A modular robot dynamics modeling method

Abstract

The embodiment of the present invention provides a modular robot dynamic modeling method, which realizes the modular robot dynamic modeling, including: obtaining a mathematical representation of the modular robot topological structure and a three-dimensional model of a modular unit, and then obtaining basic kinematic parameter information, basic dynamic parameter information, a modular unit motion transfer library and a structural equivalent library of the modular unit; according to the mathematical representation of the robot topological structure, obtaining all the robot's motion transfer branches; analyzing the connection status of the modular units in each motion transfer branch and the motion transfer mode between two modular units with a connection relationship; obtaining the modular unit equivalent structure and dynamic parameters; designing a modular robot dynamic modeling method based on distributed parameter acquisition, and obtaining a modular robot dynamic model. According to the technical solution provided by the embodiment of the present invention, rapid dynamic modeling of homogeneous modular robots can be realized.

Description

Technical field

[0001] The invention relates to a modular robot dynamics modeling method and belongs to the field of robot dynamics modeling. [Background Technology]

[0002] With the continued advancement of industrial automation, the application of robots in various fields is becoming increasingly widespread. Robots with single-function, fixed structures are difficult to adapt to tasks with diverse payloads and demands. The concept of modular robots, first proposed in 1988, generally consists of multiple identical (homogeneous) or different (heterogeneous) modules. By varying the number and relative positions of modules, the robot can be reconfigured into new configurations and acquire new functions to adapt to changing work environments and meet diverse task requirements. Therefore, research on modular robots can further advance the field of robotics in my country.

[0003] Compared to heterogeneous modular robots, homogeneous modular robots offer interchangeable modules, strong scalability and versatility, enabling mass-production design, manufacturing, assembly, and maintenance, all while being highly user-friendly. Consequently, homogeneous modular robots have a wider range of applications. Robot applications require dynamic modeling, and this applies to homogeneous modular robots as well. Traditional dynamic modeling methods for homogeneous modular robots require manual acquisition of dynamic parameters from a three-dimensional model, making them unsuitable for modular robots with fluid, dynamically changing topologies. Therefore, research on dynamic modeling for homogeneous modular robots holds significant theoretical value. [Summary of the invention]

[0004] In view of this, the present invention provides a modular robot dynamics modeling method to achieve dynamics modeling of homogeneous modular robots.

[0005] An embodiment of the present invention provides a modular robot dynamics modeling method, characterized in that the method includes:

[0006] Obtain the mathematical representation of the modular robot topology and the three-dimensional model of the modular unit;

[0007] According to the three-dimensional model of the module unit, the module unit body center coordinate system and interface coordinate system are established to obtain the basic kinematic parameter information and basic dynamic parameter information of the module unit;

[0008] According to the three-dimensional model of the module unit and the basic kinematic parameter information of the module unit, a module unit motion transfer library is obtained;

[0009] Obtain a modular unit structure equivalent library based on the modular unit three-dimensional model, the modular unit motion transfer library, and the basic dynamic parameter information of the modular unit;

[0010] According to the mathematical representation of the modular robot topology, the modular robot grounding module unit number, grounding interface number, and terminal module unit number are obtained;

[0011] According to the mathematical representation of the modular robot's topological structure and the modular robot's grounding module unit number, grounding interface number, and terminal module unit number, all motion transmission branches of the modular robot are obtained;

[0012] According to all motion transmission branches of the modular robot, the connection status of the module units in each motion transmission branch and the motion transmission mode between two module units with a connection relationship are obtained;

[0013] According to the module unit structure equivalent library, the basic dynamic parameter information of the module unit and the connection state of the module unit in each motion transmission branch, the module unit equivalent structure and the dynamic parameters of the equivalent structure are obtained;

[0014] Based on the equivalent structure of the modular unit, the dynamic parameters of the equivalent structure, and the motion transmission method between two connected modular units, a distributed parameter acquisition strategy for the modular robot is designed to obtain the dynamic parameters corresponding to the motion transmission branch chain;

[0015] According to the equivalent structure of the modular unit, the dynamic parameters of the equivalent structure, the motion transmission method between two modular units with a connection relationship, the distributed parameter acquisition strategy of the modular robot and all the motion transmission branches of the modular robot, a dynamic modeling method of the modular robot based on distributed parameter acquisition is designed to obtain the dynamic model of the modular robot.

[0016] In the above method, based on the three-dimensional model of the module unit, the module unit body center coordinate system and the interface coordinate system are established to obtain the basic kinematic parameter information and basic dynamic parameter information of the module unit, including:

[0017] According to the three-dimensional model of the module unit, the module unit body center coordinate system and interface coordinate system are established to obtain the basic kinematic parameter information of the module unit;

[0018] According to the three-dimensional model of the module unit, the module unit structure is split to obtain the substructures of the module unit and establish the centroid coordinate system of each substructure;

[0019] The basic dynamic parameters of the module unit are obtained based on the three-dimensional model of the module unit, each substructure of the module unit, and the center of mass coordinate system of each substructure.

[0020] In the above method, based on the three-dimensional model of the module unit, the module unit body center coordinate system and the interface coordinate system are established to obtain the basic kinematic parameter information of the module unit, including:

[0021] The spinor coordinates of each rotation axis in the body-centered coordinate system;

[0022] The relative posture relationship matrix between each interface coordinate system and the body center coordinate system;

[0023] The connection orientation relationship matrix that exists when two interfaces are connected is used to represent the specific docking status of the positioning device when the interfaces are docked.

[0024] In the above method, based on the modular unit three-dimensional model, the modular unit structure is split to obtain the substructures of the modular unit, and the centroid coordinate system of each substructure is established, including:

[0025] The following rules are followed to split the module unit structure:

[0026] The parts fixedly connected to the rotor of the motor in the interface can be assembled into a substructure, the parts fixedly connected to the stator of the motor in the interface can be assembled into a substructure, the parts fixedly connected to the rotor of the motor in the body center can be assembled into a substructure, and the parts fixedly connected to the stator of the motor in the body center can be assembled into a substructure;

[0027] The coordinate system of the center of mass of each substructure of the module unit is determined as follows:

[0028] The centroid of each substructure is selected as the origin of the centroid coordinate system. The selection of the axis of the centroid coordinate system of each substructure follows the following rules:

[0029] For the substructure assembled from the components that are fixedly connected to the rotor of the motor in the interface, the axial direction of its center of mass coordinate system is consistent with the interface coordinate system;

[0030] For the substructure assembled from the components fixedly connected to the stator of the motor in the interface, the center-of-mass coordinate system is axially consistent with the body-center coordinate system;

[0031] For the substructure assembled from components fixedly connected to the rotor of the motor in the body center, the center-of-mass coordinate system is axially consistent with the body center coordinate system;

[0032] For a substructure assembled from components fixedly connected to the stator of the motor in the body center, the center-of-mass coordinate system is axially consistent with the body center coordinate system.

[0033] In the above method, the basic dynamic parameters of the module unit are obtained based on the three-dimensional model of the module unit, each substructure of the module unit, and the centroid coordinate system of each substructure, including:

[0034] The quality of each substructure;

[0035] The position vector of the center of mass of each substructure relative to the interface coordinate system or the body center coordinate system that is in the same direction as the center of mass coordinate system;

[0036] The inertia tensor of each substructure relative to the center-of-mass coordinate system.

