Passive operating arm RCM geometric projection positioning method

Abstract

The application provides a passive operating arm RCM geometric projection positioning method, determines the number N of connecting rods of the passive operating arm, when N=2, the first connecting rod may deviate compared with the initial state of the first connecting rod, and the second connecting rod only performs a translation movement; according to whether the first connecting rod deviates compared with the initial state of the first connecting rod, the plane projection position of the fixed point is solved respectively; when N=3, the first connecting rod and the third connecting rod may deviate compared with the initial state of the first connecting rod and the third connecting rod, the second connecting rod and a virtual connecting rod only perform a translation movement, and the virtual connecting rod refers to a connecting line between the third connecting rod and the fixed point; according to whether the first connecting rod and the third connecting rod deviate compared with the initial state of the first connecting rod and the third connecting rod, the plane projection position of the fixed point is solved respectively; when N>3, the N connecting rods are divided into a plurality of {N=2} base modules and a plurality of {N=3} base modules, and the plane projection position of the fixed point in a combined state is solved. The above method can solve the problem that a doctor is difficult to register and position a medical instrument and a patient workbench.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a passive manipulator RCM geometric projection positioning method. Background Technology

[0002] Currently, medical robots are characterized by multiple joints and modular features. For example... Figure 1 As shown, the medical robot includes:

[0003] Base 1: Includes surgical platform device for positioning and transportation, patient surgical platform electronics and connector panel;

[0004] Central column 2: The central column moves the hanger 4 up or down;

[0005] Boom 4: Boom 4 is an adjustable rotating support structure for the machine arm;

[0006] First rotating structure 3 and second rotating structure 5: wherein the first rotating structure 3 is connected between the central column 2 and the boom 4, and the second rotating structure 5 is connected between the boom 4 and the passive operating arm 6;

[0007] Passive control arm 6: The passive control arm 6 consists of several links;

[0008] Fixed point (RCM) 11: has a fixed distance attitude constraint relationship with the passive manipulator;

[0009] Controllable arm device (7-10, 12): Patient surgical platform arm device, which can be operated to move the instrument to the desired position.

[0010] With the gradual improvement of the medical industry system, the technology of using multi-jointed medical robots to assist medical workers in performing surgeries has developed rapidly. In fact, medical robots can not only help medical workers perform a series of medical diagnoses and assist in treatment, but also effectively alleviate the problem of medical resource shortages. However, there is currently a difficulty in aligning and positioning doctors' operation of medical instruments with the patient's workstation. Summary of the Invention

[0011] To address the problems existing in the prior art, this application proposes a passive manipulator RCM geometric projection positioning method.

[0012] To achieve the above objectives, this application proposes a passive manipulator RCM geometric projection positioning method, comprising the following steps:

[0013] Step 1: Determine the number of links that make up the passive manipulator. Let the number of links be N, where N≥2 and N is an integer. When N=2, jump to step 2; when N=3, jump to step 3; when N>3, jump to step 4.

[0014] Step 2: The first link may deviate from its initial state, forming a deviation angle. The second link, which follows, only performs translational motion. Depending on whether the first link deviates from its initial state, the planar projection position of the fixed point RCM is calculated.

[0015] Step 3: The first and third links may deviate from their initial states, forming a deviation angle. The second and virtual links, which follow the movement, only perform translational motion. The virtual link refers to the line connecting the third link and the fixed point. Based on whether the first and third links deviate from their initial states, the planar projection position of the fixed point RCM is calculated respectively.

[0016] Step 4: When N > 3, assume that the N links are split into N r There are N base modules, where {N=2} base modules have N² base modules and {N=3} base modules have N. r -N2, N=2·N2+3·(N r -N2)=3N r -N2, based on the principle that the fewer the total number of base modules, the easier it is to control, i.e., stmin{N r}, using N=3N r -N2, find the minimum value of N2; combining the solution of the planar projection position of the fixed point RCM of the {N=2} base modules in step 2, and the solution of the planar projection position of the fixed point RCM of the {N=3} base modules in step 3, we can solve for N2 {N=2} base modules and N r -N2 {N=3} base modules combined state, the planar projection position of the fixed point RCM.

