Hybrid connecting rod kinematics solving method

Abstract

The invention discloses a hybrid connecting rod kinematics solving method, which comprises the following steps of: by analyzing a structural form of a moving object, enabling the moving object to be equivalent to a hybrid connecting rod mechanism; a hybrid connecting rod mechanism is divided into a plurality of plates, a rotational degree of freedom or a translational degree of freedom exists between every two adjacent plates, the distance between any two connecting nodes in one plate is always unchanged, and the included angle between any two connected equivalent connecting rods is always unchanged; classifying the plates according to the number of connecting nodes in the plates, and respectively formulating corresponding solving modules for different plate types; and analyzing a kinematics conversion relationship among the plates, and solving the position of each connection node by using corresponding solving modules in sequence according to a solving sequence, so as to obtain the motion range of the whole hybrid link mechanism. The method solves the problem of complex hybrid connecting rod kinematics solution, and can be widely applied to kinematics calculation of the hybrid connecting rod mechanism.

Description

Technical Field

[0001] The invention relates to the fields of mechanical design and robotics, in particular to a hybrid connecting rod kinematics solution method. Background Art

[0002] The connecting rod structure can be divided into three types based on the structural type: serial, parallel, and hybrid. For serial connecting rod mechanisms, patent ZL 202110712035.8 proposes a robot arm inverse kinematics solution method based on variable dimension scaling. For parallel connecting rod mechanisms, patent ZL 201210457801.1 proposes a six-degree-of-freedom parallel mechanism with closed kinematics positive solution and analytical method. For hybrid connecting rod mechanisms, a general kinematic solution method has not yet been constructed.

[0003] The kinematic solution of hybrid linkage mainly belongs to the field of mechanical engineering, especially mechanical design and robotics. This field involves the kinematic analysis and design of the linkage mechanism of mechanical systems or robots to ensure that they can move and operate in the predetermined manner. There are various hybrid linkages in complex mechanical design. This type of linkage structure includes rotational motion and sliding motion, and there is a compound kinematic transformation relationship. In the process of solving the kinematics of hybrid linkages, geometric analysis, motion coupling analysis, motion transformation analysis, control strategy analysis, etc. are required. The hybrid linkage mechanism performs hybrid rotational motion around multiple key nodes, and the motion trajectory is not a circle, and the motion analysis is more complicated. Therefore, it is urgent to propose a general kinematic solution method. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a hybrid connecting rod kinematics solution method, and to solve the complex problem of hybrid connecting rod kinematics solution.

[0005] The technical solution of the present invention is: a hybrid connecting rod kinematics solution method, comprising the following steps:

[0006] Step 1: Analyze the structural form of the moving object and equate the moving object to a hybrid linkage mechanism; the hybrid linkage mechanism is composed of a number of connection nodes and equivalent links;

[0007] Step 2: According to the structural composition and connection relationship of the hybrid linkage mechanism, the hybrid linkage mechanism is divided into multiple plates; the plate division method is as follows: there is a rotational degree of freedom or a translational degree of freedom between adjacent plates; the distance between any two connection nodes in a plate is always constant, and the angle between any two connected equivalent links is always constant;

[0008] Step 3: Classify each plate according to the number of connected nodes in the plate;

[0009] Step 4: Develop corresponding solution modules for different plate types;

[0010] Step 5: Analyze the fixed quantities in the hybrid linkage mechanism and the input quantities driving the hybrid linkage mechanism to move;

[0011] Step 6: In combination with the fixed amount, the kinematic conversion relationship between the plates is analyzed to determine the solution sequence from the input end to the output end of the hybrid linkage mechanism;

[0012] Step 7: According to the solving order, use the corresponding solving modules in turn to solve the position of each connection node; thus, according to the given input quantity variation range, the position of each connection node is solved to obtain the motion range of the entire hybrid linkage mechanism.

[0013] Furthermore, the equivalent method in step 1 is: using all rotation centers of the moving object as connection nodes, connecting the connection nodes with constant distances through equivalent connecting rods, and making the moving object equivalent to a hybrid connecting rod structure.

[0014] Furthermore, the plates are divided into line segment plates, triangle plates, and quadrilateral plates; a plate including two connecting nodes is defined as a line segment plate; a plate including three connecting nodes is defined as a triangle plate; and a plate including four connecting nodes is defined as a quadrilateral plate.

