阅读说明：本技术 一种基于弯制点密度的正畸弓丝变角度划分方法 (Orthodontic arch wire variable-angle dividing method based on bending point density ) 是由 姜金刚 郭亚峰 吴殿昊 张永德 闵兆伟 曾阳 于 2020-06-01 设计创作，主要内容包括：本发明公开了一种基于弯制点密度的正畸弓丝变角度划分方法,它涉及正畸弓丝弯制领域,根据患者的个性化正畸弓丝曲线,基于正畸弓丝曲线成形控制点信息集,成形控制点的机器人运动信息集,当患者正畸弓丝曲线上各弯制点的单位角距比均小于单位角距比上限值时,结合机器人弯制正畸弓丝的特点,设定变角度域弯制点密度上限值,得出一种基于弯制点密度的正畸弓丝变角度划分方法,划分并排列变角度域,最终得到各弯制点的弯制顺序。本发明通过对划分变角度域的弯制点密集程度进行定量约束,保证了变角度域划分的合理性,提高了规划效率。(The invention discloses an orthodontic arch wire variable angle dividing method based on bending point density, which relates to the field of orthodontic arch wire bending, and is characterized in that a control point information set and a robot motion information set of control points are formed based on an orthodontic arch wire curve according to an individual orthodontic arch wire curve of a patient, when the unit angular distance ratio of each bending point on the orthodontic arch wire curve of the patient is smaller than the upper limit value of the unit angular distance ratio, the upper limit value of the bending point density of a variable angle domain is set by combining the characteristic of the robot for bending an orthodontic arch wire, so that the orthodontic arch wire variable angle dividing method based on the bending point density is obtained, the variable angle domains are divided and arranged, and finally the bending sequence of each bending point is obtained. The method and the device have the advantages that the rationality of the division of the variable angle domain is ensured and the planning efficiency is improved by carrying out quantitative constraint on the density degree of the bending points for dividing the variable angle domain.)

1. An orthodontic arch wire variable-angle dividing method based on bending point density is characterized in that: the method comprises the following concrete implementation processes:

step one, importing variable angle domain division data:

inputting an information set M ═ M of the forming control point of the personalized orthodontic arch wire curve according to the personalized orthodontic arch wire curve with i forming control points of the patient₁，m₂，m₃，...，m_i}，m_i＝(u_i，v_i，w_i) 'for each individual orthodontic archwire curve shaping control point's coordinates, each orthodontic archwire curve shaping control point m_iAll correspond to a forming control point robot motion information unit n_iThe robot motion information set of the input shaping control point is N ═ N₁，n₂，n₃，...，n_i}，n_iRepresenting the coordinates of the forming control point and the bending angle, n, of the robot when bending the point_i＝(u_i，v_i，w_i，α_i)'，u_i、v_i、w_iFor the formation ofControl point m_iα_iActing on forming control points m for robots_iThe upper bending angle is obtained by comparing an orthodontics arch wire curve forming control point information set M, a robot motion information set N of a forming control point and a unit angular distance with an upper limit value E_maxInputting the variable angle domain bending point density threshold rho into an orthodontic arch wire bending system, and setting the variable angle domain bending point density threshold rho according to the characteristics of the robot bending orthodontic arch wire_max；

The coordinates of two end points of the personalized orthodontic arch wire curve are m_s(u_s，v_s，w_s)，m_e(u_e，v_e，w_e) The left end point m of the curve of the arch wire is adjusted_sSet as a forming control point m₀The right end point m of the arch wire curve is adjusted_eSet as a forming control point m_i+1By the midpoint of the left and right end points of the arch wire curveDefined as the center O, and forming a control point m_kAs a starting point for dividing the angle-variable domain, k is 0 or more, k is 0 or less and i or less, and a forming control point m_kThe line connecting the center O of the circle is defined as a dividing radius R_k；

