Summary of the invention:
The invention provides a kind of LIDAR point cloud method under model line constraint, the homonymous line on the LIDAR point cloud of datum station and survey station to be spliced is formed an overall topological structure by respectively, establishes model straight line collinearity condition equation.
The present invention adopts following technical scheme: a kind of LIDAR point cloud method under model line constraint, it comprises the steps
Steps A: extract homonymous line respectively on the LIDAR point cloud of datum station and survey station to be spliced;
Step B: by the homonymous line in steps A, sets up model straight line of the same name;
Step C: Modling model straight line collinearity condition equation, makes model straight line convergent-divergent to be spliced, rotates and move to and overlap with benchmark model straight line;
Step D: calculate splicing parameter.
Further, in described step B, the method for building up of model straight line is:
(B-1): on the LIDAR point cloud of survey station to be spliced, obtain any straight line l in model straight line, be expressed as: l=[0 M N O 0 M
0n
0o
0], wherein, (M, N, O) and (M
0, N
0, O
0) be respectively the direction vector of l and square vector;
(B-2): according to the method for step (1), the LIDAR point cloud of datum station obtains any straight line l ' in model straight line, is expressed as: l '=[0 M ' N ' O ' 0 M
0' N
0' O
0'], wherein, (M ', N ', O ') and (M
0', N
0', O
0') be respectively the direction vector of l ' and square vector.
Further, described step C comprises the steps
(C-1): Modling model straight line collinearity condition equation, namely spliced model straight line overlaps with the LIDAR point cloud straight line of corresponding datum station
In formula, λ is zooming parameter; I is 4 dimension unit matrixs; Q=[q
1q
2q
3q
4q
01q
02q
03q
04]; 0 is 4 dimension 0 matrixes; q
-1inverse for q;
(C-2): determine to splice initial parameter value
q
1=λ=1,q
2=q
3=q
4=q
01=q
02=q
03=q
04=0;
(C-3): the l ' on formula (C-1) the equation left side is moved on on the right of equation, then launch to obtain
(C-4): formula (C-2) is expanded to once item by Taylor's formula at q and λ:
F
1=F
10+a
11dq
1+a
12dq
2+a
13dq
3+a
14dq
4+a
15dq
01+a
16dq
02+a
17dq
03+a
18dq
04+a
19dλ
F
2=F
20+a
21dq
1+a
22dq
2+a
23dq
3+a
24dq
4+a
25dq
01+a
26q
02+a
27dq
03+a
28dq
04+a
29dλ
F
3=F
30+a
31dq
1+a
32dq
2+a
33dq
3+a
34dq
4+a
35dq
01+a
36dq
02+a
37dq
03+a
38dq
04+a
39dλ
(3)
F
4=F
40+a
41dq
1+a
42dq
2+a
43dq
3+a
44dq
4+a
45dq
01+a
46dq
02+a
47dq
03+a
48dq
04+a
49dλ
F
5=F
50+a
51dq
1+a
52dq
2+a
53dq
3+a
54dq
4+a
55dq
01+a
56dq
02+a
57dq
03+a
58dq
04+a
59dλ
F
6=F
60+a
61dq
1+a
62dq
2+a
63dq
3+a
64dq
4+a
65dq
01+a
66dq
02+a
67dq
03+a
68dq
04+a
69dλ
In formula:
a
11=2Mq
1+2Oq
3-2Nq
4a
12=2Mq
2+2Nq
3+2Oq
4
a
13=2Oq
1+2Nq
2-2Mq
3a
14=-2Nq
1+2Oq
2-2Mq
4
a
15=a
16=a
17=a
18=a
19=0
a
21=2Nq
1-2Oq
2+2Mq
4a
22=-2Nq
2-2Oq
1+2Mq
3
a
23=2Nq
3+2Oq
4+2Mq
2a
24=-2Nq
4+2Oq
3+2Mq
1
a
25=a
26=a
27=a
28=a
29=0
a
31=2Oq
1+2Nq
2-2Mq
3a
32=-2Oq
2+2Nq
1+2Mq
4
a
33=2Nq
4-2Oq
