CN103235846A - Real-time assembly simulation method and device of flexible cable - Google Patents

Abstract

The invention relates to a real-time assembly simulation method and device of a flexible cable. The assembly simulation method comprises building a physical property model of the flexible cable, describing the flexible cable by utilizing linear springs which are arranged between scattering control points on the flexible cable and describing the curve degree of the flexible cable by utilizing rotation angles of curly springs on the scattering control points; obtaining length information of the flexible cable, first position information of a first end point, second position information of a second end point, first tangential direction information at the first end point and second tangential direction information at the second end point; obtaining position information of the scattering control points on the flexible cable according to the first position information, the second position information, the first tangential direction information, the second tangential direction information and the length information of the cable; reversely evaluating position information of control polygon vertices of a Bezier curve according to the position information of the scattering control points; and performing fitting on the flexible cable according to the position information of the control polygon vertices and displaying a position posture of the flexible cable.

Description

Real-time assembly simulation method and the device of flexible cable

Technical field

The present invention relates to mechanical engineering field, relate in particular to real-time assembly simulation method and the device of flexible cable under a kind of virtual environment.

Background technology

Cable is the general name that connects flexible wire or the cable of electric components, electrical equipment or control device in electromechanics or the electric product.As medium and the bridge of signal and energy transmission, cable is widely used in the complex products such as Aeronautics and Astronautics, boats and ships, vehicle in a large number.

Assembling is one of link of most critical in the product manufacturing life cycle, also is the final tache that product obtains overall performance, in case the generation problem, what the time that causes and cost allowance will be big with respect to other early stage link is many.The assembling of flexible cable is the necessary part in the complex product assembling, also is the difficult point that technology establishment and assembling are implemented, and simultaneously, the assembly quality of cable also directly has influence on product machine performance and reliability.

In traditional cable assembling, rely on the making physical prototyping to carry out trial assembly in kind, formulate the reliability and stability of assembly technology and checking assembling by actual experiment, the cost height, the cycle is long, poor reliability.Along with the development of computer software and hardware and virtual reality technology, digital mockup begins to replace physical prototyping and is widely used in the assembling relevant design and manufacture process.Utilize the flexible cable assembly simulation technology under the virtual environment can carry out work such as assembly process planning, assembling checking, thereby reduce cost, in the shortening cycle, improve reliability.

The motion of cable in assembly simulation is a key problem.In the research of flexible article motion simulation, the LoockAchim of German Daimler-Chrysler,

The physical property of cable of having utilized the mass spring model emulation.They adopt wind spring replace being separated by coil tension spring between particle to represent crookedly improving the dynamic bending expression effect of cable, and the spatial shape of different-stiffness cable under the gravity effect of having used this modeling obtained effect preferably.

Thal-mann and Okabe have proposed particIe system technology (particle systems) respectively, this model is regarded the summit of grid as particle, to the simulation of flexible article in two stages, it is acceleration analysis stage and energy spectrometer stage, according to force analysis and energy spectrometer, finally obtain the geometric shape of research object.

The elastic deformation model based on physical attribute that Terzopoulos proposes has been set up the milestone of this research field.This model is considered the distortion of object from the angle of continuum mechanics, think that the variation of deformable body follows Newtonian mechanics and classical elasticity principle, with differential equation of the question resolves itself into, solving equation obtains the space geometry position of each point on the object, thereafter this dynamical thought has all been acted in research, has proposed many analogue techniques.

Liu of Beijing Institute of Technology examines people such as China, Zhao Tao and proposes a kind of modeling of mobile cable rerum natura and movement simulating method based on the thin elastic rod mechanical model.This method is at flexibility and the continuity characteristic of mobile cable, by three cover coordinate systems such as the Frenet coordinate system setting up fixing inertial coordinates system, be connected with the mobile cable infinitesimal and main shaft coordinate systems, and the mobile cable infinitesimal carried out force analysis under the equilibrium state, obtain the Kirchhoff equation of mobile cable under equilibrium state, and then set up mobile cable physical characteristics model.Set up the correlation test verification system at last, by test correlation model and algorithm have been carried out effective checking.Yet this model can't be realized real-time motion simulation at present.

Model in the cable assembly simulation need satisfy real-time, interactive, true form (the fixed length characteristic of cable for example that can reflect simultaneously cable again substantially, will keep certain directivity in the place of stretching out electric connector, the bending curvature of cable can not surpass certain value etc.).Yet above-mentioned model is defectiveness on real-time and authenticity mostly.Generally speaking, the research aspect the domestic and international cable assembly simulation under virtual environment at present still is in initial stage, also has a lot of technical barriers not solve.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of real-time assembly simulation method and device of flexible cable, can express distortion and the morphological feature (fixed length of cable in assembly simulation more truely and accurately, the direction that tip side stretches out, and can realize real-time cable assembly simulation the constraint of bending curvature etc.).

For solving the problems of the technologies described above, embodiments of the invention provide a kind of assembly simulation method of flexible cable, comprising:

Step 1: the physical characteristics model of setting up flexible cable, in the described flexible cable assembling physics characteristic model, described flexible cable is described with the Hookean spring between the discrete reference mark on the described flexible cable, and the degree of crook of described flexible cable adopts the anglec of rotation of the coiled springs on the described discrete reference mark to describe;

Step 2: obtain length of cable information and the primary importance information of first end points and the second place information of second end points of described flexible cable, and the second tangential direction information at the first tangential direction information at the described first end points place and the described second end points place;

Step 3: according to described primary importance information and described second place information and the described first tangential direction information and the described second tangential direction information and length of cable information, find the solution described flexible cable assembling physics characteristic model, obtain the positional information at the discrete reference mark on the described flexible cable;

Step 4: according to the counter positional information of asking the control polygon vertex of Bezier of positional information at discrete reference mark;

Step 5: according to the described flexible cable of positional information match of the control polygon vertex of described Bezier, and show the position and attitude of described flexible cable.

Further, described step 2 comprises:

Step 21: on described first tangential direction and described second tangential direction, it is L that a tangent line operating distance is set respectively;

Step 22: according to described primary importance information and described tangent line operating distance L, obtain the positional information at first reference mark adjacent with described first end points;

Step 23: according to described second place information and described tangent line operating distance L, obtain the positional information at second reference mark adjacent with described second end points;

Step 24: described first reference mark, described second reference mark are connected with straight line, and obtain the positional information at the reference mark between described first reference mark and described second reference mark according to the straight line between described first reference mark, described second reference mark and described first reference mark and described second reference mark.

Further, described step 22 is specially:

$x_2=x*\frac{L}{\sqrt{x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2}}+x_1$

According to formula: Obtain first reference mark adjacent with described first end points

$z_2=z*\frac{L}{\sqrt{x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2}}+z_1$

Positional information; Wherein, the described primary importance information coordinate (x that is first end points ₁, y ₁, z ₁), the positional information at described first reference mark is (x ₂, y ₂, z ₂), the tangential direction vector is that (z), L is tangent line operating distance for x, y;

Described step 23 is specially:

$x_{n-1}=x*\frac{L}{\sqrt{x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2}}+x_n$

According to formula:

Obtain second reference mark adjacent with described second end points

$z_{n-1}=z*\frac{L}{\sqrt{x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">z</figure-callout>}}^2}}+z_n$ Positional information; Wherein, the described second place information coordinate (x that is described second end points _n, y _n, z _n), the positional information at described second reference mark is (x _N-1, y _N-1, z _N-1), the tangential direction vector is that (z), L is tangent line operating distance for x, y, and n is the quantity at the discrete reference mark on the described flexible cable.

