A robot neck mechanism and its ball joint layout optimization method

Abstract

The present application relates to a kind of robot neck mechanism and its ball hinge layout optimization method.The mechanism includes neck support platform, head support platform, between two platforms limiting rod assembly and four circumferentially arranged servo cylinder assembly, the upper and lower ends of limiting rod assembly are connected to two platforms by first universal joint and second universal joint respectively, for limiting the distance between platform and allowing four degrees of freedom attitude change.The present application further proposes ball hinge layout optimization method, the length of servo cylinder under different attitudes is calculated by attitude transformation matrix, and the attitude angle boundary of each degree of freedom is determined in combination with stroke constraint, then three-dimensional offset search is carried out in candidate area in combination with assembly height difference and space limitation, to screen effective ball hinge layout that meets constraint condition.The present application is suitable for the case that space is limited and cylinder stroke is short, and can significantly improve the attitude range and stability of robot neck structure.

Description

Technical Field

[0001] This invention proposes a robot neck mechanism and its ball joint layout optimization method, belonging to the field of robot technology. Background Technology

[0002] With the development of humanoid robots and AI, robots with flexible necks can obtain more information from their surroundings while maintaining head stability during movement. Therefore, robot neck mechanisms with biomimetic appearance and flexible movements have become a research and development hotspot. However, traditional three-degree-of-freedom (Yaw, Pitch, Roll) neck structures often use independent drive units, with motors for each axis installed separately. This results in a large overall height or width of the neck, occupying a lot of space and making it difficult to meet miniaturization and aesthetic requirements. In a series structure, some pitch or roll movements are supported by the upper motor bearing the entire weight and inertia of the head, resulting in a large load on each actuator, which is not conducive to the selection of small actuators. Furthermore, when installation space is limited and the electric cylinder stroke is short, the attitude operating angle is restricted, and traditional structures cannot achieve a sufficient attitude range. In addition, when using a parallel structure, the ball joint mounting position is significantly affected by height and space constraints. If the layout is unreasonable, it will lead to limited attitude range or interference, making it difficult to meet the design requirements of a compact neck structure. Therefore, a robot neck structure suitable for compact spaces and possessing four-degree-of-freedom attitude adjustment capabilities, along with an optimized ball joint layout method, is needed. Summary of the Invention

[0003] This invention provides a robot neck mechanism and its ball joint layout optimization method to solve the technical problems in the prior art, such as the difficulty of humanoid robots to achieve multi-degree-of-freedom head posture adjustment in confined spaces, insufficient structural compactness, and insufficient range of motion due to the limited ball joint layout.

[0004] A robot neck mechanism, the robot neck mechanism comprising:

[0005] Neck support platform, used to connect to the robot's torso;

[0006] Head support platform, used to connect to the robot head;

[0007] A limiting rod assembly, the first end of which is connected to the neck support platform via a first universal joint, and the second end of which is connected to the head support platform via a second universal joint, is used to limit the distance between the two platforms;

[0008] The servo electric cylinder assembly is arranged symmetrically along the circumference. Each servo electric cylinder assembly includes a servo electric cylinder body. The two ends of the servo electric cylinder body are respectively connected to the head support platform through upper ball joints and to the neck support platform through lower ball joints.

[0009] When the servo electric cylinder assembly extends or retracts, it drives the limiting rod assembly to generate neck pitch and neck roll relative to the neck support platform around the first universal joint, and drives the head support platform to generate head pitch and head roll relative to the limiting rod assembly around the second universal joint, thereby realizing four-degree-of-freedom attitude adjustment of the robot head.

[0010] A method for optimizing the layout of a ball joint is provided to obtain a ball joint mounting position that meets travel constraints and attitude requirements within a confined space. The specific steps of this method are as follows:

[0011] a. Collect the posture and rotation parameters of the robot's neck and head, establish a coordinate system with the center of the first universal joint in the robot's neck mechanism as the origin, transform the four upper ball joints of the robot's head support platform in its local coordinate system to the global coordinate system one by one, calculate the global coordinates of the four lower ball joints on the neck support platform through posture adjustment, and obtain the global coordinate system of the upper and lower ball joints during the posture change process.