3-2Mq
1a
34=2Oq
4+2Nq
3+2Mq
2
a
35=a
36=a
37=a
38=a
39=0
a
41=2Mq
01+2λM
0q
1-2Nq
04-2λN
0q
4+2Oq
03+2λO
0q
3
a
42=+2Mq
02+2λM
0q
2-2Nq
03+2λN
0q
3+2Oq
04+2λO
0q
4
a
43=-2Mq
03-2λM
0q
3+2Nq
02+2λN
0q
2+2Oq
01+2λO
0q
1
a
44=-2Mq
04-2λM
0q
4-2Nq
01-2λN
0q
1+2Oq
02+2λO
0q
2
a
45=a
11,a
46=a
12,a
47=a
13,a
48=a
14
a
51=2Mq
04+2λM
0q
4+2Nq
01+2λN
0q
1-2Oq
02-2λO
0q
2
a
52=2Mq
03+2λM
0q
3-2Nq
02-2λN
0q
2-2Oq
01-2λO
0q
1
a
53=2Mq
02+2λM
0q
2+2Nq
03+2λN
0q
3+2Oq
04+2λO
0q
4
a
54=2Mq
01+2λM
0q
1-2Nq
04-2λN
0q
4+2Oq
03+2λO
0q
3
a
55=a
21,a
56=a
22,a
57=a
23,a
58=a
24
a
61=-2Mq
03-2λM
0q
3+2Nq
02+2λN
0q
2+2Oq
01+2λO
0q
1
a
62=2Mq
04+2λM
0q
4+2Nq
01+2λN
0q
1-2Oq
02-2λO
0q
2
a
63=-2Mq
01-2λM
0q
1+2Nq
04+2λN
0q
4-2Oq
03-2λO
0q
3
a
64=2Mq
02+2λM
0q
2+2Nq
03+2λN
0q
3+2Oq
04+2λO
0q
4
a
65=a
31,a
66=a
32,a
67=a
33,a
68=a
34
F
10, F
20, F
30, F
40, F
50, F
60the approximate value being respectively q and λ brings the F that formula (C-3) and formula (C-4) obtain into
1~ F
6approximate value; Dq
1, dq
2, dq
3, dq
4, dq
01, dq
02, dq
03, dq
04, d λ is respectively the correction of each splicing parameter.
The present invention has following beneficial effect: the LIDAR point cloud method under model line constraint of the present invention is compared with traditional LIDAR based on straight line point cloud method, can by zooming parameter Unified Solution, give full play to the geometrical constraint of straight line, the geometry intensity of stereoscopic model can be strengthened, thus improve the precision of LIDAR point cloud.
Embodiment:
LIDAR point cloud method under model line constraint of the present invention comprises the steps:
Steps A: extract homonymous line respectively on the LIDAR point cloud of datum station and survey station to be spliced;
Step B: by the homonymous line in steps A, sets up model straight line of the same name;
Step C: Modling model straight line collinearity condition equation, makes model straight line convergent-divergent to be spliced, rotates and move to and overlap with benchmark model straight line;
Step D: calculate splicing parameter.
Wherein: in step B, the method for building up of model straight line is:
(B-1): on the LIDAR point cloud of survey station to be spliced, obtain any straight line l in model straight line, be expressed as: l=[0 M N O 0 M
0n
0o
0], wherein, (M, N, O) and (M
0, N
0, O
0) be respectively the direction vector of l and square vector;
(B-2): according to the method for step (1), the LIDAR point cloud of datum station obtains any straight line l ' in model straight line, is expressed as: l '=[0 M ' N ' O ' 0 M
0' N
0' O
0'], wherein, (M ', N ', O ') and (M
0', N
0', O
0') be respectively the direction vector of l ' and square vector.
Wherein step step C is as follows:
(C-1): Modling model straight line collinearity condition equation, namely spliced model straight line overlaps with the LIDAR point cloud straight line of corresponding datum station:
In formula, λ is zooming parameter; I is 4 dimension unit matrixs; Q=[q
1q
2q
3q
4q
01q
02q
03q
04]; 0 is 4 dimension 0 matrixes; q
-1inverse for q.
