A human body neck rotation parallel mechanism based on ring guide rail

Abstract

This invention relates to a humanoid robot, specifically a parallel rotating mechanical joint based on a ring-shaped guide rail, mimicking the rotation of a human neck. The aim is to provide a parallel rotating mechanical joint based on a ring-shaped guide rail to achieve three degrees of freedom in the movement of a biomimetic human neck joint while ensuring high rigidity and motion accuracy. Furthermore, the joint features a simplified structure, good support performance, and sufficient movement space for the neck joint. The technical solution is a parallel rotating mechanical joint based on a ring-shaped guide rail, characterized by: a head motion platform, a neck ring-shaped guide rail base, and three PSS (Personal Stability Support) link branches connected in parallel between the head motion platform and the neck ring-shaped guide rail base; the center of the head motion platform and the center of the neck ring-shaped guide rail base are connected by a composite rotating shaft.

Description

Technical Field

[0001] This invention relates to a humanoid robot, specifically a parallel mechanical joint based on a ring-shaped guide rail that mimics the rotation of a human neck. Background Technology

[0002] In recent years, humanoid robots, with their highly human-like form and mobility, have shown broad application prospects in fields such as service, healthcare, rescue, and industrial collaboration. As an ideal medium for human interaction with complex environments, humanoid robots need to possess near-human mobility, environmental adaptability, and natural interaction. The neck, as a key component connecting the head and torso, directly determines the effectiveness of the robot's core functions such as visual perception, facial expression interaction, and posture expression, making it crucial for achieving human-like interaction.

[0003] However, current research on the necks of humanoid robots is still insufficient. While serial neck structures offer a large range of motion and simple control logic, they suffer from low load-bearing stiffness, sluggish dynamic response, and difficulty in simulating the compliant movement characteristics of the human neck. Parallel neck designs, while improving structural rigidity, suffer from complex kinematic chain coupling, making degree-of-freedom calculations difficult. They also generally exhibit limited range of motion and insufficient dexterity, making it difficult to accurately reproduce the natural nodding, shaking, and tilting movements of the human neck. Furthermore, existing solutions often employ a fully driven mode, resulting in high system inertia and energy consumption. They also lack the ability to effectively avoid singular motion configurations in complex interaction scenarios, easily leading to motion jamming or control instability, severely restricting the naturalness and reliability of humanoid robot neck expressions.

[0004] Therefore, there is an urgent need to propose a parallel mechanical joint that mimics the movement of the human neck, which can achieve a degree of freedom of movement that is closer to that of a biological neck while ensuring high rigidity and motion accuracy, and has good support performance and dexterity. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and provide a parallel mechanical joint based on a ring guide rail that mimics the rotation of the human neck. This joint achieves three degrees of freedom of movement of the biomimetic human neck joint while ensuring high rigidity and motion accuracy. It also has a simplified structure, good support performance, and can ensure the movement space of the neck joint.

[0006] The technical solution provided by this invention is: A parallel mechanical joint based on a ring guide rail, mimicking the rotation of the human neck, is characterized by comprising a head moving platform, a neck ring guide rail base, and three PSS connecting rod branches connected in parallel between the head moving platform and the neck ring guide rail base; the center position of the head moving platform and the center position of the neck ring guide rail base are connected by a composite rotating shaft. The PSS linkage branch includes a first ball joint, a first link, a second ball joint, and a sliding pair that are sequentially connected between the head moving platform and the neck annular guide rail base. The composite pivot includes a universal joint connecting the head moving platform and the neck annular guide rail base, as well as a second connecting rod.

[0007] The sliding pair includes an arc-shaped guide rail and a slider that cooperates with the arc-shaped guide rail; In the three PSS link branches, the sliders of the three sliding pairs are respectively connected to the first link through the second ball joint, and the arc-shaped guide rails of the three sliding pairs are connected to each other to form a ring guide rail.

[0008] The bottom of the head moving platform is fixed with three first spherical shells. The three first spherical shells are distributed in an equilateral triangle and respectively cooperate with the three first spheres to form the three first ball joints in the three PSS link branches.

[0009] The moving platform is provided with a hinge lug of a universal joint at its center.

[0010] The bottom end of the second connecting rod is fixed to the neck annular guide rail base, and the axis of the second connecting rod is perpendicular to the plane formed by the axis of the annular guide rail.

[0011] Each arc-shaped guide rail has a rack segment arranged along the circumference on its inner sidewall. The rack segments on the three arc-shaped guide rails are spliced ​​together to form a complete internal gear ring. The motor shafts of the three first drive motors are respectively fixed with gears that mesh with the internal gear ring, thereby obtaining the power for the slider to slide.