[0015] Furthermore, the solution module of the line segment-shaped plate is solved in the following way: using the lengths of the two connected equivalent links and the positions of the two connection nodes at the non-intersecting ends of the equivalent links, the position of the intersection of the two connected equivalent links is solved.

[0016] Furthermore, the lengths of the two connected equivalent links are: The positions of the two connection nodes of the non-intersecting ends of the equivalent link, point O1 and point C2, are (x O1 ,y O1 )、(x C2 ,y C2 ), the solution process for solving the intersection point C1 of two connected equivalent connecting rods is:

[0017] First, find the distance between point O1 and point C2:

[0018]

[0019] Then solve the angle between ∠C2O1C1 and ∠O1C2C3:

[0020]

[0021] Then solve the angle between the line segment O1 C1 formed by point O1 and point C1 and the horizontal line:

[0022] ∠O1C1=∠O1C2C3+∠C2O1C1

[0023] Finally, the position of the intersection point C1 is obtained:

[0024]

[0025] Furthermore, the solution module of the triangular plate is solved in the following way: using the lengths of three equivalent connecting rods connected to each other and the positions of two known connecting nodes, the position of the remaining unknown connecting node is solved.

[0026] Furthermore, the lengths of the three interconnected equivalent connecting rods are: The known locations of the two connecting nodes, point C2 and point C3, are (x C2 ,y C2 )、(x C3 ,y C3 ), the process of solving the position of the unknown connection node C1 is:

[0027] First solve ∠C2C3C1:

[0028]

[0029] Then solve the angle between the line segment C2 C3 formed by point C2 and point C3 and the horizontal line:

[0030]

[0031] Then solve the angle between the line segment C1 C3 formed by point C1 and point C3 and the horizontal line:

[0032] ∠C1C3=∠C2C3-∠C2C3C1

[0033] Finally, the position of C1 is obtained:

[0034]

[0035] Furthermore, the solution module of the quadrilateral plate is solved in the following way: using the lengths of four interconnected equivalent connecting rods, the lengths of two diagonals and the positions of two known connecting nodes, the positions of the remaining two unknown connecting nodes are solved.

[0036] Furthermore, the lengths of the four interconnected equivalent connecting rods are: The lengths of the two diagonals are: The known locations of the two connecting nodes, point B1 and point B2, are (x B1 ,y B1 )、(x B2 ,yB2 ), the process of solving the positions of the two unknown connection nodes B3 and B4 is as follows:

[0037] First, solve ∠B1B2B3, ∠B2B3B4:

[0038]

[0039] Then solve the angle between the line segment B1B2 formed by point B1 and point B3 and the horizontal line:

[0040]

[0041] Then solve the angle between the line segment B3B2 formed by point B3 and point B2 and the horizontal line:

[0042] ∠B3B2=∠B1B2-∠B1B2B3

[0043] And the angle between the line segment B4B3 formed by point B4 and point B3 and the horizontal line:

[0044] ∠B4B3=∠B3B2-∠B2B3B4

[0045] Finally, the position of point B3 is obtained:

[0046]

[0047] And the location of point B4:

[0048]

[0049] Furthermore, when there are multiple hybrid linkage mechanisms, in order to avoid collision between the hybrid linkage mechanisms, the method further includes step 8: under different input conditions, determining whether all equivalent links of a hybrid linkage mechanism intersect with equivalent links of another hybrid linkage mechanism, and then determining whether collision occurs between the hybrid linkage mechanisms;

[0050] The judgment method between any two equivalent links is:

[0051] A1A2 represents any equivalent link in a hybrid linkage mechanism. Point A1 and point A2 are (x A1 ,y A1 )、(x A2 ,y A2 ), B1B2 represents any equivalent link in another hybrid linkage mechanism, and point B1 and point B2 are (x B1 ,y B1 )、(x B2 ,y B2 );

[0052] First, determine whether all four conditions in the following formula are true:

[0053]

[0054] Among them, max(m,n) means taking the maximum value of m and n, and min(m,n) means taking the minimum value of m and n;

[0055] If any of the above four conditions is not true, line segment A1A2 does not intersect line segment B1B2;

[0056] If the above four conditions are all met, proceed to the next step:

[0057]

[0058] If any of the above two conditions is not true, line segment A1A2 does not intersect line segment B1B2;

[0059] If the above two conditions are both met, line segment A1A2 intersects line segment B1B2.