Step two, orthodontics arch wire curve coordinate transformation and division variable definition:

centralizing the information of the individual orthodontic arch wire forming control points into the coordinate m of each forming control point_i＝(u_i,v_i,w_i) ' w in_iAssigned a value of 0, i.e. order w_iObtaining an orthodontic arch wire conversion curve M' as 0;

for the angle-variable dividing method, an angle-variable domain b is defined_kBending point density ofWhereinIn the variable angle domain b_kThe number of bending points which are internally divided,is initially of Representing a variable angle domain b_kInner dividing radius R_kAnd dividing the radiusThe value of the angle formed between them,in a variable angle domain b_kInner maximum dividing radius, initializationAny bending point m on personalized orthodontic arch wire_xUnit angular distance ratio ofIs a bending point m_xAngle of bending α_xAt a bending distance from itRatio of (i) to (ii)WhereinIndicates a bending point m_xAnd bending point m_x+1The arc length between the two arch wires is more than or equal to 1 and less than or equal to i, and the unit angular distance ratio of each bending point on the personalized orthodontic arch wire is calculatedUnit angular distance ratio of each bending pointAre all less than the upper limit value E of the unit angular distance ratio_maxThen, jumping to the third step;

step three, searching the maximum radius in the variable angle domain

R_k+jIndicating the slave forming control point m_kTo the forming control pointThe corresponding dividing radius value of the jth forming control point in between, the initial value of j is 1,

a) judgment ofWhether the result is true or not;

if it is notIs established, determinedWhether the result is true or not;

if it is notIf true, then R is_k+jValue of (2)Namely, it isj equals j +1, and the step is returned to;

if it is notIf the condition is not satisfied,the value of (A) is kept constant, i.e.j equals j +1, and the step is returned to;

b) if it is notIf not, skipping to the fourth step;

step four, calculating the bending point density of the variable angle region:

and R_kThe angle between is recorded asUsing formulasCalculating a variable angle field b_kThe bending point density of (a);

judgment ofWhether the result is true or not;

if it is notWhen the right end point of the arch wire curve is divided, the bending point m is defined_kAnd bending pointThe variable angle domain is defined as a variable angle domain interval b_kVariable angle domain interval b_kHas a bending point density ofSkipping to the step five, and counting the number q of the divided bending points;

if it is notIf the curve is not true, the curve is not divided into the right end point of the arch wire curve, and judgment is madeWhether the result is true or not;

if it is notIf yes, the number of bending points in the variable angle domain can be continuously increased, namely, the order is givenSkipping to the third step;

if it is notIf the angle is not established, the bending point can not be added in the variable angle domain, and the step five is skipped;

step five, defining a variable angle domain interval:

will bend to point m_kAnd bending pointThe variable angle domain is defined as a variable angle domain interval b_kAnd a variable angle domain section b_kInner slave bending point m_kTo the bending pointIncluding bending pointsBut does not include the bending point m_kAll the bending points are divided, the number q of the divided bending points is counted, and an angle-variable domain interval b is calculated_kHas a bending point density ofJumping to the sixth step;

step six, judging whether to continue the variable angle domain division:

judging whether q is true or not;

if q is not satisfied, continuing to divide the variable angle domain, and continuing to start the variable angle division from the last bending point of the current bending point because the current bending point does not accord with the bending requirement, namely, continuing to divide the variable angle domain from the last bending point of the current bending pointFor dividing the starting point of the variable angle domain, orderSkipping to the second step;

if q is true, all bending points are divided, and the process skips to step seven;

step seven, obtaining a final bending point bending sequence:

outputting a variable angle domain interval information set B ═ B₁，b₂，...，b_gEach variable angle domain interval (b)₁，b₂，...，b_g) The corresponding angle values are respectively (theta)₁，θ₂，...，θ_g) And theta₁+θ₂+...+θ_gEach of the variable angle domain intervals (b) is compared₁，b₂，...，b_g) Bending point density ofTo obtainAt a bending point densityG variable angle domain intervals are arranged in a descending order for the index to obtain a descending order variable angle domain interval information set C ═ C₂，c₄，...，c_gWithin any one variable angle domain interval, according to the unit angular distance ratio of each bending pointThe bending points are arranged in a descending order for the index, the bending point angle distance ratio descending order sequence is defined as the bending point bending sequence in the variable angle domain interval, and then the coordinate descending order matrix M of the individualized orthodontic arch wire curve forming control point is obtained₁{m₄，m₆，...，m_sAnd robot motion descending order information set N₁{n₄，n₆，...，n_sIn which m is_sIndicates a variable angle domain section b_gThe bending point in the middle, and the final bending point bending sequence M is output₁{m₄，m₆，...，m_s}、N₁{n₄，n₆，...，n_sAnd the program is ended.