[0017] In some embodiments, step 2 specifically includes the following:

[0018] When N=2, and the first link does not deviate from its initial state, it is denoted as At this moment, the planar projection position of the fixed point RCM in a2 represents the length of the second link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the second link and the extension of the first link when the first link does not deviate from its initial state, and α2 represents the angle between the line connecting the end of the second link to the fixed point RCM and the extension of the second link. All of the above parameters are known quantities.

[0019] When N=2, and the first link deviates from its initial state, it is denoted as At this time, the planar projection position of the fixed point RCM in

[0020] a1 represents the length of the first link, a2 represents the length of the second link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the second link and the extension of the first link when the first link does not deviate from its initial state, and α2 represents the angle between the line connecting the end of the second link and the fixed point RCM and the extension of the second link. This represents the deviation angle of the first link from its initial state. α d，1 This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. All of the above parameters are known quantities.

[0021] In some embodiments, step 3 specifically includes the following:

[0022] When N=3, and the first and third links do not deviate from their initial states, it is denoted as... At this moment, the planar projection position of the fixed point RCM in z 33 =cos(z) 32 +α3), α1 represents the length of the first link, α2 represents the length of the second link, α3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α3 represents the angle between the line connecting the end of the third link and the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. All of the above parameters are known quantities.

[0023] When N=3, and the first link does not deviate from its initial state, while the third link deviates from its initial state, it is denoted as... At this moment, the planar projection position of the fixed point RCM in z 44 =cos z 43 , z 48 =cos(α) d，3 +z 43 -z 46 ), a1 represents the length of the first link, α2 represents the length of the second link, a3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α2 represents the angle between the extension of the third link and the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. This represents the deviation angle of the third link from its initial state. α d，3 This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link deviates from its initial state. All of the above parameters are known quantities;

[0024] When N=3, and the first link deviates from its initial state while the third link does not, it is denoted as... At this moment, the planar projection position of the fixed point RCM in

[0025] z 57 =cos(α3+z) 56 ), a1 represents the length of the first link, a2 represents the length of the second link, a3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α2 represents the angle between the extension of the third link and the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. This represents the deviation angle of the first link from its initial state. α d，1 This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. All of the above parameters are known quantities;

[0026] When N=3, and the first link deviates from its initial state, and the third link deviates from its initial state, it is denoted as... At this moment, the planar projection position of the fixed point RCM in z 64 =cos z 63 , a1 represents the length of the first link, a2 represents the length of the second link, a3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α2 represents the angle between the extension of the third link and the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. This represents the deviation angle of the first link from its initial state. α d，1 This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. This represents the deviation angle of the third link from its initial state. α d，3 This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link deviates from its initial state. All of the above parameters are known quantities.

[0027] The beneficial effect of this solution is that the above-mentioned passive manipulator RCM geometric projection positioning method can solve the problem of the difficulty in aligning and positioning the medical device with the patient's worktable, enabling the doctor to accurately and efficiently complete the surgical preparation work of positioning the medical device attitude under the suggested preoperative positioning plan. Attached Figure Description

[0028] Figure 1 A schematic diagram of the structure of a medical robot in the prior art is shown.

[0029] Figure 2 A schematic diagram of the spatial projection positioning design of the passive manipulator in the embodiment is shown.

[0030] Figure 3 This diagram illustrates the design for solving the fixed point RCM plane projection position under different deviation angle states when the passive manipulator N=2 in the embodiment. In (a) (b)

[0031] Figure 4 This diagram illustrates the design for solving the fixed point RCM plane projection position under different deviation angle states when the passive manipulator N=3 in the embodiment. In (a) (b) (c) (d)

[0032] Figure 5 A schematic diagram of the combined design based on two types of base modules is shown in the embodiment when the passive manipulator N=8.