[0012] b. Establish the attitude transformation matrix of the neck support platform. and the attitude transformation matrix of the head support platform The posture consists of four degrees of freedom: neck roll angle α1, neck pitch angle β1, head roll angle α2, and head pitch angle β2. The length of the servo electric cylinder branch under different posture combinations is calculated based on the global coordinate system through posture transformation, thereby obtaining the kinematic model of posture change.

[0013] c. Minimum length of servo cylinder branch chain under each attitude traversal range and maximum value The stroke constraint verification is performed on the branch length under each attitude to obtain the attitude boundary under the stroke range of each degree of freedom.

[0014] d. Generate discrete multidimensional offset points along the X, Y, and Z directions within the candidate regions of the ball joints of the neck support platform and the head support platform to form multiple combinations of ball joint layouts;

[0015] e. Put each layout combination into the kinematic model and perform a full traversal calculation of all attitude parameters to obtain the ball joint layout combination that satisfies the travel constraints;

[0016] f. Based on the ball joint height difference limit and platform space assembly limit, all layout calculation results are filtered, and the achievable attitude range of different layouts is filtered by combining the limit angles of each degree of freedom obtained from the servo electric cylinder stroke, to obtain an effective ball joint layout that meets the requirements.

[0017] Furthermore, in the method for optimizing the ball joint layout of the robot's neck mechanism, the upper ball joint of the head support platform is located in the global coordinate system at the [missing information]. The position of the upper ball joint in the global coordinate system is:

[0018]

[0019] in: These are the final upper spherical hinge coordinates after transformation and conversion to the global coordinate system. These are the local coordinates of the head platform. This is the fixed axis distance between the upper and lower universal joints. The corresponding global coordinates for the lower ball joint are... Then the first Length of the servo electric cylinder branch chain satisfy:

[0020] And the length of the servo electric cylinder chain To meet the stroke limit of the servo electric cylinder, that is:

[0021] Furthermore, the upper and lower ball joints of the robot's neck mechanism form four pairs of corresponding ball joint connection points on the two platforms, arranged symmetrically from left to right.

[0022] Furthermore, the servo cylinder assembly of the robot's neck mechanism is installed within a preset four-degree-of-freedom target posture range, and the extension of each servo cylinder body is within the allowable stroke range.

[0023] Furthermore, a height difference is provided between each upper ball joint on the head support platform of the robot's neck mechanism, and the height difference conforms to the overall dimensions of the neck mechanism.

[0024] In addition, this application also includes a robot, which includes a robot neck mechanism that implements a ball joint layout optimization method for the robot neck, as well as a robot head and a robot torso. The neck mechanism is rigidly connected to the torso through a neck support platform and fixedly connected to the head through a head support platform. The head can be equipped with interactive components such as cameras, sensors, and speakers. Through the four-degree-of-freedom attitude adjustment of the neck mechanism, the interactive components can achieve all-round environmental perception and precise interaction, which is suitable for various scenarios such as home service, industrial inspection, and medical assistance.

[0025] The beneficial effects of this invention are as follows: This invention employs a four-servo electric cylinder parallel structure combined with a double universal joint limiting rod universal joint, enabling four-degree-of-freedom attitude adjustment including neck pitch, neck roll, head pitch, and head roll. It features a large attitude range, fast response speed, and good structural stability. The compact layout of the servo electric cylinder components and ball joint positions results in a small overall structural height and high space utilization, making it suitable for the neck of bionic robots with limited installation space. Combined with layout optimization methods, an effective attitude range can still be achieved even with short cylinder strokes and limited platform height, thereby improving the structural feasibility and motion performance of the robot's neck mechanism. It resolves the contradiction between multiple degrees of freedom and structural compactness in confined spaces, overcoming the limitations of cylinder stroke and spatial constraints through a systematic layout optimization method. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the robot's neck structure in its initial state according to the present invention;

