阅读说明：本技术 一种基于正畸弓丝弯制点密度的空间等半径球域划分半径确定方法 (Method for determining spatial equal-radius spherical domain dividing radius based on orthodontic arch wire bending point density ) 是由 姜金刚 吴殿昊 王磊 郭亚峰 张永德 姚亮 于 2020-06-01 设计创作，主要内容包括：本发明公开了一种基于正畸弓丝弯制点密度的空间等半径球域划分半径确定方法,它涉及正畸弓丝弯制技术领域,本发明根据患者的个性化正畸弓丝曲线,基于正畸弓丝曲线弯制点信息集、弯制点的机器人弯制信息集,结合机器人弯制正畸弓丝的运动特点,建立一种基于正畸弓丝弯制点密度的空间等半径球域划分半径确定方法。技术要点为：等半径确定球域划分数据导入；计算等半径确定球域初始试划分个数；试划分等半径确定球域；寻找最佳试划分个数；输出合理密度等半径球域划分半径r<Sub>equal</Sub>。本发明采用密度判定调整试划分个数,直接对空间正畸弓丝曲线进行合理等半径球域的划分半径确定,提高等半径球域划分的效率,进而提高正畸弓丝弯制规划的效率,避免了机器人弯制正畸弓丝过程中出现干涉的问题。(The invention discloses a method for determining the partition radius of a space equal-radius spherical region based on the bending point density of an orthodontic arch wire, which relates to the technical field of the bending of orthodontic arch wires. The technical points are as follows: determining the division data import of a spherical domain by equal radius; calculating the number of initial trial division of the spherical area with equal radius; trying to divide an equal radius to determine a spherical domain; searching the optimal trial division number; outputting reasonable density equal radius sphere domain dividing radius r equal . The invention adopts density judgment to adjust the dividing number, directly determines the dividing radius of the reasonable equal-radius spherical area of the space orthodontic arch wire curve, and improves the equal radiusThe efficiency of ball territory division, and then improve the efficiency of just abnormal arch wire curved system planning, avoided the robot to bend the just abnormal arch wire in-process problem that appears interfering.)

1. A method for determining the radius of a space equal-radius spherical region based on the bending point density of an orthodontic arch wire is characterized by comprising the following steps: the method comprises the following concrete implementation processes:

step one, importing dividing data of an equal-radius determined spherical domain:

according to a spatial orthodontic arch wire curve with i bending points of a patient, calculating and inputting a spatial orthodontic arch wire curve bending point information set T ═ T₁，t₂，t₃，…，t_i}，t_i＝(x_i，y_i，z_i) ' As the coordinate of each space orthodontic arch wire curve bending point, at each bending point t_iThe upper robot executes different bending movements, and each space orthodontic arch wire curve bending point t_iAll correspond to a bending information unit r of a bending point robot_iThe bending information set of the robot for inputting the bending points is R ═ R₁，r₂，r₃，...，r_i}，r_i＝(x_i，y_i，z_i，α_i) ' denotes the coordinates of the bending point and the bending angle of the robot at the time of bending the point, α_iActing on bending points t for the robot_iAn upper bending angle;

step two, calculating equal radiuses to determine the initial trial division number of the spherical area:

according toPre-calculating the unit spherical bending point density of all i bending points on the curve of the spatial orthodontic arch wire, wherein the unit spherical bending point density of the jth bending point is regulatedUnit is one/mm³，The jth bending point on the curve of the spatial orthodontic arch wire is in a unit sphere area a₀Quantitative description of internal density, the value 1 in the formula represents only one bending point in unit sphere domain, l_jIndicates the bending point t_jLinear distance between bending points nearest thereto, unit sphere area a₀Represents any bending point t on the curve of the spatial orthodontic arch wire_jIs the center of the sphere_jIncluding only one bending point t_jJ has a value range of 1 to i, according toCumulatively summing the pre-calculated i unit sphere bending point densities, wherein ∑ rho⁰Representing the density accumulation sum of bending points of the unit sphere area; the method is characterized in that n equal-radius determined spherical areas are firstly divided on a spatial orthodontic arch wire curve in an experimental mode, and the initial value of n is equal to max { [ i/Q ]_max],[∑ρ⁰/ρ_max]Is (b) } +1, in which [ i/Q_max]Represents the pair formula i/Q_maxRounding of the calculated result, Q_maxRepresents any one constant-radius determined ball area a to be divided on the curve of the spatial orthodontic arch wire_nNumber of bending points of inner sphereUpper limit value required, in particular, Q_maxNumber of bending points of the ball region of 5Is a radius ofIs equal to the radius of the determined spherical area a_nNumber of inner bending points, [ ∑ ρ⁰/ρ_max]Expression pair ∑ ρ⁰/ρ_maxRounding of the calculated result, ρ_maxRepresents any one to be divided on the curve of the spatial orthodontic arch wireConstant radius determined sphere area a_nInner sphere bending point densityRequired upper limit value, ball bending point densityIs the spherical domain a_nInner partA bending point having a radius ofThe quantitative description of the degree of compaction in the sphere of (1), stipulateBall bending point densityUnit of (2) is one/mm³，Determining a ball area a for the nth equal radius on the curve of the spatial orthodontic arch wire_nRadius value of (1), number of bending points of sphereIs a radius ofIs equal to the radius of the determined spherical area a_nThe number of bending points in the inner part, the unit sphere region bending point density rho mentioned above in turn⁰Ball region bending point densityNumber of bending points of ball regionThe three parameters are collectively called as equal radius determined spherical area limiting parameters, and the step III is skipped;

step three, trying to divide and determining a spherical area by equal radius:

at the first bending point t₁Starting from the last bending point t_iN +1 points are selected as ball domain forming points on the space orthodontic arch wire curve segment of the terminal point, and the first ball domain forming point is a bending point t₁At the point where the last ball region forming point is the bending point t_iThe points are located so that the length of n straight line segments obtained by connecting each sphere forming point with the adjacent sphere forming points is equal, and n straight line segments scanned by the horizontal right vector in the clockwise direction are specified to be sequentially usedIndicate and existWhereinRepresenting straight line segmentsTo determine the radius of the sphere to bend the point t₁Taking the forming point of the ball region as the starting point, and sequentially carrying out The midpoint of (A) is taken as the center of sphere, toN equal radius determination spherical regions are generated as radii, the boundary surface of each equal radius determination spherical region is formed by two spherical regions,a common sphere forming point exists on the intersection line of the boundary surfaces of two adjacent equal-radius determined spheres, namely the (n-1) th equal-radius determined sphere a_n-1The right spherical region forming point is just the nth constant radius determined spherical region a_nForming point of left spherical region, defining equal radius to determine spherical region a_nThe bending point contained on the curve segment of the spatial orthodontic arch wire intercepted by the boundary surface of the spherical area is defined by the spherical area a_nDividing, when the point of the sphere forming point shared by the boundary surfaces of the two equal radius determined sphere is exactly one bending point on the curve of the space orthodontic arch wire, the bending point of the sphere forming point is divided by the previous equal radius determined sphere, if the n-1 equal radius determined sphere a_n-1Determining a spherical area a with the nth equal radius_nThe point where the common sphere forming point is located is exactly the bending point t_jBending point t_jIs determined into a spherical area a by equal radius_n-1After the division is finished, the trial division of n equal-radius determined spherical domains is carried out, and then the step four is skipped;

step four, searching the optimal trial division number:

respectively calculating the number of the bending points of the n equal-radius determined ball areas generated in the step threeObtaining a set of sphere bending pointsThe n spherical bending points in the spherical bending point number set Q are arranged in descending order, and the largest spherical bending point number is taken out and recorded as Q_amAccording to the required upper limit value Q of the number of the bending points of the sphere_maxWherein Q is_maxWhen Q is not present, the judgment is made as to whether Q is present_am≤5，

The method specifically comprises the following steps:

if Q is_amIf the value is not more than 5, the generated n equal-radius determined ball regions have upper limit values Q of the number of bending points which do not accord with the ball regions_maxIn the required sphere, it can be known that if the n value is not the optimal number of trial divisions, it is necessary to change the number of spheresCounting, so that the radius of the sphere is changed, the radius determination sphere is determined by re-trial division and the like, n is n +1, namely one is added on the basis of the number of the division when the next trial division and the like of the radius determination sphere is performed, and then the step three is skipped;

if Q is_amIf the number of the generated n equal-radius determined ball domains is less than or equal to 5, the generated n equal-radius determined ball domains all accord with the upper limit value Q of the number of the bending points of the ball domains_maxAccording to further requirements ofCalculating the n equal-radius determined spherical domain bending point densities generated in the third stepObtaining a sphere bending point density setThe n spherical bending point densities in the spherical bending point density set P are arranged in a descending order, and the maximum spherical bending point density is taken out and is recorded as rho_amAccording to the required upper limit value rho of the sphere bending point density_maxAt Q_amJudging whether rho exists or not under the condition that no more than 5 is satisfied_am≤ρ_max，

