Double-wheel omnidirectional humanoid robot and control method thereof

Abstract

The invention discloses a double-wheel omni-directional humanoid robot and a control method thereof. The double-wheel omni-directional humanoid robot comprises a head display and sensing assembly, a robot body assembly, mechanical arm assemblies in bilateral symmetry, an electric rising and falling supporting frame and a double-wheel inverted pendulum omni-directional moving chassis. The double-wheel inverted pendulum omni-directional moving chassis comprises a gear connecting rod cooperative steering mechanism, flexible posture adjustment of wheels is achieved through linkage of a driving gear and a synchronous connecting rod, a main controller of a fuselage main body assembly constructs a unified dynamics control frame, coupling angle compensation is introduced to solve the problem of torque projection attenuation, and an electric rising and falling supporting frame has a dead point self-locking function. The parking safety is ensured. According to the invention, traditional limitation is broken through, omni-directional motion and anthropomorphic operation are fused, and complex scene adaptability, attitude stability and trajectory tracking precision are improved.

Description

Technical Field

[0001] This invention relates to the field of two-wheeled humanoid robot technology, and in particular to a two-wheeled omnidirectional humanoid robot and its control method. Background Technology

[0002] With the widespread application of service robots and intelligent mobile equipment in industries such as manufacturing, warehousing, healthcare, and public services, the demand for efficient mobility of mobile robots in complex, dynamic, and confined spaces is becoming increasingly prominent. Among the many types of mobile robots, wheeled mobile robots have become the most widely used type due to their significant advantages such as simple structure, high energy efficiency, and convenient control. Mature technological systems have been developed in areas such as multi-wheel differential speed, independent steering, and omnidirectional movement. Omnidirectional movement technology is particularly crucial, as it enables movement in any direction without changing the robot's orientation, greatly improving the robot's mobility in confined spaces and providing strong support for robot applications in various complex scenarios.

[0003] Among the various configurations of wheeled mobile robots, the two-wheeled inverted pendulum robot has attracted widespread attention due to its unique advantages. It possesses dynamic balancing capabilities, a compact structure, a small footprint, and flexible movement. Employing a parallel two-wheel structure, it can achieve self-balancing control and basic movements such as forward, backward, and turning in place by adjusting the body's pitch attitude and wheel speed in real time. For example, Chinese Patent Publication No. CN203698533U discloses a two-wheeled balancing vehicle with a frame structure. This vehicle uses a frame structure and a three-dimensional coordinate design, dividing the balancing vehicle into three major systems that form a cohesive whole, improving its ability to overcome external obstacles. Another example is Chinese Patent CN209467267U, which proposes a two-wheeled coupled omnidirectional inverted pendulum mobile platform. This platform uses a parallel four-bar linkage to rigidly and synchronously connect the steering shafts of the left and right wheels, ensuring that the steering angles of the two wheels change at a strictly equal amplitude. With only two drive motors, it achieves steering assistance through differential speed, realizing the omnidirectional movement capability of the two-wheeled inverted pendulum robot within a plane. However, the above technologies all have shortcomings. Their steering mechanisms lack active driving force constraints, and the steering of the wheels is easily affected by external impacts, load changes, and other factors, resulting in poor trajectory maintenance and anti-interference performance.

[0004] Furthermore, deeply integrating a two-wheeled inverted pendulum chassis with a multi-degree-of-freedom robotic arm to construct a wheeled inverted pendulum humanoid robot capable of performing tasks in a dynamic equilibrium state has become an important development direction. For example, a two-wheeled delivery robot disclosed in Chinese patent CN108466250B, while improving the robot's endurance, mobility, and disturbance resistance in complex working conditions, uses a traditional two-wheeled differential drive method, limiting the wheel's degree of freedom and lacking omnidirectional mobility. This restricts its spatial adaptability and operational flexibility in narrow spaces and environments with dense obstacles.

[0005] Currently, the field of two-wheeled inverted pendulum humanoid robots in China is still in the early exploratory stage, and the maturity of the technology and its adaptability to different scenarios need to be improved. There are no publicly available mature technologies for two-wheeled inverted pendulum humanoid robots that can simultaneously have omnidirectional mobility and humanoid upper limb manipulation functions. Related technology combinations and integrated implementation solutions represent a clear research gap in this field. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a two-wheeled omnidirectional humanoid robot and its control method, which can flexibly switch chassis motion modes, break the limitations of non-holonomic constraints, and create a unified dynamic control framework to solve the problem of omnidirectional steering drive torque projection attenuation.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A two-wheeled omnidirectional humanoid robot includes a head display and sensing component, a main body component, a left-right symmetrical robotic arm component, an electric lifting support frame, and a two-wheeled inverted pendulum omnidirectional moving chassis.

[0009] The dual-wheeled inverted pendulum omnidirectional moving chassis is located at the bottom of the robot. The main body assembly is fixedly installed at the top center of the dual-wheeled inverted pendulum omnidirectional moving chassis. The robotic arm assembly is symmetrically hinged to both sides of the main body assembly through a shoulder joint drive assembly. The head display and sensing assembly is rotatably connected to the top of the main body assembly through a head pitch-yaw composite drive assembly. The electric lifting support frame is arranged inside the main body assembly and is fixedly connected to the dual-wheeled inverted pendulum omnidirectional moving chassis.

[0010] The dual-wheel inverted pendulum omnidirectional moving chassis includes a top frame assembly, a rotary actuator assembly, and symmetrical tire assemblies. The rotary actuator assembly is integrated between the top frame assembly and the tire assemblies and includes an active steering drive unit, a synchronous power distribution transmission unit, a synchronous constraint linkage unit, and symmetrical rotary shaft assemblies. The symmetrical rotary shaft assemblies are respectively fixed to the corresponding tire assemblies, and each rotary shaft assembly includes a force-driven end and a driven linkage end. The active steering drive unit is connected to the force-driven ends of the two rotary shaft assemblies through the synchronous power distribution transmission unit, and the two ends of the synchronous constraint linkage unit are respectively connected to the force-driven ends and driven linkage ends of the left and right rotary shaft assemblies.