Further, described first reference mark, described second reference mark connect with straight line, adopt the described cable that comprises described first end points, described second end points, described first reference mark and described second reference mark of segmentation Bezier match, obtain the flexible cable under the ultimate limit state after the match, the flexible cable under the described ultimate limit state is no more than first preset length.

Further, described step 24 is specially: the positional information that obtains the reference mark between described first reference mark and described second reference mark according to following formula:

$x_i=\frac{i-2}{n-3}*(x_{n-1}-x_2)+x_2$

$y_i=\frac{i-2}{n-3}*(y_{n-1}-y_2)+y_2$

$z_i=\frac{i-2}{n-3}*(z_{n-1}-z_2)+z_2$

The positional information at i reference mark is (x _i, y _i, z _i), n is the quantity at the discrete reference mark on the described flexible cable, (x ₂, y ₂, z ₂) be the positional information at first reference mark, (x _N-1, y _N-1, z _N-1) be the positional information at second reference mark.

Further, when described flexible cable was single cable, described step 24 comprised:

Step 240: according to Hooke's law, calculate the Hookean spring power that Hookean spring produces adjacent reference mark;

Step 241: calculate the coiled springs power that the coiled springs on the reference mark produces the reference mark that links to each other;

Step 242: according to each reference mark suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement at each reference mark in Preset Time;

Step 243: the new positional information that obtains all reference mark according to the displacement at each reference mark, calculate acceleration, speed and the displacement at all reference mark, when satisfying the calculating stop condition, obtain the pose at all reference mark, the acceleration that described calculating stop condition is all reference mark and the maximal value of speed absolute value are less than preset value.

Further, after the position at a reference mark on the cable was fixed, described step 24 comprised:

Step 240: according to Hooke's law, calculate the Hookean spring power that Hookean spring produces adjacent reference mark;

Step 241: calculate the coiled springs power that the coiled springs on the reference mark produces the reference mark that links to each other;

Step 242: according to each reference mark suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement at each reference mark in Preset Time;

Step 243: the new positional information that obtains other reference mark on this cable according to the displacement at each reference mark, calculate acceleration, speed and the displacement at all reference mark, when satisfying the calculating stop condition, obtain the pose at all reference mark, the acceleration that described calculating stop condition is all reference mark and the maximal value of speed absolute value are less than preset value.

Further, described flexible cable is take-off point at the reference mark of bifurcation, and cancels the coiled springs of described take-off point that described step 24 comprises during for the complicated flexible cable of band breakout cable:

Step 201: according to Hooke's law, calculate the Hookean spring power that Hookean spring produces take-off point;

Step 202: calculate the coiled springs power that the coiled springs on the adjacent reference mark produces take-off point;

Step 203: according to take-off point suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement of take-off point in described Preset Time;

Step 204: the positional information that obtains take-off point according to the displacement of described take-off point;

Step 205: according to Hooke's law, the Hookean spring power that Hookean spring produces adjacent reference mark on the Branch Computed cable;

Step 206: the coiled springs power that the coiled springs at reference mark produces the reference mark that links to each other on the Branch Computed cable;

Step 207: according to each reference mark on the breakout cable suffered comprise the stressed of Hookean spring power, coiled springs power, calculate the acceleration at each reference mark, speed and displacement on the breakout cable in Preset Time;

Step 208: the new positional information that obtains all reference mark according to the displacement at each reference mark on the breakout cable, calculate acceleration, speed and the displacement at all reference mark, when satisfying the calculating stop condition, obtain the pose at all reference mark on the breakout cable, the acceleration that described calculating stop condition is all reference mark and the maximal value of speed absolute value are less than preset value;

Step 209: repeating step 201-208, the acceleration at all reference mark on take-off point and breakout cable, speed stop to calculate all less than preset value.

Step 210: the pose that obtains complicated flexible cable according to the pose at all reference mark on the positional information of described take-off point, the breakout cable.

Further, when the length of single breakout cable surpassed preset length, step 24 comprised:

Step 2001: the single cable of overlength is set to an extension spring, calculates the Hookean spring power that this extension spring produces the take-off point that links to each other;

Step 2002: calculate the coiled springs power that the coiled springs on the adjacent reference mark produces take-off point;

Step 2003: according to take-off point suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement of take-off point in described Preset Time;

Step 2004: the positional information that obtains take-off point according to the displacement of described take-off point;

Step 2005: after breakout cable length is replied normally, obtain the pose at all reference mark on this breakout cable according to described step 205-step 209;

Step 2006: the pose that obtains complicated flexible cable according to the pose at all reference mark on the positional information of described take-off point, the breakout cable

Further,

Obtain the Hookean spring power that adjacent two Hookean springs produce the reference mark between these adjacent two Hookean springs successively according to following formula:

$F_{x_i}=(1-L_0/L_{P_{i-1}{P}_i})*K_l*(x_{i-1}-x_i)+(1-L_0/L_{P_{i+1}{P}_i})*K_l*(x_{i+1}-x_i)$

$F_{y_i}=(1-L_0/L_{P_{i-1}{P}_i})*K_l*(y_{i-1}-y_i)+(1-L_0/L_{P_{i+1}{P}_i})*K_l*(y_{i+1}-y_i)$

$F_{z_i}=(1-L_0/L_{P_{i-1}{P}_i})*K_l*(z_{i-1}-z_i)+(1-L_0/L_{P_{i+1}{P}_i})*K_l*(z_{i+1}-z_i)$

Wherein, F _Xi, F _Yi, F _ZiRefer to stressed on three directions in i reference mark, L ₀,

Refer to P respectively _iAnd P _I-1The former length of cable segment between the reference mark and the present physical length of cable segment,

L ₀=L/(n-1)、 $L_{P_{i-1}{P}_i}=\sqrt{{(x_{i-1}-x_i)}^2+{(y_{i-1}-y_i)}^2+{(z_{i-1}-z_i)}^2},$ L is single cable length, K _lRefer to the drawing coefficient of Hookean spring, x _i, y _i, z _iIt then is the three-dimensional coordinate at i reference mark.

