A biomimetic robot head mechanism

Abstract

The application relates to the field of bionic robots, in particular to a bionic robot head mechanism. The head mechanism is parallel layered to form multiple groups of layer plates, the layer plates include eyebrow layers, eyeball layers, upper jaw layers and lower jaw layers; a skin layer is wrapped outside the head mechanism, a crow's foot assembly is arranged at a corresponding crow's foot area below the skin layer; the board body of the crow's foot plate is provided with a crow's foot bionic protrusion corresponding to the position of the crow's foot area of the face; the two crow's foot plates produce fan-shaped opening and closing actions after being driven by a power source; the surface of the crow's foot plate towards the skin layer is provided with at least one group of traction connection areas, the traction connection areas are connected with the skin layer, and the traction connection areas drive the synchronous movement of the skin of the connection area while rotating with the crow's foot plate. The application improves the smiling expression of the robot from the mechanical mouth corner pulling to the realistic smile with the coordinated movement of the facial muscle groups, enhances the affinity and emotional expression in the human-computer interaction, and helps to overcome the uncanny valley effect.

Description

Technical Field

[0001] This invention relates to the field of bionic robots, specifically a bionic robot head mechanism. Background Technology

[0002] With the rapid development of artificial intelligence technology, robots are gradually moving from the industrial sector into social interaction scenarios such as education, healthcare, and home services. In this process, people's requirements for robots are no longer limited to completing functional tasks, but rather they expect robots to possess more natural and emotionally expressive interactive capabilities. As the core interface of human-computer interaction, the bionic robot head's ability to generate realistic, natural, and expressive facial expressions directly determines users' acceptance and affinity towards the robot.

[0003] Currently, at the hardware execution level, i.e., in terms of the physical structure for realizing facial expressions, existing technologies still have significant shortcomings. Especially for the most basic and core positive expression, the smile, the presentation effect of current bionic robots falls far short of human-like requirements. The control of smile expressions in existing bionic robots mostly uses simple push rods or single pull ropes to directly pull the silicone skin. When smiling, the corners of the mouth are merely pulled to the sides, lacking the detailed expression of facial muscle lifting and natural skin wrinkling. It is difficult to simulate the complex multi-dimensional movement trajectory of facial muscles when smiling in humans, resulting in a stiff and inconsistent smile. Simultaneously, it is difficult to simulate coordinated movements such as frowning and squinting, leading to poor expression coordination, abrupt skin deformation, and a lack of gradual muscle bulging or indentation, thus causing the uncanny valley effect. Therefore, how to improve the richness of smile expressions and enhance the human-likeness of the robot's head has become an urgent technical problem to be solved. Summary of the Invention

[0004] To avoid and overcome the technical problems existing in the prior art, this invention provides a bionic robot head mechanism. This invention elevates the robot's smiling expression from a mechanical pulling of the corners of the mouth to a realistic smile with the coordinated movement of facial muscle groups, enhancing the affinity and emotional expression in human-computer interaction, while also helping to overcome the uncanny valley effect.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A bionic robot head mechanism is provided, wherein the head mechanism is formed by multiple layers in parallel from top to bottom, including an eyebrow layer, an eyeball layer, an upper jaw layer, and a lower jaw layer; a skin layer covers the outside of the head mechanism, and a nasolabial fold component is disposed under the skin layer at the corresponding nasolabial fold area. The nasolabial fold component includes a nasolabial fold plate, the plate body of which has protrusions that correspond to the nasolabial fold area of ​​the face; the two nasolabial fold plates produce a fan-shaped opening and closing action after being driven by a power source; the nasolabial fold plate has at least one set of traction connection areas protruding on the skin layer coverage surface, the traction connection areas are connected to the skin layer, and the traction connection areas drive the skin of the connection area to move synchronously while rotating with the nasolabial fold plate. Each surface layer is equipped with an independent power source to drive the independent movement of each facial area.

[0006] As a further aspect of the present invention: with the nasolabial fold bionic protrusion as the boundary, the traction connection area is located on one side of the nasolabial fold bionic protrusion and is arranged at intervals along the arrangement direction of the nasolabial fold bionic protrusion, and the nasolabial fold rotation axis is located on the other side of the nasolabial fold bionic protrusion.

[0007] As a further embodiment of the present invention: the nasolabial fold component is installed on the face shell of the robot head mechanism or on one of the layers of the head mechanism. The nasolabial fold component is driven by a rotational power source and generates a fan-shaped opening and closing action to simulate a smile by rotating around a fixed point or sliding along a set trajectory.

[0008] As a further embodiment of the present invention: both nasolabial fold plates are provided with nasolabial fold pivots that rotate in conjunction with the nasal alar region, and the two nasolabial fold plates rotate around the nasolabial fold pivots as the rotation base.

[0009] As a further embodiment of the present invention: the nasolabial fold plate is installed on the slide plate, and the slide plate is provided with a first slide groove and a second slide groove of different lengths for guiding. After the nasolabial fold plate is driven by the power source, its two ends slide with the first slide groove and the second slide groove respectively to produce a fan-shaped opening and closing action with different head and tail movement speeds.

[0010] As a further embodiment of the present invention: a chin muscle rotating shaft is installed in the mandibular layer, and the rotation axis of the chin muscle rotating shaft is arranged parallel to the mandibular layer; a traction rotating plate embedded under the skin layer is rotatably installed on the chin muscle rotating shaft, and a traction point is provided at the end of the traction rotating plate away from the chin muscle rotating shaft, and the traction point is fixed to the chin lateral muscle group in the skin layer; when the traction rotating plate rotates, it drives the chin lateral muscle group to move synchronously. The traction point rotates with the bottom of the nasolabial fold plate to form a V-shaped opening and closing mechanism with the traction rotating plate to simulate the target's facial expression movements. Alternatively, the traction rotating plate and the nasolabial fold plate can move independently of each other to simulate the target facial expression.

[0011] As a further aspect of the present invention: the independent power source for each surface layer includes a pull-rope servo and a linkage servo; The eyebrow layer, upper jaw layer, and lower jaw layer are equipped with pull-cord servo motors. The pull-cord servo motors use pull cords as a power source to pull the skin movement of the corresponding areas of the eyebrows and mouth. The eyeball layer is equipped with a linkage-type servo motor, which uses the linkage as a power source to independently drive the eye to produce blinking and eyeball rotation movements.

[0012] As a further embodiment of the present invention: the eyeball layer is provided with an eyelid support, and the upper eyelid and the lower eyelid are rotated and fitted with the eyelid support. The rotation axis is arranged horizontally and coaxially. The upper eyelid and the lower eyelid enclose a spherical area for the hemispherical eyeball to be attached and fixed. An eyeball support is horizontally suspended on the eyeball layer. The eyeball support is equipped with a main connecting shaft for rotating the eyeball body. The main connecting shaft is arranged along the spherical axis of the eyeball body so that the eyeball body can rotate up and down around the main connecting shaft. The main connecting shaft is rotatably engaged with the eyeball support through the first vertical axis of the eyeball. The axis of rotation between the main connecting shaft and the eyeball support is arranged parallel to the main connecting shaft. The eyeball layer is equipped with three power sources to independently drive the upper and lower eyelids to blink, rotate the eyeball body up and down around the main connecting axis of the eyeball, and drive the eyeball body to rotate left and right around the first vertical axis of the eyeball.