[0011] Furthermore, the main body component is provided with a rigid space frame structure. The upper part of the rigid space frame structure is provided with a mounting plate for installing the shoulder drive motor of the robotic arm, and the lower part is fixed to the dual-wheel inverted pendulum omnidirectional moving chassis through a bottom fixing component. The outer shell of the rigid space frame structure is installed to form a closed cavity, and the main controller, power management module and communication module are arranged inside.

[0012] Furthermore, the robotic arm assembly includes a shoulder assembly, an upper arm assembly, and a forearm assembly; the shoulder assembly is equipped with a shoulder rotation drive motor and a shoulder left and right swing motor; the upper arm assembly is equipped with an elbow joint rotation motor and a forward and backward swing motor; the forearm assembly has an end gripper fixed at its front end, and each motor is electrically connected to the main controller; the head display and sensing assembly has a human-machine interaction display screen on its front side and a camera assembly on its top; the head pitch-yaw composite drive assembly includes a head yaw drive motor with its output shaft arranged vertically and a head pitch drive motor with its output shaft arranged horizontally.

[0013] Furthermore, the electric lifting support frame includes a crank-slider mechanism assembly and a two-section retractable support linkage mechanism symmetrically arranged on both sides of the frame;

[0014] The crank-slider mechanism assembly includes a lifting support drive motor, a motor mounting bracket, a slide rail mounting bracket, a slider, and a slide rail. The motor mounting bracket and the slide rail mounting bracket are fixedly connected by multiple aluminum columns and are also fixedly connected to a double-wheel inverted pendulum omnidirectional moving chassis. A rocker arm is fixedly connected to the output end of the lifting support drive motor. The rocker arm is hinged to a connecting rod via a rotating shaft. The other end of the connecting rod is hinged to a slider fixing rod. The slider fixing rod is fixedly connected to the slider. The slider is adapted to be installed on a vertical slide rail on the slide rail mounting bracket.

[0015] The two-section retractable support linkage mechanism includes an end support rod, multiple intermediate rods, and a middle support hinge. The middle support hinge is fixed to the slide rail fixing bracket and corresponds to the middle position of the multiple intermediate rods. One end of the multiple intermediate rods is hinged to a slider fixing long rod, the middle is hinged to the middle support hinge, and the other end is hinged to the end support rod.

[0016] Furthermore, the tire assembly includes upper and lower axle brackets and two drive wheels of integrated hub motors. The drive wheels of the integrated hub motors are clamped and fixed by the upper and lower axle brackets. The upper and lower axle brackets are respectively fixedly connected to the force-driven end and the driven linkage end of the corresponding rotating shaft assembly.

[0017] Furthermore, the top frame assembly of the dual-wheel inverted pendulum omnidirectional moving chassis comprises a chassis top upper cover plate, a chassis top lower cover plate, at least one top vertical support member, and a middle vertical support member forming a closed structure. The battery pack, power management circuit, and balance control board are arranged inside the top frame assembly. The rotary actuator assembly also includes upper and lower mounting plates for the rotary mechanism and front and rear rotary mechanism supports. The upper mounting plate for the rotary mechanism is fixed to the middle vertical support member of the dual-wheel inverted pendulum omnidirectional moving chassis, and the upper and lower mounting plates are fixedly connected through the front and rear rotary mechanism supports.

[0018] Furthermore, the active steering drive unit is an active gear rotary drive motor, the synchronous power distribution transmission unit is an active pinion, the force-driven end is a driven large gear, the driven linkage end is a lower gear rotating plate, and the synchronous constraint linkage unit is a synchronous connecting rod; the rotating shaft assembly also includes a rotating shaft, upper and lower bearing seats, upper and lower angular contact bearings, upper and lower bushings, a lower gear rotating plate, a support bushing between the gear and the rotating plate, and a fastening nut; the lower bearing seat is fixedly mounted on the lower mounting plate of the rotating mechanism, and the inner hole of the lower bearing seat is fitted with the outer ring of the lower angular contact bearing. The rotating shaft is arranged vertically and its lower end mates with the inner ring of the lower angular contact bearing. From bottom to top, the rotating shaft is fitted with a lower bushing, a lower gear rotating plate, a support bushing between the gear and the rotating plate, and a driven large gear. The lower gear rotating plate and the driven large gear are circumferentially fitted with the rotating shaft via a keyway. The upper part of the rotating shaft is fitted with an upper bushing, an upper angular contact bearing, and an upper bearing seat. The outer ring of the upper angular contact bearing mates with the inner ring of the upper bearing seat. The upper bearing seat is fixedly connected to the upper mounting plate of the rotating mechanism. The upper end of the rotating shaft is fixedly connected to the upper mounting plate of the rotating mechanism via a fastening nut.

[0019] A control method for a two-wheeled omnidirectional humanoid robot, wherein the robot adopts a composite closed-loop control architecture of feedforward compensation and variable parameter state feedback, and runs a unified dynamics control algorithm based on a non-coaxial inverted pendulum model; the specific steps include:

[0020] S1: For a non-coaxial inverted pendulum system with actively steerable wheels, based on the geometric positional relationship between the fuselage center of mass, the wheel steering axle center, and the wheel contact point, a unified mapping relationship from the steering configuration to the equivalent drive channel of the inverted pendulum is constructed, and the influence of wheel steering attitude change on the balance control channel is characterized as configuration parameters.

[0021] S2: Real-time calculation of the geometric deviation angle between the actual movement direction of the wheels and the pitch control direction of the fuselage, and defining the geometric deviation angle as the coupling angle. The driving torque is compensated by the coupling angle. At the same time, one or two of the coupling angle and the configuration parameters are introduced into at least one of the system driving matrix, control gain, feedforward compensation term and feedback adjustment term to compensate for the driving torque projection attenuation problem during omnidirectional steering, suppress the dynamic parameter drift caused by wheel steering, and ensure the attitude stability of the robot during the configuration change process.

