阅读说明：本技术 一种平面变半径圆域划分的正畸弓丝弯制顺序规划方法 (Method for planning bending sequence of orthodontic arch wire divided by plane variable-radius circular domain ) 是由 姜金刚 吴殿昊 郭亚峰 闵兆伟 张永德 唐德栋 于 2020-06-01 设计创作，主要内容包括：本发明公开了一种平面变半径圆域划分的正畸弓丝弯制顺序规划方法,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,建立一种平面变半径圆域划分的正畸弓丝弯制顺序规划方法。技术要点为：将正畸弓丝曲线T转换为平面曲线T′；设定圆域限制参数的上限值；确定划分圆域的半径和圆心；定义合理弯制圆域；判断是否继续进行圆域划分；以圆域弯制点密度<Image he="48" wi="61" file="DDA0002519385210000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>为指标,将各圆域降序排列,规定圆域的弯制点顺序,输出最终弯制点弯制顺序T<Sub>1</Sub>和R<Sub>1</Sub>。本发明以变半径圆域划分区域,可以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 plane variable-radius circular-domain-divided orthodontic arch wire bending sequence planning method, which relates to the technical field of orthodontic arch wire bending. The technical points are as follows: converting the orthodontic arch wire curve T into a plane curve T'; setting an upper limit value of a circle domain limiting parameter; determining the radius and the center of a circle to be divided; defining a reasonable bending circular area; judging whether to continue to divide the circular domain; with point density being bent in a circular region Arranging the circular fields in descending order as an index, and defining the bending point sequence of the circular fieldsOutputting a final bending point bending sequence T 1 And R 1 . The invention divides the areas by the variable radius circular areas, can improve the efficiency of the bending planning of the orthodontic arch wire and avoids the problem of interference in the process of bending the orthodontic arch wire by the robot.)

1. A method for planning the bending sequence of an orthodontic arch wire divided by a plane variable-radius circular domain is characterized in that: the method comprises the following concrete implementation processes:

step one, dividing data import in a variable radius circular domain and orthodontic arch wire curve conversion:

according to the orthodontic arch wire curve with i bending points of a patient, calculating and inputting an orthodontic arch wire curve bending point information set T ═ T₁，t₂，t₃，...，t_i}，t_i＝(x_i，y_i，z_i) ' coordinates of each orthodontic archwire curve bending point, at each bending point t_iThe upper robot executes different bending movements, and each 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;

centralizing the information of the individualized orthodontic arch wire curve forming control point into the coordinate t of each bending point_i＝(x_i，y_i，z_i) ' z in_iAssigned a value of 0, i.e. z_iObtaining an orthodontic arch wire curve conversion plane orthodontic arch wire curve T' which is equal to 0;

step two, setting of circle domain limiting parameters

Defining the number of bending points in the circular region by symbolsIndicating the number of bending points in the circleIs a radius ofRound area a of_nThe number of inner bending points; defining the density of bending points in a circle by symbolsIndicating, circle domain bending dot densityIs a circular domain a_nInner partA bending point having a radius ofThe degree of compactness in the circular domain of (1) is specifiedDensity of bending points in circular areaUnit of (2) is one/mm²，Dividing a circle area a for the nth variable radius on the curve of the orthodontic arch wire_nThe radius value of (d); statorThe angle-distance ratio of the bending point is represented by symbol E, the angle-distance ratio of the bending point is a quantitative description of the bending complexity of a single bending point, and the angle-distance ratio of the bending point of the ith bending point is specifiedIn particular, due to the first bending point t₁Without bending, the bending point t is specified₁Bending point-angular distance ratio E of₁0; defining the sum of the angular distances of the bending points in the circle by symbolsIt is shown that,is to divide the circular domain a_nThe divided bending points are quantitatively described in the whole bending complexity,represents the nth variable radius dividing circular area a on the curve of the orthodontic arch wire_nThe sum of the bending point angular distance ratios of all the bending points in the circle area a is divided when the radius is changed_nThe inner bending points are respectivelyWhen it is prescribedα_mTo act on the bending point t_mThe bending angle of the part is formed,indicating action at bending point t_mAt a bending distance, i.e. bending point t_m-1And t_mThe length of the curve segment between, the value range of m isq represents the completed change on the curve of the orthodontic arch wireThe number of all bending points in the circle divided by the radius circle, i.e.When the circular domain is not divided, q is 0, namely the initial value of q is 0, the value range of q is more than or equal to 0 and less than or equal to i, and the density of the bending points of the circular domain is adjustedRatio of angular distance of bending points in circular areaNumber of bending points in the harmony circle regionCollectively referred to as circular domain limiting parameters, the upper limit values of the circular domain limiting parameters are defined and setUpper limit value Q of_maxSetting upIs rho_maxSetting upUpper limit value of (∑ E)_maxDuring the whole circle division process Q_max、ρ_maxAnd (∑ E)_maxConstant, in particular Q_maxJumping to the third step when the result is 5;

