阅读说明：本技术 一种用于正畸弓丝弯制规划的平面变角度划分方法 (Plane variable angle dividing method for orthodontic arch wire bending planning ) 是由 姜金刚 郭亚峰 吴殿昊 闵兆伟 张永德 唐德栋 于 2020-06-01 设计创作，主要内容包括：本发明公开了一种用于正畸弓丝弯制规划的平面变角度划分方法,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,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,变角度域弯制点数量上限值和变角度域弯制点角距比和的上限值,建立了一种用于正畸弓丝弯制规划的平面变角度划分方法,划分并排列变角度域,最终得到各弯制点的弯制顺序。本发明通过对划分区域的弯制点密集程度及弯制复杂程度定量约束,保证了变角度域划分的连续性,提高了规划效率。(The invention discloses a plane variable angle dividing method for orthodontic arch wire bending planning, which relates to the field of orthodontic arch wire bending, sets an upper limit value of bending point density in a variable angle domain according to an individual orthodontic arch wire curve of a patient, based on an orthodontic arch wire curve forming control point information set and a robot motion information set of forming control points, and combines the characteristics of a robot bending orthodontic arch wire, and establishes a plane variable angle dividing method for orthodontic arch wire bending planning, wherein the upper limit value of the bending point number in the variable angle domain and the upper limit value of the bending point angular distance ratio in the variable angle domain are divided and arranged, and finally the bending sequence of each bending point is obtained. The method ensures the continuity of variable-angle domain division and improves the planning efficiency by quantitatively constraining the bending point density and the bending complexity of the divided region.)

1. A plane variable angle dividing method for orthodontic arch wire bending planning 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_iSo the 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 bending angle is set up, and an orthodontic arch wire curve forming control point information set M and a robot motion information set N of a forming control point are input into an orthodontic arch wire bending system; and the upper limit value rho of the bending point density of the variable angle domain is set according to the characteristics of the robot for bending the orthodontic arch wire_maxUpper limit value Q of bending point number in variable angle domain_maxThe bending point-angular distance ratio and the upper limit value of the variable angle range (∑ E)_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+1Using the middle point m of the left and right end points of the arch wire curve_o As the center O, 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;

defining a variable angle domain b_kBending point density of variable angle regionWhereinIn 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, initializationBending point m_kAngular distance ratio ofIs a bending point m_kAngle of bending α_kAt a bending distance from itRatio of (i) to (ii)WhereinIndicates a bending point m_kAnd bending point m_k+1The length of the arc between the two electrodes,representing a variable angle domain b_kBy cumulative sum of angular-to-pitch ratios of all bending points, i.e. variationAngular domain b_kThe sum of the bending point-angular distance ratios of (1);

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, and R is judged_k+j>Whether R is true;

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 density of the variable angle domain and the angular distance ratio sum of the bending points in the variable angle domain:

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 notIf the right end point of the arch wire curve is divided, the formula is usedCalculating a variable angle field b_kThe sum of the bending point-angular distance ratios of (m) will bend the point m_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 arch wire curve is not divided into the right end point, the formula is usedCalculating a variable angle field b_kAnd the bending point-angular distance ratio of (1) and (2) are determinedAnd isAnd isWhether the result is true or not;

if it is notAnd isAnd isIf so, the variable angle domain b can be continuously increased_kThe number of the inward bending points beingSkipping to the third step;

if it is notOrOrIf not, the variable angle domain b is illustrated_kNo bending point can be added, 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 first 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 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_gIn bendingPoint, output final bending point bending sequence M₁{m₄，m₆，...，m_s}、N₁{n₄，n₆，...，n_sAnd the program is ended.

Technical Field

The invention relates to a plane variable angle dividing method for orthodontic arch wire bending planning, and belongs to the technical field of orthodontic arch wire bending.

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 individualized orthodontic arch wire by the existing orthodontic arch wire bending robot (CN103892929A), due to the limitation of the structure of the robot, in order to improve the efficiency and the bending precision of the orthodontic arch wire bent by the robot, the bending sequence of the shaping control points of the orthodontic arch wire needs to be planned in advance, and the orthodontic arch wire has the characteristics of complex shape, a plurality of bending points, uneven distribution of the bending points and different bending difficulty of each bending point, the research on the dividing method of the bending points of the orthodontic arch wire is provided in the invention patent of an equal-angle divided orthodontic arch wire bending sequence planning method which is an invention patent with the authorization publication number of CN107714203B by the inventor, the equal-angle divided orthodontic arch wire method is provided, the orthodontic arch wire is divided into equal-angle domains with equal angles, and then each equal-angle domain is sequenced, so as to obtain the bending sequence of the final bending points, although the method has a certain application value to the bending planning of the orthodontic arch wire, the method only divides the curve of the orthodontic arch wire by an unachieved homogenization standard, the situation that the bending point density is too large or too small usually exists in the divided equal-angle domain intervals, the situation that the robot causes interference during bending can not be avoided, in addition, the improvement of the efficiency of the bending sequence planning of the forming control points is a necessary premise for realizing high-efficiency digital bending of the orthodontic arch wire, and the prior orthodontic arch wire bending technical field lacks a method for the bending sequence planning of the orthodontic arch wire, so that the high-efficiency digital bending of the arch wire is difficult to realize.