The method specifically comprises the following steps:

if ρ_am≤ρ_maxIf yes, the n equal-radius determined spherical domains generated in the step three all meet the upper limit value rho of the density of the bending points of the spherical domains_maxAll the equal-radius determined spherical areas meet the dividing requirement, and the n value is just the optimal dividing number, namely the n equal-radius determined spherical areas a₁、a₂、…、a_nAll are spherical areas with reasonable density and equal radius, and jumping to the step five;

if ρ_am≤ρ_maxIf the number of the ball domains is not the optimal number, the number of the ball domains needs to be changed to determine whether the n equal-radius determined ball domains generated in the step three have ball domains which do not meet the requirement of the upper limit value of the density of the bending points of the ball domainsChanging the radius of the sphere area, performing trial division again and the like to determine the sphere area, enabling n to be n +1, namely adding one to the number of the division when the next trial division and the like to determine the sphere area, and then jumping to the third step;

step five, outputting the dividing radius of the sphere with the equal radius and reasonable density

Obtaining the dividing radiuses of n reasonable density equal-radius spherical domains and n reasonable density equal-radius spherical domains with the same length output in the fourth step, wherein the dividing radius values are sequentiallyOrder toThen r is_equalNamely, the method is to divide n general dividing radiuses of reasonable density equal radius ball areas on the space orthodontic arch wire curve and output the dividing radiuses r of the reasonable density equal radius ball areas_equalAnd the routine is ended.

Technical Field

The invention relates to a method for determining the partition radius of a space equal-radius spherical region based on the bending point density of an orthodontic arch wire, belonging to the technical field of bending of orthodontic arch wires.

Background

The malocclusion deformity is the third major oral disease endangering human health, has higher morbidity, and in modern oral medicine, the fixed correction is a common and effective orthodontic treatment means, while the bending of an orthodontic arch wire is the key of the fixed correction technology.

In the process of bending the personalized orthodontic arch wire by the robot, interference may occur between the personalized orthodontic arch wire and the robot bending paw, namely the personalized orthodontic arch wire collides with the robot bending paw, and after the interference occurs, the bending precision of the personalized orthodontic arch wire is greatly influenced, so that the correction effect is influenced, and the bent personalized arch wire cannot be applied to clinical treatment; research shows that in the process of forward bending the individual orthodontic arch wire, the forward bending is to bend the unbent orthodontic arch wire into a complex formed arch wire, interference is often caused by unreasonable bending sequence of forming control points, the reasonable bending sequence of the forming control points can effectively avoid the occurrence of interference, and the obtaining of the reasonable bending sequence of the forming control points is a necessary premise for realizing digital bending of the orthodontic arch wire.

For the research of the dividing field of the orthodontic arch wire bending planning, an equal-radius circular domain dividing method is proposed in an invention patent, namely a circular domain dividing method for the orthodontic arch wire bending planning, which is granted by the inventor and has an authorization publication number of CN107647925B, the method divides the regions on the curve of the orthodontic arch wire and finally sorts each region to obtain the bending sequence of the final bending point, although the method has certain application value for the orthodontic arch wire bending planning, the method has some limitations: firstly, the method can carry out circular domain division of bending planning only on the premise of converting a space orthodontic arch wire curve into a plane curve, and the situation that projection deviation, dislocation or mutual superposition of individual bending points exists after the space curve is converted into the plane curve is inevitable, so that the distribution situation of the bending points in the circular domain after the circular domain division cannot be accurately determined, therefore, the actual bending sequence after the bending planning cannot achieve the ideal effect, secondly, the method only divides the orthodontic arch wire curve by an unachieved homogenization standard, and the situation that the density degree of the bending points is overlarge usually exists in the divided circular domain intervals, namely the divided intervals do not fully consider the personalized characteristics of distribution information of the bending points on the orthodontic arch wire curve, for example, when special function bending of space distribution exists on the orthodontic arch wire, when the circular domain division is carried out on the personalized orthodontic arch wire, the existing common plane bending planning method cannot fully exert the effectiveness of the existing plane bending planning method, the rationality of the orthodontic arch wire forming control point bending sequence planning method is poor, and the individual orthodontic arch wires cannot be efficiently and digitally bent, so that idle stroke invalid actions generated by a bending robot and mutual interference actions in the bending process due to unreasonable bending sequence planning cannot be effectively avoided, the advantages of the bending robot cannot be exerted to the maximum, and the bending efficiency cannot be obviously improved.