[0022] S3: By receiving the robot speed control target command, posture balance control target command and the robot drive actuator motion control target command, compare and calculate them one by one with the real-time robot status data fed back by the synchronously collected inertial sensors, angle sensors and motor encoders to obtain the error signals of each control dimension.

[0023] S4: Based on the error signal, a driving torque command is dynamically generated by combining feedforward compensation and variable parameter state feedback algorithms. The driving torque command drives the actions of each actuator to achieve system attitude correction and omnidirectional trajectory tracking. The driving torque command includes at least one of the following: the speed command and torque command of the drive wheels, and the position command and angle command of the chassis steering actuator.

[0024] Furthermore, in the aforementioned feedforward compensation and variable parameter state feedback composite closed-loop control architecture, the feedforward compensation term pre-calculates the compensation torque based on the coupling angle and configuration parameters to offset the projection attenuation of the driving torque during omnidirectional steering; the variable parameter state feedback term dynamically adjusts the control gain and output based on the real-time error signal to correct the robot's posture deviation in real time; the control parameters of both are dynamically and adaptively adjusted according to the wheel steering configuration, so that the non-coaxial inverted pendulum system maintains a balance margin and dynamic response characteristics similar to those of the coaxial configuration in omnidirectional motion modes such as forward, lateral, and oblique movements.

[0025] Further, in step S2, the coupling angle is the angle between the wheel motion direction axis Zr and the fuselage pitch control axis Zc, and its analytical expression is: ;in, This represents the geometric offset distance from the fuselage's center of gravity to the center of the wheel steering axle. This indicates the structural outer distance from the wheel steering axle to the wheel's center of gravity. The wheel steering angle is the dynamic parameter drift caused by the dynamic change in the geometric relationship between the fuselage center of mass, steering shaft and wheel contact point during wheel steering, resulting in the drift of at least one of the following parameters: inverted pendulum equivalent driving parameter, moment of inertia and torque transmission coefficient.

[0026] The present invention has the following beneficial effects:

[0027] 1. This invention achieves an integrated design that combines omnidirectional mobility with a humanoid upper body, breaking through the dual limitations of mobility and working space of traditional two-wheeled inverted pendulum robots. Through a gear-linkage steering mechanism, the wheel posture is flexibly adjusted, allowing the robot to switch between differential cruising, omnidirectional translation, and lateral movement through extremely narrow spaces simply by adjusting the wheel angle, while maintaining a constant body orientation and stable posture. Specifically, when moving forward / backward, both wheels rotate at the same speed; when moving diagonally, gear meshing and synchronous linkage achieve equal-angle turning of the two wheels; and when moving laterally, after completing a 90° turn, it enters narrow passages via lateral translation. This design effectively solves the problem of limited mobility in traditional humanoid robots, significantly enhancing the system's attitude robustness during nonlinear configuration changes while maintaining the high energy efficiency and compact structure of the inverted pendulum system.

[0028] 2. This invention constructs a unified dynamic control framework for a variable-topology non-coaxial inverted pendulum system. Through a geometric deviation decoupling algorithm, it effectively overcomes the problem of instability caused by the projection decay of the driving torque due to the variable configuration. By using feedforward compensation and cooperative gain adjustment for the driving effectiveness under different steering postures in the control algorithm, the non-coaxial inverted pendulum system can maintain a consistent balance margin and dynamic response characteristics similar to those of a coaxial configuration in various omnidirectional motion modes such as forward, lateral, and oblique movements. This technology not only ensures the robustness of the robot under all working conditions but also provides a general theoretical paradigm for the precise control of the non-coaxial inverted pendulum system.

[0029] 3. The electric lifting support frame design of this invention, featuring a dead-point self-locking function, significantly improves the robot's maneuverability and interactive operation range in complex dynamic environments while ensuring safe parking and disturbance-resistant operation of the high-center-of-gravity humanoid robot. Specifically, a crank-slider mechanism converts the motor's rotational motion into linear motion of the slider. A two-stage retractable support linkage mechanism enables the synchronous retraction or extension of the end support rod. When the frame is at its fully retracted or fully lowered extreme position, the mechanism is in a dead-point state, preventing displacement even when external loads are applied vertically. Combined with the real-time processing of feedback signals from attitude sensors and wheel speed encoders by the main controller, a composite closed-loop control architecture including feedforward compensation and variable parameter state feedback is formed, ensuring the robot's posture stability and accurate trajectory tracking capability during omnidirectional movement mode switching. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the overall structure of the gear-linkage cooperative steering non-coaxial inverted pendulum dual-wheel omnidirectional humanoid robot of the present invention (viewpoint 1).

[0032] Figure 2 This is a schematic diagram of the overall structure of the gear-linkage coordinated steering non-coaxial inverted pendulum dual-wheel omnidirectional humanoid robot of the present invention (viewpoint 2).

[0033] Figure 3 This is a schematic diagram of the main body structure of the gear-linkage coordinated steering non-coaxial inverted pendulum double-wheel omnidirectional humanoid robot of the present invention;

[0034] Figure 4 This is a schematic diagram of the gear and linkage coordinated steering non-coaxial inverted pendulum dual-wheel omnidirectional humanoid robot head pitch-yaw composite drive assembly of the present invention.

[0035] Figure 5 This is a schematic diagram of the gear and linkage coordinated steering non-coaxial inverted pendulum double-wheel omnidirectional humanoid robot arm assembly of the present invention;

[0036] Figure 6 This is a complete part view of the gear-linkage coordinated steering non-coaxial inverted pendulum dual-wheel omnidirectional humanoid robot electric lifting and landing support frame of the present invention;

[0037] Figure 7 This is a schematic diagram of the electric lifting and lowering support frame for the gear-linkage coordinated steering non-coaxial inverted pendulum dual-wheel omnidirectional humanoid robot of the present invention;

[0038] Figure 8 This is a schematic diagram of the dual-wheeled inverted pendulum omnidirectional humanoid robot chassis for gear and linkage coordinated steering and non-coaxial inverted pendulum movement according to the present invention.