[0027] Figure 2 This is a schematic diagram of the neck structure of the robot of the present invention;

[0028] Figure 3 This is a flowchart of the ball joint layout optimization method of the present invention. Detailed Implementation

[0029] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0030] Numerous specific details are set forth in the following description to provide a thorough understanding of the invention. The described embodiments are only a part of, and not all, of the embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0032] One embodiment of the present invention provides a robot neck mechanism, the robot neck mechanism including a neck support platform 100, a head support platform 200, a limit rod assembly 300, and a servo electric cylinder assembly 400.

[0033] The neck support platform 100 in the robot neck mechanism is used to be installed on the robot torso, and the head support platform 200 is used to connect the robot head, so that the head can adjust its posture with the neck mechanism. The neck support platform is made of high-strength lightweight alloy material and has a circular or square flat plate structure. The platform edge is provided with evenly distributed mounting holes for fixing to the robot torso through bolts, flanges and other connecting parts to ensure the stability of the connection between the neck mechanism and the torso.

[0034] The head support platform 200 in the robot's neck mechanism is structurally compatible with the neck support platform 100. Both are made of high-strength, lightweight alloy materials. The platform is equipped with an installation interface for connecting to the robot's head. The interface position can be flexibly adjusted according to the head's structural dimensions to ensure the reliability of the connection between the head and the platform, while reducing the overall weight load on the neck mechanism.

[0035] The limit rod assembly 300 is disposed between the neck support platform 100 and the head support platform 200. Its lower end is hinged to the neck support platform 100 through the first universal joint 310, and its upper end is hinged to the head support platform 200 through the second universal joint 320. It is used to provide four-degree-of-freedom attitude constraints between the two platforms, limit the relative distance between the two platforms, avoid excessive displacement of the platforms causing overload of the servo electric cylinder, and provide necessary passive constraints for the four-degree-of-freedom attitude changes between the two platforms through the upper and lower universal joints to ensure the smoothness of the motion process.

[0036] There are four servo cylinder assemblies, located symmetrically at the four circumferential positions of the neck mechanism. Each servo cylinder assembly 400 includes a servo cylinder body 401, an upper ball joint 210 at its upper end, and a lower ball joint 110 at its lower end. The upper ball joint 210 is hinged to the head support platform 200, and the lower ball joint 110 is hinged to the neck support platform 100, thus forming four retractable branch structures. The servo cylinder body 401 adopts a miniature high-precision servo cylinder with a stroke range of 20-80mm and a response speed ≤0.1s, meeting the requirements for accuracy and speed of posture adjustment. Both the upper ball joint 210 and the lower ball joint 110 adopt high-strength wear-resistant ball joints, which can achieve 360° rotation, reduce friction loss during movement, and improve the service life of the mechanism.

[0037] When the four servo electric cylinder assemblies 400 extend and retract respectively, the limiting rod assembly 300 first generates a neck pitch angle and a neck roll angle relative to the neck support platform 100 around the first universal joint 310. Then, the head support platform 200 generates a head pitch angle and a head roll angle relative to the limiting rod assembly 300 around the second universal joint 320. Through the combined movement of these two stages of universal joints, the robot head achieves four-degree-of-freedom attitude adjustment, including neck pitch, neck roll, head pitch, and head roll.

[0038] The installation positions of the four servo electric cylinder assemblies 400 in the robot's neck mechanism are within the preset four-degree-of-freedom target posture range, and the extension of each servo electric cylinder body 401 is within the allowable stroke range. The stroke range defines the posture boundary that the head support platform 200 can achieve relative to the neck support platform 100.

