The structure of the cervical node of an anthropomorphic robot

Abstract

The utility model pertains to spherical manipulators capable of implementing plane-parallel kinematics. The neck unit of the anthropomorphic robot comprises a movable upper platform and a fixed lower base on which six servomotors are mounted. The shaft of each servomotor is connected to the shaft of the pusher of each of the six rods. The ends of each rod are equipped with a lower and upper gimbal joint. The connection of the upper gimbal joint with the fastening element on the upper platform forms the upper rod mount. The connection of the lower gimbal joint with the pusher forms the lower rod mount. The lower rod mounts are arranged in pairs on the fixed lower base. The upper rod mounts are arranged in pairs on the upper movable platform. The angles between the pairs of mounts on the lower base and the angles between the pairs of mounts on the upper movable platform are 120° relative to the central vertical axis of the device.The upper mount of each rod is offset from its lower mount by 60° relative to the central vertical axis of the device. Pairs of upper mounts are formed by the ends of the lower mount rods from adjacent pairs. This allows for an increased number of movements. 12 figs.

Description

[0001] This utility model relates to robotics, specifically to spherical manipulators capable of implementing plane-parallel kinematics. It can be used in the design of a robot that imitates human movements, for moving the robot's head assembly in space.

[0002] A bionic robot head and neck structure is known from international patent application WO 2025065774, B25J 11 / 00, 2025. The neck structure is used to control the head structure to provide forward and backward tilting, left and right rotation, and circular motion. The neck structure includes a bionic neck mechanism, which consists of a head base, a head connecting element, a body base, a body connecting element, a fixing neck connecting rod, a rotation module, a tilt module, and a steering module. The lower end of the neck connecting rod is fixedly connected to the base of the body end, and the upper end of the neck connecting rod is movably connected to the lower part of the head end base. The rotation drive module is connected to the head end base and drives the head end base and the head end connecting socket, synchronously rotating them left and right.The tilt drive module is connected to the head end base and drives the head end base and the head end connector, synchronously tilting them forward and backward. The steering drive module is connected to the head base and the head connector seat, allowing the head connector seat to rotate about its axis relative to the head base. The neck locking link is equipped with a spring and a spring stop located under the head base. The spring stop is rigidly connected to the locking link, the upper end surface of the spring rests against the head base, and the lower end surface of the spring rests against the spring stop. A disadvantage is the limited range of head movements that can be reproduced using the bionic robot's neck design.

[0003] A device for the head and neck of a humanoid robot with a self-stabilization function is known under China Patent for Invention CN 16079719, B25J 19 / 02, 2023. The device comprises a neck movement mechanism, a camera unit, and a control unit. The neck movement mechanism comprises an upper platform and a lower platform. The camera unit is mounted on the upper platform of the neck movement mechanism. The control unit comprises a processor, a controller, and an inertial sensor. The inertial measurement unit (IMU) is mounted under the lower platform of the neck movement mechanism. The neck movement mechanism is fixed to the torso of the humanoid robot. The inertial measurement unit (IMU) determines the three-axis angular velocity and acceleration at the junction between the neck movement mechanism and the torso, calculates the change in position at the junction, transmits the change information to the processor, calculates the movement mode of the neck movement mechanism, and transmits it to the controller.A spherical structure is located in the center of the neck movement mechanism under the upper platform, and a linear support shaft is mounted above the lower platform. The linear support shaft is connected to a stepper motor, which is mounted centrally above the lower platform. The stepper motor and three linear actuators are located around the perimeter and connected to a controller. The neck movement mechanism is attached to the torso of the humanoid robot. The linear actuator is connected to the upper and lower platforms via a ball head and ball socket. The stepper motor drives a hinged structure that moves along the Z-axis. The linear support shaft contains a shock-absorbing spring, which is mounted between the hinged structure and the lower platform. Together, the three linear actuators provide arc motion for the upper platform.The disadvantage is that the neck movement mechanism allows for movements with a small number of degrees of freedom, specifically four degrees of freedom: yaw, pitch, roll, and movement along the Z-axis.

[0004] The closest analogue to the claimed technical solution is the neck mechanism of a robot that imitates human facial expressions, according to Chinese patent CN 110103234, B25J 11 / 00, 2019. The neck mechanism is fixed to a supporting base plate. The base of the neck mechanism is stationary. The stationary plate is connected to the base via a support cylinder. A rotary servo drive is installed in the support cylinder, while three rotary servo drives and a stationary platform are located on the stationary plate. The stationary platform is connected to the rotary servo drive via a lower connecting rod. The movable platform is connected to the upper connecting rod, and the upper connecting rod is connected to the lower connecting rod via a ball joint mechanism. The movable platform is connected to a platform for connecting to the head mechanism. A universal shaft is installed between the connecting platform and the rotary servo drive.Head rotation can be achieved by transmitting torque through a universal shaft, while tilt and lateral rotation of the head can be achieved by coordinating the drive of three rotary servos. The neck mechanism can rotate horizontally, swivel left and right, and tilt forward and backward relative to the supporting base plate. A drawback is the mechanism's limited degrees of freedom, resulting in stiff and unrealistic robotic movements.