[0033] Figure 6 A schematic diagram of the numerical solution results for the projected position of the fixed point RCM plane of the parallel constraint when the passive manipulator arm N=3 is shown in the embodiment. Detailed Implementation

[0034] The specific embodiments of this application will be further described below with reference to the accompanying drawings.

[0035] In the description of this application, it should be understood that the terms "first," "second," etc., are used to distinguish similar objects, rather than to describe or indicate a specific order or sequence. The terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0036] During preoperative preparation, to ensure the alignment of the fixed point RCM with the designated check point (poke point), under the spatial vertical projection field of view, different numbers of links N of the passive manipulator and different deviation angles were selected to address the parallel constraints of the passive manipulator. At that time, we construct the angular deviation design scheme of the passive manipulator joint space, find and solve the planar projection position of the fixed point RCM, and extend this conclusion to the case of N>3 by the combination of basic modules (in practice, N is a finite number).

[0037] Specifically, the passive manipulator RCM geometric projection positioning method involved in this application includes the following steps:

[0038] Step 1: Determine the number of links that make up the passive manipulator. Let the number of links be N, where N≥2 and N is an integer. When N=2, jump to step 2; when N=3, jump to step 3; when N>3, jump to step 4.

[0039] Step 2: The first link may deviate from its initial state, forming a deviation angle. The following second link will only perform translational motion. Specifically, Step 2 includes the following situations:

[0040] When N=2, and the first link does not deviate from its initial state, it is denoted as At this moment, the planar projection position of the fixed point RCM in a2 represents the length of the second link, R represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the second link and the extension of the first link when the first link does not deviate from its initial state, and α2 represents the angle between the line connecting the end of the second link to the fixed point RCM and the extension of the second link. All of the above parameters are known quantities.

[0041] When N=2, and the first link deviates from its initial state, it is denoted as At this moment, the planar projection position of the fixed point RCM in a1 represents the length of the first link, a2 represents the length of the second link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the second link and the extension of the first link when the first link does not deviate from its initial state, and α2 represents the angle between the line connecting the end of the second link and the fixed point RCM and the extension of the second link. This represents the deviation angle of the first link from its initial state. α d，1 This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. All of the above parameters are known quantities.

[0042] Step 3: The first and third links may deviate from their initial states, forming a deviation angle. The following second link and the virtual link only perform translational motion. The virtual link refers to the line connecting the third link and the fixed point. Specifically, step 3 includes the following situations:

[0043] When N=3, and the first and third links do not deviate from their initial states, it is denoted as... At this moment, the planar projection position of the fixed point RCM in z 33 =cos(z) 32 +α3), a1 represents the length of the first link, a2 represents the length of the second link, a3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the second link and the extension of the first link when the first link does not deviate from its initial state, α2 represents the angle between the third link and the extension of the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. All of the above parameters are known quantities.

[0044] When N=3, and the first link does not deviate from its initial state, while the third link deviates from its initial state, it is denoted as... At this moment, the planar projection position of the fixed point RCM in z 44 =cos z 43 , z 48 =cos(α) d，3 +z 43 -z 46 ), a1 represents the length of the first link, a2 represents the length of the second link, a3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α2 represents the angle between the extension of the third link and the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. This represents the deviation angle of the third link from its initial state. α d，3 This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link deviates from its initial state. All of the above parameters are known quantities.

[0045] When N=3, and the first link deviates from its initial state while the third link does not, it is denoted as... At this moment, the planar projection position of the fixed point RCM in z 53 =cos(α) d1 +α2-z52 ), z 57 =cos(α3+z) 56 ), a1 represents the length of the first link, a2 represents the length of the second link, a3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α2 represents the angle between the extension of the third link and the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. This represents the deviation angle of the first link from its initial state. α d，1 This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. All of the above parameters are known quantities.