[0012] The beneficial effects of this invention are: This invention utilizes a three-branch parallel mechanical joint to mimic the function of the human neck, offering excellent support and high load-bearing capacity. By driving three connecting branches and cooperating with a composite rotating shaft, it achieves three degrees of freedom of movement for the human neck joint, enabling flexible posture control and helping the connected head structure maintain stability and coordination during movement. This invention optimizes the internal spatial layout of the neck frame while ensuring motion accuracy, rigidity, and support performance, reducing overall weight, simplifying the structure, and decreasing material costs, while ensuring the neck joint possesses the movement space of the human neck. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the main structure of Embodiment 1 of the present invention.

[0014] Figure 2 for Figure 1 A three-dimensional structural diagram of the mid-head moving platform.

[0015] Figure 3 for Figure 1A schematic diagram of the main structure of the PSS link branch.

[0016] Figure 4 for Figure 1 A schematic diagram of the main structure of the composite rotating shaft.

[0017] Figure 5 for Figure 4 A three-dimensional structural diagram of the universal joint shaft.

[0018] Figure 6 for Figure 1 A schematic diagram showing the connection relationship between the arc-shaped guide rail, the slider, and the drive motor.

[0019] Figure 7 This is a schematic diagram showing the installation position of the present invention on a humanoid robot.

[0020] Figure label: Detailed Implementation

[0021] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0022] Example 1 Figure 1 The illustrated humanoid neck-rotating parallel mechanical joint based on a ring-shaped guide rail includes a head moving platform 1, a composite rotating shaft 2, PSS link branches 3, and a neck ring-shaped guide rail base 4. Three PSS link branches 3 are connected in parallel between the head moving platform 1 and the neck ring-shaped guide rail base 4; the neck ring-shaped guide rail base is connected to the top of the humanoid robot's torso 7.

[0023] like Figure 2 As shown, three first spherical shells 11 are fixed at the bottom of the head moving platform of the mechanism. These three spherical shells are respectively used to cooperate with the first spheres of the three PSS connecting rod branches to form the first ball joints 31. The three first spherical shells 11 are arranged in an equilateral triangle and are respectively located on the periphery of the bottom surface of the head moving platform. The hinge lug 14 of the universal joint 21 is provided at the center of the head moving platform.

[0024] like Figure 3As shown, the three PSS link branches 3 have identical structures, each including a first ball joint 31, a first link 32, a second ball joint 33, and a sliding pair sequentially connected between the head moving platform and the neck annular guide rail base. The sliding pair includes an arc-shaped guide rail 35 disposed on the neck annular guide rail base and a slider 34 that slides with the annular guide rail. A drive motor 36 is mounted on the slider, which is driven by the drive motor to move on the arc-shaped guide rail, thereby forming the sliding pair. In the three PSS link branches, the arc-shaped guide rails of the three sliding pairs have the same radius and are connected and spliced ​​together to form an annular guide rail 41; the annular guide rail is supported by the neck annular guide rail base.

[0025] In the three PSS linkage branches, the three sliders are all in sliding engagement with the annular guide rail 41; the first ball joint 31 and the sliding pair at both ends of each branch are respectively connected to the bottom surface of the head moving platform and the top surface of the neck annular guide rail base.

[0026] like Figure 4 As shown, the composite rotating shaft of the mechanism includes a universal joint 21, a second connecting rod 24, and a base 25. The base 25 is a circular plate structure. The bottom end of the second connecting rod is engaged with the center position of the base 25 to form a rotating pair. The periphery of the base is fixed to the neck annular guide rail base (the neck annular guide rail base is an annular structure. The periphery of the base 25 is fixed to the bottom end of the neck annular guide rail base, and after fixing, it still maintains a distance from the drive motor 36 to avoid interference when the slider and the drive motor slide along the annular guide rail). The axis of the second connecting rod is perpendicular to the plane formed by the axis of the annular guide rail (i.e., the plane passing through the axis of the annular guide rail). The top end of the second connecting rod is connected to the center position of the bottom end of the head moving platform through the universal joint 21.

[0027] like Figure 5 As shown, the axes of the first shaft 22 and the second shaft 22 in the universal joint are perpendicular to each other.