step three, determining the radius and the circle center of the divided circle domain:

dividing the circular field to bend the point t_q+1Taking bending points t as starting points_q+1Andthe straight line segments between the two segments are sequentially marked as line segmentsSegment of lineThe line segment with the largest middle length is recorded asNamely, it is Respectively representing line segments The length of the n-th circle segment a to be generated on the curve of the orthodontic arch wire_nIs a line segmentThe radius of the midpoint of (1) is a line segmentHalf of the lengthAt this time, exactly two bending points fall on the boundary line of the circular area, and the newly formed circular area a_nCan just divide the bending points preset in the step threeA boundary line of a predetermined circle regionAll bending points on the cut orthodontic arch wire curve segment are divided by the circular area, when the generated boundary line of the circular area passes through the bending points, the bending points are also divided by the circular area, and the orthodontic arch wire curve segment where the divided bending points are located can not be divided by other circular areas;is initially ofn is initially 1, i.e. the 1 st circular domain a is first divided₁The bending points divided by the circle area are preset to reach the upper limit value, and the bending points which can be divided at the moment are t₁、t₂、t₃、t₄、t₅And t is₁To divide a circular domain a₁A starting point of (a);

step four, defining a reasonable bending circle region:

according toCalculating by straight line segmentIs the center of a circle, toDividing a circular field by radius_nCircular domain bending point density ofAccording toCalculating by straight line segmentIs the center of a circle, toDividing a circular field by radius_nThe ratio of angular distances between the bending points of the circle anddetermine if there isAnd is

The method specifically comprises the following steps:

if it is notIs formed in a way thatWhen it is true, straight line segments are used for explanationIs the center of a circle, toRadius-based circle bending point densityDoes not exceed the set upper limit value rho of the density of the round bending points_maxAnd the ratio of the angular distance of the bending points in the circular areaDoes not exceed the set circular region bending point angular distance ratio and the upper limit value (∑ E)_maxThen, the straight line segment will be usedIs the center of a circle, toThe dividing circle area containing the curve segment of the orthodontic arch wire is defined as a reasonable bending circle area a_nCalculating the number q of all bending points which are divided by the reasonable bending circular domain on the orthodontic arch wire curve, and skipping to the fifth step;

if it is notIs out of standing orAre out of standing and existAt this time, the number of the circle domain bending points for dividing the circle domain is not less than 1, and then the number of the circle domain bending points is continuously reduced to divide the circle domain, so thatCalculating the number q of all bending points on the orthodontic arch wire curve which are divided by the reasonable bending circular domain, and skipping to the third step;

if it is notIs out of standing orAre out of standing and existTo explain this, the number of the circle bending points for dividing the circle is only 1, and will be represented by t_q+1As a circle center, with a bending point t_q+1To adjacent bending point t_q+2Half of the linear distance therebetweenThe dividing circle area generated for the radius and containing the curve segment of the orthodontic arch wire is defined as a reasonable bending circle area a_nThen the reasonable bending round area a_nComprises only one bending point t_q+1Calculating the number q of all bending points which are divided by the reasonable bending circular domain on the orthodontic arch wire curve, and skipping to the fifth step;

step five, judging whether to continue to divide the circle domain:

judging whether the number q of all bending points on the orthodontic arch wire curve divided by the reasonable bending circular domain is equal to the number i of the bending points,

the method specifically comprises the following steps:

if the number q of all bending points which are reasonably divided by the bending circular domain on the orthodontic arch wire curve is not equal to the number i of the bending points, the circular domain division is continued, n is equal to n +1, namely the next circular domain is divided, at the moment,

if i-q is more than or equal to 5, the number of the remaining undivided bending points is not less than 5, and then orderWhen the next circle domain is divided for the first time, the bending point which can be divided by the circle domain is preset to just reach the upper limit value, and the step III is skipped;

if i-q is less than 5 and i-q is not equal to 1, indicating that the number of remaining undivided bending points on the curve of the orthodontic arch wire is less than 5 but more than 1, and then controllingWhen the next circular area is divided for the first time, the number of bending points which can be divided by the circular area is equal to the number of remaining non-divided bending points on the orthodontic arch wire curve, and the step is skipped to the step three;