[0046] When N=3, and the first link deviates from its initial state, and the third link deviates from its initial state, it is denoted as... At this moment, the planar projection position of the fixed point RCM in z 64 =cos z 63 , a1 represents the length of the first link, α2 represents the length of the second link, α3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α2 represents the angle between the extension of the third link and the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. This represents the deviation angle of the first link from its initial state. α d，1 This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. This represents the deviation angle of the third link from its initial state. α d，3 This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link deviates from its initial state. All of the above parameters are known quantities.

[0047] Step 4: When N > 3, assume that the N links are split into N r There are N base modules, where the number of base modules with {N=2} is N², and the number of base modules with {N=3} is Nr-N², where N = 2·N² + 3·(N r -N2)=3N r -N2, based on the principle that the fewer the total number of base modules, the easier it is to control, i.e., stmin{N r Using N = 3Nr - N2, we find the minimum value of N2; combining the solution for the planar projection position of the fixed point RCM of the {N = 2} base modules in step 2, and the solution for the planar projection position of the fixed point RCM of the {N = 3} base modules in step 3, we can solve for N2 {N = 2} base modules and N r -N2 {N=3} base modules combined state, the planar projection position of the fixed point RCM.

[0048] Specifically, in steps 2 and 3, the even-numbered link of the follower only performs translational motion, causing the preoperative positioning of the passive manipulator to comply with the parallel constraint condition of the structural features. This means that if the length of the passive manipulator is fixed, the solution for the planar projection position of the fixed point RCM depends on different deviation angles. The size and the number of links N formed by the passive manipulator. In other words, different numbers of links or different deviation angles will result in different solutions for the final output—the planar projection position of the fixed point RCM.

[0049] Among them, the parallel constraint conditions of structural features: see Figure 2 Relative to the initial position of the link itself, regardless of the first link (or the third link) ) Angular offset generated How large is the angle (actually limited to a certain range)? Therefore, in the design of variable arm angle deviation, relative to the initial state of the link itself, the second link (or the line connecting the end of the third link to the fixed point) remains parallel before and after the deviation. That is, the second link before the deviation... After deviating from the second link Maintain parallelism (or the line connecting the end of the third link before offset to the fixed point). The line connecting the end of the offset third link to the fixed point stay parallel).

[0050] See Figure 2 Fix joint O5, select the origin O as the coordinate origin, and perform coordinate translation transformation T on joint O5. p =(d x d y The coordinates of ) are fixed, and the coordinate O is also fixed. In the projection plane of RCM (including virtual links, that is, the line connecting the end of the Nth link and the fixed point), let O = (0, 0).

[0051] In step 2, when N = 2, and the first link does not deviate from its initial state, it is denoted as... This indicates that the passive manipulator consisting of two links (a1, a2) is in its initial state.

[0052] See Figure 3 (a) Applying the properties of perpendicular triangles and the triangle sine and cosine theorems When the fixed point RCM is in a certain state, the steps for determining its planar projection position are as follows:

[0053] (1) To find the desired coordinate value A2, we need to find A1 first;

[0054] (2) To find the desired coordinate value R, we need to first find the coordinates of the desired coordinates. and Among them, △OG1R is a right triangle;

[0055] (3) It is necessary to further calculate ∠G1OR and We need to find out first. And ∠A2A1R.

[0056] By reversing the above steps, the position of the end of the Nth link can be derived. and the fixed point RCM plane projection position

[0057]

[0058]

[0059] in a1 represents the length of the first link, a2 represents the length of the second link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, and α2 represents the angle between the line connecting the end of the second link to the fixed point RCM and the extension of the second link. All of these parameters are known quantities. The above derivation results show that when At that time, the end position of the Nth link and the fixed point RCM plane projection position The value of and Irrelevant.

[0060] When N=2, and the first link deviates from its initial state, it is denoted as This indicates that the passive manipulator, consisting of two links (a1, a2), is in an angular deviation state.