[0037] In the above method, based on the three-dimensional model of the module unit and the basic kinematic parameter information of the module unit, a module unit motion transfer library is obtained, which includes:

[0038] According to the three-dimensional model of the module unit, the interface arrangement, interface type, mechanical structure size, and degree of freedom arrangement information of the module unit are obtained;

[0039] Obtain all valid connection status of the module unit based on the interface arrangement, interface type, and mechanical structure size information of the module unit;

[0040] According to the degree of freedom arrangement information of the module unit and the basic kinematic parameter information of the module unit, the rotation axis and kinematic parameters contained in each effective connection state of the module unit are obtained;

[0041] A module unit motion transfer library is obtained according to all valid connection states of the module unit, the rotation axes and kinematic parameters contained in each valid connection state of the module unit.

[0042] In the above method, all valid connection states of the module unit are obtained based on the interface arrangement, interface type, and mechanical structure size information of the module unit, including:

[0043] According to the interface arrangement and interface type of the module unit, based on the enumeration method, all connection states of the module unit are obtained through permutations and combinations;

[0044] According to the mechanical structure dimension information of the module unit and all the connection states of the module unit, the connection states with structural interference are eliminated to obtain all the valid connection states of the module unit.

[0045] In the above method, based on the modular unit three-dimensional model, the modular unit motion transfer library, and the basic dynamic parameter information of the modular unit, the modular unit structure equivalent library is obtained, including:

[0046] According to the three-dimensional model of the module unit, the interface arrangement, interface type, mechanical structure size, and degree of freedom arrangement information of the module unit are obtained;

[0047] Obtain all valid connection status of the module unit based on the interface arrangement, interface type, and mechanical structure size information of the module unit;

[0048] According to all valid connection states of the module unit, obtain the motion input end interface and the motion output end interface of each valid connection state of the module unit;

[0049] According to the motion input end interface and the motion output end interface of the module unit in each connection state and the module unit motion transfer library, the attributes corresponding to each substructure in each valid connection state of the module unit are obtained;

[0050] According to the attributes corresponding to each substructure in each effective connection state of the module unit, the equivalent structure in each effective connection state of the module unit is obtained;

[0051] According to the basic dynamic parameter information of the equivalent structure and the module unit in each effective connection state of the module unit, the dynamic parameters of the equivalent structure in each effective connection state of the module unit are obtained;

[0052] Obtain a module unit structural equivalent library based on all valid connection states of the module unit, the equivalent structure of each valid connection state of the module unit, and the dynamic parameters of the equivalent structure of each valid connection state of the module unit;

[0053] The motion input interface refers to the interface on the motion transmission branch of the modular robot that is closest to the ground module unit in the current module unit and in the current valid connection state; the motion output interface refers to the interface on the motion transmission branch of the modular robot that is closest to the terminal module unit in the current module unit and in the current valid connection state;

[0054] The attributes corresponding to each substructure in each valid connection state of the module unit are the components that transmit the motion and force of a certain rotation axis, where the rotation axis is determined according to the rotation axis included in the current valid connection state in the module unit motion transmission library;

[0055] The final representation of the equivalent structure in each valid connection state of the module unit is a collection of multiple equivalent structures;

[0056] The dynamic parameters of the equivalent structure under each effective connection state of the module unit include the mass of the equivalent structure, the position vector of the center of mass of the equivalent structure relative to the interface coordinate system or the body center coordinate system corresponding to the previous rotation axis, the inertia tensor of the equivalent structure, and the spatial inertia matrix of the equivalent structure;

[0057] The center-of-mass coordinate system of the equivalent structure is determined as follows:

[0058] The center of mass of the equivalent structure is selected as the origin of the center of mass coordinate system, and the axis of the center of mass coordinate system is consistent with the interface coordinate system or body center coordinate system corresponding to the previous rotation axis;

[0059] The mass of the equivalent structure i for:

[0060]

[0061] Among them, mk is the mass of the modular unit substructure k in the equivalent structure i, a-b Λ i (i=1, 2, 3, ...) is the set of module unit substructures contained in the equivalent structure i when the module unit is in the effective connection state ab, a is the motion input end interface of the module unit in the current effective connection state, b is the motion output end interface of the module unit in the current effective connection state, and a≠b;

[0062] The center of mass of the equivalent structure i relative to the interface coordinate system or body center coordinate system ΣJ corresponding to the previous rotation axis i Position vector for:

[0063]

[0064] in, is the mass center of the module unit substructure k in the equivalent structure i in the coordinate system ΣJ i The description below can be obtained by calculating the basic dynamic parameters of the module unit through coordinate system transformation;

[0065] Establish the center-of-mass coordinate system ΣL of the equivalent structure i i , the inertia tensor of the equivalent structure i is:

[0066]

[0067] in, is the inertia tensor of the module unit substructure k in the equivalent structure i in the coordinate system ΣL i The description below can be obtained by calculating the basic dynamic parameters of the module unit through coordinate system transformation;

[0068] The spatial inertia matrix of the equivalent structure i is:

[0069]

[0070] Among them, 0 3×3 is a zero matrix of dimension 3×3, I 3×3 is the unit matrix of dimension 3×3.

[0071] In the above method, based on the mathematical representation of the modular robot topology structure, the modular robot grounding module unit number, grounding interface number, and terminal module unit number are obtained, including:

[0072] For n topo_module The modular robot topology structure of modules is mathematically represented as

[0073]

[0074]

[0075] Among them, n topo_module Indicates the number of modules contained in the modular robot topology; m i (i=1,2,...,n topo_module ) represents the module numbers in the modular robot topology; the matrix B is called the grounding relationship matrix, ba i (i=1,2,...,n topo_module ) indicates whether the module in the modular robot topology is grounded as a base when in use, ba i =0 means module m i When not grounded, i ≠0 indicates module m i When using ba i The interface ground is used as the base; the matrix C is called the connection relationship matrix of the modular robot, c ij (i=1,2,...,n topo_module ; j=1,2,...,n topo_module )∈{1,...,n surf_con} represents the interface number between module mi and module mj. When i=j, c ij =0(i=1,2,...,n topo_module ; j=1,2,...,n topo_module ), n surf_con Represents the number of surface interfaces of a single module; the matrix O is called the connection orientation relationship matrix of the modular robot, co ij (i=1,2,...,n topo_module ; j=1,2,...,n topo_module ) represents module m i With module m j The connection orientation relationship, when i = j, co ij =0(i=1,2,...,n topo_module ; j=1,2,...,n topo_module );

[0076] According to the mathematical representation of the modular robot topology structure, including matrix M, matrix A, matrix C, and matrix O, the row numbers of matrix C containing only one non-zero element, and the non-zero elements and their positions in matrix A are obtained;

[0077] According to the matrix A, the non-zero elements in the matrix A and their positions, the non-zero elements in the matrix A are the grounding interface numbers, and the elements corresponding to the positions of the non-zero elements in the matrix M are read to obtain the modular robot grounding module unit number and the grounding interface number;

[0078] According to the row number of the matrix C containing only one non-zero element and the matrix M, the element at the position corresponding to the row number in the matrix M is read to obtain the terminal module unit number of the modular robot.