if i-q is less than 5 and i-q is 1, the bending points remained on the curve of the orthodontic arch wire and not divided at the moment are only the last 1 bending points t_iWill be given by t_iAs the center of circle, with t_i-1And t_iHalf of the linear distance therebetweenThe dividing circle area generated for the radius and containing the curve segment of the orthodontic arch wire is defined as a reasonable bending circle area a_nThen the reasonable bending round area a_nComprises only one bending point t_iJumping to the step six;

if the number q of all bending points divided by the reasonable bending circular domain on the orthodontic arch wire curve is equal to the number i of the bending points, the bending points are divided by the reasonable bending circular domain, and a reasonable bending circular domain information set A is output₁＝{a₁，a₂，...，a_nSkipping to the step six;

step six, outputting the final bending sequence

Calculating each reasonable bending circle region (a)₁，a₂，...，a_n) Circular domain bending point density ofObtaining a circle domain bending point density information setComparing the circular region bending point density of each reasonable bending circular region, and supposing to obtainThe dot density is formed by bending the circular regionArranging the n circular domains in descending order for the index to obtain a descending order reasonable bending circular domain information set A₁＝{a₃，a₁，...，a_sDefining the sequence of bending points swept clockwise by horizontal right vectors in any bending circular domain as the sequence of the bending points in the circular domain, and further obtaining the coordinate matrix T of the curve forming control points of the orthodontic arch wire₁＝{t₇，t₈，...，t_mAnd robot bending information set R₁＝{r₇，r₈，...，r_mWhere t is_mIndicating bending in the s-th rational bending circlePoint, output final bending point bending sequence T₁＝{t₇，t₈，...，t_m}、R₁＝{r₇，r₈，...，r_mAnd the program is ended.

Technical Field

The invention relates to a method for planning the bending sequence of an orthodontic arch wire by dividing a plane variable-radius circular domain, 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 method of the orthodontic arch wire bending planning, an equal-radius circular domain dividing method is proposed in an invention patent, which is granted by the inventor and has the publication number of CN107647925B, namely a circular domain dividing method for the orthodontic arch wire bending planning, the invention divides the regions on an orthodontic arch wire curve, 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, because the method only divides the orthodontic arch wire curve by an unachieved homogenization standard, the divided circular domain intervals usually have the condition that the density degree of the bending points is too large or too small, namely the divided intervals do not fully consider the individualized characteristic of the distribution information of the bending points on the orthodontic arch wire curve, thereby effectively avoiding the bending robot generating idle stroke invalid action or mutual interference action in the bending process, the maximum advantage of the bending robot is not brought into play, and the bending efficiency cannot be obviously improved.

Disclosure of Invention

Aiming at the problems, the invention provides a method for planning the bending sequence of an orthodontic arch wire by dividing a plane variable-radius circular region, which solves the problem that the prior art for bending the orthodontic arch wire lacks a method for obtaining a reasonable bending sequence of the orthodontic arch wire, provides reasonable dividing basis in the process of planning the bending sequence, quantitatively restricts the intensity of bending points and the bending complexity of the divided regions, and finally obtains the bending sequence which accords with the personalized characteristics of distribution information of the bending points on the orthodontic arch wire curve, thereby exerting the maximization of the advantages of a bending robot, ensuring the normal operation of the bending process of the orthodontic arch wire, improving the efficiency of the orthodontic bending planning of the arch wire and avoiding the problem of interference in the process of bending the arch wire by the robot.

The above purpose is mainly achieved through the following scheme:

a method for planning the bending sequence of an orthodontic arch wire divided by a plane variable-radius circular domain specifically comprises the following steps:

step one, dividing data import in a variable radius circular domain and orthodontic arch wire curve conversion:

according to the orthodontic arch wire curve with i bending points of a patient, calculating and inputting an orthodontic arch wire curve bending point information set T ═ T₁，t₂，t₃，...，t_i}，t_i＝(x_i，y_i，z_i) ' coordinates of each orthodontic archwire curve bending point at eachA bending point t_iThe upper robot executes different bending movements, and each 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;

centralizing the information of the individualized orthodontic arch wire curve forming control point into the coordinate t of each bending point_i＝(x_i，y_i，z_i) ' z in_iAssigned a value of 0, i.e. z_iObtaining an orthodontic arch wire curve conversion plane orthodontic arch wire curve T' which is equal to 0;