Further, calculate the coiled springs power that the coiled springs between per five successive control points produces the middle reference mark in described five successive control points according to following formula:

$\stackrel{\&RightArrow;}{F_{\mathrm{\&theta;}}}=K_{\mathrm{\&theta;}}*\stackrel{\&RightArrow;}{{\mathrm{\&theta;}}_1}+K_{\mathrm{\&theta;}}*\stackrel{\&RightArrow;}{{\mathrm{\&theta;}}_2}$

Wherein, ${\mathrm{\&theta;}}_1=\arccos \left(\frac{\stackrel{\&RightArrow;}{P_{i+2}{P}_{i+1}}\&CenterDot;\stackrel{\&RightArrow;}{P_{i+1}{P}_i}}{L_{P_i,P_{i+1}}\&times;L_{P_{i+1,i+2}}}\right),$ ${\mathrm{\&theta;}}_2=\arccos \left(\frac{\stackrel{\&RightArrow;}{P_{i-2}{P}_{i-1}}\&CenterDot;\stackrel{\&RightArrow;}{P_{i-1}{P}_i}}{L_{P_i,P_{i-1}}\&times;L_{P_{i-1,i-2}}}\right),$

Refer to vector

With

Do dot product, Refer to a P _iAnd P _I+1Between distance.

Further, calculate acceleration, speed and the displacement at the reference mark in Preset Time according to following formula:

$\left\{\begin{array}{c}a=\frac{F_l+F_{\mathrm{\&theta;}}+G-K_d*v_0}{M}\\ v=v_0+a*t\\ s=s_0+v*t\end{array}\right.$

Wherein, a refers to reference mark constant acceleration in described preset time t, F _lRefer to the Hookean spring power that the reference mark is subjected to, F _θRefer to the coiled springs power that the reference mark is subjected to, G refers to the gravity at reference mark, K _dRefer to the ratio of damping of reference mark in motion process, v, v ₀Be respectively the reference mark through after the preset time t, before speed, s, s ₀Be respectively the reference mark through after the preset time t, before displacement.

Further, step 4 comprises:

Select 4 reference mark, obtain per two adjacent reference mark in described 4 reference mark by following formula

$x_{i,i+1}=\frac{1}{2}*(P_{x_i}+P_{x_{i+1}})$

Mid point A, B, C: $y_{i,i+1}=\frac{1}{2}*(P_{y_i}+P_{y_{i+1}})$

$z_{i,i+1}=\frac{1}{2}*(P_{z_i}+P_{z_{i+1}})$

Wherein, x _{I, i+1}, y, _{I, i+1}z _{I, i+1}Refer to adjacent two reference mark P respectively _i, P _I+1The three-dimensional coordinate of line mid point;

Adjacent described mid point is connected acquisition line segment AB, BC, and with on parallel line segment ab, the cd that moves to through two reference mark, centre in described 4 reference mark of line segment AB, BC, and described some A is overlapping with some a, described some C is overlapping with some d, obtain polygonal six summits, the coordinate of some a uses following formula to try to achieve:

$\left\{\begin{array}{c}{a}_x=(B_x-A_x)*K+P_{2x}\\ a_y=(B_y-A_y)*K+P_{2y}\\ a_z=(B_z-A_z)*K+P_{2z}\end{array}\right.$

Wherein $K=-\frac{(B_x-A_x)*(P_{2x}-A_x)+(B_y-A_y)*(P_{2y}-A_y)+(B_z-A_z)*(P_{2z}-A_z)}{{(B_x-A_x)}^2+{(B_y-A_y)}^2+{(B_z-A_z)}^2},$ In like manner, the coordinate on b, c, polygonal summit, d reference mark also can be obtained;

Further, described segmentation Bezier refers to:

$P_i\left(u\right)=\left[\begin{array}{ccc}{u}^2& \mathrm{<figure-callout\; id="1"\; label="u"\; filenames="HDA00003030947200012.png,HDA00003030947200022.png"\; state="\{\{state\}\}">u</figure-callout>}& 1\end{array}\right]\left[\begin{array}{ccc}1& -2& 1\\ -2& 2& 0\\ 1& 0& 0\end{array}\right]\left[\begin{array}{c}{V}_i\\ V_{i+1}\\ V_{i+2}\end{array}\right]$

$\begin{array}{cc}={(1-u)}^2{V}_i+2u(1-u)*V_{i+1}+{\mathrm{<figure-callout\; id="2"\; label="u"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">u</figure-callout>}}^2*V_{i+2}& u\&Element;\left[\mathrm{0,1}\right]\end{array}$

Wherein, P _iRefer to i cable segment, V _i, V _I+1, V _I+2Refer to the three-dimensional coordinate of polygon vertex on i the cable segment, u is parameter, u ∈ [0,1].Adopt the Bezier match to control polygonal summit, obtain the attitude of flexible cable.

The present invention also provides a kind of assembly simulation device of flexible cable, comprising:

Model building module, be used for setting up the physical characteristics model of flexible cable, in the described flexible cable assembling physics characteristic model, described flexible cable is described with the Hookean spring between the discrete reference mark on the described flexible cable, and the degree of crook of described flexible cable adopts the anglec of rotation of the coiled springs on the described discrete reference mark to describe;

Acquisition module, be used for obtaining length information and the primary importance information of first end points and the second place information of second end points of described flexible cable, and the second tangential direction information at the first tangential direction information at the described first end points place and the described second end points place;

The model solution module, length information according to described primary importance information and described second place information and the described first tangential direction information and the described second tangential direction information and cable, find the solution described flexible cable assembling physics characteristic model, obtain the positional information at the discrete reference mark on the described flexible cable, utilize the counter positional information of asking the control polygon vertex of Bezier of positional information at discrete reference mark;

The motion simulation module is used for the described flexible cable of positional information match according to described control polygon vertex, and shows the position and attitude of described flexible cable.

The invention has the beneficial effects as follows: can more accurately express the accuracy of complicated flexible cable assembling, and can realize the real-time assembly simulation of complicated flexible cable under the virtual environment.

Description of drawings

Fig. 1 is the schematic flow sheet of the assembly simulation method of flexible cable of the present invention;

Fig. 2 sets up synoptic diagram for cable physical model in the example of the present invention;

Fig. 3 is for representing the synoptic diagram of complicated cable with discrete reference mark in the example of the present invention;

Fig. 4 in the example of the present invention at the synoptic diagram of the tangential direction of first end points, second end points;

Fig. 5 is for arranging the synoptic diagram of reference mark initial value in the example of the present invention;

Fig. 6 is subjected to the synoptic diagram of Hookean spring power for cable reference mark in the example of the present invention;

Fig. 7 is subjected to the synoptic diagram of coiled springs power for cable reference mark in the example of the present invention;

Fig. 8 is the stressed synoptic diagram of take-off point in the complicated cable physical model in the example of the present invention;

The processing synoptic diagram of Fig. 9 after for certain branch's overlength in the complicated cable in the example of the present invention;

Figure 10 is for adopting the synoptic diagram of segmentation Bezier match cable;

Figure 11 is the schematic flow sheet of finding the solution the single cable pose.

Embodiment

Below in conjunction with accompanying drawing structure of the present invention and principle are elaborated, illustrated embodiment only is used for explaining the present invention, is not to limit protection scope of the present invention with this.