[0060] The advantages of the present invention compared with the prior art are:

[0061] (1) The present invention proposes a kinematic solution method for a hybrid linkage mechanism. This method characterizes the moving object through an equivalent hybrid linkage mechanism by analyzing each rotation axis or rotation center point in various types of structures. In addition, a new type of plate division method is innovatively proposed, which divides the hybrid linkage mechanism into different blocks according to the structural characteristics, wherein the distance between any two connecting nodes in each block remains unchanged, the angle between any two connected equivalent links remains unchanged, and there is only one rotational degree of freedom or translational degree of freedom between adjacent blocks. Then, corresponding solution modules are formulated according to different blocks, and the corresponding solution modules are used in sequence according to the solution order to realize the kinematic solution of the hybrid linkage mechanism from the input end to the output end.

[0062] (2) The method of the present invention has strong versatility. It uses the spatial geometry method to analyze the relationship between the coupled connection nodes in the composite linkage mechanism and expresses the corresponding geometric relationship through algebraic expressions. It can be widely used in the kinematic calculation of the hybrid linkage mechanism.

[0063] (3) The present invention constructs a collision judgment module, which can improve the motion planning and coordinated control characteristics of the hybrid linkage mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a flow chart of a hybrid connecting rod kinematics solution method;

[0065] Figure 2It is the configuration diagram of single-degree-of-freedom hybrid linkage mechanism;

[0066] Figure 3 It is a schematic diagram of a single-degree-of-freedom hybrid linkage mechanism;

[0067] Figure 4 Schematic diagram of solving line segment plates, where (a) and (b) are schematic diagrams of solving by circle method and angle method respectively;

[0068] Figure 5 Schematic diagram for solving triangular plates;

[0069] Figure 6 Schematic diagram for solving quadrilateral plates;

[0070] Figure 7 It is the motion range diagram of single degree of freedom hybrid connecting rod;

[0071] Figure 8 It is a schematic diagram of a two-degree-of-freedom hybrid linkage mechanism;

[0072] Fig. 9 It is the motion range diagram of the two-degree-of-freedom hybrid connecting rod;

[0073] Fig.10 It is a schematic diagram of hybrid connecting rod collision;

[0074] Fig.11 Schematic diagram of hybrid link collision avoidance, where (a), (b), (c), and (d) are case 1, case 2, case 3, and case 4, respectively;

[0075] Fig.12 Plan a motion process diagram for the hybrid linkage, namely the tool grasping process diagram. DETAILED DESCRIPTION

[0076] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0077] Each line segment in the figure of this embodiment represents an equivalent connecting rod, and each circle center represents a rotation center point. Explanation of symbols in the present invention: symbol ∠AB is the angle between the line segment AB formed by connecting point A and point B and the horizontal line; symbol ∠ABC is the angle between line segment AB and line segment BC.

[0078] The hybrid connecting rod kinematics solution method proposed by the present invention is as follows: Figure 1 As shown, the analysis steps of this method are as follows:

[0079] Step 1: Analyze the structural form of the moving object and equate the moving object to a hybrid linkage mechanism

[0080] By analyzing the various rotation axes of the moving object, the rotation center of the moving object is regarded as a connection node, all the connection nodes are extracted, and the nodes with constant distances are connected by equivalent connecting rods, so that the moving object is equivalent to a hybrid linkage mechanism.

[0081] For example, Figure 2 The single-degree-of-freedom hybrid linkage shown is simplified to Figure 3 The schematic diagram of the connecting rod mechanism is shown.

[0082] Step 2: Divide the hybrid linkage into multiple sections based on its structural composition and connection relationship.

[0083] The plates are divided in such a way that there is one degree of rotational freedom or one degree of translational freedom between adjacent plates; the distances between all points within a plate are always fixed, and the angles within a plate are always fixed.

[0084] For example Figure 3 Taking point O1 as the origin, the mechanism is divided into eight plates: fixed body, plate O, plate A, plate B, plate C, plate D, plate E, and plate F. The distance between any two connecting nodes in each plate remains unchanged, for example, the distance between point B1 and B2 is always fixed, the distance between point B1 and B3 is always fixed, etc. And the angle between any two connected equivalent connecting rods remains unchanged, for example, the angle between line segment B1B2 and line segment B2B3 remains unchanged. This paves the way for solving the position information corresponding to each plate in turn according to the formulated solution module.