step two, setting of circle domain limiting parameters

Defining the number of bending points in the circular region by symbolsIndicating the number of bending points in the circleIs a radius ofRound area a of_nThe number of inner bending points; defining the density of bending points in a circle by symbolsIndicating, circle domain bending dot densityIs a circular domain a_nInner partA bending point having a radius ofThe degree of compactness in the circular domain of (1) is specifiedDensity of bending points in circular areaUnit of (2) is one/mm²，Dividing a circle area a for the nth variable radius on the curve of the orthodontic arch wire_nThe radius value of (d); defining a bending point angular distance ratio, denoted by the symbol E, which is a quantitative description of the bending complexity of a single bending point, the bending point angular distance ratio of the ith bending point definingIn particular, due to the first bending point t₁Without bending, the bending point t is specified₁Bending point-angular distance ratio E of₁0; defining the sum of the angular distances of the bending points in the circle by symbolsIt is shown that,is to divide the circular domain a_nThe divided bending points are quantitatively described in the whole bending complexity,represents the nth variable radius dividing circular area a on the curve of the orthodontic arch wire_nThe sum of the bending point angular distance ratios of all the bending points in the circle area a is divided when the radius is changed_nThe inner bending points are respectivelyWhen it is prescribedα_mTo act on the bending point t_mThe bending angle of the part is formed,indicating action at bending point t_mAt a bending distance, i.e. bending point t_m-1And t_mThe length of the curve segment between, the value range of m isq represents the number of all bending points in a circular domain which is divided into a variable-radius circular domain on the curve of the orthodontic arch wire, namelyWhen the circular domain is not divided, q is 0, namely the initial value of q is 0, the value range of q is more than or equal to 0 and less than or equal to i, and the density of the bending points of the circular domain is adjustedRatio of angular distance of bending points in circular areaNumber of bending points in the harmony circle regionCollectively referred to as circular domain limiting parameters, the upper limit values of the circular domain limiting parameters are defined and setUpper limit value Q of_maxSetting upIs rho_maxSetting upUpper limit value of (∑ E)_maxDuring the whole circle division process Q_max、ρ_maxAnd (∑ E)_maxConstant, in particular Q_maxJumping to the third step when the result is 5;

step three, determining the radius and the circle center of the divided circle domain:

dividing the circular field to bend the point t_q+1Taking bending points t as starting points_q+1Andthe straight line segments between the two segments are sequentially marked as line segmentsSegment of lineThe line segment with the largest middle length is recorded asNamely, it isRespectively representing line segments The length of the n-th circle segment a to be generated on the curve of the orthodontic arch wire_nIs a line segmentThe radius of the midpoint of (1) is a line segmentHalf of the lengthAt this time, exactly two bending points fall on the boundary line of the circular area, and the newly formed circular area a_nCan just divide the bending points preset in the step threeAll bending points on the orthodontic arch wire curve segment intersected by the specified circle domain boundary line are divided by the circle domain, when the generated circle domain boundary line passes through the bending points, the bending points are also divided by the circle domain, and the orthodontic arch wire curve segment where the divided bending points are located can not be divided by other circle domains any more;is initially ofn is initially 1, i.e. the 1 st circular domain a is first divided₁The bending points divided by the circle area are preset to reach the upper limit value, and the bending points which can be divided at the moment are t₁、t₂、t₃、t₄、t₅And t is₁To divide a circular domain a₁A starting point of (a);

step four, defining a reasonable bending circle region:

according toCalculating by straight line segmentIs the center of a circle, toDividing a circular field by radius_nCircular domain bending point density ofAccording toCalculating by straight line segmentIs the center of a circle, toDividing a circular field by radius_nThe ratio of angular distances between the bending points of the circle anddetermine if there isAnd is

The method specifically comprises the following steps:

if it is notIs formed in a way thatWhen it is true, straight line segments are used for explanationIs the center of a circle, toRadius-based circle bending point densityDoes not exceed the set upper limit value rho of the density of the round bending points_maxAnd the ratio of the angular distance of the bending points in the circular areaDoes not exceed the set circular region bending point angular distance ratio and the upper limit value (∑ E)_maxThen, the straight line segment will be usedIs the center of a circle, toThe dividing circle area containing the curve segment of the orthodontic arch wire is defined as a reasonable bending circle area a_nCalculating the number q of all bending points which are divided by the reasonable bending circular domain on the orthodontic arch wire curve, and skipping to the fifth step;