[0028] like Figure 6 As shown, the annular guide rail base of the neck is provided with an annular guide rail 41 and three sliders 42 that slide in cooperation with the guide rail. The annular guide rail 41 is composed of three arc-shaped guide rails spliced ​​together to form a complete annular motion track. Each arc-shaped guide rail has a rack segment arranged along the circumference on its inner sidewall (i.e., the concave side of the arc-shaped guide rail). The rack segments on the three arc-shaped guide rails are spliced ​​together to form a complete internal gear ring. Gears that mesh with the internal gear ring are fixed on the motor shafts of the three drive motors 36 respectively. When the drive motor 36 installed on each slider is started, it can drive the slider connected to it, so that it slides independently along the annular guide rail.

[0029] The upper end of each slider is connected to the bottom end of the PSS link branch via a second ball joint 33. When the slider moves along the arc-shaped guide rail, it directly drives the bottom end of the connected PSS link branch to produce a circular motion in the horizontal plane, thereby changing the spatial attitude of the branch. The top ends of the PSS link branches are connected to the head moving platform 1 via first ball joints 31.

[0030] The composite rotating shaft 2 is connected to the head moving platform through the joint universal joint 21 at its top. By controlling the synchronous or asynchronous motion of the three sliders on the annular guide rail, the motion and direction of the three PSS branches can be changed, so that the entire head moving platform 1 rotates around the axis of the second link 24 (i.e., rotates around the revolute joint), and at the same time performs pitch and yaw motions around the two rotating shaft axes of the joint universal joint.

[0031] like Figure 7 As shown, the upper limb mechanism of the humanoid robot includes a humanoid robot head 5, a neck mechanism 6, and a humanoid robot torso 7. The neck mechanism 6 is a parallel mechanical joint that mimics the movement of the human neck, as described in this invention. This mechanical joint includes a head moving platform 1 connected to the humanoid robot head 5, a neck annular guide rail base 4 connected to the humanoid robot torso 7, and three PSS connecting rod branches connected in parallel between the head moving platform 1 and the neck annular guide rail base 4; a composite rotating shaft 2 connects the head moving platform 1 and the neck annular guide rail base 4.

[0032] In this embodiment, the main body of the head moving platform is a circular plate structure; the neck annular guide rail base is a circular ring structure supported on the bottom end of the annular guide rail.

Claims

1. A parallel mechanical joint based on a ring-shaped guide rail, mimicking the rotation of a human neck, characterized in that: It includes a head moving platform (1), a neck annular guide rail base (4), three PSS connecting rod branches (3) connected in parallel between the head moving platform and the neck annular guide rail base, and a composite rotating shaft (2) connected between the center position of the head moving platform (1) and the center position of the neck annular guide rail base (4). The PSS link branch (3) includes a first ball joint (31), a first link (32), a second ball joint (33), and a sliding pair, which are connected sequentially between the head moving platform and the neck annular guide rail base. The composite pivot includes a joint universal joint (21) and a second link (24) connecting the head moving platform and the neck annular guide rail base.

2. The parallel mechanical joint based on a ring guide rail, mimicking the rotation of a human neck, as described in claim 1. Its features are: The sliding pair includes an arc-shaped guide rail (35) and a slider (34) that cooperates with the arc-shaped guide rail.

3. The parallel mechanical joint based on a ring guide rail, mimicking the rotation of a human neck, as described in claim 2. Its features are: In the three PSS link branches, the sliders of the three sliding pairs are respectively connected to the first link (32) through the second ball joint, and the arc-shaped guide rails of the three sliding pairs are connected to each other to form a ring guide rail (41).

4. The parallel mechanical joint based on a ring guide rail for mimicking the rotation of a human neck, as described in claim 3, is characterized in that: The bottom of the head moving platform is fixed with three first spherical shells (11). The three first spherical shells are distributed in an equilateral triangle and cooperate with the three first spheres to form the three first ball joints in the three PSS link branches.

5. The parallel mechanical joint based on a ring guide rail for mimicking the rotation of a human neck, as described in claim 4, is characterized in that: The moving platform is provided with a hinge lug (14) of a universal joint (21) at its center.

6. The parallel mechanical joint based on a ring guide rail for mimicking the rotation of a human neck, as described in claim 5, is characterized in that: The bottom end of the second connecting rod is fixed to the neck annular guide rail base, and the axis of the second connecting rod is perpendicular to the plane formed by the axis of the annular guide rail.

7. The parallel mechanical joint based on a ring guide rail for mimicking the rotation of a human neck, as described in claim 6, is characterized in that: Each arc-shaped guide rail has an arc-shaped rack segment arranged along the circumference on its inner sidewall. The arc-shaped rack segments on the three arc-shaped guide rails are spliced ​​together to form a complete internal gear ring. The motor shafts of the three first drive motors are respectively fixed with gears that mesh with the internal gear ring, thereby obtaining the power for the slider to slide.

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