[0085] Step 3: Classify each plate according to the number of connected nodes in the plate

[0086] Specifically, a plate including two connection nodes is defined as a line segment plate; a plate including three connection nodes is defined as a triangular plate; a plate including four connection nodes is defined as a quadrilateral plate; and a plate including N connection nodes is defined as an N-gonal plate.

[0087] For example Figure 3 Plate A in the figure includes points A1 and A2, which are line segment plates. Plate C includes points C1, C2, and C3, which are triangular plates. Plate B includes points B1, B2, B3, and B4, which are quadrilateral plates. The plates are connected by connection points, which can be divided into translation points (such as point A1), fixed rotation points (such as point B1), and non-fixed rotation points (such as point B2).

[0088] Step 4: Develop corresponding solution modules for different plate types

[0089] According to the structure of the moving object, the plate division is performed in step 2, and it is decomposed into several plates, and the plate types are classified in step 3. In this step, corresponding solution modules are formulated according to different plates, and kinematic analysis is performed on each plate through the solution modules. The solution modules can be divided into the following types: (1) segment plate solution module; (2) triangle plate solution module; (3) quadrilateral plate solution module; (4) other solution modules.

[0090] (1) Line segment plate solving module

[0091] In the connecting rod structure, the most basic structure is a connecting rod, which has no fixed connection with other connecting rods and has one translational degree of freedom or one rotational degree of freedom relative to other connecting rods.

[0092] The two ends of a single connecting rod are two connection nodes. Under the premise that one connection node is known and the constraint condition or coupling condition is known, this solution module can be used to solve the other connection node. This solution module can also be used to solve the connection node between two single connecting rods.

[0093] The following example introduces how to solve the unknown points in the line segment plate. Figure 4 As shown, the lengths of two adjacent connecting rods are known: And the positions of the connecting rod rotation center point O1 and point C2: x O1 ,y O1 、x C2 ,y C2 , solve the position of the intersection point C1 of two adjacent connecting rods: x C1 ,y C1 .

[0094] There are many ways to find the intersection point between two line segments, such as Figure 4 (a) The method of making a circle. With point O1 as the center, Make a circle with radius C2 as the center. Draw a circle with radius . The intersection of the two circles is point C1, but there are two intersections, and it is necessary to analyze which intersection is the desired solution, so this method is not used.

[0095] In order to avoid the phenomenon of two solutions and point position mutation, the present invention adopts the following method: Figure 4 The intersection point is solved by the angle method shown in (b), and the specific process is described as follows.

[0096] First, find the distance between point O1 and point C2:

[0097]

[0098] Then solve the angle between ∠C2O1C1 and ∠O1C2C3:

[0099]

[0100] Then solve the angle between the line segment O1C1 formed by point O1 and point C1 and the horizontal line:

[0101] ∠O1C1=∠O1C2C3+∠C2O1C1

[0102] Finally, the position of the intersection point C1 is obtained:

[0103]

[0104] (2) Triangular plate solving module

[0105] In the connecting rod structure, there are two fixedly connected connecting rods. The intersection of these two connecting rods is the fixed point. Together with the end points at both ends of the connecting rods, there are three points in total. The relative positions of these three points are always unchanged. This module is a triangular plate. In this module, two of the points are known, and the position of the third point is solved. For some structures, irregular shapes can be equivalent to regular triangular configurations.

[0106] by Figure 5 For example, find the position of point C1 based on points C2 and C3. The lengths of the three interconnected equivalent connecting rods are: The known locations of the two connecting nodes, point C2 and point C3, are (x C2 ,y C2 )、(x C3 ,y C3 ), the process of solving the position of the unknown connection node C1 is:

[0107] First solve ∠C2C3C1:

[0108]

[0109] Then solve the angle between the line segment C2C3 formed by point C2 and point C3 and the horizontal line:

[0110]

[0111] Then solve the angle between the line segment C1 C3 formed by point C1 and point C3 and the horizontal line:

[0112] ∠C1C3=∠C2C3-∠C2C3C1

[0113] Finally, the position of C1 is obtained:

[0114]

[0115] (3) Quadrilateral plate solving module

[0116] For some structures, the irregular shape can be equivalent to a regular quadrilateral configuration. The four vertices on the quadrilateral correspond to four connection nodes. Through two known connection nodes, the other two unknown connection nodes can be solved.