(C-2): determine to splice initial parameter value.
q
1=λ=1,q
2=q
3=q
4=q
01=q
02=q
03=q
04=0。
(C-3): the l ' on formula (C-1) the equation left side is moved on on the right of equation, then launch to obtain:
(C-4): formula (C-2) is expanded to once item by Taylor's formula at q and λ:
F
1=F
10+a
11dq
1+a
12dq
2+a
13dq
3+a
14dq
4+a
15dq
01+a
16dq
02+a
17dq
03+a
18dq
04+a
19dλ
F
2=F
20+a
21dq
1+a
22dq
2+a
23dq
3+a
24dq
4+a
25dq
01+a
26q
02+a
27dq
03+a
28dq
04+a
29dλ
F
3=F
30+a
31dq
1+a
32dq
2+a
33dq
3+a
34dq
4+a
35dq
01+a
36dq
02+a
37dq
03+a
38dq
04+a
39dλ
(3)
F
4=F
40+a
41dq
1+a
42dq
2+a
43dq
3+a
44dq
4+a
45dq
01+a
46dq
02+a
47dq
03+a
48dq
04+a
49dλ
F
5=F
50+a
51dq
1+a
52dq
2+a
53dq
3+a
54dq
4+a
55dq
01+a
56dq
02+a
57dq
03+a
58dq
04+a
59dλ
F
6=F
60+a
61dq
1+a
62dq
2+a
63dq
3+a
64dq
4+a
65dq
01+a
66dq
02+a
67dq
03+a
68dq
04+a
69dλ
In formula:
a
11=2Mq
1+2Oq
3-2Nq
4a
12=2Mq
2+2Nq
3+2Oq
4
a
13=2Oq
1+2Nq
2-2Mq
3a
14=-2Nq
1+2Oq
2-2Mq
4
a
15=a
16=a
17=a
18=a
19=0
a
21=2Nq
1-2Oq
2+2Mq
4a
22=-2Nq
2-2Oq
1+2Mq
3
a
23=2Nq
3+2Oq
4+2Mq
2a
24=-2Nq
4+2Oq
3+2Mq
1
a
25=a
26=a
27=a
28=a
29=0
a
31=2Oq
1+2Nq
2-2Mq
3a
32=-2Oq
2+2Nq
1+2Mq
4
a
33=2Nq
4-2Oq
3-2Mq
1a
34=2Oq
4+2Nq
3+2Mq
2
a
35=a
36=a
37=a
38=a
39=0
a
41=2Mq
01+2λM
0q
1-2Nq
04-2λN
0q
4+2Oq
03+2λO
0q
3
a
42=+2Mq
02+2λM
0q
2-2Nq
03+2λN
0q
3+2Oq
04+2λO
0q
4
a
43=-2Mq
03-2λM
0q
3+2Nq
02+2λN
0q
2+2Oq
01+2λO
0q
1
a
44=-2Mq
04-2λM
0q
4-2Nq
01-2λN
0q
1+2Oq
02+2λO
0q
2
a
45=a
11,a
46=a
12,a
47=a
13,a
48=a
14
a
51=2Mq
04+2λM
0q
4+2Nq
01+2λN
0q
1-2Oq
02-2λO
0q
2
a
52=2Mq
03+2λM
0q
3-2Nq
02-2λN
0q
2-2Oq
01-2λO
0q
1
a
53=2Mq
02+2λM
0q
2+2Nq
03+2λN
0q
3+2Oq
04+2λO
0q
4
a
54=2Mq
01+2λM
0q
1-2Nq
04-2λN
0q
4+2Oq
03+2λO
0q
3
a
55=a
21,a
56=a
22,a
57=a
23,a
58=a
24
a
61=-2Mq
03-2λM
0q
3+2Nq
02+2λN
0q
2+2Oq
01+2λO
0q
1
a
62=2Mq
04+2λM
0q
4+2Nq
01+2λN
0q
1-2Oq
02-2λO
0q
2
a
63=-2Mq
01-2λM
0q
1+2Nq
04+2λN
0q
4-2Oq
03-2λO
0q
3
a
64=2Mq
02+2λM
0q
2+2Nq
03+2λN
0q
3+2Oq
04+2λO
0q
4
a
65=a
31,a
66=a
32,a
67=a
33,a
68=a
34
F
10, F
20, F
30, F
40, F
50, F
60the approximate value being respectively q and λ brings the F that formula (C-3) and formula (C-4) obtain into
1~ F
6approximate value; Dq
1, dq
2, dq
3, dq
4, dq
01, dq
02, dq
03, dq
04, d λ is respectively the correction of each splicing parameter.