[0005] The technical objective of the utility model is to expand the arsenal of means related to the cervical nodes of anthropomorphic robots.

[0006] The technical result of the utility model is the implementation of this purpose by creating a device for the neck unit of the robot with an increased number of movements performed.

[0007] The technical result is achieved due to the fact that in the device of the neck unit of a robot simulating human movements, containing a movable upper platform and a lower fixed base on which servo drives are mounted, connected to rods pivotally connected to the movable upper platform, according to the utility model, six servo drives are mounted on the fixed base, the shaft of each servo drive is connected by a belt drive to the shaft of the pusher of each of the six rods, the ends of each rod are provided with a lower and upper cardan joint, the connection of the upper cardan joint with the fastening element on the upper platform forms the upper fastening of the rod, the connection of the lower cardan joint with the pusher forms the lower fastening of the rod, the lower fastenings of the rods are located in pairs on the lower fixed base, the upper fastenings of the rods are located in pairs on the upper movable platform,the angles between the pairs of fasteners on the lower base and the angles between the pairs of fasteners on the upper movable platform are 120° relative to the central vertical axis of the device, the upper fastener of each rod is offset from its lower fastener by an angle of 60° relative to the central vertical axis of the device, the pairs of upper fasteners are formed by the ends of the rods of the lower fasteners from adjacent pairs.

[0008] The technical result is achieved through the use of six servo drives mounted on a fixed base, each connected to a single rod connected to the moving platform. Each servo drive pushes the rod attached to its axis via a belt drive, resulting in the spatial position of the moving platform being determined by the codependent position of each servo drive. This ensures the organization of a kinematic connection within the structure based on the principle of transmitting position and torque according to the servo drive-rod-seal diagram on the moving platform. Using six such connections in pairs allows for a closed kinematic circuit comprising six degrees of freedom, unlike similar systems, which represent a linear kinematic circuit with three or four degrees of freedom.The arrangement of the rod mount pairs on both the fixed base and the moving platform at an angle of 120° to each other relative to the central vertical axis of the device, and the offset of the upper mount of each rod from its lower mount by 60° relative to the central vertical axis of the device, allows for an expanded range of motion for the moving platform due to this arrangement and the codependent position of the shaft of each servo drive. The use of cardan joints at the ends of each rod ensures freedom of movement with the codependent motion of all six rods, enabling linear movements, tilts, and rotations, ensuring high mobility of the mounted object.Thus, the use of six servo drives, angular displacements of the ends of each rod, the use of cardan joints in the rods makes it possible to create a closed kinematic chain with six degrees of freedom and ensure the movement in space of the upper movable platform along three axes X, Y, Z linearly and ensure the possibility of its rotation Rx, Ry, Rz, around these axes.

[0009] Fig. 1 shows a general view of the neck unit of the anthropomorphic robot in the basic position.

[0010] Fig. 2 shows a frontal view of the neck unit of the anthropomorphic robot in the basic position.

[0011] Fig. 3 shows a top view of the neck unit device of the anthropomorphic robot in the basic position.

[0012] Fig. 4 shows a top view of the neck unit of the anthropomorphic robot when turning left.

[0013] Fig. 5 shows a frontal view of the neck unit of the anthropomorphic robot when leaning forward.

[0014] Fig. 6 shows a frontal view of the neck unit device of the anthropomorphic robot when tilted backward.

[0015] Figure 7 shows a frontal view of the neck unit device of the anthropomorphic robot when tilted to the right.

[0016] Figure 8 shows a frontal view of the neck unit device of the anthropomorphic robot when tilted to the left.

[0017] Fig. 9 shows a side view of the neck unit device of the anthropomorphic robot during lifting.

[0018] Fig. 10 shows a side view of the neck unit device of the anthropomorphic robot during descent.

[0019] Fig. 11 shows a side view of the neck unit device of the anthropomorphic robot during forward movement.

[0020] Fig. 12 shows a side view of the neck unit device of the anthropomorphic robot when moving backward.