[0061] See Figure 3 (b) Applying the properties of perpendicular triangles and the triangle sine and cosine theorems. When the fixed point is projected onto the RCM plane, the solution steps are as follows:

[0062] (1) To find the desired coordinate value A d,2 We need to find out first. and Where △OH d，1 A d，2 It is a right triangle;

[0063] (2) Further calculation is needed. and ∠A1OA d,2 We need to first find ∠A d,1 OA d,2 ;

[0064] (3) To find the desired coordinate value R d We need to find out first. and Where △OG d，1 R d It is a right triangle;

[0065] (4) Further calculations are needed. and ∠G d,1 OR d We need to first find ∠A d,2 OR d ;

[0066] (5) It is necessary to further calculate ∠OA d,2 R d We need to find out first. and ∠OA d,2 A d,1 .

[0067] By reversing the above steps, the position of the end of the Nth link can be derived. and the fixed point RCM plane projection position

[0068]

[0069]

[0070] in a1 represents the length of the first link, a2 represents the length of the second link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the second link and the extension of the first link when the first link does not deviate from its initial state, and α2 represents the angle between the line connecting the end of the second link and the fixed point RCM and the extension of the second link. This represents the deviation angle of the first link from its initial state. α d，1 This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. All the above parameters are known quantities. The above derivation results show that when At that time, the end position of the Nth link and the fixed point RCM plane projection position The value of and related.

[0071] In step 3, when N = 3, and the first and third links do not deviate from their initial states, it is denoted as... This indicates that the passive manipulator, consisting of three links (a1, a2, a3), is in its initial state.

[0072] See Figure 4 (a) Applying the properties of perpendicular triangles and the triangle sine and cosine theorems When the fixed point is projected onto the RCM plane, the solution steps are as follows:

[0073] (1) To find the desired coordinate value A3, we need to first find the coordinates of A3. and Where △OH2A3 is a right triangle;

[0074] (2) Further calculation is needed. and We need to find out first. and ∠A1A2O;

[0075] (3) To obtain the desired coordinate value R, we need to first obtain the coordinates of the desired coordinates. and Among them, △OG2R is a right triangle;

[0076] (4) It is necessary to further calculate ∠G2OR and We need to find out first. And ∠A3OR.

[0077] By reversing the above steps, the position of the end of the Nth link can be derived. and the fixed point RCM plane projection position

[0078]

[0079]

[0080] in z 33 =cos(z 32 +α3), a1 represents the length of the first link, a2 represents the length of the second link, a3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α2 represents the angle between the extension of the third link and the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. All of these parameters are known quantities. The above derivation results show that when... At that time, the end position of the Nth link and the fixed point RCM plane projection position The value of and Irrelevant.

[0081] When N=3, and the first link does not deviate from its initial state, while the third link deviates from its initial state, it is denoted as... Select This indicates that the third link of the passive control arm, which consists of three links (a1, a2, a3), is in an angular deviation state.

[0082] See Figure 4 (b) Applying the properties of perpendicular triangles and the triangle sine and cosine theorems. When the fixed point is projected onto the RCM plane, the solution steps are as follows:

[0083] (1) To find the desired coordinate value A d,3 We need to find out first. and Where △OH d，2 A d，3 It is a right triangle;

[0084] (2) Further calculation is needed. and ∠H d,2 OA d,3 We need to find out first. and ∠A2OA d,3 ;

[0085] (3) To find the desired coordinate value Rd We need to find out first. and Where △OG d，2 R d It is a right triangle;

[0086] (4) Further calculations are needed. and ∠G d,2 OR d We need to first find ∠A d,3 OR d ;

[0087] (5) It is necessary to further calculate ∠OA d,3 R d We need to find out first. and ∠OA d,3 A2.