[0079] In the above method, all motion transmission branches of the modular robot are obtained based on the mathematical representation of the modular robot topology structure and the modular robot grounding module unit number, grounding interface number, and terminal module unit number, including:

[0080] Starting from the grounding interface number of the modular robot's grounding module unit number and ending with the modular robot's terminal module unit number, based on the matrix C in the mathematical representation of the modular robot's topological structure, and based on depth-first traversal, the modules and their interface information that the modular robot needs to pass through for motion transmission from the starting point to the end point are searched, and all the motion transmission branches of the modular robot are obtained.

[0081] In the above method, based on all motion transmission branches of the modular robot, the connection status of the module units in each motion transmission branch and the motion transmission mode between two module units with a connection relationship are obtained, including:

[0082] There are two ways to transfer motion between two connected module units:

[0083] The motion output of the previous module unit is an interface including a motor;

[0084] The motion output of the previous module unit is an interface without a motor.

[0085] In the above method, based on the equivalent structure of the modular unit, the dynamic parameters of the equivalent structure, and the motion transmission mode between two connected modular units, a distributed parameter acquisition strategy for the modular robot is designed to obtain the dynamic parameters corresponding to the motion transmission branch chain, including:

[0086] According to the equivalent structure of the module unit, the dynamic parameters of the equivalent structure, and the motion transmission mode between the two module units having a connection relationship, a dynamic parameter processing strategy corresponding to the motion transmission mode between the two module units having a connection relationship is obtained;

[0087] Based on the dynamic parameter processing strategy corresponding to the motion transmission mode between two connected modular units, a distributed parameter acquisition strategy for modular robots is designed to obtain the dynamic parameters corresponding to the motion transmission branch chain;

[0088] Among them, the dynamic parameter processing strategies corresponding to the motion transmission mode between two connected module units include:

[0089] When the motion transmission mode between two connected module units is that the motion output end of the previous module unit is an interface containing a motor, the starting equivalent structure of the latter module unit and the ending equivalent structure of the previous module unit are recalculated according to the process of obtaining the ending equivalent structure of the previous module unit;

[0090] When the motion transmission mode between two connected module units is that the motion output end of the previous module unit is an interface that does not include a motor, the end equivalent structure of the previous module unit is directly merged with the start equivalent structure of the next module unit.

[0091] In the above method, a dynamic modeling method based on distributed parameter acquisition of a modular robot is designed based on the equivalent structure of the modular unit, the dynamic parameters of the equivalent structure, the motion transmission method between two connected modular units, the distributed parameter acquisition strategy of the modular robot, and all motion transmission branches of the modular robot. The dynamic model of the modular robot is obtained, including:

[0092] A modular robot motion transmission chain consisting of m modular units and n degrees of freedom is subjected to an external force. Under the action of

[0093]

[0094] in, is the Jacobian matrix, and Described in the same coordinate system; is the inertia force matrix, as shown below; are the Coriolis force and centrifugal force terms on each joint during the motion of the modular robot, as shown in the following formula; is the gravitational force on the modular robot during its motion, as shown in the following equation; The order is the joint angle, joint angular velocity, joint angular acceleration, and driving torque vector on the current motion transmission branch;

[0095] One containing The dynamic model of the modular robot with a motion transmission branch chain is:

[0096]

[0097] Among them, q i 、 τ i They are the joint angle, joint angular velocity, joint angular acceleration, and driving torque vector on the i-th motion transmission branch, is the external force rotation amount received by the end of the i-th motion transmission branch,

[0098] By analyzing the motion transmission branch chain, it can be split into ζ non-bifurcation motion branches, and then the modular robot dynamics model can be further converted into:

[0099]

[0100] in, represents the driving torque provided by the joint of the k-th non-bifurcation motion branch during the motion of the i-th motion branch, It represents the inertial force coupling influence matrix generated by the joint motion of the j-th non-bifurcation motion branch and the joint motion of the k-th non-bifurcation motion branch during the motion of the i-th motion branch. According to the inertial force matrix M of the i-th motion branch i Obtained, represents the influence of the inertial force of the joint acceleration of the j-th non-bifurcation motion branch on the joint motion of the k-th non-bifurcation motion branch, It represents the Coriolis force and centrifugal force coupling influence matrix generated by the joint motion of the j-th non-bifurcation motion branch and the k-th non-bifurcation motion branch during the motion of the i-th motion branch. According to the inertia force matrix C of the i-th motion branch i Obtained, represents the influence of the acceleration of the j-th non-bifurcation motion branch joint on the Coriolis force and centrifugal force of the k-th non-bifurcation motion branch joint motion, It represents the gravitational force on the joint motion of the kth non-bifurcation motion branch during the motion of the i-th motion branch, The Jacobian matrix representing the joint motion contained in the k-th branch of non-bifurcation motion relative to the i-th end motion;

[0101] Among them, the non-bifurcation motion branch means that during the motion of each joint on the current branch, the transmission of motion or force has only a single direction.

[0102] It can be seen from the above technical solutions that the embodiments of the present invention have the following beneficial effects:

[0103] In the technical solution of the embodiment of the present invention, a mathematical representation of the modular robot topological structure and a three-dimensional model of the modular unit are obtained. Based on the three-dimensional model of the modular unit, a body-centered coordinate system and an interface coordinate system of the modular unit are established to obtain the basic kinematic parameter information and basic dynamic parameter information of the modular unit. Based on the three-dimensional model of the modular unit and the basic kinematic parameter information of the modular unit, a modular unit motion transfer library is obtained. Based on the three-dimensional model of the modular unit, the modular unit motion transfer library and the basic dynamic parameter information of the modular unit, a modular unit structure equivalent library is obtained. Based on the mathematical representation of the modular robot topological structure, the modular robot grounding module unit number, grounding interface number and terminal module unit number are obtained. Based on the mathematical representation of the modular robot topological structure and the modular robot grounding module unit number, grounding interface number and terminal module unit number, all motion transmission branches of the modular robot are obtained. Based on all motion transmission branches of the modular robot, the connection status of the modular units in each motion transmission branch and the motion transmission method between two modular units with a connection relationship are obtained. According to the modular unit structure equivalent library, the basic dynamic parameter information of the modular unit and the connection status of the modular unit in each motion transmission branch, the modular unit equivalent structure and the dynamic parameters of the equivalent structure are obtained. According to the modular unit equivalent structure and the dynamic parameters of the equivalent structure and the motion transmission method between the two modular units with a connection relationship, the modular robot distributed parameter acquisition strategy is designed to obtain the dynamic parameters corresponding to the motion transmission branch. According to the modular unit equivalent structure and the dynamic parameters of the equivalent structure, the motion transmission method between the two modular units with a connection relationship, the modular robot distributed parameter acquisition strategy and all motion transmission branches of the modular robot, the modular robot dynamic modeling method based on distributed parameter acquisition is designed to obtain the dynamic model of the modular robot. Therefore, the modular robot dynamic modeling can be realized. Combined with the characteristics of the modular robot, based on the dynamic parameters of the modular unit, more efficient homogeneous modular robot dynamic modeling is achieved, providing a model basis for the application of modular robots.

Brief Description of the Drawings

[0104] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without inventiveness and labor.