[0013] As a further embodiment of the present invention: the power source for the eyeball layer includes three sets of linkage servo motors. The servo motor linkages driven by the three sets of linkage servo motors are respectively equipped with the main linkage of the eyelid, the first driving linkage of the eyeball, and the second driving linkage of the eyeball. The ends of the linkages connected to each linkage servo motor are in rotational cooperation with the servo motor linkages, and the rotation axis is arranged horizontally.

[0014] As a further embodiment of the present invention: the driving end of the main connecting rod of the eyelid is fixed with a first ball joint connecting rod of the eyelid, which is arranged perpendicularly to the main connecting rod of the eyelid. The two ends of the first ball joint connecting rod of the eyelid are respectively spherically hinged to two sets of second ball joint connecting rods of the eyelid. The ends of the two sets of second ball joint connecting rods of the eyelid are respectively spherically hinged to the upper eyelid and the lower eyelid. When the main connecting rod of the eyelid moves linearly under the drive of the linkage servo motor, it drives the upper eyelid and the lower eyelid to rotate through the first ball joint connecting rod and the second ball joint connecting rod of the eyelid.

[0015] As a further embodiment of the present invention: an eyeball fixing shaft is provided in the eyeball body, which is arranged parallel to the main connecting shaft of the eyeball. The first driving link of the eyeball is spherically hinged to the eyeball fixing shaft through the eyeball universal joint. When the first driving link of the eyeball moves linearly after being driven by the linkage servo motor, it drives the eyeball body to pitch and rotate through the eyeball fixing shaft. The main connecting shaft of the eyeball is equipped with a second vertical shaft of the eyeball that is parallel to the first vertical shaft of the eyeball. The second driving link of the eyeball is rotatably engaged with the second vertical shaft of the eyeball, and the axis of rotation is parallel to the axis of rotation of the main connecting shaft of the eyeball. When the second driving link of the eyeball moves linearly under the drive of the linkage servo motor, it drives the main connecting shaft of the eyeball to rotate around the first vertical shaft of the eyeball. When the eyeball rotates left and right and / or pitches, the corresponding linkage-type servo motors of the first and second drive links of the eyeball move synchronously to achieve position compensation.

[0016] As a further embodiment of the present invention: the pull-cord servo includes a servo linkage driven to rotate by the servo and a guide sleeve corresponding to the position of the servo linkage; the rotation axis of the servo linkage is arranged vertically, and a pull cord is connected to the end of the servo linkage away from the rotation axis. The pull cord passes through the guide sleeve and is connected to the corresponding skin area. The patches include eyebrow patches and lip patches. There are four sets of eyebrow patches, with each pair of eyebrow patches corresponding to the two ends of the eyebrow. There are six sets of lip patches, with three sets of lip patches on the upper lip and three on the lower lip. Each patch has barbs on its surface, and the corresponding skin area has grooves that engage with the barbs on the patch surface for positioning.

[0017] As a further embodiment of the present invention: the head mechanism is fixed on the rotary platform and rotates synchronously with the rotary platform, and also includes a pitch platform for supporting the rotary platform; the pitch platform includes a mounting base, on which two layers of parallel four-bar linkages are configured. The mounting base is equipped with two sets of horizontally arranged first and second pitch shafts. The first and second pitch shafts are respectively equipped with meshing first and second shaft gears. A driven gear is installed at the shaft end of the first or second pitch shaft. A driving gear is fixed on the motor shaft of the pitch drive motor on the mounting base. The driving gear and the driven gear mesh with each other. A linear first pivot link is coaxially fixed on the first pitch pivot, and a first arc-shaped link is rotatably mounted on the mounting base. The mounting base, the first pivot link, the first arc-shaped link, and the rotary platform cooperate to form an upper parallel four-bar linkage mechanism. A linear second pivot link is coaxially fixed on the second pivot axis of the pitch, and a second arc-shaped link is rotatably mounted on the mounting base. The mounting base, the second pivot link, the second arc-shaped link, and the base of the pitch platform cooperate to form a lower parallel four-bar linkage mechanism. While the drive gear rotates, it drives the upper and lower parallel four-bar linkages to move synchronously through gear transmission to simulate the flexion and swaying of the cervical spine.

[0018] As a further aspect of the invention: the skin layer is configured to be elastic, and the skin layer is connected to at least one set of facial components in the head mechanism by an adhesive to form a basic facial appearance, the facial components including any one of a head shell, eyelids, and nasolabial fold components; each facial component has an interlocking structure on its surface opposite to the skin layer, the interlocking structure including at least one recess for receiving the adhesive and / or a protrusion for embedding in the recess, so that a mechanical lock is formed between the facial component and the skin layer in at least two directions.

[0019] As a further embodiment of the present invention: the nasolabial fold component and / or the structure connected to the nasolabial fold component are made of a flexible material or a drivable deformable material, wherein the material includes, but is not limited to, at least one of silicone, silicone rubber, programmable robotic materials, liquid crystal elastomers, electroactive polymers, and shape memory alloys.

[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, through the combined design of symmetrically arranged nasolabial fold plates, biomimetic protrusions of nasolabial folds, and traction connection areas, combined with fan-shaped opening and closing movements, breaks through the technical limitations of existing technologies that can only achieve simple pulling of the corners of the mouth. Driven by servo motors, the biomimetic protrusions of nasolabial folds can move along a predetermined trajectory with the nasolabial fold plates, actively pushing the external biomimetic skin, forming natural bulges and wrinkles in the area from the sides of the nose to the outer corners of the mouth, accurately simulating the formation process of nasolabial folds when a human smiles. This elevates the robot's smiling expression from mechanical pulling of the corners of the mouth to a realistic smile with a sense of coordinated facial muscle movement, effectively overcoming the uncanny valley effect and significantly enhancing the affinity and emotional expression in human-computer interaction.

[0021] 2. This invention features a multi-layered head structure with parallel layers for the eyebrows, eyes, upper jaw, and lower jaw. Each layer functions independently, facilitating assembly, maintenance, and drive control. Simultaneously, the skin layer provides overall coverage, ensuring a cohesive appearance and coordinated movement. This allows for coordinated movement of the mouth, nose, eyes, and forehead at the structural level, mimicking the complex interplay of human facial muscles. For example, the contraction of the orbicularis oculi muscle and the lifting of the zygomaticus major muscle occur simultaneously during a smile, generating coherent, natural, and layered facial expressions. The modular design of each layer and the vertical stacking of layers allow for the rational arrangement of the drive mechanisms within the limited head space, avoiding the problems of bulky internal structures and messy wiring caused by the dispersed stacking of drive sources in existing technologies. The modular design also reduces assembly complexity, facilitating manufacturing and subsequent maintenance. While ensuring a rich variety of multi-degree-of-freedom expressions, it achieves miniaturization and lightweighting of the head structure, providing a solid structural foundation for the commercial application of bionic robot heads.