[0088] By reversing the above steps, the position of the end of the Nth link can be derived. and the fixed point RCM plane projection position

[0089]

[0090]

[0091] in z 44 =cos z 43 , z 48 =cos(α) d，3 +z 43 -z 46 ), a1 represents the length of the first link, a2 represents the length of the second link, a3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α2 represents the angle between the extension of the third link and the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. This represents the deviation angle of the third link from its initial state. α d，3 This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link deviates from its initial state. All the above parameters are known quantities. The above derivation results show that when At that time, the end position of the Nth link and the fixed point RCM plane projection position The value of and related.

[0092] When N=3, and the first link deviates from its initial state while the third link does not, it is denoted as... Select This indicates that the first link of the passive control arm, which consists of three links (a1, a2, a3), is in an angular deviation state.

[0093] See Figure 4 (c) Applying the properties of perpendicular triangles and the triangle sine and cosine theorems. When the fixed point RCM is in a certain state, the steps for determining its planar projection position are as follows:

[0094] (1) To find the desired coordinate value A d,3 We need to find out first. and Where △OH d，2 A d，3 It is a right triangle;

[0095] (2) Further calculation is needed. and ∠H d,2 OA d,3 We need to find out first. and ∠A d,2 OA d,3 ;

[0096] (3) To find the desired coordinate value R d We need to find out first. and Where △OG d，2 R d It is a right triangle;

[0097] (4) Further calculations are needed. and ∠G d,2 OR d We need to first find ∠A d,3 OR d ;

[0098] (5) It is necessary to further calculate ∠OA d,3 R d We need to find out first. and ∠OA d,3 A d,2 .

[0099] By reversing the above steps, the position of the end of the Nth link can be derived. and the fixed point RCM plane projection position

[0100]

[0101]

[0102] in z 53 =cos(α) d1 +α2-z 52 ), z 57 =cos(α3+z) 56 ), α1 represents the length of the first link, a2 represents the length of the second link, a3 represents the length of the third link, r represents the length from the end of the Nth link to the fixed point RCM, α1 represents the angle between the extension of the second link and the extension of the first link when the first link does not deviate from its initial state, α2 represents the angle between the extension of the third link and the extension of the second link when the third link does not deviate from its initial state, and α3 represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. This represents the deviation angle of the first link from its initial state. α d，1 This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. All the above parameters are known quantities. The above derivation results show that when At that time, the end position of the Nth link and the fixed point RCM plane projection position The value of and related.

[0103] When N=3, and the first link deviates from its initial state, and the third link deviates from its initial state, it is denoted as... Select This indicates that the first and third links of the passive control arm, which consists of three links (a1, a2, a3), are both in an angular deviation state.

[0104] See Figure 4 (d) Applying the properties of perpendicular triangles and the sine and cosine theorems of triangles, When the fixed point is projected onto the RCM plane, the solution steps are as follows:

[0105] (1) To find the desired coordinate value Ad,3 We need to find out first. and Where △OH d，2 A d，3 It is a right triangle;

[0106] (2) Further calculation is needed. and ∠H d,2 OA d,3 We need to find out first. and ∠A d,2 OA d,3 ;

[0107] (3) To find the desired coordinate value R d We need to find out first. and Where △OG d，2 R d It is a right triangle;

[0108] (4) Further calculations are needed. and ∠G d,2 OR d We need to first find ∠A d,3 OR d ;

[0109] (5) It is necessary to further calculate ∠OA d,3 R d We need to find out first. and ∠OA d,3 A d,2 .

[0110] By reversing the above steps, the position of the end of the Nth link can be derived. and the fixed point RCM plane projection position

[0111]

[0112]

[0113] in z 64 =cos z 63 , ∠OA d，3 H d，2 =z 66 , ∠OR d G d，2 =z 610Let a1 represent the length of the first link, a2 represent the length of the second link, a3 represent the length of the third link, r represent the length from the end of the Nth link to the fixed point RCM, α1 represent the angle between the extension of the second link and the first link when the first link does not deviate from its initial state, α2 represent the angle between the extension of the third link and the second link when the third link does not deviate from its initial state, and α3 represent the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. This represents the deviation angle of the first link from its initial state. α d，1 This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. This represents the deviation angle of the third link from its initial state. α d，3 This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link deviates from its initial state. All the above parameters are known quantities. The above derivation results show that when At that time, the end position of the Nth link and the fixed point RCM plane projection position The value of and related.