[0105] Figure 1 1 is a flow chart of a modular robot dynamics modeling method provided by an embodiment of the present invention;

[0106] Figure 2 is a schematic diagram of a three-dimensional model of a module unit in an embodiment of the present invention;

[0107] Figure 3 This is a schematic diagram of establishing a module unit coordinate system in an embodiment of the present invention;

[0108] Figure 4 Schematic diagram of the arrangement of the module unit motion spinors in an embodiment of the present invention;

[0109] Figure 5 is the expected motion trajectory of each joint in the modular robot in the embodiment of the present invention;

[0110] Figure 6 is the driving torque curve of each joint of the first module unit calculated by the dynamic modeling method based on distributed parameter acquisition of the modular robot in an embodiment of the present invention;

[0111] Figure 7 is a driving torque curve of each joint of the second module unit calculated by the dynamic modeling method based on distributed parameter acquisition of the modular robot in an embodiment of the present invention;

[0112] Figure 8 is a driving torque curve of each joint of the third module unit calculated by the dynamic modeling method based on distributed parameter acquisition of the modular robot in an embodiment of the present invention;

[0113] Figure 9 3. This is a comparison diagram of the first three joint driving torques of the modular robot according to the embodiment of the present invention, based on the dynamic modeling method of distributed parameter acquisition and the ADAMS software simulation results;

[0114] Figure 10 This is a comparison chart of the last three joint driving torques of the modular robot based on the dynamic modeling method of distributed parameter acquisition and the ADAMS software simulation results in an embodiment of the present invention. [Specific embodiment]

[0115] 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.

[0116] It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0117] The embodiment of the present invention provides a modular robot dynamics modeling method, please refer to Figure 1 , which is a flow chart of a dynamic modeling method based on distributed parameter acquisition for a modular robot provided by an embodiment of the present invention, such as Figure 1 As shown, the method includes the following steps:

[0118] Step 101: Obtain a mathematical representation of the modular robot topology structure and a three-dimensional model of the modular unit.

[0119] Specifically, the module unit three-dimensional model is as follows Figure 2 As shown, 1 represents the connecting plane of the two hemispherical shells; 2 and 18 represent the two hemispherical shells; 3, 6, 11, and 15 represent the positioning device on the male interface; 4 and 14 represent the torque output shaft of the motor module of the active interface; 5 and 12 represent the motor module body on the active interface; 7, 10, 13, and 20 represent the mechanical structure components on the interface; 8, 9, 19, and 21 represent the positioning grooves on the female interface that match the positioning device; 16 represents the motor module body at the center of the module unit body; 17 represents the torque output shaft of the motor module at the center of the module unit body;

[0120] The mathematical representation of the topological structure of the homogeneous modular robot is:

[0121] M=[1,2,3]

[0122] B=[1,0,0]

[0123]

[0124] Step 102: Based on the three-dimensional model of the module unit, a module unit body center coordinate system and an interface coordinate system are established to obtain basic kinematic parameter information and basic dynamic parameter information of the module unit.

[0125] Specifically, the module unit body center coordinate system is established. The interface coordinate system is as follows Figure 3 As shown, the motion spinor arrangement is as follows Figure 4 As shown, the basic kinematic parameter information of the module unit includes: the spinor coordinates of each rotation axis in the body center coordinate system; the relative posture relationship matrix between each interface coordinate system and the body center coordinate system The connection orientation relationship matrix when two interfaces are connected Used to indicate the specific docking status of the positioning device when the interface is docked;

[0126] According to the three-dimensional model of the module unit, the module unit structure is split to obtain the substructures of the module unit and establish the centroid coordinate system of each substructure;

[0127] According to the three-dimensional model of the module unit, each substructure of the module unit, and the centroid coordinate system of each substructure, the basic dynamic parameters of the module unit are obtained;

[0128] The module unit structure is split into the following 7 substructures: Figure 2 12, 17, and 18 form substructure 1; Figure 2 11, 13, 14, and 15 form substructure 2; Figure 2 19, 20, and 21 form substructure 3; Figure 2 2 and 5 form substructure 4; Figure 2 3, 4, 6, and 7 form substructure 5; Figure 2 8, 9, and 10 form substructure 6; Figure 2 The middle 16 constitutes substructure 7;

[0129] The masses of each substructure are m1, m2, m3, m4, m5, m6, and m7 respectively; the position vectors of the center of mass of each substructure relative to the interface coordinate system or the body center coordinate system in the same direction as the center of mass coordinate system are E PC Sub_1 、 E PC Sub_4 、 E PC Sub_7 ; The inertia tensors of each substructure relative to the center of mass coordinate system are

[0130] Step 103: Obtain a module unit motion transfer library based on the module unit three-dimensional model and basic kinematic parameter information of the module unit.

[0131] Specifically, based on the modular unit's three-dimensional model, the modular unit's interface layout, interface type, mechanical structure dimensions, and degree of freedom arrangement information are obtained. Based on the modular unit's interface layout and interface type, all connection states of the modular unit are obtained through permutations and combinations based on enumeration. Based on the modular unit's mechanical structure dimensions and all connection states, connection states with structural interference are eliminated to obtain all valid connection states of the modular unit. Based on the modular unit's degree of freedom arrangement information and basic kinematic parameter information, the rotation axes and kinematic parameters included in each valid connection state of the modular unit are obtained. Based on all valid connection states of the modular unit and the rotation axes and kinematic parameters included in each valid connection state of the modular unit, a modular unit motion transfer library is obtained. Table 1 shows the modular unit motion transfer library.

[0132] Table 1 Module unit motion transfer library

[0133]

[0134]

[0135] Step 104 : obtaining a modular unit structure equivalent library based on the modular unit three-dimensional model, the modular unit motion transfer library, and the basic dynamic parameter information of the modular unit.

[0136] Specifically, according to the three-dimensional model of the module unit, the interface arrangement, interface type, mechanical structure size, and degree of freedom arrangement information of the module unit are obtained;

[0137] Obtain all valid connection status of the module unit based on the interface arrangement, interface type, and mechanical structure size information of the module unit;

[0138] According to all valid connection states of the module unit, obtain the motion input end interface and the motion output end interface of each valid connection state of the module unit;

[0139] According to the motion input end interface and the motion output end interface of the module unit in each connection state and the module unit motion transfer library, the attributes corresponding to each substructure in each valid connection state of the module unit are obtained;

[0140] According to the corresponding attributes of each substructure in each valid connection state of the module unit, the equivalent structure of each valid connection state of the module unit is obtained. Table 2 shows the corresponding numbers of the equivalent structures in each valid connection state of the module unit.