Disclosure of Invention

Aiming at the problems, the invention provides a method for determining the dividing radius of a spatial equal-radius spherical region based on the bending point density of an orthodontic arch wire, which solves the problem that the prior orthodontic arch wire bending technical field lacks a method for determining the dividing radius of an equal-radius spherical region for directly planning the bending sequence of a spatial orthodontic arch wire curve, provides reasonable spherical region limiting parameters in the process of determining the dividing radius of the spatial equal-radius spherical region, quantitatively restricts the intensity degree of the bending points divided by the equal-radius spherical region, obtains a series of reasonable density equal-radius spherical regions with the bending point density meeting the requirements in the regions, finally obtains the dividing radius of the equal-radius spherical region suitable for directly planning the bending point of the spatial orthodontic arch wire curve, provides convenience for the method for dividing the equal-radius spherical region of the spatial orthodontic arch wire bending, avoids the bending sequence planning deviation caused by curve conversion, thereby improving the efficiency of the orthodontic arch wire bending planning, the maximum advantage of the bending robot is exerted, the normal operation of the orthodontic arch wire bending process is ensured, and the problem of interference in the process of bending the orthodontic arch wire by the robot is avoided.

The above purpose is mainly achieved through the following scheme: a method for determining the partition radius of a space equal-radius spherical domain based on the bending point density of an orthodontic arch wire is specifically realized by the following steps:

step one, importing dividing data of an equal-radius determined spherical domain:

according to a spatial orthodontic arch wire curve with i bending points of a patient, calculating and inputting a spatial orthodontic arch wire curve bending point information set T ═ T₁，t₂，t₃，...，t_i}，t_i＝(x_i，y_i，z_i) ' As the coordinate of each space orthodontic arch wire curve bending point, at each bending point t_iThe upper robot executes different bending movements, and each space orthodontic arch wire curve bending point t_iAll correspond to a bending information unit r of a bending point robot_iThe bending information set of the robot for inputting the bending points is R ═ R₁，r₂，r₃，...，r_i}，r_i＝(x_i，y_i，z_i，α_i) ' denotes the coordinates of the bending point and the bending angle of the robot at the time of bending the point, α_iActing on bending points t for the robot_iAn upper bending angle;

step two, calculating equal radiuses to determine the initial trial division number of the spherical area:

according toPre-calculating the unit spherical bending point density of all i bending points on the curve of the spatial orthodontic arch wire, wherein the unit spherical bending point density of the jth bending point is regulatedUnit is one/mm³，The jth bending point on the curve of the spatial orthodontic arch wire is in a unit sphere area a₀Quantitative description of internal density, the value 1 in the formula represents only one bending point in unit sphere domain, l_jIndicates the bending point t_jLinear distance between bending points nearest thereto, unit sphere area a₀Represents any bending point t on the curve of the spatial orthodontic arch wire_jIs the center of the sphere_jIncluding only one bending point t_jJ has a value range of 1 to i, according toCumulatively summing the pre-calculated i unit sphere bending point densities, wherein ∑ rho⁰Representing the density accumulation sum of bending points of the unit sphere area; the method is characterized in that n equal-radius determined spherical areas are firstly divided on a spatial orthodontic arch wire curve in an experimental mode, and the initial value of n is equal to max { [ i/Q ]_max],[∑ρ⁰/ρ_max]Is (b) } +1, in which [ i/Q_max]Represents the pair formula i/Q_maxRounding of the calculated result, Q_maxRepresents any one constant-radius determined ball area a to be divided on the curve of the spatial orthodontic arch wire_nNumber of bending points of inner sphereUpper limit value required, in particular, Q_maxNumber of bending points of the ball region of 5Is a radius ofIs equal to the radius of the determined spherical area a_nNumber of inner bending points, [ ∑ ρ⁰/ρ_max]Expression pair ∑ ρ⁰/ρ_maxRounding of the calculated result, ρ_maxRepresents any one constant-radius determined ball area a to be divided on the curve of the spatial orthodontic arch wire_nInner sphere bending point densityRequired upper limit value, ball bending point densityIs the spherical domain a_nInner partA bending point having a radius ofThe quantitative description of the degree of compaction in the sphere of (1), stipulateBall bending point densityUnit of (2) is one/mm³，Determining a ball area a for the nth equal radius on the curve of the spatial orthodontic arch wire_nRadius value of (1), number of bending points of sphereIs a radius ofIs equal to the radius of the determined spherical area a_nThe number of bending points in the inner part, the unit sphere region bending point density rho mentioned above in turn⁰Bending point of ball regionDensity ofNumber of bending points of ball regionThe three parameters are collectively called as equal radius determined spherical area limiting parameters, and the step III is skipped;