[0039] The connection points of the upper ball joint 210 and the lower ball joint 110 on their respective platforms are symmetrically distributed, that is, the horizontal projections of the two upper ball joints 210 on the left side coincide with the two lower ball joints 110 on the left side, and the same applies to the right side. This ensures that the forces on both sides are balanced, avoids overload on one side, and ensures the balance of structural forces and the coordination of movement. At the same time, the height difference between each upper ball joint 210 on the head support platform 200 is controlled within 5mm, and the height difference between the upper ball joint 210 and the lower ball joint 110 is controlled within the range of 10 to 30mm. The above height difference conforms to the overall dimensions of the neck mechanism, effectively controls the overall structural dimensions of the neck, and avoids that the overall length of the neck exceeds the expected structural dimensions due to excessive height difference between the upper and lower ball joints, thus adapting to the installation requirements of compact spaces.

[0040] The motion principle of the robot's neck mechanism in this invention is as follows: Four servo electric cylinder assemblies 400 receive control signals and extend and retract independently. Changes in the length of the branches generate driving force. On one hand, the driving force causes the limiting rod assembly 300 to rotate around the first universal joint 310 relative to the neck support platform 100, forming a neck pitch angle and a neck roll angle. On the other hand, the driving force simultaneously causes the head support platform 200 to rotate around the second universal joint 320 relative to the limiting rod assembly 300, forming a head pitch angle and a head roll angle. Through the combined motion of the two-stage universal joints, four-degree-of-freedom attitude adjustment of the robot's head is ultimately achieved, with an attitude adjustment accuracy of ±0.5°, meeting the requirements for high-precision interaction and environmental perception.

[0041] In another embodiment of the present invention, in practical applications, the stroke range of the four servo electric cylinder assemblies 400 defines the attitude boundaries that the head support platform 200 can achieve relative to the neck support platform 100. Therefore, the present invention further provides a ball joint layout optimization method to obtain a ball joint mounting position that meets stroke limitations and attitude requirements within a confined space.

[0042] This method involves establishing a coordinate system to generate a kinematic model, verifying travel constraints, generating multi-dimensional offsets for the ball joint, performing full-attitude traversal calculations, and filtering layout effectiveness. Based on the kinematic model and constraints, it systematically calculates and selects the optimal ball joint installation position. The specific steps are as follows:

[0043] a. Set the neck mechanism to its initial state, where the pitch and roll angles of the first and second universal joints are both 0°, and the limit rod assembly is in a vertical position. Establish a global coordinate system O-xyz with the center of the first universal joint as the origin, where the z-axis points vertically to the axis of the limit rod assembly (vertically upward), the x-axis is the rotation axis (horizontal left-right direction) for the first universal joint to perform roll motion, and the y-axis is the rotation axis (horizontal forward-backward direction) for the first universal joint to perform pitch motion. The three axes are mutually perpendicular and satisfy the right-hand rule. The distance d between the centerlines of the universal joints at the upper and lower ends of the limit rod assembly 300 is preset according to the design height of the robot's neck.

[0044] In the initial state, the global coordinates of the four lower ball joints 110 on the neck support platform 100 are preset as Q1(x1, 0, 0), Q2(0, y1, 0), Q3(-x1, 0, 0), and Q4(0, -y1, 0) (unit: mm), where x1 and y1 are actual measured values. The positions of the four lower ball joints 110 on the neck support platform 100 in the global coordinate system are also preset known points. The local coordinates of the four upper ball joints 210 on the head support platform 200 are preset. A local coordinate system is established with the center of the head support platform (200) as the origin. The local coordinates of the four upper ball joints 210 can be set as p1(x, 0, 0), p2(0, y, 0), p3(-x, 0, 0), and p4(0, -y1, 0) (unit: mm). -y,0), where x and y are actual measured values. The positions of the four upper ball joints 210 on the head support platform 200 in their own local platform coordinate system are known fixed points. Substituting the local platform coordinate system of the head platform into the global coordinate system, the position of the overall local platform coordinate system relative to the first universal joint 310 is moved upward by a distance d along the axial direction of the limiting rod, thereby determining the final spatial position of each upper ball joint 210 in the global coordinate system. ( The distance between the ball joint and the global coordinates of the ball joint 110 on the neck support platform 100 is calculated to obtain the length of the four servo cylinder branches under each attitude change. The length of the servo cylinder branches under different attitude combinations is obtained by calculating the global coordinate system through attitude change to ensure that the initial positions of the upper and lower ball joints correspond and reduce the risk of motion interference.