[0141] Table 2 Corresponding numbers of equivalent structures in each effective connection state of the module unit

[0142]

[0143]

[0144] According to the basic dynamic parameter information of the equivalent structure and the module unit in each effective connection state of the module unit, the dynamic parameters of the equivalent structure in each effective connection state of the module unit are obtained;

[0145] Obtain a module unit structural equivalent library based on all valid connection states of the module unit, the equivalent structure of each valid connection state of the module unit, and the dynamic parameters of the equivalent structure of each valid connection state of the module unit;

[0146] The motion input interface refers to the interface on the motion transmission branch of the modular robot that is closest to the ground module unit in the current module unit and in the current valid connection state; the motion output interface refers to the interface on the motion transmission branch of the modular robot that is closest to the terminal module unit in the current module unit and in the current valid connection state;

[0147] The attributes corresponding to each substructure in each valid connection state of the module unit are the components that transmit the motion and force of a certain rotation axis, where the rotation axis is determined according to the rotation axis included in the current valid connection state in the module unit motion transmission library;

[0148] The final representation of the equivalent structure in each valid connection state of the module unit is a collection of multiple equivalent structures;

[0149] The dynamic parameters of the equivalent structure under each effective connection state of the module unit include the mass of the equivalent structure, the position vector of the center of mass of the equivalent structure relative to the interface coordinate system or the body center coordinate system corresponding to the previous rotation axis, the inertia tensor of the equivalent structure, and the spatial inertia matrix of the equivalent structure;

[0150] The center-of-mass coordinate system of the equivalent structure is determined as follows:

[0151] The center of mass of the equivalent structure is selected as the origin of the center of mass coordinate system, and the axis of the center of mass coordinate system is consistent with the interface coordinate system or body center coordinate system corresponding to the previous rotation axis;

[0152] The mass of the equivalent structure i for:

[0153]

[0154] Among them, m k is the mass of the modular unit substructure k in the equivalent structure i, a-b Λ i (i=1, 2, 3, ...) is the set of module unit substructures contained in the equivalent structure i when the module unit is in the effective connection state ab, a is the motion input end interface of the module unit in the current effective connection state, b is the motion output end interface of the module unit in the current effective connection state, and a≠b;

[0155] The center of mass of the equivalent structure i relative to the interface coordinate system or body center coordinate system ΣJ corresponding to the previous rotation axis i Position vector for:

[0156]

[0157] in, is the mass center of the module unit substructure k in the equivalent structure i in the coordinate system ΣJ i The description below can be obtained by calculating the basic dynamic parameters of the module unit through coordinate system transformation;

[0158] Establish the center-of-mass coordinate system ΣL of the equivalent structure i i , the inertia tensor of the equivalent structure i is:

[0159]

[0160] in, is the inertia tensor of the module unit substructure k in the equivalent structure i in the coordinate system ΣL i The description below can be obtained by calculating the basic dynamic parameters of the module unit through coordinate system transformation;

[0161] The spatial inertia matrix of the equivalent structure i is:

[0162]

[0163] Step 105 : Obtain the modular robot grounding module unit number, grounding interface number, and terminal module unit number based on the mathematical representation of the modular robot topology structure.

[0164] Specifically, for n topo_module The topological structure of a homogeneous modular robot with modules is mathematically represented as

[0165]

[0166] Among them, n topo_module Represents the number of modules contained in the homogeneous modular robot topology; m i (i=1,2,...,n topo_module ) represents the module numbers in the topology of the homogeneous modular robot; the matrix A is called the grounding relationship matrix, ba i (i=1,2,...,n topo_module ) indicates whether the module in the homogeneous modular robot topology is grounded as a base when in use, ba i =0 means module m i When not grounded, i ≠0 means module m i When using ba i The interface ground serves as the base; the matrix C is called the connection relationship matrix of the homogeneous modular robot, c ij (i=1,2,...,n topo_module ; j=1,2,...,n topo_module )∈{1,...,n surf_con} indicates module m i With module m j The number of the connected interface. When i=j, c ij =0(i=1,2,...,n topo_module ; j=1,2,...,n topo_module ), n surf_con Represents the number of surface interfaces of a single module; the matrix O is called the connection orientation relationship matrix of the homogeneous modular robot, co ij (i=1,2,...,n topo_module ; j=1,2,...,n topo_module ) indicates module m i With module m j The connection orientation relationship, when i = j, co ij=0(i=1,2,...,n topo_module ; j=1,2,...,n topo_module );

[0167] Based on the mathematical representation of the topological structure of the homogeneous modular robot, including matrix M, matrix A, matrix C, and matrix O, the row numbers of matrix C containing only one non-zero element, and the non-zero elements and their locations in matrix B are obtained;

[0168] According to the matrix B, the non-zero elements in the matrix B and their positions, the non-zero elements in the matrix B are the grounding interface numbers, and the elements corresponding to the positions of the non-zero elements in the matrix M are read to obtain the grounding module unit number and the grounding interface number of the homogeneous modular robot;

[0169] According to the row number of the matrix C containing only one non-zero element and the matrix M, the element at the position corresponding to the row number in the matrix M is read to obtain the terminal module unit number of the homogeneous modular robot.

[0170] It can be seen that in the homogeneous modular robot, the grounding module unit is numbered 1 and the grounding interface is numbered 1; the robot represented by the topological structure only contains one robot end, and the robot module unit is numbered 3.

[0171] Step 106 , obtaining all motion transmission branches of the modular robot based on the mathematical representation of the modular robot topology structure and the modular robot grounding module unit number, grounding interface number, and terminal module unit number.

[0172] Specifically, starting from the grounding interface number of the grounding module unit number of the homogeneous modular robot and ending with the terminal module unit number of the homogeneous modular robot, based on the matrix C in the mathematical representation of the topological structure of the homogeneous modular robot, based on depth-first traversal, the modules and their interface information that the homogeneous modular robot needs to pass through for motion transmission from the starting point to the end point are searched, and all motion transmission branches of the homogeneous modular robot are obtained.

[0173] Step 107 , based on all motion transmission branches of the modular robot, obtain the connection status of the module units in each motion transmission branch and the motion transmission mode between two module units that have a connection relationship.

[0174] Specifically, there are two modes of motion transmission between two connected module units: the motion output end of the preceding module unit is an interface including a motor; the motion output end of the preceding module unit is an interface not including a motor.

[0175] Step 108 , obtaining the module unit equivalent structure and the dynamic parameters of the equivalent structure based on the module unit structure equivalent library, the basic dynamic parameter information of the module unit and the connection status of the module unit in each motion transmission branch.

[0176] Step 109 , based on the equivalent structure of the module unit, the dynamic parameters of the equivalent structure, and the motion transmission mode between two connected module units, a distributed parameter acquisition strategy of the modular robot is designed to obtain the dynamic parameters corresponding to the motion transmission branch chain.

[0177] Specifically, according to the equivalent structure of the module unit, the dynamic parameters of the equivalent structure, and the motion transmission mode between the two module units having a connection relationship, a dynamic parameter processing strategy corresponding to the motion transmission mode between the two module units having a connection relationship is obtained;

[0178] Based on the dynamic parameter processing strategy corresponding to the motion transmission mode between two connected modular units, a distributed parameter acquisition strategy for modular robots is designed to obtain the dynamic parameters corresponding to the motion transmission branch chain;

[0179] Among them, the dynamic parameter processing strategies corresponding to the motion transmission mode between two connected module units include:

[0180] When the motion transmission mode between two connected module units is that the motion output end of the previous module unit is an interface containing a motor, the starting equivalent structure of the latter module unit and the ending equivalent structure of the previous module unit are recalculated according to the process of obtaining the ending equivalent structure of the previous module unit;

[0181] When the motion transmission mode between two connected module units is that the motion output end of the previous module unit is an interface that does not include a motor, the end equivalent structure of the previous module unit is directly merged with the start equivalent structure of the next module unit.