step three, trying to divide and determining a spherical area by equal radius:

at the first bending point t₁Starting from the last bending point t_iN +1 points are selected as ball domain forming points on the space orthodontic arch wire curve segment of the terminal point, and the first ball domain forming point is a bending point t₁At the point where the last ball region forming point is the bending point t_iThe points are located so that the length of n straight line segments obtained by connecting each sphere forming point with the adjacent sphere forming points is equal, and n straight line segments scanned by the horizontal right vector in the clockwise direction are specified to be sequentially usedIndicate and existWhereinRepresenting straight line segmentsTo determine the radius of the sphere to bend the point t₁Taking the forming point of the ball region as the starting point, and sequentially carrying out The midpoint of (A) is taken as the center of sphere, toN equal radius determination spherical domains are generated as the radius, the boundary surface of each equal radius determination spherical domain is formed by two spherical domain forming points, and a common spherical domain forming point exists on the intersection line of the adjacent two equal radius determination spherical domain boundary surfaces, namely the n-1 th equal radius determination spherical domain a_n-1The right spherical region forming point is just the nth constant radius determined spherical region a_nForming point of left spherical region, defining equal radius to determine spherical region a_nThe bending point contained on the curve segment of the spatial orthodontic arch wire intercepted by the boundary surface of the spherical area is defined by the spherical area a_nDividing, when the point of the sphere forming point shared by the boundary surfaces of the two equal radius determined sphere is exactly one bending point on the curve of the space orthodontic arch wire, the bending point of the sphere forming point is divided by the previous equal radius determined sphere, if the n-1 equal radius determined sphere a_n-1Determining a spherical area a with the nth equal radius_nThe point where the common sphere forming point is located is exactly the bending point t_jBending point t_jIs determined into a spherical area a by equal radius_n-1After the division is finished, the trial division of n equal-radius determined spherical domains is carried out, and then the step four is skipped;

step four, searching the optimal trial division number:

respectively calculating the number of the bending points of the n equal-radius determined ball areas generated in the step threeCan obtain the number set of the bending points of the sphereThe n spherical bending points in the spherical bending point number set Q are arranged in descending order, and the largest spherical bending point number is taken out and recorded as Q_amAccording to the required upper limit value Q of the number of the bending points of the sphere_maxWherein Q is_maxWhen Q is not present, the judgment is made as to whether Q is present_am≤5，

The method specifically comprises the following steps:

if Q is_amThe condition that the radius is less than or equal to 5 is not satisfied, the generated n equal-radius determined ball regions have upper limit of the number of the bending points which do not accord with the ball regionsValue Q_maxIf the required sphere area is known that the value n is not the optimal trial division number, the radius of the sphere area needs to be changed by changing the number of the sphere areas, the radius of the sphere area is determined by trial division again, and the like, so that n is equal to n +1, namely, one sphere area is added on the basis of the division number when the next trial division and the like determine the sphere area, and then the step three is skipped;

if Q is_amIf the number of the generated n equal-radius determined ball domains is less than or equal to 5, the generated n equal-radius determined ball domains all accord with the upper limit value Q of the number of the bending points of the ball domains_maxAccording to further requirements ofCalculating the n equal-radius determined spherical domain bending point densities generated in the third stepCan obtain the density set of the bending points of the spherical regionThe n spherical bending point densities in the spherical bending point density set P are arranged in a descending order, and the maximum spherical bending point density is taken out and is recorded as rho_amAccording to the required upper limit value rho of the sphere bending point density_maxAt Q_amJudging whether rho exists or not under the condition that no more than 5 is satisfied_am≤ρ_max，