SUMMARY OF THE PATENT FOR INVENTION

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

The scheme adopted by the invention to solve the problems is as follows: a plane variable angle dividing method for orthodontic arch wire bending planning is specifically realized by the following steps:

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_iSo the 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 bending angle is set up, and an orthodontic arch wire curve forming control point information set M and a robot motion information set N of a forming control point are input into an orthodontic arch wire bending system; and the upper limit value rho of the bending point density of the variable angle domain is set according to the characteristics of the robot for bending the orthodontic arch wire_maxUpper limit value Q of bending point number in variable angle domain_maxThe bending point-angular distance ratio and the upper limit value of the variable angle range (∑ E)_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+1Using the middle point m of the left and right end points of the arch wire curve_o As the center O, 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;

defining a variable angle domain b_kBending point density of variable angle regionWhereinIn 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, initializationBending point m_kAngular distance ratio ofIs a bending point m_kAngle of bending α_kAt a bending distance from itRatio of (i) to (ii)WhereinIndicates a bending point m_kAnd bending point m_k+1The length of the arc between the two electrodes,representing a variable angle domain b_kThe sum of the angular-to-distance ratios of all bending points in the inner space, i.e. the variable-angle field b_kThe sum of the bending point-angular distance ratios of (1);

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, and R is judged_k+j>Whether R is true;

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 density of the variable angle domain and the angular distance ratio sum of the bending points in the variable angle domain:

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 notIf the right end point of the arch wire curve is divided, the formula is usedCalculating a variable angle field b_kThe sum of the bending point-angular distance ratios of (m) will bend the point m_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 arch wire curve is not divided into the right end point, the formula is usedCalculating a variable angle field b_kBending point-to-angular distance ratio ofAnd judgeAnd isAnd isWhether the result is true or not;

if it is notAnd isAnd isIf so, the variable angle domain b can be continuously increased_kThe number of the inward bending points beingSkipping to the third step;

if it is notOrOrIf not, the variable angle domain b is illustrated_kNo bending point can be added, 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 pointm_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 first 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 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.

The invention has the beneficial effects that:

1. in the process of executing variable-angle division, the invention comprehensively judges the density of bending points in the variable-angle region, the number of the bending points and the sum of the angular distances of the bending points, and combines the bending characteristics of the orthodontic arch wire of the robot, so that the bending points in each divided variable-angle region meet the bending requirements of the robot, the condition that the robot cannot generate interference during bending is ensured, and necessary support is provided for realizing high-efficiency digital bending of the orthodontic arch wire.

2. When the variable-angle domain bending point density is calculated, the maximum dividing radius in the current variable-angle domain is searched and usedThe bending points in the current variable-angle domain are scanned, so that the bending points in the divided regions can be completely contained, and the calculation of the density of the bending points in the variable-angle domain is more accurate.

3. The invention further specifies the dividing direction of the dividing method on the orthodontic arch wire by specifying the position of the starting point, and the end point of the previous variable angle interval is taken as the starting point for dividing the next variable angle interval during each division, thereby ensuring that the divided variable angle intervals are not overlapped and ensuring the continuity of the division of the variable angle domain.

4. The method of coordinate transformation in the step two is used for converting the three-dimensional orthodontic arch wire curve into the orthodontic arch wire curve on the two-dimensional plane, so that the calculation amount of the orthodontic arch wire bending sequence planning method is reduced, and the planning speed of the orthodontic arch wire bending sequence planning method is improved.

5. The invention has the bending point density according to each intervalAfter the angle-variable intervals are arranged in descending order, the angle-distance ratio of each bending point in each angle-variable domain is determinedThe descending order of the angle distance ratio of the bending points is used as the order of the bending points in the interval, and finally, a reasonable bending order can be output, so that the completeness of the orthodontic arch wire bending planning is ensured.

6. Compared with the invention patent ' an orthodontic arch wire variable angle dividing method based on bending point density ' which is filed by the inventor on the same day, the method provided by the invention does not require that the unit angle distance ratio of each bending point on the personalized orthodontic arch wire curve meets the upper limit requirement of the unit angle distance ratio in advance, and in addition, compared with the invention patent ' an orthodontic arch wire variable angle dividing method based on the bending point angle distance ratio ' and the invention patent ' which is filed by the inventor on the same day, the method provided by the invention does not require that the unit bending point density of each bending point on the personalized orthodontic arch wire curve meets the upper limit requirement of the unit bending point density in advance.

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 of planar variable angle division for orthodontic archwire bending planning;

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

fig. 3 is a schematic view of a variable angle-divided individualized orthodontic archwire curve;

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 descriptions taken in conjunction with the accompanying drawings, which are to be construed in an illustrative manner and not a limitation of the scope of the invention, and further, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the concepts of the invention