[0117] by Figure 6 Take as an example, find the positions of points B3 and B4 based on points B1 and B2. The lengths of the four interconnected equivalent connecting rods are: The lengths of the two diagonals are: The known locations of the two connecting nodes, point B1 and point B2, are (x B1 ,y B1 )、(x B2 ,y B2 ), the process of solving the positions of the two unknown connection nodes B3 and B4 is as follows:

[0118] First, solve ∠B1B2B3, ∠B2B3B4:

[0119]

[0120] Then solve the angle between the line segment B1B2 formed by point B1 and point B3 and the horizontal line:

[0121]

[0122] Then solve the angle between the line segment B3B2 formed by point B3 and point B2 and the horizontal line:

[0123] ∠B3B2=∠B1B2-∠B1B2B3

[0124] Finally, the position of point B3 is obtained:

[0125]

[0126] Similarly, according to ∠B3B2 and ∠B2B3B4, ∠B4B3 can be solved:

[0127] ∠B4B3=∠B3B2-∠B2B3B4

[0128] Then we can find the position of point B4:

[0129]

[0130] (4) Other solution modules

[0131] The plates in the hybrid connecting rod structure are usually of the three types mentioned above. If the structure is a pentagon or a more polygonal shape, it can be further divided into line segments, triangles or quadrilaterals. The method for solving the connection node position is similar to the solution method of the above modules, which will not be described in detail here.

[0132] Step 5: Analyze the fixed quantities in the hybrid linkage mechanism and the input quantities that drive the hybrid linkage mechanism motion

[0133] (1) Fixed quantities, mainly including the fixed connection node positions and the angles between equivalent connecting rods.

[0134] For example: Figure 3 x in O1 ,y O1 ,y A1 、x B2 ,y B2 ; Figure 3 ∠B1B2B3, etc.

[0135] (2) Input quantity: the amount of action that drives the hybrid linkage mechanism to move. The range of motion of the hybrid linkage mechanism can be obtained based on the range of change of the input quantity.

[0136] For example: Figure 3 The input variable is the rotation angle N of the drive motor. Based on this variable, the position coordinates of the first connecting rod can be obtained. Figure 3 The position of the midpoint A1 in the x-axis direction is as follows:

[0137] x A1 =K·N

[0138] In the formula, K is the transmission coefficient and N is the motor angle.

[0139] Step 6: Combined with the fixed amount, analyze the kinematic conversion relationship between the plates and determine the solution sequence from the input end to the output end of the hybrid linkage mechanism.

[0140] According to the structure of the moving object, the solution order is analyzed from the input end, the conversion relationship between the mutually coupled plates is analyzed, and then the kinematic conversion relationship between the plates is analyzed, laying the foundation for the motion analysis of the entire moving object.

[0141] Step 7: According to the solving order, use the corresponding solving modules in turn to solve the position of each connection node; thus, according to the given input quantity variation range, solve the position change of each connection node and obtain the motion range of the entire hybrid linkage mechanism.

[0142] Step 8: Motion Planning and Collision Avoidance

[0143] Input the motor position, and the position data of each connection node can be obtained through the above steps. When there are multiple hybrid linkages, in order to avoid collisions between hybrid linkages, the present invention constructs a hybrid linkage collision monitoring module, which determines whether an equivalent linkage in one hybrid linkage intersects with an equivalent linkage in another hybrid linkage, and then determines whether a collision occurs between hybrid linkages.

[0144] A1A2 represents any equivalent link in a hybrid linkage mechanism. Point A1 and point A2 are (x A1 ,y A1 )、(x A2 ,y A2 ), B1B2 represents any equivalent link in another hybrid linkage mechanism, and point B1 and point B2 are (x B1 ,y B1 )、(x B2 ,y B2 );

[0145] To determine whether line segment A1A2 intersects line segment B1B2, first analyze whether all four conditions in the following formula are true:

[0146]

[0147] Among them, max(m,n) means taking the maximum value of m and n, and min(m,n) means taking the minimum value of m and n;

[0148] If any of the above four conditions is not met, line segment A1A2 does not intersect line segment B1B2.

[0149] If the above four conditions are all met, proceed to the next step:

[0150]

[0151] If the above two conditions are not met, the line segment A1A2 does not intersect with the line segment B1B2.

[0152] If all six conditions proposed by the hybrid link collision monitoring module are met, line segment A1A2 intersects line segment B1B2.

[0153] Example 1: Single degree of freedom finger.