[0039] Figure 9 This is a diagram illustrating the position of the drive wheels of a two-wheeled inverted pendulum omnidirectional moving chassis when it moves forward or backward.

[0040] Figure 10 This is a diagram illustrating the position of the drive wheels of a two-wheeled inverted pendulum omnidirectional moving chassis during oblique movement.

[0041] Figure 11 This is a diagram illustrating the position of the drive wheels of a dual-wheeled inverted pendulum omnidirectional moving chassis during lateral movement.

[0042] Figure 12 An illustration of a two-wheeled inverted pendulum omnidirectional moving chassis performing a 90° turn to enter a narrow passage and move laterally during forward movement;

[0043] Figure 13 A schematic diagram showing the deployment of the electric lifting support frame;

[0044] Figure 14 This is a schematic diagram of the dynamic vector analysis of the non-coaxial inverted pendulum of the robot of the present invention when the configuration changes due to wheel steering;

[0045] Figure 15 This is a schematic diagram of the dynamic force analysis of a single wheel according to the present invention;

[0046] Figure 16 This is a diagram of a composite closed-loop control architecture that includes feedforward compensation and variable parameter state feedback according to the present invention.

[0047] In the diagram: 101. Head display and sensing component; 102. Main body component; 103. Left robotic arm component; 104. Right robotic arm component; 105. Electric lifting support frame; 106. Dual-wheel inverted pendulum omnidirectional moving chassis; 1. Camera component; 2. Human-machine interaction display screen; 3. Upper shell; 4. Lower shell; 5. Vertical profile; 6. Lateral profile; 7. First shoulder motor mounting plate; 8. Frame top cover plate; 9. Right-angle connecting plate; 10. Second shoulder motor mounting plate; 11. Lateral profile; 12. T-shaped connecting plate; 13. L-shaped profile bottom fixing piece; 14. Chassis top cover plate; 15. Head yaw drive motor; 16. Yaw motor output flange; 17. Intermediate connecting flange; 18. Cross-shaped neck brace; 19. Head pitch drive motor; 20. Pitch motor output flange; 21. Pitch drive connecting support; 22. Shoulder rotation drive motor; 23. Output shaft; 24. Bearing assembly; 25. Shoulder support vertical plate; 26. First shoulder support side plate; 27. Second shoulder support side plate; 28. Shoulder left and right swing motor; 29. ​​Left and right swing motor output flange; 30. Swing shaft; 31. First L-shaped motor connector; 32. Second L-shaped motor connector; 33. Elbow joint rotation motor; 34. Elbow joint rotation output flange; 35. Upper arm support horizontal plate; 36. Third L-shaped motor connector; 37. Upper arm support vertical plate; 38. Elbow forward and backward swing output flange; 39. Elbow 40. Front and rear swing motor; 41. Lower end plate of the boom support; 42. Fourth L-shaped motor connector; 43. Front and rear swing shaft; 44. End gripper mounting plate; 45. Shoulder rear housing; 46. Shoulder front housing; 47. Boom rear housing; 48. Boom lower housing; 49. Forearm upper housing; 50. Forearm lower housing; 51. End gripper; 52. Motor mounting bracket; 53. Lifting support drive motor; 54. First aluminum column; 55. Slide rail mounting bracket; 56. Second aluminum column; 57. Third aluminum column; 58. Fourth aluminum column; 59. Rocker arm; 60. Connecting rod; 61. Slider fixing long rod; 62. Slider; 63. Slide rail; 64. Middle support hinge; 65. First intermediate rod; 66. Second intermediate rod 67. Third intermediate rod; 68. Fourth intermediate rod; 69. End support rod; 70. Lower mounting plate of rotary actuator; 71. Lower bearing seat; 72. Lower angular contact bearing; 73. Lower bushing; 74. Lower gear rotating plate; 75. Support bushing between gear and rotating plate; 76. Driven large gear; 77. Rotary shaft; 78. Upper bushing; 79. Upper angular contact bearing; 80. Upper bearing seat; 81. Rotary shaft end fastening nut; 82. Upper mounting plate of rotary mechanism; 83. First middle vertical support; 84. First top vertical support; 85. Second top vertical support; 86. Third top vertical support; 87. Battery; 88. Fourth top vertical support; 89. Lower cover plate of chassis top; 90. Second middle vertical support;91. Drive gear rotary motor; 92. Drive gear drive flange; 93. Drive pinion; 94. Upper wheel axle bracket; 95. Drive wheel of integrated hub motor; 96. Lower wheel axle bracket; 97. Synchronous connecting rod; 98. Front rotation mechanism support; 99. Rear rotation mechanism support. Detailed Implementation

[0048] The technical solutions in the embodiments of the present invention will now be clearly and completely described 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.

[0049] like Figures 1 to 8 As shown, a two-wheeled omnidirectional humanoid robot and its control method include a head display and sensing component 101, a main body component 102, a left robotic arm component 103, a right robotic arm component 104, an electric lifting support frame 105, and a two-wheeled inverted pendulum omnidirectional moving chassis 106, with the chassis 106 located at the bottom of the robot. The main body component 102 is fixedly mounted at the top center of the chassis 106. The left robotic arm component 103 and the right robotic arm component 104 are symmetrically arranged on both sides of the main body component 102 and are hinged to the main body component 102 via shoulder joint drive components. The head display and sensing component 101 is mounted on the top of the main body component 102 and is rotatably connected to the main body component 102 via a head pitch-yaw composite drive component. The electric lifting support frame 105 is arranged in the internal central area of ​​the main body component 102 and is fixedly connected to the chassis 106.