[0045] b. A transformation matrix is ​​established based on the posture changes of the neck support platform. Transformation matrix From neck roll angle and neck tilt angle The single-axis rotation matrix is ​​defined as follows:

[0046]

[0047] Its expression is: ,in Let be the rotation matrix about the x-axis. Let be the rotation matrix about the y-axis;

[0048] A transformation matrix is ​​constructed based on the posture changes of the head support platform 200. Transformation matrix From head roll angle and head pitch angle The decision, expressed as: ,

[0049] According to the principle of kinematic transformation, the final position of the i-th upper ball joint 210 on the head platform in the global coordinate system. Calculated using the following formula: ,in These are the final upper spherical hinge coordinates after transformation and conversion to the global coordinate system. These are the local coordinates of the head platform. This represents the initial z-axis offset of the head platform relative to the first gimbal. This is the fixed axis distance between the upper and lower universal joints.

[0050] Calculated Then, the distance between two points in space is calculated using the formula for the first point. Length of the servo electric cylinder branch chain Then the first Length of the servo electric cylinder branch chain satisfy: ,

[0051] ,in , , for The three coordinate components, , , for The three coordinate components are used to obtain the kinematic model of attitude change.

[0052] c. Calculate the length of the servo cylinder branch corresponding to each of the four attitude angles, and record the minimum and maximum lengths of the four branches respectively, thereby preset the minimum stroke of the servo cylinder body 401. Maximum travel For each pose combination ( , , , The lengths of the four branches were calculated. , , , Then, determine whether all conditions are met. ≤ ≤ (i=1,2,3,4), if the length of a branch exceeds the stroke range in a certain posture, then the posture is an unreachable posture. Record the corresponding posture angle as the limit angle boundary of the degree of freedom. Use this to constrain and verify the stroke of the servo cylinder branch. The stroke constraint verification step is used to filter the achievable posture range based on the minimum and maximum stroke of the servo cylinder.

[0053] d. This step involves generating multi-dimensional offsets for the ball joints. This includes generating discrete multi-dimensional offset points along the X, Y, and Z directions within the candidate ball joint regions of the neck support platform 100 and the head support platform 200, forming multiple ball joint layout combinations. Each layout combination undergoes a full calculation of all attitude parameters to obtain ball joint layout combinations that satisfy the travel constraints. Specifically, the candidate ball joint region is defined with the initial ball joint position as the center, delineating offset space in the X, Y, and Z directions. Discrete offset points are generated within this region along the X, Y, and Z directions, and an offset step size is set. The process iterates from negative to positive offsets in the X direction, and the same applies to the Y and Z directions. Multiple ball joint layout combinations are formed through these combinations. For example, the above ball joint... For example, its offset local coordinates Can be set as ( +Δx, +Δy, +Δz), where Δx, Δy, and Δz are the offsets in the X, Y, and Z directions, respectively. The offsets are initially traversed with a coarse step size of 1mm, and then switched to a fine step size of 0.2mm around the effective layout to achieve a balance between search efficiency and accuracy. This method generates a massive number of layout combinations to ensure comprehensive optimization coverage.