[0154] Step 1: Figure 2 and Figure 3 As shown, the moving object is equivalent to a hybrid connecting rod structure.

[0155] Step 2: Divide into blocks. Figure 3With point O1 as the origin, the mechanism is divided into eight plates, namely, fixed body, plate O, plate A, plate B, plate C, plate D, plate E, and plate F. The distance between any two connecting nodes in each plate is always fixed, for example, the distance between points B1 and B2 is always fixed, the distance between points B1 and B3 is always fixed, etc. And the angle between any two connected equivalent links is always constant, for example, the angle between line segment B1B2 and line segment B2B3 is always constant.

[0156] Step 3: Classify the plates. Figure 3 The fixed body in is always fixed, that is, the position coordinates of point O1 and point B2 are always fixed. Plate A includes points A1 and A2, which is a line segment plate. Plate B includes points B1, B2, B3, and B4, which is a quadrilateral plate. Plate B rotates around point B2. Plate C includes points C1, C2, and C3, which is a triangular plate. Plate D includes points D1 and D2, which is a line segment plate. Plate E includes points E1 and E2, which is a line segment plate. Plate F includes points F1 and F2, which is a line segment plate.

[0157] The plates are connected by connection points, which can be divided into translation points (such as point A1), fixed-position rotation points (such as point B1), and non-fixed-position rotation points (such as point B2).

[0158] Step 4: Construct a solution module. Construct a segment plate solution module (solution module 1), a triangle plate solution module (solution module 2), and a quadrilateral plate solution module (solution module 3).

[0159] Step 5: Analyze fixed quantities and input quantities. (1) Fixed quantities. Figure 3 x in O1 ,y O1 ,y A1 、x B2 ,y B2 ; Angle between the relative fixed links, Figure 3 ∠B1B2B3 in (2) Input quantity. The input quantity is the rotation angle N of the drive motor. Based on this variable, the position coordinates of the first connecting rod can be obtained. Figure 3 The position of the midpoint A1 in the x-axis direction is as follows:

[0160] x A1 =K·N

[0161] In the formula, K is the transmission coefficient and N is the motor angle.

[0162] Step 6: Analyze the solution sequence. The solution sequence is as follows:

[0163] (1) Using solution module 1, solve point A1 (i.e., point B1) based on point A1 and point B2;

[0164] (2) Using solution module 3, solve point B3 and point B4 based on point B1 and point B2;

[0165] (3) Using the solving module 1, solve the point O2 (i.e., point C1) based on the point O1 and the point C2 (i.e., point B3);

[0166] (4) Using solution module 2, solve point C3 (i.e., point E2, point F1) based on point C1 and point C2;

[0167] (5) Using the solving module 1, solve the point D2 (i.e., point E1) based on the point C3 and the point D1 (i.e., point B4);

[0168] (5) Using solution module 2, solve point F2 based on point C3 and point D2.

[0169] Step 7: Solve the positions and related data of all connection nodes. According to steps 1 to 6, solve the coordinates of each connection node. Then solve the terminal position, posture, angle and other data, and save the relevant data.

[0170] For example, the vertical and horizontal coordinate values ​​of the coordinates of each connection node can be saved in the form of an array: X = [x A1 ,x B1 ,x B2 ,x B3 ,x B4 ,x C1 ,x C3 ,x D2 ,x F2 ]; Y = [y A1 ,y B1 ,y B2 ,y B3 ,y B4 ,y C1 ,y C3 ,y D2 ,y F2 ].

[0171] Step 8: Motion planning and collision avoidance analysis.

[0172] Based on the calculation methods and corresponding inputs of steps 1 to 7, the kinematic coupling relationship between the plates of a single hybrid connecting rod is analyzed, and motion planning can be performed for it, and the motion range of the hybrid connecting rod can also be obtained, such as Figure 7 shown.

[0173] The distance monitoring module is used to determine whether all line segments of one finger intersect with all line segments of another finger, thereby determining whether the opposing fingers collide.

[0174] Example 2: Two-degree-of-freedom finger.

[0175] Step 1: Figure 8 As shown, the two-degree-of-freedom finger of the moving object is equivalent to a hybrid link structure.

[0176] Step 2 to Step 5 are similar to Step 2 to Step 5 of “Example 1”.