[0114] In step 4, if N is a large random number (N>3), it is usually difficult to directly solve for the RCM plane projection position. Therefore, two types of base modules, N=2 and N=3, are first constructed. When N>3, the target number of links can be regarded as a combination of several {N=2} base modules and several {N=3} base modules. Finally, the combined solution yields the RCM plane projection position for any number of links when N>3. Figure 5 As shown, for example when N=8, the 8 links can be regarded as a combination of 1 {N=2} base module and 2 {N=3} base modules. Finally, the combined solution is used to obtain the RCM plane projection position when N=8.

[0115] See Figure 2 Select the initial parameter d of the passive manipulator. x =0.13m,d y =0.0425m, a1=0.22m, a2=0.115m, a3=0.22m, r=0.3228m, φ i =0.75πrad, i = 1, 2, 3, j = 1, 2. Where d xd represents the horizontal distance along the x-axis from node O5 to node O. y φ represents the perpendicular distance along the y-axis from node O5 to node O. i This represents the angle between the i-th link and the (i+1)-th link. (See also...) Figure 6 The final calculation results show that the target position's RCM projection onto the x-axis and y-axis coordinates is controlled within a "narrow fan-shaped area." This means that: in Figure 2 With the passive manipulator angle deviated from the design, the RCM of this mechanism basically falls on the negative half of the y-axis in the XOY projection plane scanning range, with the initial value being... The endpoint value is The lowest inflection point is Within an irregular fan-shaped area. The puncture point of the surgical lesion was detected to fall within the fan-shaped area of ​​the RCM projection scan. This result indicates that the passive manipulator RCM geometric projection positioning method proposed in this patent application can meet the preoperative positioning design requirements of surgical equipment, and surgical operations within this range are safe and effective.

[0116] Currently, medical robots are widely recognized both domestically and internationally as the future trend in high-end medical equipment and surgical procedures. This patent application, addressing the need for precise surgical manipulation, utilizes the parallel constraints of a passive manipulator to analyze its motion mechanism and verify the accuracy of RCM projection positioning. Therefore, this patent application discloses a passive manipulator RCM geometric projection positioning method that can solve the current problem of difficulty in aligning and positioning medical instruments with the patient's worktable. The passive manipulator RCM geometric projection positioning method described in this patent application has wide applications in high-tech fields such as industrial robots, medical robots, and space robots.

[0117] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and concept of this application, should be included within the scope of protection of this application.