As shown in Figure 1, embodiments of the invention provide a kind of assembly simulation method of flexible cable, comprising: a kind of assembly simulation method of flexible cable comprises:

Step 1: the physical characteristics model of setting up flexible cable, in the described flexible cable assembling physics characteristic model, described flexible cable is described with the Hookean spring between the discrete reference mark on the described flexible cable, and the degree of crook of described flexible cable adopts the anglec of rotation of the coiled springs on the described discrete reference mark to describe;

Step 2: obtain length of cable information and the primary importance information of first end points and the second place information of second end points of described flexible cable, and the second tangential direction information at the first tangential direction information at the described first end points place and the described second end points place;

Step 3: according to described primary importance information and described second place information and the described first tangential direction information and the described second tangential direction information and length of cable information, find the solution described flexible cable assembling physics characteristic model, obtain the positional information at the discrete reference mark on the described flexible cable;

Step 4: according to the counter positional information of asking the control polygon vertex of Bezier of positional information at discrete reference mark;

Step 5: according to the described flexible cable of positional information match at described discrete reference mark, and show the position and attitude of described flexible cable.

By setting up the physical characteristics model of flexible cable, find the solution described physical characteristics model and carry out the assembling motion simulation of flexible cable according to this solving result, thereby realized the assembling motion simulation process of flexible cable, can more accurately express the accuracy of cable assembling by simulation process.

Shown in Fig. 2,3,4, with all reference mark numberings 1,2...n, the reference mark is provided with coiled springs A, Hookean spring B between the reference mark represents flexible cable, on described first tangential direction 21 and described second tangential direction 22, it is L that a tangent line operating distance is set respectively, and this tangent line operating distance L is the tangent line operating distance of stretching out the certain-length that the end points place of electric connector 24 arranges at cable 23, make first end points and the second end points place cable keep certain tangential direction

Described step 2 comprises:

Step 21: on described first tangential direction 21 and described second tangential direction 22, it is L that a tangent line operating distance is set respectively;

Step 22: according to described primary importance information and described tangent line operating distance L, obtain the positional information at first reference mark adjacent with described first end points;

Step 23: according to described second place information and described tangent line operating distance L, obtain the positional information at second reference mark adjacent with described second end points;

Step 24: described first reference mark, described second reference mark are connected with straight line, and obtain the positional information at the reference mark between described first reference mark and described second reference mark according to described first reference mark, described second reference mark.

Wherein, described step 22 is specially:

$x_2=x*\frac{L}{\sqrt{x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">z</figure-callout>}}^2}}+x_1$

According to formula: Obtain (namely being numbered 1 control with described first end points

${\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">z</figure-callout>}}_2=z*\frac{L}{\sqrt{x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">z</figure-callout>}}^2}}+{\mathrm{<figure-callout\; id="1"\; label="z"\; filenames="HDA00003030947200012.png,HDA00003030947200022.png"\; state="\{\{state\}\}">z</figure-callout>}}_1$ Point processed) positional information at adjacent first reference mark (namely being numbered 2 reference mark); Wherein, the described primary importance information coordinate (x that is first end points ₁, y ₁, z ₁), the positional information at described first reference mark is (x ₂, y ₂, z ₂), the tangential direction vector is that (z), L is tangent line operating distance for x, y;

Described step 23 is specially:

$x_{n-1}=x*\frac{L}{\sqrt{x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">z</figure-callout>}}^2}}+x_n$

According to formula:

Obtain (namely being numbered the control of n with described second end points

$z_{n-1}=z*\frac{L}{\sqrt{x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">z</figure-callout>}}^2}}+z_n$

Point processed) positional information at adjacent second reference mark (namely being numbered the reference mark of n-1); Wherein, the described second place information coordinate (x that is described second end points _n, y _n, z _n), the positional information at described second reference mark is (x _N-1, y _N-1, z _N-1), the tangential direction vector is that (z), L is tangent line operating distance for x, y, and n is the quantity at the discrete reference mark on the described flexible cable.

At this moment, can carry out the cable overlength detects, described first reference mark, described second reference mark connect with straight line, adopt the described cable that comprises described first end points, described second end points, described first reference mark and described second reference mark of segmentation Bezier match, obtain the flexible cable under the ultimate limit state after the match, flexible cable under the described ultimate limit state is no more than first preset length, and the cable that is no more than first preset length meets reality, otherwise does not meet reality.

Described step 24 is specially: the positional information that obtains the reference mark between described first reference mark and described second reference mark according to following formula:

$x_i=\frac{i-2}{n-3}*(x_{n-1}-x_2)+x_2$

$y_i=\frac{i-2}{n-3}*(y_{n-1}-y_2)+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}_2$

$z_i=\frac{i-2}{n-3}*(z_{n-1}-z_2)+{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">z</figure-callout>}}_2$

The positional information at i reference mark is (x _i, y _i, z _i), n is the quantity at the discrete reference mark on the described flexible cable.

As shown in Figure 5, with No. 2, the connection of n-1 reference mark employing straight line,

Then will be numbered 3, the reference mark of 4...n-2 is evenly distributed on the straight-line segment, obtains being numbered the reference mark positional information of i according to following formula:

$x_i=\frac{i-2}{n-3}*(x_{n-1}-x_2)+x_2$

$y_i=\frac{i-2}{n-3}*(y_{n-1}-y_2)+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">y</figure-callout>}}_2$

$z_i=\frac{i-2}{n-3}*(z_{n-1}-z_2)+{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">z</figure-callout>}}_2$

Cable physical characteristics model solution described in the step 3 refers to, arrive the positional information at all reference mark of n according to numbering on the cable that obtains in the step 21, stressed according to the Hookean spring that the Hookean spring between the described cable of step 1 reference mark calculates between the reference mark, stressed according to the coiled springs that the coiled springs of installing on each reference mark is calculated between the reference mark, obtain the stressed of each reference mark, then according to stressing conditions, provide a small time increment t, calculate acceleration, speed and displacement that all reference mark produce in the time at t.1 stressed to the cycle calculations at all reference mark of n by numbering, obtain the positional information that the stressed and speed in all reference mark is 0 moment reference mark, this moment, the position at all reference mark was the pose of cable.

If certain reference mark is in and is limited location status on the cable, then the position at this reference mark can not change along with the displacement that produces in the time at t in above-mentioned computation process, but still can produce the effect of Hookean spring power and coiled springs power to other reference mark.

In complicated cable motion solution procedure, cable is applied the constant restriction of length, by drawing coefficient and the complicated cable overlength special setting afterwards that limits its Hookean spring, make cable in motion process, keep length constant substantially, described special setting refers to as shown in Figure 9, reference mark in the cable of overlength part is removed, only keep a Hookean spring, calculate it to the effect of the Hookean spring power of sub-to-point generation, thereby guarantee not overlength of cable

The concrete operations step is by following realization:

When described flexible cable was single cable, described step 24 comprised:

Step 240: according to Hooke's law, calculate the Hookean spring power that Hookean spring produces adjacent reference mark;

Step 241: calculate the coiled springs power that the coiled springs on the reference mark produces the reference mark that links to each other;

Step 242: according to each reference mark suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement at each reference mark in Preset Time;

Step 243: the new positional information that obtains all reference mark according to the displacement at each reference mark, calculate acceleration, speed and the displacement at all reference mark, when satisfying the calculating stop condition, obtain the pose at all reference mark, the acceleration that described calculating stop condition is all reference mark and the maximal value of speed absolute value are less than preset value.

Do not calculate stop condition if do not satisfy, then continue the reposition according to step 240,241,242 cycle calculations reference mark, until satisfying described calculating stop condition, stop to calculate, obtain the pose at all reference mark.