[0050] The dual-wheel inverted pendulum omnidirectional moving chassis 106 includes a top frame assembly, a rotary actuator assembly, and left and right symmetrical tire assemblies;

[0051] The top frame assembly includes a chassis top cover plate 14, a first top vertical support member 84, a second top vertical support member 85, a third top vertical support member 86, a battery 87, a fourth top vertical support member 88, a chassis top lower cover plate 89, a first central vertical support member 83, and a second central vertical support member 90. The four top vertical support members are arranged around the chassis top cover plate 14 and the chassis top lower cover plate 89 and are fixedly connected. The battery 87 is arranged in the central area surrounded by the four top vertical support members. The two central vertical support members are fixedly installed on both sides of the lower part of the chassis top lower cover plate 89.

[0052] The rotary actuator assembly includes a lower mounting plate 70, an upper mounting plate 82, a drive gear rotary drive motor 91, a drive gear drive flange 92, a drive pinion 93, a synchronizing link 97, a left rotary shaft assembly, a right rotary shaft assembly, a front rotary mechanism support 98, and a rear rotary mechanism support 99.

[0053] The left and right rotating shaft assemblies are symmetrically and vertically arranged on both sides of the center of the double-wheel inverted pendulum omnidirectional moving chassis 106, and have the same structure. Taking the left rotating shaft assembly as an example, the left rotating shaft assembly includes a lower bearing seat 71, a lower angular contact bearing 72, a lower bushing 73, a gear lower rotating plate 74, a support bushing 75 between the gear and the rotating plate, a driven large gear 76, a rotating shaft 77, an upper bushing 78, an upper angular contact bearing 79, an upper bearing seat 80, and a rotating shaft end fastening nut 81. The lower bearing seat 71 is fixed to one side of the mounting plate 70 under the rotating mechanism, and its inner hole is connected to... The lower angular contact bearing 72 has an outer ring that mates with it; the rotating shaft 77 is arranged vertically, and its lower end mates with the inner ring of the lower angular contact bearing 72; the upper part of the lower angular contact bearing 72 is mounted on the rotating shaft 77 in sequence with a lower bushing 73, a lower gear rotating plate 74, a support bushing 75 between the gear and the rotating plate, and a driven large gear 76; keyways are provided on the lower gear rotating plate 74 and the driven large gear 76 and circumferentially mate with the rotating shaft 77; the upper part of the driven large gear 76 is mounted on the rotating shaft 77 in sequence with an upper bushing 78, an upper angular contact bearing 79, and an upper bearing seat 80; the upper end of the rotating shaft 77 mates with the upper angular contact bearing 79. 9. The inner ring of the upper angular contact bearing 79 mates with the inner hole of the upper bearing housing 80; the upper bearing housing 80 is fixedly connected to the upper mounting plate 82 of the rotating mechanism; the upper end of the rotating shaft 77 extending out of the upper mounting plate 82 of the rotating mechanism is threaded and connected by a fastening nut 81 at the end of the rotating shaft; the two sides of the upper mounting plate 82 of the rotating mechanism are fixedly installed with the first central vertical support 83 and the second central vertical support 90; the upper mounting plate 82 of the rotating mechanism and the lower mounting plate 70 of the rotating mechanism are fixedly connected by the front rotating mechanism support 98 and the rear rotating mechanism support 99; active The gear rotary drive motor 91 is fixedly mounted on the center position of the mounting plate 82 on the rotary mechanism; the output shaft end of the drive gear rotary drive motor 91 is fixed with the drive flange 92, and the drive flange 92 is fixedly connected to the drive pinion 93; the drive pinion 93 meshes with the driven large gear 76 of the left rotary shaft assembly and the right rotary shaft assembly respectively; the synchronous connecting rod 97 is arranged at the front position between the driven large gear 76 and the gear lower rotating plate 74, and its two ends are respectively hinged to the driven large gear 76 and the gear lower rotating plate 74 of the left rotary shaft assembly and the right rotary shaft assembly through small rotating shafts respectively;

[0054] The tire assemblies are symmetrically and vertically arranged on both sides of the center of the dual-wheel inverted pendulum omnidirectional moving chassis 106, and have the same structure. Taking the right tire assembly as an example, the right tire assembly includes an upper wheel axle bracket 94, a drive wheel 95 with an integrated hub motor, and a lower wheel axle bracket 96. The upper wheel axle bracket 94 and the lower wheel axle bracket 96 are fixedly connected by bolts and clamp the output shaft of the drive wheel 95 with the integrated hub motor. The upper wheel axle bracket 94 is fixedly connected to the driven large gear 76 in the right rotating shaft assembly. The lower wheel axle bracket 96 is fixedly connected to the gear lower rotating plate 74 in the right rotating shaft assembly. Each tire assembly includes an upper wheel axle bracket 94, a drive wheel 95 with an integrated hub motor, and a lower wheel axle bracket 96. The motor output shaft of the drive wheel 95 with the integrated hub motor is clamped by the upper wheel axle bracket 94 and the lower wheel axle bracket 96 and fixedly connected to the driven large gear 76 and the gear lower rotating plate 74 in the corresponding rotating shaft assembly, so as to realize the direct drive of the drive wheel 95 with the integrated hub motor and the integrated arrangement of the hub and steering shaft. The active gear rotary drive motor 91 and the two hub motors are controlled by their respective motor drivers. The motor drivers are connected to the main controller via a CAN bus. The main controller generates steering motor position commands and left and right hub motor speed / torque commands based on feedback signals from attitude sensors, wheel speed encoders, etc., thereby enabling the robot to move forward, backward, diagonally, laterally, and turn in place in multiple modes of omnidirectional motion.

[0055] This invention introduces an integrated design concept of a "non-coaxial inverted pendulum" at the chassis control level: as the gear-linkage steering mechanism drives the wheels to turn, the geometric relationship between the chassis center of mass, steering shaft, and wheel contact point changes synchronously. The same pair of drive wheels needs to simultaneously undertake both translational drive and self-balancing control functions under any steering posture. Therefore, based on structural analysis, this invention abstracts the influence of the steering configuration on the equivalent drive channel of the inverted pendulum into analytical configuration parameters, and establishes a unified mapping relationship from the mechanical configuration to the balance control channel. In the control algorithm, feedforward compensation and cooperative gain adjustment are performed on the drive effectiveness under different steering postures. Through the above method, the dual-wheel self-balancing omnidirectional moving chassis can maintain a consistent balance margin and dynamic response characteristics similar to the coaxial configuration in various omnidirectional motion modes such as forward, lateral, and oblique movements, thereby ensuring the stability and reliability of the overall machine attitude control while achieving omnidirectional maneuverability.