[0054] e. Full attitude traversal calculation: This step includes traversing neck pitch, neck roll, head pitch, and head roll. Specifically, for each ball joint configuration combination, the kinematic model is substituted to perform a traversal calculation of all attitude parameters. When the length of a certain servo cylinder reaches its limit stroke, the corresponding attitude angle is recorded as the limit angle of that degree of freedom. All four-degree-of-freedom attitude combinations are traversed according to a preset step size, for example... , The traversal step size is 1°, and the range is (-45°, 45°). , The traversal step size is 1°, ranging from (-45°, 45°). The branch length for each group of attitudes is calculated sequentially to determine if the stroke constraint is met. When the length of a servo cylinder reaches its limit stroke, the corresponding attitude angle is recorded as the limit angle for that degree of freedom. The traversal process is automated using computer programming to improve efficiency; for example, a traversal calculation program based on MATLAB or Python can be written to output the set of reachable attitudes for each layout.

[0055] f. Layout Screening and Optimization: This step involves screening effective layouts based on the ball joint height difference limit and the ball joint installation distance limit. Combined with the attitude angle range obtained in the stroke constraint verification step, the achievable attitude performance of different layouts is compared. Then, a three-dimensional offset search is performed within the candidate area, considering the assembly height difference and spatial constraints, to screen effective ball joint layouts that meet the constraints. Specifically, based on the ball joint height difference limit, layout combinations with a ball joint height difference exceeding 5mm on the head platform and a height difference between corresponding upper and lower ball joints exceeding the range of 10-30mm are eliminated. Next, based on the assembly distance limit, the minimum assembly distance between adjacent ball joints and between the ball joint and the servo cylinder body is ensured to be no less than 3mm to avoid motion interference. Furthermore, motion simulation is performed on the effective layouts to check the dynamic interference between the ball joints and the servo cylinder and limit rod, ensuring practical assembly feasibility.

[0056] For the selected effective layouts, the optimal ball joint layout is selected. Specifically, a comprehensive evaluation is conducted based on the reachable attitude range, ease of ball joint assembly, and travel margin. The closer the reachable attitude range is to the preset target range, the higher the score (e.g., neck pitch ±30°, neck roll ±20°, head pitch ±45°, head roll ±30°); the higher the score is also the score for reasonable and unobstructed ball joint assembly distance; and the higher the travel margin (i.e., the difference between the branch length and the limit travel), the higher the score. The reachable attitude range has a weight of 0.5, the ease of ball joint assembly has a weight of 0.3, and the travel margin has a weight of 0.2. The effective layouts are ranked according to the evaluation scores, and the layout with the highest comprehensive score is selected as the optimal ball joint layout.

[0057] Furthermore, the ball joint layout optimization method of the present invention can also be used to solve the reverse equation of the servo cylinder stroke: if the target posture range of the robot head is known (e.g., neck pitch -25° to 25°, neck roll -18° to 18°, head pitch -40° to 40°, head roll -28° to 28°), the length change of each branch can be calculated by traversing all posture combinations within the target posture range, and the global minimum value can be taken for the minimum value of all branches. Take the global maximum value for the maximum value of all branches. This allows us to obtain the required stroke range of the servo electric cylinder. = - Based on this, a servo electric cylinder was customized to further improve the adaptability of the neck mechanism.

[0058] By using the above layout optimization method, a ball joint mounting position that meets the motion range requirements can be automatically obtained under conditions of short electric cylinder stroke and limited space height, thereby improving the attitude capability and feasibility of the parallel neck structure.

[0059] The robot neck mechanism provided by this invention has a compact structure, high degree of freedom, and optimizable layout, and is suitable for humanoid robots, service robots, and robot platforms that require independent head posture control.