The method specifically comprises the following steps:

if ρ_am≤ρ_maxIf yes, the n equal-radius determined spherical domains generated in the step three all meet the upper limit value rho of the density of the bending points of the spherical domains_maxAll the equal-radius determined spherical areas meet the dividing requirement, and the n value is just the optimal dividing number, namely the n equal-radius determined spherical areas a₁、a₂、…、a_nAll are spherical areas with reasonable density and equal radius, and jumping to the step five;

if ρ_am≤ρ_maxIf not, it means that the n equal radius ball regions generated in step three have ball regions which do not meet the requirement of the upper limit value of the bending point density of the ball region,knowing that the value n is not the optimal trial division number, the radius of the sphere domain needs to be changed by changing the number of the sphere domains, the trial division is performed again, the sphere domain is determined according to the radius, n is n +1, namely, one is added on the basis of the division number when the next trial division is performed, and then the step three is skipped;

step five, outputting the dividing radius of the sphere with the equal radius and reasonable density

Obtaining the dividing radiuses of n reasonable density equal-radius spherical domains and n reasonable density equal-radius spherical domains with the same length output in the fourth step, wherein the dividing radius values are sequentiallyOrder toThen r is_equalNamely, the method can divide n universal dividing radiuses of reasonable density equal radius ball areas on the space orthodontic arch wire curve and output the dividing radiuses r of the reasonable density equal radius ball areas_equalAnd the routine is ended.

The invention has the beneficial effects that:

1. aiming at determining the dividing radius of the equal-radius spherical area of the curve of the space orthodontic arch wire, the invention adopts three spherical area limiting parameters as the basis for determining the dividing radius of the equal-radius spherical area, and mentions the number of bending points of the spherical areaUnit sphere domain bending point density rho⁰Ball region bending point densityThe concept of (1) quantitatively describing the bending point density degree in a unit sphere and the bending point total bending density degree in the sphere, firstly determining the initial value of the trial division number n of the sphere based on the bending point density average division and the sphere bending point number average division principle, and performing trial division by taking the initial value of n as a starting point instead of performing the trial division of the equal-radius sphere by taking the initial value of n without basis as the starting point, thereby effectively improving the searching of the most important pointDividing the speed of the number n; first using Q after generating equal radius determined sphere region_maxThe number of bending points is restricted, and then the upper limit value rho of the density of the bending points in the sphere region is utilized_maxThe calculation efficiency of the algorithm can be fully improved by carrying out condition constraint, namely Q is not satisfied_maxThe method can immediately feed back when the conditions are limited, and a plurality of reasonable-density equal-radius spherical areas meeting the set requirements can be formed on a space orthodontic arch wire curve through the upper limit limitation of the two, so that the dividing radius r of the equal-radius spherical areas meeting the requirements is obtained_equalWhen the dividing radius determined by the method is adopted to divide the spherical region of the spatial orthodontic arch wire in any form, the phenomenon that the density of bending points is overlarge in the divided spherical region can be effectively avoided, so that the problem that the robot interferes in the bending process is avoided to the greatest extent, the spherical region limiting parameter is used as a planning index to be applied to the field of orthodontic arch wire bending planning, and a theoretical basis is provided for a series of methods for determining the spherical region dividing radius of the spatial orthodontic arch wire.

2. The invention adopts a space equal-radius ball domain trial division method to determine the division radius, the number n of the divided ball domains is used as a central variable, the change of the number n of the divided ball domains can change the distribution condition of the forming points of the ball domains on the orthodontic arch wire curve, thereby causing the change of the ball centers and the radius of the ball domains, namely, the position and the size of the ball domains with equal radius can be uniquely determined as long as the number n of the divided ball domains is determined, the system is convenient to calculate the data of the divided ball domains, and the efficiency of determining the division radius by the method is improved.