[0182] Step 110, based on the equivalent structure of the modular unit, the dynamic parameters of the equivalent structure, the motion transmission method between two modular units with a connection relationship, the distributed parameter acquisition strategy of the modular robot and all motion transmission branches of the modular robot, design a dynamic modeling method of the modular robot based on distributed parameter acquisition to obtain the dynamic model of the modular robot.

[0183] Specifically, a modular robot motion transmission chain consisting of m modular units and n degrees of freedom is subjected to an external force. Under the action of

[0184]

[0185] in, is the Jacobian matrix, and Described in the same coordinate system; is the inertia force matrix, as shown below; are the Coriolis force and centrifugal force terms on each joint during the motion of the modular robot, as shown in the following formula; is the gravitational force on the modular robot during its motion, as shown in the following equation; The order is the joint angle, joint angular velocity, joint angular acceleration, and driving torque vector on the current motion transmission branch;

[0186] One containing The dynamic model of the modular robot with a motion transmission branch chain is:

[0187]

[0188] Among them, q i 、 τ i They are the joint angle, joint angular velocity, joint angular acceleration, and driving torque vector on the i-th motion transmission branch, is the external force rotation amount received by the end of the i-th motion transmission branch,

[0189] By analyzing the motion transmission branch chain, it can be split into ζ non-bifurcation motion branches, and then the modular robot dynamics model can be further converted into:

[0190]

[0191] in, represents the driving torque provided by the joint of the k-th non-bifurcation motion branch during the motion of the i-th motion branch, It represents the inertial force coupling influence matrix generated by the joint motion of the j-th non-bifurcation motion branch and the joint motion of the k-th non-bifurcation motion branch during the motion of the i-th motion branch. According to the inertial force matrix M of the i-th motion branch i Obtained, represents the influence of the inertial force of the joint acceleration of the j-th non-bifurcation motion branch on the joint motion of the k-th non-bifurcation motion branch, It represents the Coriolis force and centrifugal force coupling influence matrix generated by the joint motion of the j-th non-bifurcation motion branch and the k-th non-bifurcation motion branch during the motion of the i-th motion branch. According to the inertia force matrix C of the i-th motion branch i Obtained, represents the influence of the acceleration of the j-th non-bifurcation motion branch joint on the Coriolis force and centrifugal force of the k-th non-bifurcation motion branch joint motion, It represents the gravitational force on the joint motion of the kth non-bifurcation motion branch during the motion of the i-th motion branch, The Jacobian matrix representing the joint motion contained in the k-th branch of non-bifurcation motion relative to the i-th end motion;

[0192] Among them, the non-bifurcation motion branch means that during the motion of each joint on the current branch, the transmission of motion or force has only a single direction.

[0193] According to the above method provided by the embodiment of the present invention, simulation was performed.

[0194] Design the expected motion trajectory of each joint of the modular robot. The expected motion trajectory of the joint is as follows: Figure 5 The driving torque of the modular robot when executing the desired trajectory is calculated using the dynamic modeling method of the modular robot based on distributed parameter acquisition. The driving torque of each joint of the three modular units is as follows: Figure 6 、 Figure 7 、 Figure 8 The calculation results are compared with the simulation results of ADAMS software. The comparison results are shown in Figures 9 and Figure 10 By comparison, it can be concluded that the driving torque calculated by the proposed modular robot dynamic modeling method based on distributed parameter acquisition is basically consistent with the ADAMS software simulation results, which proves the correctness and effectiveness of the modular robot dynamic modeling method based on distributed parameter acquisition.

[0195] The technical solution of the embodiment of the present invention has the following beneficial effects:

[0196] In the technical solution of the embodiment of the present invention, a mathematical representation of the modular robot topological structure and a three-dimensional model of the modular unit are obtained. Based on the three-dimensional model of the modular unit, a body-centered coordinate system and an interface coordinate system of the modular unit are established to obtain the basic kinematic parameter information and basic dynamic parameter information of the modular unit. Based on the three-dimensional model of the modular unit and the basic kinematic parameter information of the modular unit, a modular unit motion transfer library is obtained. Based on the three-dimensional model of the modular unit, the modular unit motion transfer library and the basic dynamic parameter information of the modular unit, a modular unit structure equivalent library is obtained. Based on the mathematical representation of the modular robot topological structure, the modular robot grounding module unit number, grounding interface number and terminal module unit number are obtained. Based on the mathematical representation of the modular robot topological structure and the modular robot grounding module unit number, grounding interface number and terminal module unit number, all motion transmission branches of the modular robot are obtained. Based on all motion transmission branches of the modular robot, the connection status of the modular units in each motion transmission branch and the motion transmission method between two modular units with a connection relationship are obtained. According to the modular unit structure equivalent library, the basic dynamic parameter information of the modular unit and the connection status of the modular unit in each motion transmission branch, the modular unit equivalent structure and the dynamic parameters of the equivalent structure are obtained. According to the modular unit equivalent structure and the dynamic parameters of the equivalent structure and the motion transmission method between the two modular units with a connection relationship, the modular robot distributed parameter acquisition strategy is designed to obtain the dynamic parameters corresponding to the motion transmission branch. According to the modular unit equivalent structure and the dynamic parameters of the equivalent structure, the motion transmission method between the two modular units with a connection relationship, the modular robot distributed parameter acquisition strategy and all motion transmission branches of the modular robot, the modular robot dynamic modeling method based on distributed parameter acquisition is designed to obtain the dynamic model of the modular robot. Therefore, the modular robot dynamic modeling can be realized. Combined with the characteristics of the modular robot, based on the dynamic parameters of the modular unit, more efficient homogeneous modular robot dynamic modeling is achieved, providing a model basis for the application of modular robots.

[0197] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0198] 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 modular robot dynamics modeling method, characterized in that: The method comprises: Obtain the mathematical representation of the modular robot topology and the three-dimensional model of the modular unit; According to the three-dimensional model of the module unit, the module unit body center coordinate system and interface coordinate system are established to obtain the basic kinematic parameter information and basic dynamic parameter information of the module unit; According to the three-dimensional model of the module unit and the basic kinematic parameter information of the module unit, a module unit motion transfer library is obtained; Obtain a modular unit structure equivalent library based on the modular unit three-dimensional model, the modular unit motion transfer library, and the basic dynamic parameter information of the modular unit; According to the mathematical representation of the modular robot topology, the modular robot grounding module unit number, grounding interface number, and terminal module unit number are obtained; According to the mathematical representation of the modular robot's topological structure and the modular robot's grounding module unit number, grounding interface number, and terminal module unit number, all motion transmission branches of the modular robot are obtained; According to all motion transmission branches of the modular robot, the connection status of the module units in each motion transmission branch and the motion transmission mode between two module units with a connection relationship are obtained; According to the module unit structure equivalent library, the basic dynamic parameter information of the module unit and the connection state of the module unit in each motion transmission branch, the module unit equivalent structure and the dynamic parameters of the equivalent structure are obtained; Based on the equivalent structure of the modular unit, the dynamic parameters of the equivalent structure, and the motion transmission method between two connected modular units, a distributed parameter acquisition strategy for the modular robot is designed to obtain the dynamic parameters corresponding to the motion transmission branch chain; According to the equivalent structure of the modular unit, the dynamic parameters of the equivalent structure, the motion transmission method between two modular units with a connection relationship, the distributed parameter acquisition strategy of the modular robot and all the motion transmission branches of the modular robot, a dynamic modeling method of the modular robot based on distributed parameter acquisition is designed to obtain the dynamic model of the modular robot.