After the position at a reference mark on the cable was fixed, described step 24 comprised:

Step 240: according to Hooke's law, calculate the Hookean spring power that Hookean spring produces adjacent reference mark;

Step 241: calculate the coiled springs power that the coiled springs on the reference mark produces the reference mark that links to each other;

Step 242: according to each reference mark suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement at each reference mark in Preset Time;

Step 243: the new positional information that obtains other reference mark on this cable according to the displacement at each reference mark, calculate acceleration, speed and the displacement at all reference mark, when satisfying the calculating stop condition, obtain the pose at all reference mark, the acceleration that described calculating stop condition is all reference mark and the maximal value of speed absolute value are less than preset value.

Described flexible cable is take-off point at the reference mark of bifurcation, and cancels the coiled springs of described take-off point that described step 24 comprises during for the complicated flexible cable of band breakout cable:

Step 201: according to Hooke's law, calculate the Hookean spring power that Hookean spring produces take-off point;

Step 202: calculate the coiled springs power that the coiled springs on the adjacent reference mark produces take-off point;

Step 203: according to take-off point suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement of take-off point in described Preset Time;

Step 204: the positional information that obtains take-off point according to the displacement of described take-off point;

Step 205: according to Hooke's law, the Hookean spring power that Hookean spring produces adjacent reference mark on the Branch Computed cable;

Step 206: the coiled springs power that the coiled springs at reference mark produces the reference mark that links to each other on the Branch Computed cable;

Step 207: according to each reference mark on the breakout cable suffered comprise the stressed of Hookean spring power, coiled springs power, calculate the acceleration at each reference mark, speed and displacement on the breakout cable in Preset Time;

Step 208: the new positional information that obtains all reference mark according to the displacement at each reference mark on the breakout cable, calculate acceleration, speed and the displacement at all reference mark, when satisfying the calculating stop condition, obtain the pose at all reference mark on the breakout cable, the acceleration that described calculating stop condition is all reference mark and the maximal value of speed absolute value are less than preset value;

Step 209: repeating step 201-208, the acceleration at all reference mark on take-off point and breakout cable, speed stop to calculate all less than preset value.

Step 210: the pose that obtains complicated flexible cable according to the pose at all reference mark on the positional information of described take-off point, the breakout cable.

As shown in Figure 8, the place arranges Hookean spring at take-off point, the coiled springs at cancellation take-off point place, according to step 201,202, the acceleration at 203 Branch Computeds point place, speed and displacement, after obtaining the reposition of take-off point according to displacement, the cable segment (OA as shown in the figure between per two take-off points (comprising end points) that link to each other by Hookean spring, OB, the OC section), calculate the new pose of this cable segment according to step 204, repeating step 201,202,203, acceleration until this take-off point, velocity amplitude is less than a certain specific small value (for example 0.01), obtains the position of take-off point and then obtains the pose of complicated cable.

Wherein, the restriction of specific position, reference mark refers in cycle calculations reference mark speed and displacement on the described cable, the reference mark that is applied in the position restriction is adopted the constraint of invariant position, but still the reference mark that links to each other is produced the effect of power, make other reference mark produce new displacement, until reaching the calculating stop condition, obtain the cable pose.

Wherein, described during to the motion of complicated cable the constant substantially restriction of length refer to:

1) suitable drawing coefficient is set, the drawing coefficient of Hookean spring is set to can be with the control of the error between cable post exercise length and the former length of cable within 5% between 1.5～2;

2) after the complicated cable overlength, wherein single cable is set to a big extension spring (as shown in Figure 9, reference mark in the middle of wherein OC section cable is cancelled, OC section head and the tail reference mark is connected with an extension spring), calculate this spring to the effect of the power of 7 continuous described take-off points generations, direction is along OC, and the single cable that reference mark is therewith linked to each other according to 7 described methods is carried out pose and calculated again.

In the practical application, whether the acceleration that described calculating stop condition is all reference mark and the maximal value of speed be less than a small value (for example 0.01), detailed process is as follows: will number from the acceleration at all reference mark of 1 to n and the maximal value of speed absolute value and choose, with this value and above-mentioned small value (for example 0.01) relatively, if less than this small value, then calculate and stop, otherwise reference mark acceleration, speed, calculation of displacement are carried out in circulation, calculate stop condition until satisfying, obtain the position at all reference mark.

When the length of single breakout cable surpassed preset length, step 24 comprised:

Step 2001: the single cable of overlength is set to an extension spring, calculates the Hookean spring power that this extension spring produces the take-off point that links to each other;

Step 2002: calculate the coiled springs power that the coiled springs on the adjacent reference mark produces take-off point;

Step 2003: according to take-off point suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement of take-off point in described Preset Time;

Step 2004: the positional information that obtains take-off point according to the displacement of described take-off point;

Step 2005: after breakout cable length is replied normally, obtain the pose at all reference mark on this breakout cable according to described step 205-step 209

Step 2006: the pose that obtains complicated flexible cable according to the pose at all reference mark on the positional information of described take-off point, the breakout cable.

As shown in Figure 6, in the present embodiment, obtain the Hookean spring power that adjacent two Hookean springs produce the reference mark between these adjacent two Hookean springs successively according to following formula:

$F_{x_i}=(1-L_0/L_{P_{i-1}{P}_i})*K_l*(x_{i-1}-x_i)+(1-L_0/L_{P_{i+1}{P}_i})*K_l*(x_{i+1}-x_i)$

$F_{y_i}=(1-L_0/L_{P_{i-1}{P}_i})*K_l*(y_{i-1}-y_i)+(1-L_0/L_{P_{i+1}{P}_i})*K_l*(y_{i+1}-y_i)$

$F_{z_i}=(1-L_0/L_{P_{i-1}{P}_i})*K_l*(z_{i-1}-z_i)+(1-L_0/L_{P_{i+1}{P}_i})*K_l*(z_{i+1}-z_i)$

Wherein, F _Xi, F _Yi, F _ZiRefer to stressed on three directions in i reference mark, L ₀, Refer to P respectively _iAnd P _I-1The former length of cable segment between the reference mark and the present physical length of cable segment,

L ₀=L/(n-1)、 $L_{P_{i-1}{P}_i}=\sqrt{{(x_{i-1}-x_i)}^2+{(y_{i-1}-y_i)}^2+{(z_{i-1}-z_i)}^2},$ L is single cable length, K _lRefer to the drawing coefficient of Hookean spring, x _i, y _i, z _iIt then is the three-dimensional coordinate at i reference mark.

Among one embodiment, begin to obtain the Hookean spring power that Hookean spring produces middle reference mark between these three reference mark according to per three the successive control points of above-mentioned formula till the reference mark of numbering n from numbering 1 reference mark.