[0056] In this embodiment, a human-computer interaction display screen 2 is provided at the center of the front side of the head display and sensing component 101. A camera component 1 is provided at the top front side of the head display and sensing component 101 to acquire external image information and realize visual perception function. The head pitch-yaw composite drive component includes a head yaw drive motor 15 (its output shaft is arranged in the vertical direction), a yaw motor output flange 16, an intermediate connecting flange 17, a cross-shaped neck bracket 18, a head pitch drive motor 19 (its output shaft is arranged in the horizontal direction), a pitch motor output flange 20, and a pitch drive connecting support 21. The output shaft of the head yaw drive motor 15 is fixedly connected to the output flange 16 of the yaw motor and the cross-shaped neck bracket 18, respectively, so as to realize the torque transmission of the yaw drive; the head pitch drive motor 19 is installed on the top horizontal output end of the cross-shaped neck bracket 18, and its output shaft is fixedly connected to the pitch drive connecting support 21 through the pitch motor output flange 20; the top of the cross-shaped neck bracket 18 has a circular hole with an embedded bearing, which cooperates with the shaft end of the pitch drive connecting support 21; the pitch drive connecting support 21 has a planar structure for cooperating with the head base for installation, thereby realizing the pitch movement of the head.

[0057] The main body component 102 of this invention has an internal structural frame and an external upper shell 3 and a lower shell 4. The structural frame is formed by four vertical profiles 5, six lateral profiles 6, and four lateral profiles 11, which are fixed together by T-shaped connecting plates 12 and right-angle connecting plates 9. A frame cover plate 8 is fixedly installed on the upper part of the structural frame, and a first shoulder motor mounting plate 7 and a second shoulder motor mounting plate 10 are fixedly installed on the left and right sides of the structural frame, respectively, for supporting and positioning the drive motors of the left and right robotic arms. The bottom of the structural frame is fixed by four L-shaped profile bottom fasteners 1 located at the four corners. 3 is fixedly connected to the top cover plate 14 of the chassis; the upper shell 3 and the lower shell 4 are detachably connected to the structural frame and the top cover plate 14 of the chassis by screws respectively; the lower part of the frame is reliably connected to the top cover plate 14 of the chassis by several bottom fixing parts set at the four corners; the upper shell 3 and the lower shell 4 are installed on the outside of the frame to form a closed body cavity; the main body component 102 is equipped with electromechanical system components such as the main controller, power management module and communication module; the main controller and the power management module are connected by wires and powered by a 24V battery pack in the double-wheeled inverted pendulum omnidirectional moving chassis 106. Because the internal spatial frame structure of the main body component 102 has high strength and rigidity, it can withstand various forces and torques generated during robot movement, ensuring the stability of the body. The upper frame cover plate 8 fixed to the upper part of the frame structure provides protection and support for the internal components of the body. The first shoulder motor mounting plate 7 and the second shoulder motor mounting plate 10 installed on the left and right sides are used to install the drive motors of the robotic arm, providing power support for the movement of the robotic arm. The lower part of the frame of the main body component 102 is rigidly connected to the top cover plate 14 of the chassis through bottom fixing parts set at the four corners, making the body and the chassis a whole, ensuring the stability of the overall structure of the robot during movement. The upper shell 3 and the lower shell 4 installed on the outside of the frame structure form a closed body cavity, further protecting the internal components of the main body component 102 from the influence of the external environment.

[0058] To achieve tight coupling between the electromechanical system and the mechanical structure, the main controller is installed on the structural frame inside the main body component 102. It is electrically connected to the motor drivers, power modules, attitude sensors, and encoders on the head, robotic arm, electric lifting support frame 105, and dual-wheel inverted pendulum omnidirectional moving chassis 106 via wiring harnesses. The inertial measurement unit and wheel speed encoder installed inside the dual-wheel inverted pendulum omnidirectional moving chassis 106 feed back the robot's pitch angle, yaw angle, and wheel speed to the main controller in real time. The robotic arm joint encoder and head attitude sensor feed back the upper body attitude information to the main controller. The main controller outputs control quantities to each actuator under a unified timing and communication protocol.

[0059] The left robotic arm assembly 103 and the right robotic arm assembly 104 of this invention have identical structures and are arranged symmetrically. To facilitate the explanation of the internal structure, the outer shell of the left robotic arm assembly 103 is hidden in the drawings, while the outer shell of the right robotic arm assembly 104 remains visible. The robotic arm assembly of this invention includes a shoulder assembly, a large arm assembly, and a forearm assembly. The outer shell of the robotic arm assembly includes a rear shoulder shell 44, a front shoulder shell 45, a rear large arm shell 46, a front large arm shell 47, a lower large arm shell 48, an upper forearm shell 49, a lower forearm shell 50, and an end gripper 51. Adjacent shell parts are fixedly connected by screws. A shoulder rotation drive motor 22 is installed inside the shoulder assembly. A bearing assembly 24 is mounted on the output shaft 23 of the shoulder rotation drive motor 22 and is supported by a shoulder support vertical plate 25 and a first shoulder support side. Plate 26 and the second shoulder support side plate 27 together constitute the support structure of the shoulder assembly. The output shaft 23 of the shoulder rotation drive motor 22 is fixedly connected to this support structure, thereby realizing the rotational movement of the shoulder assembly. The shoulder left and right swing motor 28 is installed in the lateral area of ​​the shoulder and fixed to the first shoulder support side plate 26 and the second shoulder support side plate 27. The output end of the shoulder left and right swing motor 28 is equipped with a left and right swing motor output flange 29. The other end of the output shaft 23 of the shoulder rotation drive motor 22 is hinged to a swing shaft 30 for providing this degree of freedom of rotation. The left and right swing motor output flange 29 is fixedly connected to the rear shell 46 of the upper arm, and the swing shaft 30 is hinged and fixed to the front shell 47 of the upper arm, thereby realizing the left and right swinging movement of the upper arm.