[0022] 3. The eyeball layer of the present invention uses three sets of independent linkage servo motors to control the blinking action of the upper / lower eyelids, the pitch and rotation of the eyeballs, and the separation and coordinated movement of the eyeballs and eyelids. With the help of the position compensation mechanism, it can realistically simulate the complex movements of human eyeballs such as fixation, saccade and blinking.

[0023] 4. The eyebrow and mouth areas of this invention utilize a pull-cord servo motor. The pull-cord pulls the patch, driving the skin movement. This design is simple, easy to control, and allows for subtle facial expression changes. The barbs on the patch surface engage with the skin grooves for reliable positioning, preventing detachment during movement. The combination of pull-cord and linkage servo motors in the overall structure addresses the requirements of different areas for driving force, motion accuracy, and spatial layout, facilitating multi-degree-of-freedom and multi-area coordinated control. The composite transmission method, combining servo motors with hinges, pull cords, and linkages, transforms the rigid rotational motion of the drive source into flexible, multi-point traction and support for the silicone skin. This avoids abrupt skin deformation caused by rigid transmission, significantly improving the realism and smoothness of facial expressions.

[0024] 5. This invention uses a two-layer parallel four-bar linkage combined with gear transmission to realize the pitching and swinging of the head mechanism around the horizontal axis. The structure is compact and the movement is stable. It can realistically simulate the flexion and extension of the cervical spine and enhance the overall movement flexibility of the head. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the robot head mechanism of the present invention.

[0026] Figure 2 This is a magnified view of a portion of the eyeball layer in this invention.

[0027] Figure 3 This is a schematic diagram of the structure of the eyeball layer in this invention.

[0028] Figure 4 This is a partially enlarged view of the internal connection structure of the eyeball in this invention.

[0029] Figure 5 This is a schematic diagram of the nasolabial fold plate in this invention.

[0030] Figure 6 This is a schematic diagram of the pitch platform in this invention.

[0031] Figure 7 This is a schematic diagram of the rope-operated servo motor in this invention.

[0032] Figure 8 This is a front view of the head mechanism of the present invention.

[0033] Figure 9This is a schematic diagram of the structure of the present invention when a gear set drives the nasolabial fold plate.

[0034] Figure 10 This is a schematic diagram of the structure of the present invention when a sliding plate drives a nasolabial fold plate.

[0035] Figure 11 for Figure 10 A schematic diagram of the back side in its current state.

[0036] Figure 12 This is a magnified view of a portion of the chin muscle rotation axis in this invention.

[0037] In the picture: 10. Eyebrow layer; 11. Eyebrow implants; 20. Eyeball layer; 21. Eyelid framework; 22. Upper eyelid; 23. Lower eyelid; 24. Body of the eyeball; 241. Main connecting axis of the eyeball; 242. First vertical axis of the eyeball; 243. Second vertical axis of the eyeball; 244. Eyeball fixing axis; 245. Eyeball universal joint; 25. Eyelid main connecting rod; 251. First ball-end connector at the eyelid; 252. Second ball-end connector at the eyelid; 26. First drive link of the eyeball; 27. Second drive link of the eyeball; 28. Eyeball support; 30. Maxilla; 31. Nasal bridge support; 32. Nasolabial fold pivot; 33. Nasolabial fold plate; 331. Biomimetic raised nasolabial folds; 332. Traction connection area; 34. Gear set; 341. Driving gear; 342. Driven gear; 35. Slide plate; 351. First slide; 352. Second slide; 353. Slide plate motor; 354. Swing rod; 40. Mandibular layer; 41. Mouth patch; 50. Rotation platform; 60. Pitch platform; 61. Mounting base; 611. Driving gear; 612. Driven gear; 62. First arc-shaped connecting rod; 63. First pivot shaft for pitch; 631. First pivot shaft gear; 632. First pivot shaft connecting rod; 64. Pitch second shaft; 641. Second shaft gear; 642. Second shaft connecting rod; 65. Second arc-shaped connecting rod; 66. Pitch drive motor; 70. Cable-operated servo; 701. Servo linkage; 702. Guide sleeve; 703. Cable; 80. Linkage servo motor; 91. Chin muscle pivot; 92. Traction rotating plate; 93. Traction point. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Please see Figure 1~Figure 12 In this embodiment of the invention, a biomimetic robot head mechanism is provided, comprising, from top to bottom, parallel layers of an eyebrow layer 10, an eyeball layer 20, an upper jaw layer 30, and a lower jaw layer 40. A biomimetic skin layer completely covers the outer side of the head mechanism. The skin layer may be made of medical-grade silicone material with a Shore A hardness of 10A to 30A and a thickness of 2mm to 5mm. A head shell is placed on the outer layer of the head mechanism, forming a support and then contacting the skin layer. The skin layer is configured to be elastic and is connected to at least one set of facial components in the head mechanism by an adhesive to form a basic facial appearance. The facial components include any one of the head shell, eyelids, and nasolabial fold components. The parts of the head mechanism that contact the skin layer may be arranged in a manner that uses one of the following methods: through holes, blind holes, bosses, grooves, recesses, or interlocking mechanisms, to adhere to the skin layer by adhesive force or elastic recovery force. The interlocking structure includes at least one recess for receiving an adhesive and / or a protrusion for embedding in the recess, so as to form a mechanical lock between the facial component and the skin layer in at least two directions.

[0040] A nose bridge support 31 is formed by extending downwards at the center of the front end of the eyeball layer 20. A biomimetic nasolabial fold component is mounted on the nose bridge support 31. Specifically, the structure includes nasolabial fold plates 33 symmetrically arranged on both sides of the nose bridge support 31. Each nasolabial fold plate 33 has a curved biomimetic protrusion 331, which corresponds to the position of the nasolabial fold area on the face and is adapted to the direction of human nasolabial folds, pushing against the external biomimetic skin to form nasolabial folds. Both nasolabial fold plates 33 are equipped with nasolabial fold pivots 32 that rotate in conjunction with the nose bridge support 31. The two nasolabial fold plates 33 rotate around the pivots 32 and, driven by a power source, produce synchronized fan-shaped opening and closing movements. The ends of the nasolabial fold plates 33 extend to the upper side of the upper lip.

[0041] In this embodiment, the power source for the biomimetic nasolabial fold component is a pull-cord servo motor 70. The pull-cord servo motor 70 includes a servo linkage 701 driven to rotate by the servo motor and a guide sleeve 702 corresponding to the position of the servo linkage 701. The rotation axis of the servo linkage 701 is arranged vertically, and a pull cord 703 is connected to the end away from the rotation axis. The pull cord 703 passes through the guide sleeve 702 and connects to the corresponding skin area. Its specific location is in the maxillary layer, and the traction position of the pull cord is at the corner of the nasolabial fold plate 33 away from the nasolabial fold rotation axis 32.

[0042] In this embodiment, the guide sleeve 702 is a stainless steel conduit with an inner diameter of 1.5 mm and an outer diameter of 2.5 mm. A 0.8 mm diameter steel wire rope is threaded inside the conduit. One end of the steel wire rope is fixedly connected to the end of the servo motor's connecting rod, and the other end extends from the end of the conduit and connects to a silicone patch. The silicone patch connects to the skin layer, and the connection method is not limited. In this embodiment, each patch surface is provided with barbs, and corresponding skin areas have grooves. The patch is positioned by engaging the barbs with the grooves, achieving a reliable connection. Alternatively, the patch can be bonded and fixed to the skin layer using medical-grade adhesive.