if it is notIs out of standing orAre out of standing and existAt this time, the number of the circle domain bending points for dividing the circle domain is not less than 1, and then the number of the circle domain bending points is continuously reduced to divide the circle domain, so thatCalculating the number q of all bending points on the orthodontic arch wire curve which are divided by the reasonable bending circular domain, and skipping to the third step;

if it is notIs out of standing orAre out of standing and existTo explain this, the number of the circle bending points for dividing the circle is only 1, and will be represented by t_q+1As a circle center, with a bending point t_q+1To adjacent bending point t_q+2Half of the linear distance therebetweenThe dividing circle area generated for the radius and containing the curve segment of the orthodontic arch wire is defined as a reasonable bending circle area a_nThen the reasonable bending round area a_nComprises only one bending point t_q+1Calculating the number q of all bending points which are divided by the reasonable bending circular domain on the orthodontic arch wire curve, and skipping to the fifth step;

step five, judging whether to continue to divide the circle domain:

judging whether the number q of all bending points on the orthodontic arch wire curve divided by the reasonable bending circular domain is equal to the number i of the bending points,

the method specifically comprises the following steps:

if the number q of all bending points which are reasonably divided by the bending circular domain on the orthodontic arch wire curve is not equal to the number i of the bending points, the circular domain division is continued, n is equal to n +1, namely the next circular domain is divided, at the moment,

if i-q is more than or equal to 5, the number of the remaining undivided bending points is not less than 5, and then orderWhen the next circle domain is divided for the first time, the bending point which can be divided by the circle domain is preset to just reach the upper limit value, and the step III is skipped;

if i-q is less than 5 and i-q is not equal to 1, indicating that the number of remaining undivided bending points on the curve of the orthodontic arch wire is less than 5 but more than 1, and then controllingWhen the next circular area is divided for the first time, the number of bending points which can be divided by the circular area is equal to the number of remaining non-divided bending points on the orthodontic arch wire curve, and the step is skipped to the step three;

if i-q is less than 5 and i-q is 1, the bending points remained on the curve of the orthodontic arch wire and not divided at the moment are only the last 1 bending points t_iWill be given by t_iAs the center of circle, with t_i-1And t_iHalf of the linear distance therebetweenThe dividing circle area generated for the radius and containing the curve segment of the orthodontic arch wire is defined as a reasonable bending circle area a_nThen the reasonable bending round area a_nComprises only one bending point t_iJumping to the step six;

if the number q of all bending points divided by the reasonable bending circular domain on the orthodontic arch wire curve is equal to the number i of the bending points, the bending points are divided by the reasonable bending circular domain, and a reasonable bending circular domain information set A is output₁＝{a₁，a₂，...，a_nSkipping to the step six;

step six, outputting the final bending sequence

Calculating each reasonable bending circle region (a)₁，a₂，...，a_n) Circular domain bending point density ofObtaining a circle domain bending point density information setComparing the circular region bending point density of each reasonable bending circular region, and supposing to obtainThe dot density is formed by bending the circular regionArranging the n circular domains in descending order for the index to obtain a descending order reasonable bending circular domain information set A₁＝{a₃，a₁，...，a_sDefining the sequence of bending points swept clockwise by horizontal right vectors in any bending circular domain as the sequence of the bending points in the circular domain, and further obtaining the coordinate matrix T of the curve forming control points of the orthodontic arch wire₁＝{t₇，t₈，...，t_mAnd robot bending information set R₁＝{r₇，r₈，...，r_mWhere t is_mThe bending points in the s-th reasonable bending circular domain are shown, and the final bending point bending sequence T is output₁＝{t₇，t₈，...，t_m}、R₁＝{r₇，r₈，...，r_mAnd the program is ended.

The invention has the beneficial effects that:

1. the invention aims at the orthodontic arch wire bending planning method, defines the circular domain limiting parameters and provides the number of the circular domain bending pointsAnd circle bending point densityThe concept of (1) quantitatively describing the tightness degree of the bending point, and provides the angular distance ratio sum of the bending points in a circular domainThe concept of (2) quantitatively describes the bending complexity of the bending points in the divided circular domain, and setsThe upper limit value of (2) can ensure that the number of bending points in each divided circle region is not more than the upper limit value, and setUpper limit value ρ of_maxAndupper limit value of (∑ E)_maxThereby a plurality of reasonable bending circular areas meeting the set requirements can be formed on one orthodontic arch wire curve, the phenomena of overlarge bending point density and overhigh bending complexity degree of the divided circular areas are avoided, the problem of interference of the robot in the bending process is avoided to the maximum extent, and the bending process is finished by the pairThe definition of the equal circle domain limiting parameters is convenient for dividing bending points by using the circle domain limiting parameters as a planning index in the orthodontic arch wire bending planning, and provides theoretical basis for the orthodontic arch wire bending planning.