[0060] An elbow joint rotary motor 33 is installed inside the boom assembly and is fixedly mounted on the lower outer shell 48 of the boom via a first L-shaped motor connector 31 and a second L-shaped motor connector 32. An elbow joint rotary output flange 34 is provided at the output end of the elbow joint rotary motor 33. The boom support horizontal plate 35, the boom support vertical plate 37, and the boom support lower end plate 40 constitute the support structure of the boom assembly. The elbow joint rotary output flange 34 is fixedly connected to the boom support horizontal plate 35 to achieve the rotational freedom of the elbow joint. An elbow forward and backward swing motor 39 is fixedly mounted on the boom support vertical plate 37 via a third L-shaped motor connector 36 and a fourth L-shaped motor connector 41. The output end of the 39 is provided with an elbow swing output flange 38, and the other side of the output shaft is provided with a swing shaft 42. The elbow swing output flange 38 is fixedly connected to the upper outer shell 49 of the forearm, and the swing shaft 42 is hinged to the upper outer shell 49 of the forearm, which is used to realize the swinging movement of the forearm assembly in the forward and backward direction. An end gripper mounting plate 43 is fixedly installed inside the forearm assembly, and the end gripper 51 is fixedly installed on the end gripper mounting plate 43. All the joint motors mentioned above are electrically connected to the main controller through motor drivers. The main controller sends position or speed commands to each joint motor according to the task requirements and reads the feedback from the joint position sensor to realize the coordinated movement control of the anthropomorphic upper limb.

[0061] The electric lifting support frame 105 of the present invention includes a crank-slider mechanism assembly, a two-section retractable support linkage mechanism arranged on both sides of the frame, a motor fixing bracket 52, and a slide rail fixing bracket 55; the motor fixing bracket 52 and the slide rail fixing bracket 55 are fixedly connected by a first aluminum column 54, a second aluminum column 56, a third aluminum column 57, and a fourth aluminum column 58, and the motor fixing bracket 52 and the slide rail fixing bracket 55 are respectively fixedly installed on the top cover plate 14 of the chassis.

[0062] The crank-slider mechanism assembly includes a lifting support drive motor 53, a rocker arm 59, a connecting rod 60, a slider fixing rod 61, a slider 62, and a slide rail 63. The lifting support drive motor 53 is fixedly mounted on a motor mounting bracket 52, and its output end is fixedly connected to a rocker arm 59. The rocker arm 59 is hinged to the connecting rod 60 via a pivot shaft, and the connecting rod 60 is connected to the slider fixing rod 61 via a pivot shaft hinge. The slider fixing rod 61 is fixedly mounted on the slider 62, and the slide rail 63 is vertically fixedly mounted on a slide rail mounting bracket 55. The slider 62 moves linearly along the vertical direction on the slide rail 63.

[0063] The two-section retractable support linkage mechanism arranged on both sides of the frame includes a first intermediate rod 65, a second intermediate rod 66, a third intermediate rod 67, a fourth intermediate rod 68, an end support rod 69, a central support hinge 64 located near the slider in the middle of the intermediate rod, and a drive hinge point connected to the slider fixed long rod 61. The central support hinge 64 is fixedly mounted on the slide rail fixed bracket 55, providing a hinge fulcrum for the two-section linkage mechanism. The first intermediate rod 65, the second intermediate rod 66, the third intermediate rod 67, and the fourth intermediate rod 68 are respectively hinged to the slider fixed long rod 61, and the intermediate rods are respectively hinged to the central support hinge 64 near the slider end. The other end of each intermediate rod is hinged to the end support rod 69. This invention, through a landing frame with dead-point self-locking function and adaptive balance control, ensures safe docking and disturbance-resistant operation of the high-center-of-gravity humanoid robot, while significantly improving the robot's maneuverability and interactive operation range in complex dynamic environments.

[0064] The working process of the key components in this invention is described below with reference to the accompanying drawings:

[0065] like Figures 1 to 8 As shown, the camera component 1 on top of the head display and perception component 101 of the present invention can acquire three-dimensional information of the surrounding environment in real time. By analyzing this information, the robot can identify the position, shape and distance of obstacles, thereby realizing obstacle avoidance, navigation and other functions. The human-machine interaction display screen 2 on the front of the head display and perception component 101 can display various information of the robot, such as operating status, sensor data, etc. At the same time, the user can send commands to the robot by touching the human-machine interaction display screen 2 or by cooperating with other input devices to realize human-machine interaction.

[0066] like Figures 9 to 12As shown, the dual-wheeled inverted pendulum omnidirectional moving chassis 106 of the present invention has omnidirectional movement function. When the robot needs to move forward or backward, linear movement is achieved by controlling the drive wheels 95 of the left and right integrated hub motors to rotate at the same speed. When the robot needs to switch to diagonal movement after moving to a designated position, the active gear rotation drive motor 91 is activated to output power, causing the active pinion 93 to rotate and drive the two driven large gears 76 to rotate. Under the linkage of the synchronous linkage 97, the two driven large gears maintain strictly opposing equal-angle rotation during transmission. When the robot reaches the target position and needs to switch to lateral movement, its... The working process is the same as that of diagonal movement, which involves the drive wheels 95 of the two integrated hub motors completing a 90° turn. Specifically, when the robot needs to make a 90° turn to enter a narrow passage and move laterally during its forward movement, the robot first moves forward to the corner position, and then starts the active gear rotation drive motor 91, which drives the active pinion 93 to rotate. Under the coordinated steering action of gear meshing transmission and synchronous linkage 97, the drive wheels 95 of the two integrated hub motors complete a 90° turn. After the turn is completed, the robot can enter the narrow passage by moving laterally, thereby improving its ability to pass through confined spaces.

