阅读说明：本技术 一种基于弯制点角距比和的正畸弓丝变角度划分方法 (Orthodontic arch wire variable-angle dividing method based on bending point-angle distance ratio sum ) 是由 姜金刚 郭亚峰 左晖 姚亮 张永德 吴殿昊 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角距比和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弯制点密度均小于单位弯制点密度上限值时,结合机器人弯制正畸弓丝的特点,设定变角度域弯制点角距比和上限值,得出一种基于弯制点角距比和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复杂程度进行定量约束,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 angle distance ratio and bending sequence, which relates to the field of orthodontic arch wire bending, wherein according to the individualized orthodontic arch wire curve of a patient, a control point information set is formed based on the orthodontic arch wire curve, and a robot motion information set of control points is formed. The method and the device have the advantages that the bending complexity for dividing the variable-angle domain is quantitatively restrained, the rationality of the division of the variable-angle domain is guaranteed, and the planning efficiency is improved.)

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

step one, importing variable angle domain division data:

personalized orthodontic archwire curvature with i shaping control points for a patientInputting an information set M ═ M of a curve forming control point of the personalized orthodontic arch wire₁，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 combining an orthodontic arch wire curve forming control point information set M, a robot motion information set N of forming control points and a unit bending point density upper limit value rho_maxInputting the variable angle domain bending point and the angle distance ratio and the threshold value into an orthodontic arch wire bending system, and setting the variable angle domain bending point and the angle distance ratio and the threshold value according to the characteristics of the robot bending orthodontic arch wire (∑ 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+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，Representing a division variable angle domain b_kThe number of bending points which are internally divided,is initially of

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 variable angle division method, a bending point m is defined_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 summation of the angular distance ratios of all the bending points in the arch wire and the sum of the angular distance ratios of any one bending point m on the personalized orthodontic arch wire_xUnit bending point density rho_mx＝2/β_xR_x+1Wherein β_xIndicates a bending point m_xIs divided into radii R_xAnd bending point m_x+1Is divided into radii R_x+1X is more than or equal to 1 and less than or equal to i, and the unit bending point density of each bending point on the personalized orthodontic arch wire is calculatedUnit bending point density of each bending pointAre all less than the upper limit value rho of the density of unit bending point_maxThen, jumping to the third step;

step three, calculating the sum of the angle distance ratio of the bending points in the variable angle domain:

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 bending point-angular distance ratio of (1) is added up to bend the point m_kAnd bending pointThe angle domain of the change is defined as changeAngular domain interval b_kVariable angle domain interval b_kIs a cumulative sum of the angular-to-distance ratios ofSkipping to the fourth step, 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_kThe bending point-angular distance ratio of (1) is added up and judgedWhether 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 a;

b) if it is notIf the bending point is not increased, the bending point cannot be increased in the variable angle domain, and the step C is skipped to;

step four, 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 bending systemDotIncluding 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_kThe bending point-angular distance ratio of is accumulated asSkipping to the step five;

step five, 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 step six is skipped;

step six, 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-to-angular distance ratio ofTo obtainThen the sum of the bending point-angular distance ratioG 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, bending point density is measured in units of each bending pointThe bending points are arranged in a descending order for the index, the density descending order sequence of the single bending points is defined as the bending point bending sequence in the variable angle domain interval, and then the coordinate descending order matrix M of the control point for the individualized orthodontic arch wire curve forming 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{m₂，m₄，...，m_g}，N₁{n₂，n₄，...，n_gAnd the program is ended.

Technical Field

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

Background

The malocclusion deformity is the third major oral disease which crisis the health of human body, the incidence rate is higher among people, in modern oral medicine, the fixed correction is a common and effective orthodontic treatment means, the bending of the orthodontic arch wire is the key of the fixed correction technology, in recent years, the fixed correction is deeply influenced by the digital manufacturing technology, the traditional oral manufacturing and processing technology is revolutionarily changed, the oral orthodontic field also benefits from the digital technology, the processing of the arch wire in the orthodontic appliance is developing towards digitization, however, the efficient planning of the bending point sequence is the premise of realizing the digital processing of the arch wire, improving the efficiency of bending the orthodontic arch wire by a robot and ensuring the bending precision.

When the sequence of the bending points of the individual orthodontic arch wire is planned, the distribution of the bending points on the individual orthodontic arch wire is relatively dispersed, namely the density of the unit bending points of each bending point on the orthodontic arch wire is very low, when the density value of the unit bending points of each bending point on the arch wire curve is smaller than the upper limit value of the density of the unit bending points 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 bending sequence of the existing orthodontic arch wire forming control points is relatively large, the time consumption during the planning period is relatively large, and the prior art of the orthodontic bending technology of the arch wire lacks a method for sequentially planning 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 angular distance ratio sum, which solves the problem that the prior orthodontic arch wire bending technical field lacks an efficient bending sequence planning method aiming at an orthodontic arch wire with relatively low bending point density of each bending point unit, so as to avoid the situation of high bending difficulty in a dividing region when the bending points of the orthodontic arch wire with special attributes are divided, is favorable for reasonably planning the bending sequence, avoids the interference situation in the bending process and further realizes the efficient 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 angular distance ratio sum 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_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 combining an orthodontic arch wire curve forming control point information set M, a robot motion information set N of forming control points and a unit bending point density upper limit value rho_maxInputting the variable angle domain bending point and the angle distance ratio and the threshold value into an orthodontic arch wire bending system, and setting the variable angle domain bending point and the angle distance ratio and the threshold value according to the characteristics of the robot bending orthodontic arch wire (∑ 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+1By the midpoint of the left end point and the right end point of the curve of the orthodontic arch wireDefined 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，Representing a division variable angle domain b_kThe number of bending points which are internally divided,is initially of