(C-5): row write error equation and method, normal equation is separated.
V=AX+F (4)
Wherein:
V=[v
1,v
2,v
3,v
4,v
5,v
6]
T
X=[dq
1dq
2dq
3dq
4dq
01dq
02dq
03dq
04dλ]
T
F=[F
10F
20F
30F
40F
50F
60]
T
N is had to homonymous line in hypothesized model straight line, can the error equation of a row formula (4) to often pair of homonymous line.
(C-6): according to the principle of least square:
X=-(A
TA)
-1A
TF (5)
X is the correction of splicing parameter undetermined.
(C-7): upgrade splicing parameter.
By splicing parameter approximate value and the splicing parameter correction sum that calculates of last iteration as new splicing parameter approximate value, when solving the X=[dq obtained
1dq
2dq
3dq
4dq
01dq
02dq
03dq
04d λ]
tbe less than setting 10
-6shi Jixu step (C-7); Otherwise return step (C-3).
(C-8): calculate splicing parameter.
Final splicing parameter is substituted into following formula (C-5), formula (C-6) and formula (C-7), to splicing parameter.
The translation parameters formula of splicing is as follows:
Dx=2(q
1q
02-q
2q
01+q
3q
04-q
4q
03)
Dy=2(q
1q
03-q
2q
04-q
3q
01+q
4q
02) (6)
Dz=2(q
1q
04+q
2q
03-q
3q
02-q
4q
01)
The rotational transformation matrix M formula of splicing is as follows:
ω=-M
23(8)
κ=artan(M
21/Μ
22)
In formula, M
i,j(i=1,2,3, j=1,2,3) representing matrix M
3,3i-th row jth row element.
LIDAR point cloud method under model line constraint of the present invention is described below by a specific embodiment:
LIDAR point cloud is carried out according to certain building object point cloud that the LMS-Z420 series of ground LIDAR equipment of Austrian Riegl company collects, scanner type is pulsed, laser emission frequency is 27000 points per second, range is 2m-1000m, scanning accuracy is 10mm (in 100 meters of distances), sweep velocity is that vertical direction 1-20 line is per second, horizontal direction 0.01 ° ~ 15 ° is per second, scanning angle is vertical direction 0 ° ~ 80 °, horizontal direction 0 ° ~ 360 °, angular resolution is vertical direction 0.002 °, horizontal direction 0.0025 °.From the LIDAR point cloud of datum station and survey station to be spliced, respectively extract 4 straight lines respectively, direction vector and the square vector of datum station homonymous line are as shown in table 1, and direction vector and the square vector of survey station homonymous line subject to registration are as shown in table 2, l
1and l
1', l
2and l
2', l
3and l
3', l
4and l
4' be respectively straight line of the same name.
Table 1 survey station model subject to registration straight line
Table 2 datum station model straight line
According to the model straight line in table 1 and table 2, utilize joining method of the present invention, splicing parameter can be solved: X
s=23.011m, Y
sfor 29.391m, Z
sfor-2.317m,
be 12.593 °, ω is 1.063 °, and κ is 28.898 °, λ=0.9998.Splicing precision is 2.0mm, reaches the requirement of high-precision three-dimensional mapping.
The above is only the preferred embodiment of the present invention, it should be pointed out that for those skilled in the art, can also make some improvement under the premise without departing from the principles of the invention, and these improvement also should be considered as protection scope of the present invention.