Technical Field

The invention relates to an orthodontic arch wire variable-angle dividing method based on bending point density, and belongs to the technical field of orthodontic arch wire bending.

Background

At present, malocclusion deformity is an oral disease with high morbidity in people, the malocclusion deformity not only affects the development of jaw and facial soft tissues of patients, the health and function of oral cavity, appearance and sound function, but also may cause the serious consequences of dyspnea and gastrointestinal function disorder, and the like.

When the sequence planning of the bending points of the individual orthodontic arch wire is carried out, the bending complexity of each bending point is relatively low, namely the unit angular distance ratio of each bending point is relatively small, when the unit angular distance ratio of each bending point on the arch wire curve is smaller than the upper limit value of the unit angular distance ratio set according to the bending orthodontic arch wire of the robot, due to the distribution particularity of the bending points, when the variable-angle domain division is carried out on the individual orthodontic arch wire, the planning calculation amount of the existing orthodontic arch wire forming control point bending sequence is relatively large, the time consumption during the planning is relatively large, and the existing orthodontic arch wire bending technical field lacks a method for the sequence planning of the bending points of the individual orthodontic arch wire, and cannot realize the efficient digital bending of the individual orthodontic arch wire.

Disclosure of Invention

Aiming at the problems, the invention provides an orthodontic arch wire variable-angle dividing method based on bending point density, which solves the problem that the prior orthodontic arch wire bending technical field lacks a method for sequentially planning the bending points of the individual orthodontic arch wire, provides reasonable dividing basis in the bending sequence planning process, and quantitatively restricts the density degree of the bending points in the divided areas, thereby realizing high-efficiency digital bending of the orthodontic arch wire.

The scheme adopted by the invention to solve the problems is as follows: an orthodontic arch wire variable-angle dividing method based on bending point density is characterized in that: the method comprises the following concrete implementation processes:

step one, importing variable angle domain division data:

inputting an information set M ═ M of the forming control point of the personalized orthodontic arch wire curve according to the personalized orthodontic arch wire curve with i forming control points of the patient₁，m₂，m₃，...，m_i}，m_i＝(u_i，v_i，w_i) 'for each individual orthodontic archwire curve shaping control point's coordinates, each orthodontic archwire curve shaping control point m_iAll correspond to a forming control point robot motion information unit n_iThe robot motion information set of the input shaping control point is N ═ N₁，n₂，n₃，...，n_i}，n_iRepresenting the coordinates of the forming control point and the bending angle, n, of the robot when bending the point_i＝(u_i，v_i，w_i，α_i)'，u_i、v_i、w_iFor the forming control point m_iα_iActing on forming control points m for robots_iThe upper bending angle is obtained by comparing an orthodontics arch wire curve forming control point information set M, a robot motion information set N of a forming control point and a unit angular distance with an upper limit value E_maxInputting the variable angle domain bending point density threshold rho into an orthodontic arch wire bending system, and setting the variable angle domain bending point density threshold rho according to the characteristics of the robot bending orthodontic arch wire_max；

The coordinates of two end points of the personalized orthodontic arch wire curve are m_s(u_s，v_s，w_s)，m_e(u_e，v_e，w_e) The left end point m of the curve of the arch wire is adjusted_sSet as a forming control point m₀The right end point m of the arch wire curve is adjusted_eSet as a forming control point m_i+1By the midpoint of the left and right end points of the arch wire curveDefined as the center O, and forming a control point m_kAs a starting point for dividing the angle-variable domain, k is 0 or more, k is 0 or less and i or less, and a forming control point m_kThe line connecting the center O of the circle is defined as a dividing radius R_k；