[0043] In this embodiment, the guide sleeve 702 can also be made of polytetrafluoroethylene (PTFE), which has self-lubricating properties and can further reduce the friction of the pull rope when it moves within the guide sleeve 702. The pull rope is made of high-molecular-weight polyethylene fiber braided rope, which has the characteristics of high strength and low elongation, ensuring motion accuracy after long-term use.

[0044] In this embodiment, the power source for the biomimetic nasolabial fold component can also be replaced by an independent motor installed at the nasolabial fold shaft 32, driving the two sets of nasolabial fold plates 33 to rotate synchronously in opposite directions via gear transmission. Alternatively, a linear drive mechanism such as a lead screw slider mechanism or an electric actuator can be used, with a pull rope fixed to the end of the linear drive mechanism to pull the nasolabial fold plates 33 to rotate; the specific rotation method is not limited. Alternatively, a sliding groove mechanism can be installed on the head mechanism, fixing the nasolabial fold plates 33 to the groove, and a linear power source can be installed to drive the nasolabial fold plates 33 to slide along the set trajectory of the groove, simulating the direction of nasolabial folds when smiling. The nasolabial fold plates 33, through a fan-shaped opening and closing drive method, reproduce the upward and outward lifting movement characteristics of the muscles on both sides of the nose when a human smiles.

[0045] Specifically, based on the use of a pull-rope servo motor 70 to drive the nasolabial fin plate 33 to rotate, such as Figure 9As shown, the power source of the pull-rope servo motor 70 can be replaced by a gear set 34. The gear set 34 includes a drive gear 341 and driven gears 342 symmetrically arranged on both sides of the drive gear 341. The two sets of driven gears 342 are coaxially fixed with the nasolabial fold shaft 32 of the nasolabial fold plate 33. While the drive gear 341 is driven to rotate by the motor, it drives the two sets of driven gears 342 to rotate synchronously in opposite directions through gear meshing, so as to realize the fan-shaped opening and closing action of the nasolabial fold plate 33.

[0046] Specifically, based on the use of a pull-rope servo motor 70 to drive the nasolabial fin plate 33 to rotate, such as Figure 10~Figure 11 As shown, the power source can also be replaced by a sliding plate 35. The sliding plate 35 is fixed to the lower layer of the nasolabial fold plate 33. The sliding plate 35 is symmetrically arranged on both sides, and two sets of nasolabial fold plates 33 are symmetrically installed on the sliding plate 35. The sliding plate 35 has a first sliding groove 351 and a second sliding groove 352 on the mounting surface of the two nasolabial fold plates 33. The first sliding groove 351 is connected to the top of the nasolabial fold plate 33, and the second sliding groove 352 is connected to the bottom of the nasolabial fold plate 33. The length of the first sliding groove 351 is less than the length of the second sliding groove 352. A sliding plate motor 353 is installed on the back of the sliding plate 35. A swing rod 354 arranged parallel to the nasolabial fold plate 33 is fixed on the motor shaft of the sliding plate motor 353. Both ends of the swing rod 354 are fixed with traction lines. The traction lines pass through the first sliding groove 351 and the second sliding groove 352 respectively, and are connected and fixed to the top and bottom of the nasolabial fold plate 33. When the sliding plate motor 353 drives the swing rod 354 to rotate, it causes the top and bottom of the nasolabial fold plate 33 to slide along the corresponding sliding groove at different speeds. Rotating and swinging with the nasolabial fold pivot 32 as the base point, it forms a fan-shaped opening and closing motion, achieving two composite motion dimensions: first, the nasolabial fold plate 33 is pulled horizontally outward from the midline of the nose; second, it is pulled obliquely along the track of the sliding groove. This composite motion causes differences in the linear velocity of different parts of the nasolabial fold plate 33 during the opening and closing process; that is, the end closer to the nasolabial fold pivot 32 has a smaller amplitude of movement, while the end farther from the nasolabial fold pivot 32 has a larger amplitude of movement, thus creating a natural gradient effect where the nasolabial fold area gradually deepens from the root of the nose to the outer corner of the mouth when smiling.

[0047] Based on the structure driven by the slide plate 35, the difference in length between the first slide plate 351 and the second slide plate 352 creates a speed difference between the head and tail movements. A differential gear can be installed on the motor shaft of the slide plate motor 353. Two sets of traction lines with different radii are wound on the differential gear. The rotation of the gear rewinds the traction lines, driving the top and bottom of the nasolabial fold plate 33 to rotate around the motor shaft. Due to the different winding radii of the two sets of traction lines, the top and bottom of the nasolabial fold plate 33 obtain different motion speed curves at the same time point, thus achieving a gradual smile. From a slight upturn of the corners of the mouth to a natural smile, the phase difference of the movement of each part of the nasolabial fold plate 33 can be precisely controlled, forming a natural transition of the nasolabial folds from shallow to deep during the development of a smile. Independent control and driving of the top and bottom of the nasolabial fold plate 33, through the coordinated movement of the controller, achieves more complex smile dynamics. In the gentle smile mode, only the bottom of the nasolabial fold plate 33 moves slightly to simulate a subtle smile with slightly upturned lips; in the laughing mode, the top and bottom of the nasolabial fold plate 33 move at different speeds to simulate the full stretching of facial muscles. The independent drive of the top and bottom allows for a continuous transition of expression from a gentle smile to a laughing hearty smile.

[0048] Based on the above embodiments, to further enhance the expressive richness of a smile, a chin muscle pivot 91 is installed on the mandibular layer 40, with the axis of rotation of the chin muscle pivot 91 arranged parallel to the mandibular layer 40. A traction pivot plate 92 embedded under the skin layer is rotatably mounted on the chin muscle pivot 91. A traction point 93 is provided at the end of the traction pivot plate 92 away from the chin muscle pivot 91, and the traction point 93 is fixed to the chin lateral muscle group in the skin layer. When the traction pivot plate 92 rotates, it drives the chin lateral muscle group to move synchronously, thereby enhancing the expressive richness of a smile. The traction point 93 can be directly fixed to the bottom of the nasolabial fold plate 33. When the nasolabial fold plate 33 swings, it drives the traction pivot plate 92 to rotate synchronously. At this time, the nasolabial fold plate 33 and the traction pivot plate 92 cooperate to form a V-shaped opening and closing mechanism. Alternatively, the nasolabial fold plate 33 and the traction pivot plate 92 can be set independently, with the chin muscle pivot 92 as an independent drive source to drive the traction pivot plate 92 to rotate independently.