3. In the invention, the dividing radius is determined by adopting a spatial equal-radius ball domain trial dividing method, and in the process of determining the bending points by the equal-radius ball domain trial dividing method, the region to which each bending point belongs is strictly defined, so that the situation that the bending points are repeatedly divided by the same equal-radius determined ball domain does not exist, the determined equal-radius ball domain dividing radius is the dividing data with absolute significance, and the rationality and the accuracy of the dividing radius determining method are improved.

4. Compared with the invention patent of CN107647925B granted by the inventor, namely a method for dividing the circular domain for the orthodontic arch wire bending planning, the invention patent of CN107647925B belongs to a method for dividing the circular domain with equal radius, a space orthodontic arch wire curve needs to be subjected to plane curve conversion before the circular domain is divided, and the situation that the density of bending points in the divided circular domain interval is overlarge easily exists, namely, the generated circular domain interval does not fully consider the individualized characteristic of distribution information of the bending points on the orthodontic arch wire curve, the orthodontic arch wire curve is divided only by an unjustified homogenization standard, in addition, the proposed circular domain dividing process only divides the orthodontic arch wire curve by the circular arc to obtain areas, but not strictly divides the circular domain, and belongs to a method for determining the dividing the radius of the spherical domain with equal radius, the determination of the dividing radius of the bending spherical area can be carried out without converting a space curve, the method is also effective for an orthodontic arch wire curve containing a special-function curve, and the conditions of projection deviation, dislocation or mutual superposition of individual bending points caused by curve planarization are avoided, so that the equal-radius spherical areas generated by the dividing radius determined by the method can accurately plan the bending sequence, and the actual bending effect is more ideal; in addition, in the process of determining the dividing radius, the method relates to the dividing of the equal-radius ball area, can form a regular complete space area, defines the ball area limiting parameters required by the dividing based on the regular area, carries out quantitative constraint on the bending points of the divided equal-radius ball area according to the proposed number of the ball area bending points and the ball area bending point density, thereby causing the dividing radius of the equal-radius ball area to change according with the regulation of the ball area limiting parameters, finally obtains the reasonable density dividing radius of the equal-radius ball area according with the individual characteristics of the orthodontic space arch wire curve, carries out the ball area dividing by using the determined dividing radius, can effectively avoid the condition that the density of the bending points in each divided ball area is greatly different, improves the uniformity of the bending points in each space area, and a bending robot can not generate idle stroke invalid action or bending movement complex action, therefore, the advantage maximization of the bending robot can be exerted, the normal operation of the orthodontic arch wire bending process is ensured, the efficiency of orthodontic arch wire bending planning is improved, and the problem of interference in the process of bending the orthodontic arch wire by the robot is avoided.

5. Compared with the invention patent of a method for determining the radius of the circular domain with equal radius for the orthodontic arch wire bending planning and the like filed on the same day by the inventor, the two methods define the limiting parameters required by the domain division, and the determination thinking of dividing the radius is approximately the same, but the method is provided for the equal radius spherical domain division of the bending sequence planning, the method can directly determine the equal-radius spherical division radius of the space orthodontic arch wire curve without performing plane conversion on the orthodontic arch wire curve, thereby avoiding the condition that the projection deviation, the dislocation or the mutual superposition of the individual bending points are caused by curve planarization, so that the equal-radius spherical domain generated by the determined dividing radius can accurately plan the bending sequence, the actual bending effect is more ideal, so that the advantage of the bending robot is further maximized, and the problem of interference in the process of bending the orthodontic arch wire by the robot is avoided.

Drawings

For ease of illustration, the invention is described in detail by the following detailed description and the accompanying drawings.

FIG. 1 is a flow chart of a method for determining the radius of a space equal-radius spherical area based on the bending point density of an orthodontic arch wire;

fig. 2 is a schematic diagram of distribution of spatially individualized orthodontic arch wire bending points;

fig. 3 is a schematic view of an initial trial division space personalized orthodontic archwire curve in an equal radius spherical region;

fig. 4 is a schematic view of an orthodontics arch wire curve in which trial division of space is completed in an equal radius spherical area;

Detailed Description

For the purposes of promoting a clear understanding of the objects, aspects and advantages of the invention, reference will now be made to the following description of the preferred embodiments illustrated in the accompanying drawings, with the understanding that the description is illustrative only and is not intended to limit the scope of the invention, and that the following description will omit descriptions of well-known structures and techniques in order to avoid unnecessarily obscuring the concepts of the invention.