In the present embodiment, calculate the coiled springs power that the coiled springs between per five successive control points produces the middle reference mark in described five successive control points according to following formula:

$\stackrel{\&RightArrow;}{F_{\mathrm{\&theta;}}}=K_{\mathrm{\&theta;}}*\stackrel{\&RightArrow;}{{\mathrm{\&theta;}}_1}+K_{\mathrm{\&theta;}}*\stackrel{\&RightArrow;}{{\mathrm{\&theta;}}_2}$

Wherein, ${\mathrm{\&theta;}}_1=\arccos \left(\frac{\stackrel{\&RightArrow;}{P_{i+2}{P}_{i+1}}\&CenterDot;\stackrel{\&RightArrow;}{P_{i+1}{P}_i}}{L_{P_i,P_{i+1}}\&times;L_{P_{i+1,i+2}}}\right),$ ${\mathrm{\&theta;}}_2=\arccos \left(\frac{\stackrel{\&RightArrow;}{P_{i-2}{P}_{i-1}}\&CenterDot;\stackrel{\&RightArrow;}{P_{i-1}{P}_i}}{L_{P_i,P_{i-1}}\&times;L_{P_{i-1,i-2}}}\right),$

Refer to vector

With Do dot product,

Refer to a P _iAnd P _I+1Between distance.

As shown in Figure 7, begin till the reference mark of numbering n from numbering 1 reference mark, per five successive control points are obtained between these five reference mark coiled springs to the coiled springs power of middle reference mark generation according to above-mentioned formula.

In the present embodiment, calculate acceleration, speed and the displacement at the reference mark in Preset Time according to following formula:

$\left\{\begin{array}{c}a=\frac{F_l+F_{\mathrm{\&theta;}}+G-K_d*v_0}{M}\\ v=v_0+a*t\\ s=s_0+v*t\end{array}\right.$

Wherein, a refers to reference mark constant acceleration in described preset time t, F _lRefer to the Hookean spring power that the reference mark is subjected to, F _θRefer to the coiled springs power that the reference mark is subjected to, G refers to the gravity at reference mark, K _dRefer to the ratio of damping of reference mark in motion process, v, v ₀Be respectively the reference mark through after the preset time t, before speed, s, s ₀Be respectively the reference mark through after the preset time t, before displacement.

The external force that in above-mentioned steps all reference mark is subjected to is calculated, add self gravity and the reference mark because the damping force that motion produces obtains the bonding force at all reference mark, a given small time increment t(hypothesis t=0.01s), calculate acceleration, speed and the displacement in the time at t according to the suffered occlusometer in Newton second law, kinematical equation and reference mark, described Newton second law, kinematical equation refer to following formula: $\left\{\begin{array}{c}a=\frac{F_l+F_{\mathrm{\&theta;}}+G-K_d*v_0}{M}\\ v=v_0+a*t\\ s=s_0+v*t\end{array}\right.$

As shown in figure 11, in the practical application, described first reference mark, described second reference mark are connected with straight line, and according to the length L of the straight line between described first reference mark, described second reference mark and described first reference mark and described second reference mark _dObtain the particular flow sheet of the positional information at the reference mark between described first reference mark and described second reference mark, comprising:

Give n-1 section cable segment according to given single cable length average mark;

Obtain the positional information (if the first step is then got initial value, if not the result of calculation of then getting previous step) at all reference mark;

Calculate acceleration, speed and the displacement at all reference mark;

Obtain acceleration in all reference mark and the maximal value of speed;

Judge whether this maximal value arrives the calculating stop condition, if stop to calculate, if not then all new positions of arrival, reference mark are carried out acceleration, speed and displacement calculating again, until reaching the calculating stop condition.

Complicated flexible cable for band branch, as shown in Figure 8, the complicated cable of band branch is divided for by OA, OB, three sections single cable of OC are formed, in take-off point O place cancellation coiled springs, try to achieve OA, OB, the Hookean spring power that the reference mark that links to each other with take-off point on three sections single cable of OC produces O, try to achieve the acceleration of take-off point O in small time increment t according to step 33 again, speed and displacement, try to achieve the reposition of take-off point O, again to OA, OB, three sections single cable of OC are calculated the pose of three single cable, whether the absolute value of judging the acceleration of take-off point this moment and speed is less than given small value (for example 0.01), calculate if then stop, obtain the pose of complicated cable, otherwise continue cycle calculations until satisfying stop condition, obtain the pose of complicated cable.

In the present embodiment, step 4 comprises:

Select 4 reference mark, obtain per two adjacent reference mark in described 4 reference mark by following formula

$x_{i,i+1}=\frac{1}{2}*(P_{x_i}+P_{x_{i+1}})$

Mid point A, B, C: $y_{i,i+1}=\frac{1}{2}*(P_{y_i}+P_{y_{i+1}})$

$z_{i,i+1}=\frac{1}{2}*(P_{z_i}+P_{z_{i+1}})$

Wherein, x _{I, i+1}, y, _{I, i+1}z _{I, i+1}Refer to adjacent two reference mark P respectively _i, P _I+1The three-dimensional coordinate of line mid point;

Adjacent described mid point is connected acquisition line segment AB, BC, and with on parallel line segment ab, the cd that moves to through two reference mark, centre in described 4 reference mark of line segment AB, BC, and described some A is overlapping with some a, described some C is overlapping with some d, obtain polygonal six summits, the coordinate of some a uses following formula to try to achieve:

$\left\{\begin{array}{c}{a}_x=(B_x-A_x)*K+P_{2x}\\ a_y=(B_y-A_y)*K+P_{2y}\\ a_z=(B_z-A_z)*K+P_{2z}\end{array}\right.$

Wherein $K=-\frac{(B_x-A_x)*(P_{2x}-A_x)+(B_y-A_y)*(P_{2y}-A_y)+(B_z-A_z)*(P_{2z}-A_z)}{{(B_x-A_x)}^2+{(B_v-A_v)}^2+{(B_z-A_z)}^2},$ In like manner, the coordinate on b, c, polygonal summit, d reference mark also can be obtained; Above-mentioned six reference mark P ₁, a, b, c, d, P ₂Be the control polygon vertex of segmentation Bezier, adopt the match of segmentation Bezier to control polygonal summit, obtain the attitude of flexible cable.

As shown in figure 10, in concrete the application,

Be example with four reference mark, P ₁, P ₂, P ₃, P ₄Be the reference mark on the cable that obtains by step 24, these four reference mark are coupled together mid point A, B, the C of the line segment that obtains per two continuous reference mark, the described line segment mid point that obtains is to calculate by following formula:

$x_{i,i+1}=\frac{1}{2}*(P_{x_i}+P_{x_{i+1}})$

$y_{i,i+1}=\frac{1}{2}*(P_{y_i}+P_{y_{i+1}})$

$z_{i,i+1}=\frac{1}{2}*(P_{z_i}+P_{z_{i+1}})$

Wherein, x _{I, i+1}, y, _{I, i+1}z _{I, i+1}Refer to a P respectively _i, P _I+1The three-dimensional coordinate of line mid point;

Connect AB and BC with these two parallel moving to through P of line segment ₂, P ₃The position at two reference mark, A moves to a, and C moves to d, obtains P ₁, a, b, c, d, P ₄Polygonal six summits, reference mark;

Described line segment AB is moved to through a P ₂Line segment ab refer to, the coordinate of some a uses following formula to try to achieve:

$\left\{\begin{array}{c}{a}_x=(B_x-A_x)*K+P_{2x}\\ a_y=(B_y-A_y)*K+P_{2y}\\ a_z=(B_z-A_z)*K+P_{2z}\end{array}\right.$

Wherein $K=-\frac{(B_x-A_x)*(P_{2x}-A_x)+(B_y-A_y)*(P_{2y}-A_y)+(B_z-A_z)*(P_{2z}-A_z)}{{(B_x-A_x)}^2+{(B_y-A_y)}^2+{(B_z-A_z)}^2},$ In like manner, the coordinate of some b, c, d also can be obtained, and like this, polygonal six summits are under control;

Simulate the cable pose according to the segmentation Bezier, described segmentation Bezier refers to:

$P_i\left(u\right)=\left[\begin{array}{ccc}{u}^2& \mathrm{<figure-callout\; id="1"\; label="u"\; filenames="HDA00003030947200012.png,HDA00003030947200022.png"\; state="\{\{state\}\}">u</figure-callout>}& 1\end{array}\right]\left[\begin{array}{ccc}1& -2& 1\\ -2& 2& 0\\ 1& 0& 0\end{array}\right]\left[\begin{array}{c}{V}_i\\ V_{i+1}\\ V_{i+2}\end{array}\right]$

$\begin{array}{cc}={(1-u)}^2{V}_i+2u(1-u)*V_{i+1}+{\mathrm{<figure-callout\; id="2"\; label="u"\; filenames="HDA00003030947200022.png,HDA00003030947200023.png"\; state="\{\{state\}\}">u</figure-callout>}}^2*V_{i+2}& u\&Element;\left[\mathrm{0,1}\right]\end{array}$

Wherein, P _iRefer to i cable segment, V _i, V _I+1, V _I+2Refer to the three-dimensional coordinate of three control polygon vertexs on i the cable segment, u is parameter, u ∈ [0,1].Obtain one section Bezier in per three summit substitution formulas, connect the attitude that can obtain the whole piece cable.

The present invention also provides a kind of assembly simulation device of flexible cable, comprising:

Model building module, be used for setting up the physical characteristics model of flexible cable, in the described flexible cable assembling physics characteristic model, described flexible cable is described with the Hookean spring between the discrete reference mark on the described flexible cable, and the degree of crook of described flexible cable adopts the anglec of rotation of the coiled springs on the described discrete reference mark to describe;

Acquisition module, for the primary importance information of first end points that obtains described flexible cable and the second place information of second end points, and the second tangential direction information at the first tangential direction information at the described first end points place and the described second end points place;

The model solution module, according to described primary importance information and described second place information and the described first tangential direction information and the described second tangential direction information, find the solution described flexible cable assembling physics characteristic model, obtain the positional information at the discrete reference mark on the described flexible cable, utilize the counter positional information of asking the control polygon vertex of Bezier of positional information at discrete reference mark;

The motion simulation module is used for the described flexible cable of positional information match according to described control polygon vertex, and shows the position and attitude of described flexible cable.

The above is preferred embodiment of the present invention, should be pointed out that to those skilled in the art, under the prerequisite that does not break away from principle of the present invention, can also make some improvements and modifications, and these improvements and modifications also should be considered as protection domain of the present invention.

Claims (15)

1. the assembly simulation method of a flexible cable is characterized in that, comprising:

Step 1: the physical characteristics model of setting up flexible cable, in the described flexible cable assembling physics characteristic model, described flexible cable is described with the Hookean spring between the discrete reference mark on the described flexible cable, and the degree of crook of described flexible cable adopts the anglec of rotation of the coiled springs on the described discrete reference mark to describe;

Step 2: obtain length information and the primary importance information of first end points and the second place information of second end points of described flexible cable, and the second tangential direction information at the first tangential direction information at the described first end points place and the described second end points place;

Step 3: according to described primary importance information and described second place information and the described first tangential direction information and the described second tangential direction information and length of cable information, find the solution described flexible cable assembling physics characteristic model, obtain the positional information at the discrete reference mark on the described flexible cable;

Step 4: according to the counter positional information of asking the control polygon vertex of Bezier of positional information at discrete reference mark;

Step 5: according to the described flexible cable of positional information match of the control polygon vertex of described Bezier, and show the position and attitude of described flexible cable.

2. the assembly simulation method of flexible cable according to claim 1 is characterized in that, described step 2 comprises:

Step 21: on described first tangential direction and described second tangential direction, it is L that a tangent line operating distance is set respectively;

Step 22: according to described primary importance information and described tangent line operating distance L, obtain the positional information at first reference mark adjacent with described first end points;

Step 23: according to described second place information and described tangent line operating distance L, obtain the positional information at second reference mark adjacent with described second end points;

Step 24: described first reference mark, described second reference mark are connected with straight line, and obtain the positional information at the reference mark between described first reference mark and described second reference mark according to the straight line between described first reference mark, described second reference mark and described first reference mark and described second reference mark.

3. the assembly simulation method of flexible cable according to claim 2 is characterized in that, described step 22 is specially:

According to formula:

Obtain first reference mark adjacent with described first end points

Positional information; Wherein, the described primary importance information coordinate (x that is first end points ₁, y ₁, z ₁), the positional information at described first reference mark is (x ₂, y ₂, z ₂), the tangential direction vector is that (z), L is tangent line operating distance for x, y;

Described step 23 is specially:

According to formula:

Obtain second reference mark adjacent with described second end points

Positional information; Wherein, the described second place information coordinate (x that is described second end points _n, y _n, z _n), the positional information at described second reference mark is (x _N-1, y _N-1, z _N-1), the tangential direction vector is that (z), L is tangent line operating distance for x, y, and n is the quantity at the discrete reference mark on the described flexible cable.

4. the assembly simulation method of flexible cable according to claim 3, it is characterized in that, described first reference mark, described second reference mark connect with straight line, adopt the described cable that comprises described first end points, described second end points, described first reference mark and described second reference mark of segmentation Bezier match, obtain the flexible cable under the ultimate limit state after the match, the flexible cable under the described ultimate limit state is no more than first preset length.

5. according to the assembly simulation method of claim 3 or 4 described flexible cables, it is characterized in that,

Described step 24 is specially: the positional information that obtains the reference mark between described first reference mark and described second reference mark according to following formula:

The positional information at i reference mark is (x _i, y _i, z _i), n is the quantity at the discrete reference mark on the described flexible cable, (x ₂, y ₂, z ₂) be the positional information at first reference mark, (x _N-1, y _N-1, z _N-1) be the positional information at second reference mark.

6. the assembly simulation method of flexible cable according to claim 5 is characterized in that, when described flexible cable was single cable, described step 24 comprised:

Step 240: according to Hooke's law, calculate the Hookean spring power that Hookean spring produces adjacent reference mark;

Step 241: calculate the coiled springs power that the coiled springs on the reference mark produces the reference mark that links to each other;

Step 242: according to each reference mark suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement at each reference mark in Preset Time;

Step 243: the new positional information that obtains all reference mark according to the displacement at each reference mark, calculate acceleration, speed and the displacement at all reference mark, when satisfying the calculating stop condition, obtain the pose at all reference mark, the acceleration that described calculating stop condition is all reference mark and the maximal value of speed absolute value are less than preset value.