[0060] In this document, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when a range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0061] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for optimizing the ball joint layout of a robot neck mechanism, the robot neck mechanism comprising: Neck support platform (100) for connecting to the robot torso; Head support platform (200) for connecting to the robot head; A limiting rod assembly (300) has its first end connected to the neck support platform (100) via a first universal joint (310) and its second end connected to the head support platform (200) via a second universal joint (320), which is used to limit the distance between the two platforms; The servo cylinder assembly (400) is arranged symmetrically in the circumferential direction. Each servo cylinder assembly (400) includes a servo cylinder body (401). The two ends of the servo cylinder body (401) are connected to the head support platform (200) through upper ball joints (210) and to the neck support platform (100) through lower ball joints (110). When the servo electric cylinder assembly (400) extends or retracts, it drives the limiting rod assembly (300) to generate neck pitch and neck roll relative to the neck support platform (100) around the first universal joint (310), and drives the head support platform (200) to generate head pitch and head roll relative to the limiting rod assembly (300) around the second universal joint (320), thereby realizing four-degree-of-freedom attitude adjustment of the robot head; The method for optimizing the ball joint layout of the robot's neck mechanism is characterized by: a. Collect the rotation parameters of the robot's neck and head postures, establish a coordinate system with the center of the first universal joint (310) in the robot's neck mechanism as the origin, transform the four upper ball joints (210) of the robot's head support platform (200) in its local coordinate system to the global coordinate system one by one, calculate the global coordinates of the four lower ball joints (110) on the neck support platform (100) through posture adjustment, and obtain the global coordinate system of the upper and lower ball joints during the posture change process; b. Establish the posture transformation matrix of the neck support platform (100). and the attitude transformation matrix of the head support platform (200) The posture consists of four degrees of freedom: neck roll angle α1, neck pitch angle β1, head roll angle α2, and head pitch angle β2. The length of the servo electric cylinder branch under different posture combinations is calculated based on the global coordinate system through posture transformation, thereby obtaining the kinematic model of posture change. c. Minimum length of servo cylinder branch chain under each attitude traversal range and maximum value The stroke constraint verification is performed on the branch length under each attitude to obtain the attitude boundary under the stroke range of each degree of freedom. d. Generate discrete multidimensional offset points along the X, Y, and Z directions within the candidate regions of the ball joints of the neck support platform (100) and the head support platform (200), forming multiple combinations of ball joint layouts; e. Put each layout combination into the kinematic model and perform a full traversal calculation of all attitude parameters to obtain the ball joint layout combination that satisfies the travel constraints; f. Based on the ball joint height difference limit and platform space assembly limit, all layout calculation results are filtered, and the reachable attitude range of different layouts is filtered by combining the limit angles of each degree of freedom obtained from the servo electric cylinder stroke, so as to obtain an effective ball joint layout that meets the requirements. The upper ball joint of the head support platform is in the global coordinate system, the first... The position of the upper ball joint (210) in the global coordinate system is: in: These are the final upper spherical hinge coordinates after transformation and conversion to the global coordinate system. These are the local coordinates of the head platform. The fixed axis distance between the upper and lower universal joints corresponds to the global coordinates of the lower ball joint (110). Then the first Length of the servo electric cylinder branch chain satisfy Distance limitations, and the length of the servo electric cylinder branch chain. satisfy The stroke limit of the servo electric cylinder.

2. The method for optimizing the ball joint layout of a robot neck mechanism according to claim 1, characterized in that... The upper ball joint (210) and the lower ball joint (110) form four pairs of corresponding ball joint connection points on the two platforms, arranged symmetrically from left to right.

3. The method for optimizing the ball joint layout of a robot neck mechanism according to claim 1, characterized in that... The installation position of the servo electric cylinder assembly (400) is within the preset four-degree-of-freedom target attitude range, and the extension of each servo electric cylinder body (401) is within the allowable stroke range.

4. The method for optimizing the ball joint layout of a robot neck mechanism according to claim 1, characterized in that... The head support platform (200) has a height difference between each upper ball joint (210), and the height difference conforms to the overall size of the neck mechanism.

5. A robot, said robot comprising a robot neck, a robot head, and a robot torso, characterized in that, The robot includes the ball joint mounting position in the robot neck mechanism determined by implementing the robot neck mechanism ball joint layout optimization method according to any one of claims 1 to 4.

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