[0049] On the skin layer covering surface of the nasolabial fold plate 33, at least one set of traction connection areas 332 are protruding. These traction connection areas 332 are fixedly connected to the skin layer. When the nasolabial fold plate 33 rotates, the traction connection areas 332 cause the connected skin area to move synchronously. With the nasolabial fold bionic protrusion 331 as the boundary, the traction connection areas 332 are located on one side of the nasolabial fold bionic protrusion 331 and are spaced apart along the arrangement direction of the nasolabial fold bionic protrusion 331; the nasolabial fold pivot 32 is located on the other side of the nasolabial fold bionic protrusion 331. Specifically, the traction connection areas 332 can be composed of a matrix of distributed silicone protrusions, each protrusion having a diameter of 1mm to 3mm and a height of 1mm to 2mm, used to form fixing points.

[0050] The nasolabial fold plate 33 pushes the skin to form wrinkles through the biomimetic protrusions 331, and then pulls the skin through the traction connection area 332 to simulate muscle coordinated movement, forming a push-pull combined coordinated movement mechanism. Since the biomimetic protrusions 332 and the traction connection area 332 are distributed on different sides with the biomimetic protrusions 331 as the boundary, the distributed layout allows the protruding area and the traction area to generate complementary motion coupling when the nasolabial fold plate 33 rotates, and after coordination, a complete smile mechanical field is generated.

[0051] The nasolabial fold plate 33 is made of carbon fiber, while the biomimetic protrusions 331 are injection molded from ABS plastic. When the nasolabial fold plate 33 rotates counterclockwise, the arc-shaped outer edge of the biomimetic protrusions 331 pushes against the biomimetic skin on the outer side of the upper lip, forming natural bulges and wrinkles in the area from the sides of the nose to the outer corners of the mouth, accurately simulating the formation of nasolabial folds when a human smiles. When reversed and reset, the biomimetic protrusions 331 retract, and the nasolabial folds disappear.

[0052] A stiffness layer can be added between the nasolabial fold plate 33 and the skin layer. The stiffness layer may include shape memory alloy wire or electroactive polymer, which can change the local stiffness of the skin layer under smiling intensity, so that the formation depth of the nasolabial fold can be dynamically adjusted.

[0053] Based on carbon fiber, other alternative materials can be selected. For example, the material of the nasolabial fold plate 33 itself and the material connected to the nasolabial fold plate 33 can be silicone, silicone rubber, metamaterials, programmable robotic materials, liquid crystal elastomers, various other materials, shape memory alloys, etc. Metamaterials are materials whose expansion, contraction, deformation, and movement can be controlled by external magnetic or electric fields. Programmable robotic materials are materials that can switch between solid and fluid states, possess both high strength and high flexibility, and are capable of self-shaping and self-repairing. Electroactive polymers can be dielectric elastomers. Shape memory alloys, under specific temperature or magnetic field stimulation, recover a preset memory shape, thereby generating driving force to complete the preset movement. The nasolabial fold components and their connected structures form the nasolabial fold contour required for a smile and achieve the action of the nasolabial folds moving left and right to squeeze and lift the skin, thus completing the smile.

[0054] The eyebrow layer 10, upper jaw layer 30, and lower jaw layer 40 are equipped with pull-cord servo motors 70. The pull-cord servo motors 70 use pull cords 703 as a power source to pull the skin movement of the corresponding areas of the eyebrows and mouth, respectively. The eyeball layer 20 is equipped with a linkage-type servo motor 80, which uses a linkage as a power source to independently drive the eyes to produce blinking and eyeball rotation movements. The eyebrow layer 10 is equipped with a skull support to simulate the curvature of the top of the head.

[0055] In this embodiment, the eyebrow layer 10 is equipped with four sets of pull-cord servo motors 70. The ends of the pull cords of every two sets of pull-cord servo motors 70 are connected to the skin areas at both ends of the eyebrow through eyebrow patches 11. As the pull cords move linearly along the guide sleeve 702, they drive the bionic skin to move through the patches, thereby realizing the up-and-down movement of the eyebrows.

[0056] The eyeball layer 20 is provided with an eyelid support 21. The upper eyelid 22 and the lower eyelid 23 are both rotated and engaged with the eyelid support 21, and their rotation axes are coaxial and horizontally arranged. The upper eyelid 22 and the lower eyelid 23 enclose a spherical area for the hemispherical eyeball body 24 to be attached and fixed.

[0057] An eyeball support 28 is horizontally suspended on the eyeball layer 20. The eyeball support 28 is equipped with a main eyeball connecting shaft 241 for rotatably mounting the eyeball body 24. The main eyeball connecting shaft 241 is arranged along the spherical axis of the eyeball body 24, allowing the eyeball body 24 to simulate vertical rotation around the main eyeball connecting shaft 241. The main eyeball connecting shaft 241 is rotatably engaged with the eyeball support 28 via a first vertical axis 242 of the eyeball, and the axis of rotation between the main eyeball connecting shaft 241 and the eyeball support 28 is arranged parallel to the main eyeball connecting shaft 241.

[0058] The eyeball layer 20 is equipped with three independent power sources, which are used to drive the upper eyelid 22 and the lower eyelid 23 to rotate to produce blinking; drive the eyeball body 24 to rotate up and down around the main connecting shaft 241 of the eyeball; and drive the main connecting shaft 241 of the eyeball to drive the eyeball body 24 to rotate left and right around the first vertical axis 242 of the eyeball.

[0059] The three power sources for the eyeball layer 20 are all linkage-type servo motors 80. Each linkage-type servo motor 80 drives a servo linkage with a main eyelid linkage 25, a first eyeball drive linkage 26, and a second eyeball drive linkage 27, respectively. The forward and reverse rotation of the servo linkages drives the linear motion of each linkage. The ends of each linkage are rotatably engaged with the servo linkages, and the axis of rotation is horizontally arranged.

[0060] When transmitting the blinking motion, the driving end of the main eyelid connecting rod 25 is fixed with a first ball-head connecting rod 251 arranged perpendicularly to it. Both ends of this ball-head connecting rod are spherically hinged to two sets of second ball-head connecting rods 252. The ends of the two sets of second ball-head connecting rods 252 are spherically hinged to the upper eyelid 22 and lower eyelid 23, respectively. When the main eyelid connecting rod 25 is driven linearly by the linkage-type servo motor 80, the ball-head connecting rod structure drives the upper and lower eyelids to open and close, thus realizing the blinking motion.

[0061] When the eyeball rotates up and down, an eyeball fixing shaft 244 is provided inside the eyeball body 24, which is arranged parallel to the main connecting shaft 241 of the eyeball. The first drive link 26 of the eyeball is spherically hinged to the eyeball fixing shaft 244 through the eyeball universal joint 245. When the first drive link 26 of the eyeball is driven by the linkage servo motor 80 to move linearly, it drives the eyeball body 24 to complete the up and down rotation through the eyeball fixing shaft 244.

[0062] When the eyeball rotates left and right, a second vertical shaft 243 of the eyeball, arranged parallel to the first vertical shaft 242 of the eyeball, is mounted on the main connecting shaft 241 of the eyeball. The second driving link 27 of the eyeball is rotatably engaged with the second vertical shaft 243 of the eyeball, and the axis of rotation is parallel to the axis of rotation of the main connecting shaft 241 of the eyeball. When the second driving link 27 of the eyeball is driven by the linkage servo motor 80 to move linearly, it drives the main connecting shaft 241 of the eyeball to rotate around the first vertical shaft 242 of the eyeball, thereby realizing the left and right rotation of the eyeball body 24.

