the first camera having a first sensor with light-sensitive regions that are disposed in a first row having ends, the first camera providing a signal V A (I A ), where V A is a voltage proportional to light intensity at a light-sensitive region of the first row and I A is an integer corresponding to the distance between the respective light-sensitive region and a predetermined end of the first row; a second camera directed toward the target object to view the target object from a second perspective, the second camera having a second sensor with light-sensitive regions that are disposed in a second row having ends, the second camera providing a signal V B (I B ), where V B is a voltage proportional to light intensity at a light-sensitive region of the second row and I B is an integer corresponding to the distance between the respective light-sensitive region and a predetermined end of the second row; and means for finding a disparity function D(I A ) which maps V A (I A ) onto V B (I B ) for every I A in an interval, the interval including a plurality of consecutive integers, and for using the disparity function D(I A ) to determine the range of the target object at a plurality of points on the target object.

Claim 22

Dependent Claim 45 words

The apparatus of claim 19, wherein said means for finding comprises a memory and means for establishing a disparity matrix in the memory, the disparity matrix having rows corresponding to different values of I B and columns corresponding to different values of I A .

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-09-21	1991-03-23	1991-09-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-09-21	1995-03-23	1995-09-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-09-21	1999-03-23	1999-09-22	$7700.00	Window Closed / Lapsed

Range finding method and apparatus

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