[0021] The device of the neck unit of the anthropomorphic robot comprises a lower fixed base 1, intended for attachment to the body of the robot, a movable upper platform 2, intended for attachment of the robot head unit to it, six servo drives 3 mounted on the lower fixed base 1. Each servo drive 3 is connected to one of the rods 4, 5, 6, 7, 8, 9. The servo drive 3 is connected to the corresponding rod by means of a belt drive. Belt 10 transmits rotation from shaft 11 of each servo drive 3 to shaft 12. A pusher 13, made in the form of a curvilinear lever, is fixed on shaft 12. Each belt transmission is provided with a tensioner 14 of the belt 10. Each of the six rods is provided with an upper cardan joint 15 and a lower cardan joint 16. The upper end of each of the six rods is pivotally fixed to the lower surface of the movable upper platform 2, and the lower end of each of the six rods is pivotally fixed to the surface of its pusher 13.The ends of the rods are secured in pairs; the angles between the pairs of rod fastenings on the lower fixed base 1 are 120° relative to the central vertical axis of the device, and the angles between the pairs of fastenings on the movable upper platform 2 are 120° relative to the central vertical axis of the device. On the movable upper platform, two pairs of upper fastenings are rotated relative to the pairs of lower rod fastenings by 60° relative to the central vertical axis of the device. The lower ends of the rods form one pair on the lower base 1, and on the upper movable platform 2, the upper ends of these same rods diverge along two adjacent upper pairs. Moreover, the rods of one lower pair are deflected at the top in opposite directions relative to the vertical axis. On the lower fixed base 1, the first pair of lower rod fastenings are rod fastenings 4 and 5, the second lower pair are rod fastenings 6 and 7, and the third lower pair are rod fastenings 9 and 8.On the upper movable platform, 2 pairs of fastenings are formed by the ends of other rods, one upper pair are fastenings of rods 5 and 8, the second upper pair are fastenings 4 and 6, the third upper pair are fastenings 7 and 9. Thus, the places of termination of pairs of rods on the base 1 are shifted by 60º relative to the places of termination of rods on the movable platform 2. Fastening of the ends of six rods on the lower fixed base 1 and on the upper movable platform 2, the above-described arrangement of fastenings of the ends of the rods and the use of cardan joints at the ends of the rods makes it possible to create a closed kinematic scheme of the device with six degrees of freedom.

[0022] The device of the neck unit of the anthropomorphic robot works as follows.

[0023] When a specific movement is required, the robot's control system sends a signal to each of the six servo drives 3 to execute a specific algorithm. The operating algorithm for servo drives 3 is based on kinematic formulas for a given closed kinematic chain. Each servo drive 3 pushes the rod attached to its axis via a belt drive. Codependent changes in the rotation angles of the axes 11 of the output shafts of servo drives 3 ensure the mechanics of the unit's task execution by transmitting a specific motion to each pusher 13 of each rod. The operation of cardan joints 15 and 16 codependently changes the positions of the rods in space and alters the position of the movable upper platform 2, which serves as the mounting platform for the robot's head.The closed kinematics of the unit enables three degrees of linear movement and three degrees of rotation, such as roll, pitch, and rolling. The combination of these degrees of freedom enables plane-parallel movement of the upper platform and linear changes in the unit's geometry. Codependent changes in the spatial positions of the robot's neck unit elements enable the following movements of the movable upper platform 2: left turn, right turn, forward tilt, backward tilt, right tilt, left tilt, ascent, vertical descent, forward movement, backward movement, tilt down and up, right and left turns, tilt with rotation, and forward and backward extension. All these possible movements enable the upper movable platform 2 to be moved linearly along three axes (XYZ) and to rotate along the same axes (RxRyRz).Thus, the design of the proposed neck unit combines three types of mechanical actuators—radial, linear, and spherical—allowing the upper movable platform 2 to be positioned in any position within the work area, enabling more precise and smooth manipulation of the object secured to the upper movable platform 2. Furthermore, the interconnected operation of the servo drives and rods prevents excess equilibrium forces, reducing the load on the drives and increasing the durability of the structure. By distributing the forces across multiple attachment points, the structure can withstand heavy loads while maintaining compact dimensions.

[0024] Thus, the utility model makes it possible to expand the arsenal of means related to the cervical nodes of anthropomorphic robots, to increase the mobility of the node by increasing the number of possible realistic movements that are closest to human movements.

Claims

A device for the neck unit of an anthropomorphic robot, comprising a movable upper platform and a lower fixed base on which servo drives are mounted, connected to rods that are pivotally connected to the movable upper platform, characterized in that six servo drives are mounted on the fixed base, the shaft of each servo drive is connected to the shaft of the pusher of each of the six rods, the ends of each rod are provided with a lower and an upper cardan joint, the connection of the upper cardan joint with the fastening element on the upper platform forms the upper rod fastening, the connection of the lower cardan joint with the pusher forms the lower rod fastening, the lower rod fastenings are arranged in pairs on the lower fixed base, the upper rod fastenings are arranged in pairs on the upper movable platform, the angles between the pairs of fastenings on the lower base and the angles between the pairs of fastenings on the upper movable platform are 120° relative to the central vertical axis of the device,the upper fastening of each rod is offset from its lower fastening by an angle of 60° relative to the central vertical axis of the device; the pairs of upper fastenings are formed by the ends of the rods of the lower fastenings from adjacent pairs.

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