[0063] When the eyeball body 24 rotates left and right and / or pitches, the linkage-type servo motors 80 corresponding to the first drive linkage 26 and the second drive linkage 27 of the eyeball move synchronously to avoid dead points, form position compensation, and ensure smooth eyeball movement. In addition to the above embodiment, the eyeball body 24 can also be driven independently to produce left and right rotation and up and down rotation through gear transmission.

[0064] A miniature attitude sensor can be embedded within the eyeball body 24. When the eyeball body 24 pitches or rotates left or right, the sensor provides real-time position information, calculates and outputs a position compensation signal. Through closed-loop control combining sensing and compensation, the sensitivity of eyeball movement is improved.

[0065] A total of six sets of mouth patches 41 are provided, with three sets each for the upper and lower lips, corresponding to the positions of the maxillary layer 30 and the mandibular layer 40, respectively. One set of mouth patches 41 is placed in the central area of ​​both the upper and lower lips, and another set of mouth patches 41 is symmetrically arranged on both sides of the central area. The upper and lower lips can produce anthropomorphic movements by pulling the rope of the pull-rope servo motor 70.

[0066] In this embodiment, a connecting pin is provided between the maxillary and mandibular layers, allowing the mandibular layer to rotate around the connecting pins at both ends. A servo motor is provided on the rear side of the maxillary layer, connected to the mandibular layer via a connecting rod, driving the mandibular layer to rotate around the connecting pin, thus realizing the opening and closing movement of the mouth. The driving method is not limited and can be achieved by gear meshing transmission or direct motor drive to realize the opening and closing action between the maxilla and mandible.

[0067] The head mechanism is fixed on the rotary platform 50 and can rotate synchronously with the rotary platform 50. The output shaft of the rotary platform 50 is connected to the head body, driving the entire head to rotate around the vertical axis; it has a built-in motor mechanism.

[0068] It also includes a pitch platform 60 for supporting the slewing platform 50. The pitch platform 60 includes a mounting base 61, on which a two-layer parallel four-bar linkage is configured.

[0069] Two sets of horizontally arranged pitch first shafts 63 and pitch second shafts 64 are mounted on the mounting base 61. A first shaft gear 631 and a second shaft gear 641, which mesh with each other, are respectively mounted on the two shafts. A driven gear 612 is mounted on the end of the shaft of either the pitch first shaft 63 or the pitch second shaft 64. A driving gear 611 is fixed on the motor shaft of the pitch drive motor 66 on the mounting base 61, and the driving gear 611 and the driven gear 612 mesh with each other.

[0070] A linear first pivot link 632 is coaxially fixed on the first pitch pivot 63, and a first arc-shaped link 62 is rotatably mounted on the mounting base 61. The mounting base 61, the first pivot link 632, the first arc-shaped link 62, and the rotary platform 50 together constitute the upper parallel four-bar linkage mechanism.

[0071] A linear second pivot link 642 is coaxially fixed on the second pitch pivot 64, and a second arc-shaped link 65 is rotatably mounted on the mounting base 61. The mounting base 61, the second pivot link 642, the second arc-shaped link 65, and the base of the pitch platform together constitute the lower parallel four-bar linkage mechanism.

[0072] When the drive gear 611 rotates, it drives the upper and lower parallel four-bar linkages to move synchronously through gear transmission, forming a superimposed linkage structure, thereby simulating the pitching and swaying movements of the cervical spine. In addition to the above implementation, the pitch platform 60 can be configured as an upper and lower double platform structure, with the two platforms directly connected by three sets of electric actuators. By controlling the extension and retraction length of the three sets of electric actuators, the three degrees of freedom of head movement (pitch, yaw, and roll) can be realized.

[0073] Based on the aforementioned pitch platform 60, an elastic connector can be added between the pitch platform 60 and the skin layer. This elastic connector transmits the movement of the cervical spine to the skin layer. When the cervical spine pitches up or down, the overall tension distribution of the facial skin changes. This change is transmitted to the nasolabial fold area through the elastic connector, making the realism of the expression independent of independent expression drivers. Adjustments in head posture can drive coordinated facial expressions. For example, when the robot smiles with its head down, the nasolabial folds are deeper than when it smiles with its head up. By coupling head movement with the smile, the realism of the smiling expression is improved.

[0074] The eyebrow layer 10, eyeball layer 20, upper jaw layer 30, and lower jaw layer 40 are each designed as independent modular components. The modules are connected through standard interfaces, such as snap-fit ​​connections or positioning pin connections. The modular design facilitates independent assembly, debugging, and maintenance of each layer, improving production efficiency and maintainability.

[0075] In this embodiment, the head structure is also equipped with an attitude sensor and a position feedback sensor: the attitude sensor is used to detect the real-time attitude of the head; the position feedback sensor is set at the output end of each servo motor to detect the real-time position of each moving part, realize closed-loop control, and improve motion accuracy and response speed.

[0076] When controlling a smile, use the level of pleasure. h expressiveness e Orbicularis oculi muscle contraction s Mouth opening range m and asymmetry of the corners of the mouth a The input variables are used to control each control point on the face; The range of values ​​for each input variable is [0, 1]; Among them, pleasure level h This indicates the level of inner, genuine happiness; as the value increases, the level of happiness gradually increases. expressiveness e This indicates the degree of inhibition / release of emotions. As the value increases, the emotion changes from inhibition to release (i.e., exaggeration). Orbicularis oculi muscle contraction s This indicates the degree of squinting / crow's feet wrinkles. As the value increases, it indicates that the eyes change from a fully open state to an almost closed state (with more obvious crow's feet wrinkles). Mouth opening range m This indicates the degree of separation between the upper and lower lips. As the value increases, it indicates that the lips change from a closed state to an open state. asymmetry of the corners of the mouth a This indicates the degree of asymmetry between the left and right corners of the mouth. As the value increases, it indicates that the corners of the mouth change from being completely symmetrical to being extremely asymmetrical.

[0077] In a specific embodiment, when performing a polite fake smile, h= 0.2, e= 0.7, s= 0, m= 0, a= 0.

[0078] When laughing sincerely, h= 0.9, e= 0.9, s= 0.8, m= 0.5, a= 0.1.

[0079] When smiling subtly, h= 0.6, e= 0.3, s= 0.4, m= 0, a= 0.

[0080] The control points are as follows: i L The angle of the left corner of the mouth upward; the unit is degrees, indicating the upward rotation angle of the left corner of the mouth relative to the horizontal line; i R The upward angle of the right corner of the mouth; the unit is degrees, indicating the upward rotation angle of the right corner of the mouth relative to the horizontal line; d Lx This represents the outward displacement of the left corner of the mouth; the unit is mm, indicating the horizontal displacement of the left corner of the mouth outward (away from the midline); d Rx This represents the outward displacement of the right corner of the mouth; the unit is mm, indicating the horizontal displacement of the right corner of the mouth outward (away from the midline); h UL The height of the upper lip is indicated by the unit mm, representing the vertical upward movement of the midpoint of the upper lip. d LL This represents the downward displacement of the lower lip; the unit is mm, indicating the vertical downward movement of the midpoint of the lower lip. c L The percentage of the left cheek's protrusion indicates the degree of protrusion of the left cheekbone. c R The percentage of the right cheek's protrusion indicates the degree of protrusion of the right cheekbone. e L The value represents the degree of elevation of the lower eyelid of the left eye; the range is [0,1], which indicates the degree of squinting of the left eye. A value of 0 indicates no squinting, and a value of 1 indicates that the eye is completely closed.