Step two, orthodontics arch wire curve coordinate transformation and division variable definition:

centralizing the information of the individual orthodontic arch wire forming control points into the coordinate m of each forming control point_i＝(u_i,v_i,w_i) ' w in_iAssigned a value of 0, i.e. order w_iObtaining an orthodontic arch wire conversion curve M' as 0;

for the angle-variable dividing method, an angle-variable domain b is defined_kBending point density ofWhereinIn the variable angle domain b_kThe number of bending points which are internally divided,is initially ofRepresenting a variable angle domain b_kInner dividing radius R_kAnd dividing the radiusThe value of the angle formed between them,in a variable angle domain b_kInner maximum dividing radius, initializationAny bending point m on personalized orthodontic arch wire_xUnit angular distance ratio ofIs a bending point m_xAngle of bending α_xAt a bending distance from itRatio of (i) to (ii)WhereinIndicates a bending point m_xAnd bending point m_x+1The arc length between the two arch wires is more than or equal to 1 and less than or equal to i, and the unit angular distance ratio of each bending point on the personalized orthodontic arch wire is calculatedUnit angular distance ratio of each bending pointAre all less than the upper limit value E of the unit angular distance ratio_maxThen, jumping to the third step;

step three, searching the maximum radius in the variable angle domain

R_k+jIndicating the slave forming control point m_kTo the forming control pointThe corresponding dividing radius value of the jth forming control point in between, the initial value of j is 1,

a) judgment ofWhether the result is true or not;

if it is notIs established, determinedWhether the result is true or not;

if it is notIf true, then R is_k+jValue of (2)Namely, it isj equals j +1, and the step is returned to;

if it is notIf the condition is not satisfied,the value of (A) is kept constant, i.e.j equals j +1, and the step is returned to;

b) if it is notIf not, skipping to the fourth step;

step four, calculating the bending point density of the variable angle region:

and R_kThe angle between is recorded asUsing formulasCalculating a variable angle field b_kThe bending point density of (a);

judgment ofWhether the result is true or not;

if it is notWhen the right end point of the arch wire curve is divided, the bending point m is defined_kAnd bending pointThe variable angle domain is defined as a variable angle domain interval b_kVariable angle domain interval b_kHas a bending point density ofSkipping to the step five, and counting the number q of the divided bending points;

if it is notIf the curve is not true, the curve is not divided into the right end point of the arch wire curve, and judgment is madeWhether the result is true or not;

if it is notIf yes, the number of bending points in the variable angle domain can be continuously increased, namely, the order is givenSkipping to the third step;

if it is notIf the angle is not established, the bending point can not be added in the variable angle domain, and the step five is skipped;

step five, defining a variable angle domain interval:

will bend to point m_kAnd bending pointThe variable angle domain is defined as a variable angle domain interval b_kAnd a variable angle domain section b_kInner slave bending point m_kTo the bending pointIncluding bending pointsBut does not include the bending point m_kAll the bending points are divided, the number q of the divided bending points is counted, and an angle-variable domain interval b is calculated_kHas a bending point density ofJumping to the sixth step;

step six, judging whether to continue the variable angle domain division:

judging whether q is true or not;

if q is not satisfied, continuing to divide the variable angle domain, and continuing to start the variable angle division from the last bending point of the current bending point because the current bending point does not accord with the bending requirement, namely, continuing to divide the variable angle domain from the last bending point of the current bending pointFor dividing the starting point of the variable angle domain, orderSkipping to the second step;

if q is true, all bending points are divided, and the process skips to step seven;

step seven, obtaining a final bending point bending sequence:

outputting a variable angle domain interval information set B ═ B₁，b₂，...，b_gEach variable angle domain interval (b)₁，b₂，...，b_g) The corresponding angle values are respectively (theta)₁，θ₂，...，θ_g) And theta₁+θ₂+...+θ_gEach of the variable angle domain intervals (b) is compared₁，b₂，...，b_g) Bending point density ofTo obtainAt a bending point densityG variable angle domain intervals are arranged in a descending order for the index to obtain a descending order variable angle domain interval information set C ═ C₂，c₄，...，c_gWithin any one variable angle domain interval, according to the unit angular distance ratio of each bending pointThe bending points are arranged in a descending order for the index, the bending point angle distance ratio descending order sequence is defined as the bending point bending sequence in the variable angle domain interval, and the coordinate descending order matrix M of the individualized orthodontic arch wire curve forming control point is obtained₁{m₄，m₆，...，m_sAnd robot motion descending order information set N₁{n₄，n₆，...，n_sIn which m is_sIndicates a variable angle domain section b_gThe bending point in the middle, and the final bending point bending sequence M is output₁{m₄，m₆，...，m_s}、N₁{n₄，n₆，...，n_sAnd the program is ended.