7. the assembly simulation method of single cable according to claim 6, after the position at a reference mark on the cable was fixed, described step 24 comprised:

Step 240: according to Hooke's law, calculate the Hookean spring power that Hookean spring produces adjacent reference mark;

Step 241: calculate the coiled springs power that the coiled springs on the reference mark produces the reference mark that links to each other;

Step 242: according to each reference mark suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement at each reference mark in Preset Time;

Step 243: the new positional information that obtains other reference mark on this cable according to the displacement at each reference mark, calculate acceleration, speed and the displacement at all reference mark, when satisfying the calculating stop condition, obtain the pose at all reference mark, the acceleration that described calculating stop condition is all reference mark and the maximal value of speed absolute value are less than preset value.

8. the assembly simulation method of flexible cable according to claim 6, it is characterized in that described flexible cable is take-off point at the reference mark of bifurcation during for the complicated flexible cable of band breakout cable, and cancel the coiled springs of described take-off point, described step 24 comprises:

Step 201: according to Hooke's law, calculate the Hookean spring power that Hookean spring produces take-off point;

Step 202: calculate the coiled springs power that the coiled springs on the adjacent reference mark produces take-off point;

Step 203: according to take-off point suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement of take-off point in described Preset Time;

Step 204: the positional information that obtains take-off point according to the displacement of described take-off point;

Step 205: according to Hooke's law, the Hookean spring power that Hookean spring produces adjacent reference mark on the Branch Computed cable;

Step 206: the coiled springs power that the coiled springs at reference mark produces the reference mark that links to each other on the Branch Computed cable;

Step 207: according to each reference mark on the breakout cable suffered comprise the stressed of Hookean spring power, coiled springs power, calculate the acceleration at each reference mark, speed and displacement on the breakout cable in Preset Time;

Step 208: the new positional information that obtains all reference mark according to the displacement at each reference mark on the breakout cable, calculate acceleration, speed and the displacement at all reference mark, when satisfying the calculating stop condition, obtain the pose at all reference mark on the breakout cable, the acceleration that described calculating stop condition is all reference mark and the maximal value of speed absolute value are less than preset value;

Step 209: repeating step 201-208, the acceleration at all reference mark on take-off point and breakout cable, speed stop to calculate all less than preset value.

Step 210: the pose that obtains complicated flexible cable according to the pose at all reference mark on the positional information of described take-off point, the breakout cable.

9. the assembly simulation method of band breakout cable according to claim 8, when the length of single breakout cable surpassed preset length, step 24 comprised:

Step 2001: the single cable of overlength is set to an extension spring, calculates the Hookean spring power that this extension spring produces the take-off point that links to each other;

Step 2002: calculate the coiled springs power that the coiled springs on the adjacent reference mark produces take-off point;

Step 2003: according to take-off point suffered comprise the stressed of Hookean spring power, coiled springs power, calculate acceleration, speed and the displacement of take-off point in described Preset Time;

Step 2004: the positional information that obtains take-off point according to the displacement of described take-off point;

Step 2005: after breakout cable length is replied normally, obtain the pose at all reference mark on this breakout cable according to described step 205-step 209;

Step 2006: the pose that obtains complicated flexible cable according to the pose at all reference mark on the positional information of described take-off point, the breakout cable.

10. according to the assembly simulation method of each described flexible cable of claim 7-9, it is characterized in that,

Obtain the Hookean spring power that adjacent two Hookean springs produce the reference mark between these adjacent two Hookean springs successively according to following formula:

Wherein, F _Xi, F _Yi, F _ZiRefer to stressed on three directions in i reference mark, L ₀, Refer to P respectively _iAnd P _I-1The former length of cable segment between the reference mark and the present physical length of cable segment,

L ₀=L/ (n-1),

L is single cable length, K _lRefer to the drawing coefficient of Hookean spring, x _i, y _i, z _iIt then is the three-dimensional coordinate at i reference mark.

11. the assembly simulation method according to each described flexible cable of claim 7-9 is characterized in that,

Calculate the coiled springs power that the coiled springs between per five successive control points produces the middle reference mark in described five successive control points according to following formula:

Wherein,

Refer to vector

Do dot product,

Refer to a P _iAnd P _I+1Between distance.

12. the assembly simulation method according to each described flexible cable of claim 7-9 is characterized in that,

Calculate acceleration, speed and the displacement at the reference mark in Preset Time according to following formula:

Wherein, a refers to reference mark constant acceleration in described preset time t, F _lRefer to the Hookean spring power that the reference mark is subjected to, F _θRefer to the coiled springs power that the reference mark is subjected to, G refers to the gravity at reference mark, K _dRefer to the ratio of damping of reference mark in motion process, v, v ₀Be respectively the reference mark through after the preset time t, before speed, s, s ₀Be respectively the reference mark through after the preset time t, before displacement.

13. the assembly simulation method according to each described flexible cable of claim 7-9 is characterized in that step 4 comprises:

Select 4 reference mark, obtain per two adjacent reference mark in described 4 reference mark by following formula

Mid point A, B, C:

Wherein, x _{I, i+1}, y _{I, i+1}z _{I, i+1}Refer to adjacent two reference mark P respectively _i, P _I+1The three-dimensional coordinate of line mid point;

Adjacent described mid point is connected acquisition line segment AB, BC, and with on parallel line segment ab, the cd that moves to through two reference mark, centre in described 4 reference mark of line segment AB, BC, and described some A is overlapping with some a, described some C is overlapping with some d, obtain polygonal six summits, the coordinate of some a uses following formula to try to achieve:

Wherein

In like manner, the coordinate on b, c, polygonal summit, d reference mark also can be obtained.

14. the assembly simulation method of flexible cable according to claim 1 is characterized in that, described segmentation Bezier refers to:

Wherein, P _iRefer to i cable segment, V _i, V _I+1, V _I+2Refer to the three-dimensional coordinate of polygon vertex on i the cable segment, u is parameter, u ∈ [0,1].Adopt the Bezier match to control polygonal summit, obtain the attitude of flexible cable.

15. the assembly simulation device of a flexible cable is characterized in that, comprising:

Model building module, be used for setting up the physical characteristics model of flexible cable, in the described flexible cable assembling physics characteristic model, described flexible cable is described with the Hookean spring between the discrete reference mark on the described flexible cable, and the degree of crook of described flexible cable adopts the anglec of rotation of the coiled springs on the described discrete reference mark to describe;

Acquisition module, be used for obtaining length information and the primary importance information of first end points and the second place information of second end points of described flexible cable, and the second tangential direction information at the first tangential direction information at the described first end points place and the described second end points place;

The model solution module, according to described primary importance information and described second place information and the described first tangential direction information and the described second tangential direction information and length of cable information, find the solution described flexible cable assembling physics characteristic model, obtain the positional information at the discrete reference mark on the described flexible cable, utilize the counter positional information of asking the control polygon vertex of Bezier of positional information at discrete reference mark;

The motion simulation module is used for the described flexible cable of positional information match according to described control polygon vertex, and shows the position and attitude of described flexible cable.

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