[0177] Step 5: Analyze the solution sequence. The solution sequence is as follows:

[0178] (1) Using solution module 1, solve point B2 based on point A1 and point B1;

[0179] (2) Using solution module 3, solve point B3 and point B4 based on point B1 and point B2;

[0180] (3) Using solution module 1, solve point D1 based on point C1 and point B2 (i.e., point D2);

[0181] (4) Using solution module 2, solve point D3 based on point D1 and point D2;

[0182] (5) Using solution module 1, solve point E2 based on point E1 (i.e., point D3) and point B3;

[0183] (6) Using solving module 2, solve point F3 based on point F1 (i.e., point E2) and point F2 (i.e., point B3);

[0184] (7) Using solving module 2, solve point G3 based on point G1 (i.e., point F2) and point G2 (i.e., point F3);

[0185] (8) Using solving module 1, solve point H2 based on point H1 (i.e., point B4) and point G3;

[0186] (9) Using solution module 2, solve point J2 based on point G3 and point H2.

[0187] Step 7 is similar to Step 7 of “Example 1”.

[0188] Step 8: Motion planning and collision avoidance analysis.

[0189] The motion range of the hybrid connecting rod is obtained, such as Fig. 9 shown.

[0190] The distance monitoring module is used to determine whether all line segments of one finger intersect with all line segments of another finger, thereby determining whether the opposing fingers collide.

[0191] like Fig.10 As shown, the facing fingers collided, and the line segment G3J2 in the upper finger intersected with the line segment B3G3 in the lower finger.

[0192] like Fig.11 As shown, the facing fingers did not collide.

[0193] According to the present invention, autonomous local planning of the hybrid connecting rod can be realized, the grasping of various tools can be realized, and steady-state grasping can be achieved through the control system. Fig.12 As shown, by planning the motion trajectory of the hybrid connecting rod, a tool grasping process diagram can be obtained, and the circle in the figure is the handle of the tool.

[0194] The present invention proposes a general operation solving method for hybrid connecting rod structures. The method analyzes each rotation axis or rotation center point in various types of structures and characterizes the model through an equivalent hybrid connecting rod mechanism. The hybrid connecting rod mechanism is divided into several blocks according to the structure. The distance between each point in each block remains unchanged, and the angle between the lines connected by the points remains unchanged. The position information corresponding to each block is solved in turn according to the formulated solution module.

[0195] The solution method proposed in the present invention can be applied to fields such as dexterous hands, deformation mechanisms, bionic mechanisms such as bionic wings, hybrid mechanisms such as wooden oxen and flowing horses, and connecting rod mechanisms such as wipers. The moving objects in these fields can all be equivalently converted into hybrid connecting rod structures.

[0196] It is to be understood that the present invention is described by way of embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and embodiments that can fall within the scope of the claims of this application all fall within the scope protected by the present invention.

[0197] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A hybrid connecting rod kinematics solution method, characterized in that: The steps include: Step 1: Analyze the structural form of the moving object and equate the moving object to a hybrid linkage mechanism; the hybrid linkage mechanism is composed of a number of connection nodes and equivalent links; Step 2: According to the structural composition and connection relationship of the hybrid linkage mechanism, the hybrid linkage mechanism is divided into multiple plates; the plate division method is as follows: there is a rotational degree of freedom or a translational degree of freedom between adjacent plates; the distance between any two connection nodes in a plate is always constant, and the angle between any two connected equivalent links is always constant; Step 3: Classify each plate according to the number of connected nodes in the plate; Step 4: Develop corresponding solution modules for different plate types; Step 5: Analyze the fixed quantities in the hybrid linkage mechanism and the input quantities driving the hybrid linkage mechanism to move; Step 6: In combination with the fixed amount, the kinematic conversion relationship between the plates is analyzed to determine the solution sequence from the input end to the output end of the hybrid linkage mechanism; Step 7: According to the solving order, use the corresponding solving modules in turn to solve the position of each connection node; thus, according to the given input quantity variation range, the position of each connection node is solved to obtain the motion range of the entire hybrid linkage mechanism.

2. The hybrid connecting rod kinematics solution method according to claim 1, characterized in that: The equivalent method in step 1 is: using all rotation centers of the moving object as connection nodes, connecting the connection nodes with constant distances through equivalent connecting rods, and making the moving object equivalent to a hybrid connecting rod structure.

3. The hybrid connecting rod kinematics solution method according to claim 1, characterized in that: The plates are divided into line-segment plates, triangular plates, and quadrilateral plates; a plate including two connecting nodes is defined as a line-segment plate; a plate including three connecting nodes is defined as a triangular plate; and a plate including four connecting nodes is defined as a quadrilateral plate.