2. The invention adopts the variable radius circular domain dividing method, the circle center and the radius of the divided region are determined by the distribution condition of the bending points in the region, the change of the number of the bending points in the region causes the change of the circle center and the radius of the circular domain, the information of the bending points in the region can be more fully reflected, the calculation and the selection of the system on the divided circular domain data are convenient, and the dividing efficiency of the method is improved.

3. The invention adopts the method of dividing the variable radius circular domain, and the division of the bending area is determined by the bending point information, so that the situation that the bending points are repeatedly divided when a new area is divided is avoided, the divided areas are ensured to be meaningful to plan, and the rationality and the accuracy of the orthodontic arch wire bending planning are improved.

4. After all bending points are divided, the invention uses the circle domain bending point density defined aiming at the circle domain divisionThe n circular domains are subjected to descending order arrangement for indexes to obtain descending order reasonable bending circular domain information sets, any bending circular domain is defined, the bending point sequence scanned clockwise by the horizontal right vector is defined as the bending point sequence of the circular domain, each bending point is ensured to have a determined bending sequence, and therefore the operability and accuracy of the orthodontic arch wire bending planning are improved.

5. Compared with the invention patent of 'a method for dividing the variable-radius circular domain of the orthodontic arch wire based on the bending point angular distance ratio' filed on the same day by the inventor, the method provided by the invention does not require that the bending points of the personalized orthodontic arch wire curve meet the upper limit constraint of the unit bending point density in advance, and in addition, compared with the invention patent of 'a method for dividing the variable-radius circular domain of the orthodontic arch wire based on the bending point density' filed on the same day by the inventor, the method provided by the invention does not require oneThe bending points of the sexual orthodontic arch wire curve meet the upper limit constraint of the angle distance ratio of the bending points in advance, so compared with the two methods, the method has the advantage that the density of the bending points in the circular area is reduced in the circular area dividing processAnd bending point-to-angular distance ratioThe two limiting factors are combined, and in conclusion, the method is not only suitable for individual orthodontic arch wire curves with special attributes, but also suitable for all orthodontic arch wire curves which can adopt a plane division method, so that the method has universal applicability and comprehensiveness in a series of plane division methods for orthodontic arch wire bending planning.

6. Compared with the invention patent of CN107647925B, the invention patent of a circular domain dividing method for orthodontic arch wire bending planning, the radius of the circular domain dividing defined in the invention patent of the circular domain dividing method for orthodontic arch wire bending planning is equal, the situation that the intensity of the bending points in the divided circular domain interval is too large or too small exists, namely the generated circular domain interval does not fully consider the individual characteristics of the distribution information of the bending points on the orthodontic arch wire curve, the orthodontic arch wire is divided only by an un-based homogenization standard, and the invention carries out the quantitative constraint of the bending complexity and the intensity of the bending points of the divided arch wire area according to the defined circular domain limiting parameters, thereby leading the radius of the divided circular domain to change according with the regulation of the circular domain limiting parameters, and finally obtaining the reasonable bending circular domain with different radii according with the distribution information characteristics of the bending points on the orthodontic arch wire individual curve, the conditions that the intensity of bending points in each divided circle region is very different from the bending complexity are effectively avoided, and the rationality of the orthodontic arch wire bending planning method is enhanced to a certain extent.

7. Compared with the invention patent of invention 'a circle domain dividing method for orthodontic arch wire bending planning', which is granted by the inventor and has the publication number of CN107647925B, the circle domain does not have the condition that the density of bending points is too large or too small after the division is finished, so that the bending robot can not generate idle stroke invalid action or mutual interference action in the bending process after the bending sequence planning is finished, thereby the maximization of the advantages of the bending robot can be exerted, the normal operation of the orthodontic arch wire bending process is ensured, the efficiency of the orthodontic arch wire bending planning is improved, and the problem of interference in the orthodontic arch wire bending process of 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 planning a bending sequence of an orthodontic arch wire divided by a plane variable-radius circular domain;

fig. 2 is a schematic view of distribution of individual orthodontic arch wire bending points;

fig. 3 is a schematic view of a variable radius circle divided individual orthodontic archwire curve;

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.