2. The method according to claim 1, characterized in that Based on the three-dimensional model of the module unit, the module unit body center coordinate system and interface coordinate system are established to obtain the basic kinematic parameter information and basic dynamic parameter information of the module unit, including: According to the three-dimensional model of the module unit, the module unit body center coordinate system and interface coordinate system are established to obtain the basic kinematic parameter information of the module unit; According to the three-dimensional model of the module unit, the module unit structure is split to obtain the substructures of the module unit and establish the centroid coordinate system of each substructure; The basic dynamic parameters of the module unit are obtained based on the three-dimensional model of the module unit, each substructure of the module unit, and the center of mass coordinate system of each substructure.

3. The method according to claim 2, characterized in that Based on the three-dimensional model of the module unit, the module unit body center coordinate system and interface coordinate system are established to obtain the basic kinematic parameter information of the module unit, including: The spinor coordinates of each rotation axis in the body-centered coordinate system; The relative posture relationship matrix between each interface coordinate system and the body center coordinate system; The connection orientation relationship matrix that exists when two interfaces are connected is used to represent the specific docking status of the positioning device when the interfaces are docked.

4. The method according to claim 2, characterized in that Based on the modular unit 3D model, the modular unit structure is split to obtain the substructures of the modular unit and establish the centroid coordinate system of each substructure, including: The following rules are followed to split the module unit structure: The parts fixedly connected to the rotor of the motor in the interface can be assembled into a substructure, the parts fixedly connected to the stator of the motor in the interface can be assembled into a substructure, the parts fixedly connected to the rotor of the motor in the body center can be assembled into a substructure, and the parts fixedly connected to the stator of the motor in the body center can be assembled into a substructure; The coordinate system of the center of mass of each substructure of the module unit is determined as follows: The centroid of each substructure is selected as the origin of the centroid coordinate system. The selection of the axis of the centroid coordinate system of each substructure follows the following rules: For the substructure assembled from the components that are fixedly connected to the rotor of the motor in the interface, the axial direction of its center of mass coordinate system is consistent with the interface coordinate system; For the substructure assembled from the components fixedly connected to the stator of the motor in the interface, the center-of-mass coordinate system is axially consistent with the body-center coordinate system; For the substructure assembled from components fixedly connected to the rotor of the motor in the body center, the center-of-mass coordinate system is axially consistent with the body center coordinate system; For a substructure assembled from components fixedly connected to the stator of the motor in the body center, the center-of-mass coordinate system is axially consistent with the body center coordinate system.

5. The method according to claim 2, characterized in that Based on the three-dimensional model of the module unit, each substructure of the module unit, and the centroid coordinate system of each substructure, the basic dynamic parameters of the module unit are obtained, including: The quality of each substructure; The position vector of the center of mass of each substructure relative to the interface coordinate system or the body center coordinate system that is in the same direction as the center of mass coordinate system; The inertia tensor of each substructure relative to the center-of-mass coordinate system.

6. The method according to claim 1, wherein According to the three-dimensional model of the module unit and the basic kinematic parameter information of the module unit, the module unit motion transfer library is obtained, including: According to the three-dimensional model of the module unit, the interface arrangement, interface type, mechanical structure size, and degree of freedom arrangement information of the module unit are obtained; Obtain all valid connection status of the module unit based on the interface arrangement, interface type, and mechanical structure size information of the module unit; According to the degree of freedom arrangement information of the module unit and the basic kinematic parameter information of the module unit, the rotation axis and kinematic parameters contained in each effective connection state of the module unit are obtained; A module unit motion transfer library is obtained according to all valid connection states of the module unit, the rotation axes and kinematic parameters contained in each valid connection state of the module unit.

7. The method according to claim 6, characterized in that According to the interface arrangement, interface type, and mechanical structure size information of the module unit, all valid connection status of the module unit is obtained, including: According to the interface arrangement and interface type of the module unit, based on the enumeration method, all connection states of the module unit are obtained through permutations and combinations; According to the mechanical structure dimension information of the module unit and all the connection states of the module unit, the connection states with structural interference are eliminated to obtain all the valid connection states of the module unit.

8. The method according to claim 1, characterized in that Based on the modular unit three-dimensional model, modular unit motion transfer library, and basic dynamic parameter information of the modular unit, a modular unit structure equivalent library is obtained, including: According to the three-dimensional model of the module unit, the interface arrangement, interface type, mechanical structure size, and degree of freedom arrangement information of the module unit are obtained; Obtain all valid connection status of the module unit based on the interface arrangement, interface type, and mechanical structure size information of the module unit; According to all valid connection states of the module unit, obtain the motion input end interface and the motion output end interface of each valid connection state of the module unit; According to the motion input end interface and the motion output end interface of the module unit in each connection state and the module unit motion transfer library, the attributes corresponding to each substructure in each valid connection state of the module unit are obtained; According to the attributes corresponding to each substructure in each effective connection state of the module unit, the equivalent structure in each effective connection state of the module unit is obtained; According to the basic dynamic parameter information of the equivalent structure and the module unit in each effective connection state of the module unit, the dynamic parameters of the equivalent structure in each effective connection state of the module unit are obtained; Obtain a module unit structural equivalent library based on all valid connection states of the module unit, the equivalent structure of each valid connection state of the module unit, and the dynamic parameters of the equivalent structure of each valid connection state of the module unit; The motion input interface refers to the interface on the motion transmission branch of the modular robot that is closest to the ground module unit in the current module unit and in the current valid connection state; the motion output interface refers to the interface on the motion transmission branch of the modular robot that is closest to the terminal module unit in the current module unit and in the current valid connection state; The attributes corresponding to each substructure in each valid connection state of the module unit are the components that transmit the motion and force of a certain rotation axis, where the rotation axis is determined according to the rotation axis included in the current valid connection state in the module unit motion transmission library; The final representation of the equivalent structure in each valid connection state of the module unit is a collection of multiple equivalent structures; The dynamic parameters of the equivalent structure under each effective connection state of the module unit include the mass of the equivalent structure, the position vector of the center of mass of the equivalent structure relative to the interface coordinate system or the body center coordinate system corresponding to the previous rotation axis, the inertia tensor of the equivalent structure, and the spatial inertia matrix of the equivalent structure; The center-of-mass coordinate system of the equivalent structure is determined as follows: The center of mass of the equivalent structure is selected as the origin of the center of mass coordinate system, and the axis of the center of mass coordinate system is consistent with the interface coordinate system or body center coordinate system corresponding to the previous rotation axis; The mass of the equivalent structure i for: Among them, m k is the mass of the modular unit substructure k in the equivalent structure i, a-b Λ i (i=1, 2, 3, ...) is the set of module unit substructures contained in the equivalent structure i when the module unit is in the effective connection state ab, a is the motion input end interface of the module unit in the current effective connection state, b is the motion output end interface of the module unit in the current effective connection state, and a≠b; The center of mass of the equivalent structure i relative to the interface coordinate system or body center coordinate system ΣJ corresponding to the previous rotation axis i Position vector for: in, is the mass center of the module unit substructure k in the equivalent structure i in the coordinate system ΣJ i The description below can be obtained by calculating the basic dynamic parameters of the module unit through coordinate system transformation; Establish the center-of-mass coordinate system ΣL of the equivalent structure i i , the inertia tensor of the equivalent structure i is: in, is the inertia tensor of the module unit substructure k in the equivalent structure i in the coordinate system ΣL i The description below can be obtained by calculating the basic dynamic parameters of the module unit through coordinate system transformation; The spatial inertia matrix of the equivalent structure i is: Among them, 0 3×3 is a zero matrix of dimension 3×3, I 3×3 is the unit matrix of dimension 3×3.