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 variable angle division method, a bending point m is defined_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 summation of the angular distance ratios of all the bending points in the arch wire and the sum of the angular distance ratios of any one bending point m on the personalized orthodontic arch wire_xUnit bending point density ofβ therein_xIndicates a bending point m_xIs divided into radii R_xAnd bending point m_x+1Is divided into radii R_x+1X is more than or equal to 1 and less than or equal to i, and the unit bending point density of each bending point on the personalized orthodontic arch wire is calculatedUnit bending point density of each bending pointAre all less than the upper limit value rho of the density of unit bending point_maxThen, jumping to the third step;

step three, calculating the sum of the angle distance ratio of the bending points in the variable angle domain:

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_kBending point ofThe angular-to-distance ratio is summed up to bend the point m_kAnd bending pointThe variable angle domain is defined as a variable angle domain interval b_kVariable angle domain interval b_kIs a cumulative sum of the angular-to-distance ratios ofSkipping to the fourth step, 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_kThe bending point-angular distance ratio of (1) is added up and judgedWhether 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 a;

b) if it is notIf the bending point is not increased, the bending point cannot be increased in the variable angle domain, and the step C is skipped to;

step four, defining a variable angle domain interval:

will bend to point m_kAnd bending pointAngle of change therebetweenThe 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_kThe bending point-angular distance ratio of is accumulated asSkipping to the step five;

step five, 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 pointDividing the starting point of the variable angle domain intoSkipping to the first step;

if q is true, all bending points are divided, and the step six is skipped;

step six, 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-to-angular distance ratio ofTo obtainThen the sum of the bending point-angular distance ratioG 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, bending point density rho is measured in unit of each bending point_mkThe bending points are arranged in a descending order for the index, the density descending order sequence of the single bending points is defined as the bending point bending sequence in the variable angle domain interval, and then the coordinate descending order matrix M of the control point for the individualized orthodontic arch wire curve forming 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{m₂，m₄，...，m_g}，N₁{n₂，n₄，...，n_gAnd the program is ended.

The invention has the beneficial effects that:

1. when the orthodontics arch wire is subjected to variable-angle division, the concept of unit bending point density is provided, so that the distribution condition of bending points on an orthodontics arch wire curve is quantitatively described, and the upper limit value rho of the unit bending point density is set according to the characteristics of the orthodontics arch wire bent by the robot_maxTherefore, the concentration degree of distribution of bending points on the orthodontic arch wire curve is limited, and the bending point angular distance ratio and the orthodontics arch wire curve can be conveniently divided into variable angle areas in the next step.

2. Compared with the invention patent ' a plane variable angle dividing method for orthodontic arch wire bending planning ' filed by the inventor on the same day ', the method firstly judges the concentration degree of distribution of bending points on an orthodontic arch wire curve, namely judges that the unit bending point density of each bending point on the orthodontic arch wire curve meets the dividing requirement, and then performs variable angle division on the orthodontic arch wire curve, and only needs to calculate the cumulative sum of the angle distance ratios of the bending points in a variable angle domain during division, thereby reducing the cycle number, reducing the calculation scale and improving the dividing efficiency.

3. After the angle intervals of the bending points in the variable angle domain are accumulated and arranged in a descending order according to the angle distance ratio of the bending points in the variable angle domain, the descending order of the unit bending point density of each bending point is used as the arrangement order of the bending points in the interval in each variable angle 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 aiming at the arch wire with specific attributes, namely the density of the bending points on the individual orthodontic arch wire of a patient is relatively smaller, the density of the bending points on each bending point is smaller than the specified upper limit value, the dividing method for dividing the curve of the orthodontic arch wire is provided based on the bending point angular distance ratio of the variable angle domain, so that the dividing process is not divided by a non-basis homogenization standard, but the divided variable angle domain is continuously changed to meet the upper limit requirement of the bending complexity, a series of variable-angle-domain intervals meeting the variable-angle-domain bending point-angle distance ratio and the requirement are generated, the rationality of the planning method of the bending sequence of the orthodontic arch wire forming control point 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 played to the maximum, and the bending efficiency is obviously improved.

5. Patent of invention patent of orthodontic arch wire variable angle division method based on bending point density filed on the same day by the same inventorCompared with the prior art, although both methods are suitable for individual orthodontic arch wire curves with special attributes, the method mentioned in the orthodontic arch wire variable-angle dividing method based on bending point density emphasizes on the premise that the unit angular distance ratio of each bending point meets the set requirement, and then the bending point density is only in a variable-angle domainThe method is used as a basis for dividing the variable angle domain, and the method is emphasized on the premise that the unit bending point density of the bending points meets the set requirement, and further, the sum of the angular distance ratio of the bending points 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-to-angle distance ratio and bending point-to-angle distance ratio;

FIG. 2 is a schematic diagram of a unit bending point density calculation;

fig. 3 is a schematic diagram of a personalized orthodontic archwire curve divided based on a bending point angular distance ratio and a variable angle;

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.