[0081] e R The value represents the degree of elevation of the lower eyelid of the right eye; the range is [0,1], which indicates the degree of squinting of the right eye. A value of 0 indicates no squinting, and a value of 1 indicates that the eye is completely closed.

[0082] i J This refers to the mandibular opening angle; the unit is degrees, indicating the opening angle of the mandible.

[0083] Each output point must be physically limited to ensure that the mechanical structure is not damaged when it moves to its maximum position.

[0084] When calculating for each control point, the following intermediate variables are calculated first: G he =he ; G hs =tanh ( 2h+s ); G emb =1－0.3m ; G he This indicates the true intensity of a smile; G hs This indicates the coupling between pleasure level and the orbicularis oculi muscle, ranging from 0 to 1; G emb This indicates the inhibitory effect of opening the mouth on smiling, ranging from 0.7 to 1. I. Calculation i L as well as i R First, calculate the reference value of the upward angle. i base : i base = 22× s (4) G he －1 ) G emb ; in, s express sigmoid function; Based on benchmark value i base By introducing contraction of the orbicularis oculi muscle, the correction amount of the upward angle baseline value is obtained. i base-final : i base-final =θ base ( 1－0.2s 2 ); Upward corner of the left mouth i L for: i L =clip [ i base-final (1+0.5) a [0°, 25°]; Right corner of the mouth upturned i R for: iR =clip [ i base-final (1) － 0.5 a [0°, 25°]; 2. When calculating the outward displacement of the corner of the mouth, first calculate the outward reference amount. d base : ; Left corner of the mouth pulled outward displacement d Lx for: d Lx (1+0.3) a ); Right corner of mouth pulled outward displacement d Rx for: d Rx (1) － 0.3 a ); III. When calculating the displacement of the upper and lower lips: ; ; IV. When calculating the percentage of cheek lift, first calculate the baseline value of cheek lift. c base : c base =100% 0.4σ ( 5h 2 ) +0.6s 1.5 e 0.7 ; Percentage of left cheek bulge c L for: c L =clip [ c base (1+0.2) a [0%, 100%]; Percentage of right cheek bulge c R for: cR =clip [ c base (1) 0.2 a [0%, 100%]; V. When calculating the degree of eyelid closure, first calculate the baseline value of eyelid closure. e base : e base =clip [ 0.2σ ( 1 4 )+0.8 sh 0.5 [,0,1]; Based on benchmark value e base By introducing the mouth opening amplitude, the correction amount of the eyelid closure reference value is obtained. e final : e final =e base ( 1 0.1m ); left lower eyelid lifting degree e L for: e L =e final (1+0.05) a ); right lower eyelid lifting degree e R for: e R =e final (1) 0.05 a ).

[0085] VI. Calculate the mandibular opening angle i J : .

[0086] In terms of pleasure h expressiveness e Orbicularis oculi muscle contraction s Mouth opening range m and asymmetry of the corners of the mouth aThese five sets of input variables output eleven sets of control values ​​for control points, combined with... Sigmoid The mapping formulas of functions, power functions, cross-suppression terms, and asymmetric adjustment enable robots to express a variety of smiling expressions, from fake smiles to genuine smiles, from slight smiles to maniacal laughter, and from symmetrical smiles to deliberately crooked smiles.

[0087] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0088] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

Claims

1. A biomimetic robot head mechanism, characterized in that, The head structure is divided into multiple layers from top to bottom, including an eyebrow layer (10), an eyeball layer (20), a maxillary layer (30), and a mandibular layer (40); the skin layer covers the outside of the head structure, and the nasolabial fold component is set in the corresponding nasolabial fold area under the skin layer. The nasolabial fold component includes a nasolabial fold plate (33), and the plate body of the nasolabial fold plate (33) is provided with biomimetic protrusions (331) corresponding to the position of the nasolabial fold area on the face; the two nasolabial fold plates (33) generate a fan-shaped opening and closing action after being driven by a power source; the surface of the nasolabial fold plate (33) facing the skin layer is provided with at least one set of traction connection areas (332), the traction connection areas (332) are connected to the skin layer, and the traction connection areas (332) drive the skin of the connection area to move synchronously while rotating with the nasolabial fold plate (33); Each surface layer is equipped with an independent power source to drive the independent movement of each facial area; The nasolabial fold component is installed on the face shell of the robot's head mechanism or on one of the layers of the head mechanism. The nasolabial fold component is driven by a rotational power source and slides along a set trajectory to produce a fan-shaped opening and closing motion to simulate a smile. The nasolabial fold plate (33) is installed on the slide plate (35). The slide plate (35) has a first slide groove (351) and a second slide groove (352) of different lengths for guiding. After the nasolabial fold plate (33) is driven by the power source, its two ends slide with the first slide groove (351) and the second slide groove (352) respectively to produce a fan-shaped opening and closing action with different head and tail movement speeds.

2. The bionic robot head mechanism according to claim 1, characterized in that, With the nasolabial fold bionic protrusion (331) as the boundary, the traction connection area (332) is located on one side of the nasolabial fold bionic protrusion (331) and is arranged at intervals along the arrangement direction of the nasolabial fold bionic protrusion (331), and the nasolabial fold pivot (32) is located on the other side of the nasolabial fold bionic protrusion (331).

3. The bionic robot head mechanism according to claim 1, characterized in that, A chin muscle pivot (91) is installed on the mandibular layer (40), and the axis of rotation of the chin muscle pivot (91) is arranged parallel to the mandibular layer (40); a traction pivot plate (92) embedded under the skin layer is installed on the chin muscle pivot (91), and a traction point (93) is set at the end of the traction pivot plate (92) away from the chin muscle pivot (91), and the traction point (93) is fixed to the chin lateral muscle group in the skin layer; when the traction pivot plate (92) rotates, it drives the chin lateral muscle group to move synchronously; The traction point (93) rotates with the bottom of the nasolabial fold plate (33) so that the nasolabial fold plate (33) and the traction rotating plate (92) cooperate to form a V-shaped opening and closing mechanism to simulate the target facial expression. Alternatively, the traction rotating plate (92) and the nasolabial fold plate (33) can move independently of each other to simulate the target facial expression.

4. A bionic robot head mechanism according to any one of claims 1 to 3, characterized in that, Each surface layer has an independent power source, including a pull-wire servo (70) and a linkage servo (80). The eyebrow layer (10), maxillary layer (30) and mandibular layer (40) are equipped with pull-cord servo motors (70), which use pull cords (703) as power sources to pull the skin movement of the corresponding areas of the eyebrows and mouth. The eyeball layer (20) is equipped with a linkage servo motor (80), which independently drives the eye to produce blinking and eyeball rotation movements using the linkage as a power source.