9. The method according to claim 1, characterized in that According to the mathematical representation of the modular robot topology, the modular robot grounding module unit number, grounding interface number, and terminal module unit number are obtained, including: For n topo_module The modular robot topology structure of modules is mathematically represented as Among them, n topo_module Indicates the number of modules contained in the modular robot topology; m i (i=1,2,...,n topo_module ) represents the module numbers in the modular robot topology; the matrix B is called the grounding relationship matrix, ba i (i=1,2,...,n topo_module ) indicates whether the module in the modular robot topology is grounded as a base when in use, ba i =0 means module m i When not grounded, i ≠0 indicates module m i When using ba i The interface ground is used as the base; the matrix C is called the connection relationship matrix of the modular robot, c ij (i=1,2,...,n topo_module ; j=1,2,...,n topo_module )∈{1,...,n surf_con } indicates module m i With module m j The number of the connected interface. When i=j, c ij =0(i=1,2,...,n topo_module ; j=1,2,...,n topo_module ), n surf_con Represents the number of surface interfaces of a single module; the matrix O is called the connection orientation relationship matrix of the modular robot, co ij (i=1,2,...,n topo_module ; j=1,2,...,n topo_module ) represents module m i With module m j The connection orientation relationship, when i = j, co ij =0(i=1,2,...,n topo_module ; j=1,2,...,n topo_module ); According to the mathematical representation of the modular robot topology structure, including matrix M, matrix A, matrix C, and matrix O, the row numbers of matrix C containing only one non-zero element, and the non-zero elements and their positions in matrix A are obtained; According to the matrix A, the non-zero elements in the matrix A and their positions, the non-zero elements in the matrix A are the grounding interface numbers, and the elements corresponding to the positions of the non-zero elements in the matrix M are read to obtain the modular robot grounding module unit number and the grounding interface number; According to the row number of the matrix C containing only one non-zero element and the matrix M, the element at the position corresponding to the row number in the matrix M is read to obtain the terminal module unit number of the modular robot.

10. The method according to claim 1, characterized in that According to the mathematical representation of the modular robot topology structure and the modular robot grounding module unit number, grounding interface number, and terminal module unit number, all motion transmission branches of the modular robot are obtained, including: Starting from the grounding interface number of the modular robot's grounding module unit number and ending with the modular robot's terminal module unit number, based on the matrix C in the mathematical representation of the modular robot's topological structure, and based on depth-first traversal, the modules and their interface information that the modular robot needs to pass through for motion transmission from the starting point to the end point are searched, and all the motion transmission branches of the modular robot are obtained.

11. The method according to claim 1, wherein According to all motion transmission branches of the modular robot, the connection status of the module units in each motion transmission branch and the motion transmission mode between two module units with a connection relationship are obtained, including: There are two ways to transfer motion between two connected module units: The motion output of the previous module unit is an interface including a motor; The motion output of the previous module unit is an interface without a motor.

12. The method according to claim 1, characterized in that Based on the equivalent structure of the modular unit, the dynamic parameters of the equivalent structure, and the motion transmission method between two connected modular units, a distributed parameter acquisition strategy for the modular robot is designed to obtain the dynamic parameters corresponding to the motion transmission branch chain, including: According to the equivalent structure of the module unit, the dynamic parameters of the equivalent structure, and the motion transmission mode between the two module units having a connection relationship, a dynamic parameter processing strategy corresponding to the motion transmission mode between the two module units having a connection relationship is obtained; Based on the dynamic parameter processing strategy corresponding to the motion transmission mode between two connected modular units, a distributed parameter acquisition strategy for modular robots is designed to obtain the dynamic parameters corresponding to the motion transmission branch chain; Among them, the dynamic parameter processing strategies corresponding to the motion transmission mode between two connected module units include: When the motion transmission mode between two connected module units is that the motion output end of the previous module unit is an interface containing a motor, the starting equivalent structure of the latter module unit and the ending equivalent structure of the previous module unit are recalculated according to the process of obtaining the ending equivalent structure of the previous module unit; When the motion transmission mode between two connected module units is that the motion output end of the previous module unit is an interface that does not include a motor, the end equivalent structure of the previous module unit is directly merged with the start equivalent structure of the next module unit.

13. The method according to claim 1, wherein Based on the equivalent structure of the modular unit, the dynamic parameters of the equivalent structure, the motion transmission method between two connected modular units, the distributed parameter acquisition strategy of the modular robot, and all the motion transmission branches of the modular robot, a dynamic modeling method based on distributed parameter acquisition of the modular robot is designed to obtain the dynamic model of the modular robot, including: A modular robot motion transmission chain consisting of m modular units and n degrees of freedom is subjected to an external force. Under the action of in, is the Jacobian matrix, and Described in the same coordinate system; is the inertial force matrix; It is the Coriolis force and centrifugal force on each joint during the movement of the modular robot; is the gravitational force on the modular robot during its motion; The order is the joint angle, joint angular velocity, joint angular acceleration, and driving torque vector on the current motion transmission branch; One containing The dynamic model of the modular robot with a motion transmission branch chain is: Among them, q i 、 τ i They are the joint angle, joint angular velocity, joint angular acceleration, and driving torque vector on the i-th motion transmission branch, is the external force rotation amount received by the end of the i-th motion transmission branch, By analyzing the motion transmission branch chain, it can be split into ζ non-bifurcation motion branches, and then the modular robot dynamics model can be further converted into: in, represents the driving torque provided by the joint of the k-th non-bifurcation motion branch during the motion of the i-th motion branch, It represents the inertial force coupling influence matrix generated by the joint motion of the j-th non-bifurcation motion branch and the joint motion of the k-th non-bifurcation motion branch during the motion of the i-th motion branch. According to the inertial force matrix M of the i-th motion branch i Obtained, represents the influence of the inertial force of the joint acceleration of the j-th non-bifurcation motion branch on the joint motion of the k-th non-bifurcation motion branch, It represents the Coriolis force and centrifugal force coupling influence matrix generated by the joint motion of the j-th non-bifurcation motion branch and the k-th non-bifurcation motion branch during the motion of the i-th motion branch. According to the inertia force matrix C of the i-th motion branch i Obtained, represents the influence of the acceleration of the j-th non-bifurcation motion branch joint on the Coriolis force and centrifugal force of the k-th non-bifurcation motion branch joint motion, It represents the gravitational force on the joint motion of the kth non-bifurcation motion branch during the motion of the i-th motion branch, The Jacobian matrix representing the joint motion contained in the k-th branch of non-bifurcation motion relative to the i-th end motion; Among them, the non-bifurcation motion branch means that during the motion of each joint on the current branch, the transmission of motion or force has only a single direction.

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