The invention has the beneficial effects that:

1. the invention is in alignment with the abnormal bowWhen the wire is subjected to variable angle division, a concept of a unit angular distance ratio is provided, the bending complexity of each bending point on an orthodontics arch wire curve is quantitatively described through the ratio of the bending angle of each bending point to the bending arc length, and an upper limit value E of the unit angular distance ratio is set according to the characteristics of the orthodontics arch wire bent by the robot_maxTherefore, the bending complexity of each bending point on the orthodontic arch wire curve is limited, and the orthodontic arch wire curve can be conveniently divided into variable-angle domains by utilizing the bending point density value in the next step.

2. Compared with the invention patent 'an orthodontic arch wire bending sequence planning method with variable angle division' filed by the inventor on the same day, the method judges the bending complexity of each bending point on the orthodontic arch wire curve, namely judges that the unit angular distance ratio of each bending point on the orthodontic arch wire curve meets the division requirement, and then performs variable angle division on the orthodontic arch wire curve, and only needs to calculate the density of the bending points in the variable angle domain during division, thereby reducing the cycle number, reducing the calculation scale and improving the division efficiency.

3. The invention bends the point density according to the variable angle domainAfter the angle-variable intervals are arranged in a descending order, the descending order of the unit angular distance ratio of each bending point is used as the arrangement order of the bending points in the intervals in each angle-variable interval, and finally, a reasonable bending order can be output, so that the completeness of the orthodontic arch wire bending planning is ensured.

4. Compared with the invention patent of an orthodontic arch wire bending sequence planning method with equal angle division, which is already granted by the inventor and has the publication number of CN107714203B, the method fully considers the individual characteristics of the distribution information of the bending points on the curve of the orthodontic arch wire on the basis of plane variable angle division and aims at the class of arch wires with specific attributes, namely the unit angular distance ratio of the bending points on the individual orthodontic arch wire of a patient is relatively smaller, the unit angular distance ratio of each bending point is smaller than the upper limit value of the specified unit angular distance ratio, the concept based on the density of the bending points in the variable angle domain is provided for dividing the curve of the orthodontic arch wire, the dividing process is not divided by an unjustified homogenization standard, but the angle value of the variable angle domain is continuously changed in order that the divided variable angle domain meets the upper limit requirement of the distribution density degree of the bending points, a series of variable-angle domain intervals meeting the requirement of variable-angle domain bending point density are generated, the rationality of the method for planning the bending sequence of the orthodontic arch wire forming control points is improved, idle stroke invalid actions, mutual interference actions in the bending process and complex bending movement actions of the bending robot are effectively avoided, the advantages of the bending robot are fully exerted to the maximum, and the bending efficiency is obviously improved.

5. Compared with the invention patent namely ' a bending point angular distance ratio and orthodontic arch wire variable angle dividing method based on the bending point angular distance ratio ', which is filed by the inventor on the same day, although both methods are suitable for a class of individual orthodontic arch wire curves with special attributes, the method mentioned in ' an orthodontic arch wire variable angle dividing method based on the bending point angular distance ratio and the bending point angular distance ratio ' emphasizes the premise that the unit bending point density of each bending point meets the set requirement, and further only the bending point angular distance ratio and the bending point angular distance ratio in the variable angle domain and the variable angle dividing method in the variable angle domain ' are usedThe method is used as a basis for dividing the variable angle domain, and the method emphasizes on the premise that the unit angular distance ratio of the bending points meets the set requirement, and further, the bending point density in the variable angle domain is only usedAs a basis for dividing the variable angle domain, the two methods have different application conditions when the orthodontic arch wire bending sequence planning is carried out, so that the method is mutually compensated with the other method, and further, the series of methods for the orthodontic arch wire bending sequence planning are perfected.

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 an orthodontic archwire variable angle dividing method based on bending point density;

FIG. 2 is a schematic diagram of a variable angle domain bending point density calculation;

fig. 3 is a schematic view of an individualized orthodontic archwire curve divided based on variable angle of bending point density;

fig. 4 is a schematic diagram of distribution of control points for forming a personalized orthodontic archwire;

fig. 5 is a schematic view of a planned bending point bending sequence after the variable-angle division of the personalized orthodontic arch wire curve is completed;

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.