4. The hybrid connecting rod kinematics solution method according to claim 3 is characterized in that: The solution module for line segment-shaped plates is solved by using the lengths of two connected equivalent links and the positions of two connection nodes at the non-intersecting ends of the equivalent links to solve for the position of the intersection of the two connected equivalent links.

5. The hybrid connecting rod kinematics solution method according to claim 4, characterized in that: The lengths of the two connected equivalent links are: The positions of the two connection nodes of the non-intersecting ends of the equivalent link, point O1 and point C2, are (x O1 ,y O1 )、(x C2 ,y C2 ), the solution process for solving the intersection point C1 of two connected equivalent connecting rods is: First, find the distance between point O1 and point C2: Then solve the angle between ∠C2O1C1 and ∠O1C2C3: Then solve the angle between the line segment O1 C1 formed by point O1 and point C1 and the horizontal line: ∠O1C1=∠O1C2C3+∠C2O1C1 Finally, the position of the intersection point C1 is obtained:

6. The hybrid connecting rod kinematics solution method according to claim 3 is characterized in that: The solution module for triangular plates uses the lengths of three interconnected equivalent connecting rods and the positions of two known connection nodes to solve for the position of the remaining unknown connection node.

7. The hybrid connecting rod kinematics solution method according to claim 6, characterized in that: The lengths of the three interconnected equivalent links are: The known locations of the two connecting nodes, point C2 and point C3, are (x C2 ,y C2 )、(x C3 ,y C3 ), the process of solving the position of the unknown connection node C1 is: First solve ∠C2C3C1: Then solve the angle between the line segment C2 C3 formed by point C2 and point C3 and the horizontal line: Then solve the angle between the line segment C1 C3 formed by point C1 and point C3 and the horizontal line: ∠C1C3=∠C2C3-∠C2C3C1 Finally, the position of C1 is obtained:

8. The hybrid connecting rod kinematics solution method according to claim 3 is characterized in that: The solution module for quadrilateral plates is solved by using the lengths of four interconnected equivalent connecting rods, the lengths of two diagonals and the positions of two known connection nodes to solve for the positions of the remaining two unknown connection nodes.

9. The hybrid connecting rod kinematics solution method according to claim 8, characterized in that: The lengths of the four interconnected equivalent links are: The lengths of the two diagonals are: The known locations of the two connecting nodes, point B1 and point B2, are (x B1 ,y B1 )、(x B2 ,y B2 ), the process of solving the positions of the two unknown connection nodes B3 and B4 is as follows: First, solve ∠B1B2B3, ∠B2B3B4: Then solve the angle between the line segment B1B2 formed by point B1 and point B3 and the horizontal line: Then solve the angle between the line segment B3B2 formed by point B3 and point B2 and the horizontal line: ∠B3B2=∠B1B2-∠B1B2B3 And the angle between the line segment B4B3 formed by point B4 and point B3 and the horizontal line: ∠B4B3=∠B3B2-∠B2B3B4 Finally, the position of point B3 is obtained: And the location of point B4:

10. The hybrid connecting rod kinematics solution method according to claim 1, characterized in that: When there are multiple hybrid linkage mechanisms, in order to avoid collision between the hybrid linkage mechanisms, the method further includes step 8: under different input conditions, determining whether all equivalent links of one hybrid linkage mechanism intersect with equivalent links of another hybrid linkage mechanism, and then determining whether collision occurs between the hybrid linkage mechanisms; The judgment method between any two equivalent links is: A1A2 represents any equivalent link in a hybrid linkage mechanism. Point A1 and point A2 are (x A1 ,y A1 )、(x A2 ,y A2 ), B1B2 represents any equivalent link in another hybrid linkage mechanism, and point B1 and point B2 are (x B1 ,y B1 )、(x B2 ,y B2 ); First, determine whether all four conditions in the following formula are true: Among them, max(m,n) means taking the maximum value of m and n, and min(m,n) means taking the minimum value of m and n; If any of the above four conditions is not true, line segment A1A2 does not intersect line segment B1B2; If the above four conditions are all met, proceed to the next step: If any of the above two conditions is not true, line segment A1A2 does not intersect line segment B1B2; If the above two conditions are both met, line segment A1A2 intersects line segment B1B2.

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