Claims

1. A passive manipulator RCM geometric projection positioning method, characterized in that: Includes the following steps: Step 1: Determine the number of links that make up the passive manipulator. Let the number of links be N, where N≥2 and N is an integer. When N=2, jump to step 2; when N=3, jump to step 3; when N>3, jump to step 4. Step 2: The first link may deviate from its initial state, forming a deviation angle. The following second link only performs translational motion. Solve for the fixed point based on whether the first link has deviated from its initial state. RCM The planar projection position; Step 3: Links 1 and 3 may deviate from their initial states, forming a deviation angle. Links 2 and 3, which are followed by a virtual link, only perform translational motion. The virtual link refers to the line connecting link 3 and the fixed point. Based on whether links 1 and 3 have deviated from their initial states, the fixed point is determined. RCM The planar projection position; Step 4: When N > 3, assume that the N links are split into... One basic module, among which The base module is indivual, The number of base modules is , Based on the principle that the fewer the total number of base modules, the easier it is to control, that is... ,use ,beg The minimum value; combined with step 2 Base module fixed point RCM Solving for the planar projection position, and in step 3 Base module fixed point RCM The planar projection position can be solved to obtain... indivual base module and indivual Fixed point in the base module combination state RCM The planar projection position; Specifically, step 2 includes the following situations: When N=2, and the first link does not deviate from its initial state, it is denoted as At this point, the point remains stationary. RCM Planar projection position ,in , , Indicates the length of the second link. This represents the length from the end of the Nth link to the fixed point RCM. This represents the angle between the extension of the second link and the extension of the first link when the first link does not deviate from its initial state. The angle between the line connecting the end of the second link to the fixed point RCM and the extension of the second link is given. All of the above parameters are known quantities. When N=2, and the first link deviates from its initial state, it is denoted as... At this point, the point remains stationary. RCM Planar projection position ,in , , , , Indicates the length of the first link. Indicates the length of the second link. This represents the length from the end of the Nth link to the fixed point RCM. This represents the angle between the extension of the second link and the extension of the first link when the first link does not deviate from its initial state. This represents the angle between the line connecting the end of the second link to the fixed point RCM and the extension of the second link; This represents the deviation angle of the first link from its initial state. ; This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. All of the above parameters are known quantities.

2. The passive manipulator RCM geometric projection positioning method according to claim 1, characterized in that: Step 3 specifically includes the following situations: When N=3, and the first and third links do not deviate from their initial states, it is denoted as... At this point, the point remains stationary. RCM Planar projection position ,in , , , , , Indicates the length of the first link. Indicates the length of the second link. This indicates the length of the third link. This represents the length from the end of the Nth link to the fixed point RCM. This represents the angle between the extension of the second link and the extension of the first link when the first link does not deviate from its initial state. This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link does not deviate from its initial state. All of the above parameters are known quantities. When N=3, and the first link does not deviate from its initial state, while the third link deviates from its initial state, it is denoted as... At this point, the point remains stationary. RCM Planar projection position ,in , , , , , , , , , , Indicates the length of the first link. Indicates the length of the second link. This indicates the length of the third link. This represents the length from the end of the Nth link to the fixed point RCM. This represents the angle between the extension of the second link and the extension of the first link when the first link does not deviate from its initial state. This represents the angle between the extensions of the third link and the second link when the third link does not deviate from its initial state. This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link, when the third link does not deviate from its initial state. This represents the deviation angle of the third link from its initial state. , This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link deviates from its initial state. All of the above parameters are known quantities; When N=3, and the first link deviates from its initial state while the third link does not, it is denoted as... At this point, the point remains stationary. RCM Planar projection position ,in , , , , , , , , , Indicates the length of the first link. Indicates the length of the second link. This indicates the length of the third link. This represents the length from the end of the Nth link to the fixed point RCM. This represents the angle between the extension of the second link and the extension of the first link when the first link does not deviate from its initial state. This represents the angle between the extensions of the third link and the second link when the third link does not deviate from its initial state. This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link, when the third link does not deviate from its initial state. This represents the deviation angle of the first link from its initial state. , This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. All of the above parameters are known quantities; When N=3, and the first link deviates from its initial state, and the third link deviates from its initial state, it is denoted as... At this point, the point remains stationary. RCM Planar projection position ,in , , , , , , , , , , Indicates the length of the first link. Indicates the length of the second link. This indicates the length of the third link. This represents the length from the end of the Nth link to the fixed point RCM. This represents the angle between the extension of the second link and the extension of the first link when the first link does not deviate from its initial state. This represents the angle between the extensions of the third link and the second link when the third link does not deviate from its initial state. This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link, when the third link does not deviate from its initial state. This represents the deviation angle of the first link from its initial state. , This represents the angle between the extension of the second link and the extension of the first link when the first link deviates from its initial state. , This represents the deviation angle of the third link from its initial state. , This represents the angle between the line connecting the end of the third link to the fixed point RCM and the extension of the third link when the third link deviates from its initial state. All of the above parameters are known quantities.

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