5. The bionic robot head mechanism according to claim 4, characterized in that, The eyeball layer (20) is equipped with an eyelid support (21). The upper eyelid (22) and the lower eyelid (23) are rotated and matched with the eyelid support (21). The rotation axis is arranged horizontally and coaxially. The upper eyelid (22) and the lower eyelid (23) form a spherical area for the hemispherical eyeball body (24) to be attached and fixed. An eyeball support (28) is horizontally suspended on the eyeball layer (20). The eyeball support (28) is equipped with an eyeball main connecting shaft (241) for rotating the eyeball body (24). The eyeball main connecting shaft (241) is arranged along the spherical axis of the eyeball body (24) so ​​that the eyeball body (24) can rotate up and down around the eyeball main connecting shaft (241). The eyeball main connecting shaft (241) is rotated with the eyeball support (28) through the first vertical axis (242) of the eyeball. The axis of rotation between the eyeball main connecting shaft (241) and the eyeball support (28) is arranged parallel to the eyeball main connecting shaft (241). The eyeball layer (20) is equipped with three power sources to independently drive the upper eyelid (22) and lower eyelid (23) to blink, the eyeball body (24) to rotate up and down around the main connecting axis (241), and the main connecting axis (241) to drive the eyeball body (24) to rotate left and right around the first vertical axis (242) of the eyeball.

6. The bionic robot head mechanism according to claim 5, characterized in that, The power source of the eyeball layer (20) includes three sets of linkage servo motors (80). The servo motor linkages driven by the three sets of linkage servo motors (80) are respectively equipped with the main eyelid linkage (25), the first eyeball drive linkage (26) and the second eyeball drive linkage (27). The ends of the linkages connected to each linkage servo motor (80) are in rotational cooperation with the servo motor linkages, and the rotation axis is arranged horizontally.

7. The bionic robot head mechanism according to claim 6, characterized in that, The driving end of the main connecting rod (25) of the eyelid is fixed with a first ball joint connecting rod (251) of the eyelid that is arranged perpendicular to the main connecting rod (25). The two ends of the first ball joint connecting rod (251) of the eyelid are respectively spherically hinged to two sets of second ball joint connecting rods (252) of the eyelid. The ends of the two sets of second ball joint connecting rods (252) of the eyelid are respectively spherically hinged to the upper eyelid (22) and the lower eyelid (23). When the main connecting rod (25) of the eyelid is driven by the linkage servo motor (80) to move linearly, it drives the upper eyelid (22) and the lower eyelid (23) to rotate through the first ball joint connecting rod (251) and the second ball joint connecting rod (252).

8. A bionic robot head mechanism according to claim 6, characterized in that, An eyeball fixed shaft (244) is provided inside the eyeball body (24) and arranged parallel to the main connecting shaft (241) of the eyeball. The first driving link (26) of the eyeball is spherically hinged to the eyeball fixed shaft (244) through the eyeball universal joint (245). When the first driving link (26) of the eyeball is driven by the linkage servo motor (80) and moves linearly, it drives the eyeball body (24) to pitch and rotate through the eyeball fixed shaft (244). The main connecting shaft (241) of the eyeball is equipped with a second vertical shaft (243) of the eyeball arranged parallel to the first vertical shaft (242) of the eyeball. The second driving link (27) of the eyeball is rotatably engaged with the second vertical shaft (243) of the eyeball, and the axis of rotation is parallel to the axis of rotation of the main connecting shaft (241) of the eyeball. When the second driving link (27) of the eyeball is driven by the linkage servo motor (80) and moves linearly, it drives the main connecting shaft (241) of the eyeball to rotate around the first vertical shaft (242) of the eyeball. When the eyeball body (24) rotates left and right and / or pitches, the linkage servo (80) corresponding to the first drive link (26) and the second drive link (27) of the eyeball moves synchronously to form position compensation.

9. A bionic robot head mechanism according to claim 4, characterized in that, The pull-cord servo (70) includes a servo linkage (701) driven to rotate by the servo and a guide sleeve (702) corresponding to the position of the servo linkage (701); the rotation axis of the servo linkage (701) is arranged vertically, and a pull cord (703) is connected to the end of the servo linkage (701) away from the rotation axis. The pull cord (703) passes through the guide sleeve (702) and is connected to the corresponding skin area. The patch includes an eyebrow patch (11) and a mouth patch (41). There are four sets of eyebrow patches (11), with each pair of eyebrow patches (11) corresponding to the two ends of the eyebrow. There are six sets of mouth patches (41), with three sets of mouth patches (41) arranged on the upper lip and the lower lip respectively. Each patch has barbs on its surface, and the corresponding skin area has a groove that engages with the barbs on the patch surface for positioning.

10. A bionic robot head mechanism according to any one of claims 1 to 3, characterized in that, The head mechanism is fixed on the rotary platform (50) and rotates synchronously with the rotary platform (50). It also includes a pitch platform (60) for supporting the rotary platform (50). The pitch platform (60) includes a mounting base (61) on which two parallel four-bar linkages are configured. Two sets of horizontally arranged pitch first shafts (63) and pitch second shafts (64) are mounted on the mounting base (61). The pitch first shaft (63) and pitch second shaft (64) are respectively equipped with a first shaft gear (631) and a second shaft gear (641) that mesh with each other. A driven gear (612) is installed on the shaft end of the pitch first shaft (63) or the pitch second shaft (64). A driving gear (611) is fixed on the motor shaft of the pitch drive motor (66) on the mounting base (61). The driving gear (611) and the driven gear (612) mesh with each other. A linear first pivot link (632) is coaxially fixed on the first pivot (63), and a first arc link (62) is rotatably mounted on the mounting base (61). The mounting base (61), the first pivot link (632), the first arc link (62) and the rotary platform (50) cooperate to form an upper parallel four-bar linkage mechanism. A linear second shaft link (642) is coaxially fixed on the second pitch shaft (64), and a second arc-shaped link (65) is rotatably mounted on the mounting base (61). The mounting base (61), the second shaft link (642), the second arc-shaped link (65) and the base of the pitch platform cooperate to form a lower parallel four-bar linkage mechanism. While the active gear (611) rotates, it drives the upper and lower parallel four-bar linkages to move synchronously through gear transmission to simulate the flexion and sway of the cervical spine.

11. A bionic robot head mechanism according to any one of claims 1 to 3, characterized in that, The skin layer is configured to be elastic and is connected to at least one set of facial components in the head mechanism by an adhesive to form a basic facial appearance. The facial components include any one of a head shell, eyelids, and nasolabial fold components. Each facial component has an interlocking structure on its surface opposite to the skin layer. The interlocking structure includes at least one recess for receiving the adhesive and / or a protrusion for embedding in the recess, so that a mechanical lock is formed between the facial component and the skin layer in at least two directions.

12. A bionic robot head mechanism according to any one of claims 1 to 3, characterized in that, The nasolabial fold assembly and / or the structure connected to the nasolabial fold assembly are made of flexible or drivable deformable materials, including but not limited to at least one of silicone, silicone rubber, programmable robotic materials, liquid crystal elastomers, electroactive polymers, and shape memory alloys.

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