[0067] like Figure 13 As shown, when the robot needs static support, the lifting support drive motor 53 starts, driving the rocker arm 59 to rotate. The rocker arm 59, through the transmission relationship between the connecting rod 60 and the slider 62 fixed long rod 61, enables the slider fixed long rod 61 to complete the movement process of the crank-slider mechanism, thereby converting the rotational motion of the rocker arm 59 into the linear motion of the slider fixed long rod 61 in the vertical direction. With the linear motion of the slider fixed long rod 61, each intermediate rod swings accordingly, driving the end support rods 69 on both sides to synchronously retract or extend, thus completing the overall lifting and lowering action of the electric lifting support frame 105. The electric lifting support frame 105 of the present invention adopts a crank-slider mechanism design and utilizes the dead point characteristic of this mechanism: when the electric lifting support frame 105 is in the extreme position of being fully retracted or fully lowered, the mechanism is in a dead point state, and even if an external load is applied in the vertical direction, it cannot cause displacement, thereby effectively ensuring the support safety of the robot.

[0068] This invention also constructs a unified dynamic control framework for a variable topology non-coaxial inverted pendulum system, employing a composite closed-loop control architecture of feedforward compensation and variable parameter state feedback, and running a unified dynamic control algorithm based on a non-coaxial inverted pendulum model. By introducing a coupling angle to compensate for the driving torque, and utilizing a geometric deviation decoupling algorithm, the problem of driving torque projection attenuation instability caused by variable configuration is effectively overcome, ensuring attitude stability during variable configuration. This technology not only ensures the robustness of the robot under all working conditions, but also provides a general theoretical paradigm for the precise control of non-coaxial inverted pendulum systems.

[0069] like Figure 14 As shown, to address the issue of dynamic parameter drift caused by configuration changes during gear and linkage coordinated steering of the robot in this invention, a unified dynamic control algorithm based on a non-coaxial inverted pendulum model runs internally in the main controller; the specific steps include:

[0070] S1: For a non-coaxial inverted pendulum system with actively steerable wheels, based on the geometric positional relationship between the fuselage center of mass, the wheel steering axle center, and the wheel contact point, a unified mapping relationship from the steering configuration to the equivalent drive channel of the inverted pendulum is constructed, and the influence of wheel steering attitude change on the balance control channel is characterized as configuration parameters.

[0071] S2: Real-time calculation of the geometric deviation angle between the actual movement direction of the wheels and the pitch control direction of the fuselage, and defines the geometric deviation angle as the coupling angle. The driving torque is compensated by the coupling angle. At the same time, one or two of the coupling angle and configuration parameters are introduced into at least one of the system driving matrix, control gain, feedforward compensation term and feedback adjustment term to compensate for the driving torque projection attenuation problem during omnidirectional steering, suppress the dynamic parameter drift caused by wheel steering, and ensure the attitude stability of the robot during the configuration change process.

[0072] S3: By receiving the robot speed control target command, posture balance control target command and the robot drive actuator motion control target command, compare and calculate them one by one with the real-time robot status data fed back by the synchronously collected inertial sensors, angle sensors and motor encoders to obtain the error signals of each control dimension.

[0073] S4: Based on the error signal, a driving torque command is dynamically generated by combining feedforward compensation and variable parameter state feedback algorithms. The driving torque command drives the actions of each actuator to achieve system attitude correction and omnidirectional trajectory tracking. The driving torque command includes at least one of the following: the speed command and torque command of the drive wheels, and the position command and angle command of the chassis steering actuator.

[0074] Specifically, in this embodiment, the center of rotation of the fuselage is defined as point O, the center of the wheel steering axis is defined as point P, and the center of mass of the wheel is defined as point Q. The longitudinal orientation axis Zo of the fuselage is defined as the reference direction for the inverted pendulum balance control, i.e., the desired pitch balance plane of the fuselage. The actual movement direction axis Zr of the wheel represents the rolling direction of the drive wheel. Because this invention uses a gear and linkage mechanism, when the wheel produces a symmetrical steering angle relative to the fuselage... At that time, the fuselage attitude axis relative to the configuration axis, i.e., the line connecting point O and point Q, will produce a deflection angle. Based on the structural geometric constraints of this invention, the deflection angle... The parsing expression is:

[0075] ;in, This represents the geometric offset distance from the fuselage center of gravity to the wheel steering axle center, i.e., the length of the connecting rod OP. This represents the structural distance from the wheel's steering axle to its center of gravity, i.e., the length of the connecting rod PQ. When the wheel performs a steering action, i.e. The instantaneous configuration vector of the system changes. The spatial direction of the wheels continuously deflects, resulting in a geometric angle between the direction of the driving force generated by the wheels and the direction of the pitch balancing torque required by the fuselage. To quantify this nonlinear coupling effect, this invention defines the coupling angle between the wheel motion direction axis Zr and the fuselage pitch control axis Zc. for:

[0076] ;

[0077] In this model, As a key configuration parameter proposed in this invention, it directly characterizes the degree of "non-coaxial" coupling between the current steering configuration and the equivalent drive channel of the inverted pendulum: when At this time, the direction of the wheel driving force is completely collinear with the direction of pitch control, and the system degenerates into a traditional coaxial two-wheel inverted pendulum model; when At this point, a fixed coupling angle exists between the driving force and the pitch control axis, and the system structurally evolves from a "coaxial inverted pendulum" to a "non-coaxial inverted pendulum system." In this case, the same driving force needs to be decomposed in vector space, undertaking both the translation of the vehicle and participating in pitch stability control. Traditional two-wheeled self-balancing vehicle control generally assumes that the driving direction and the pitch control direction are strictly collinear (an implicit assumption). Because it is difficult to describe the intrinsic mechanism by which the same pair of drive wheels simultaneously completes translation and self-balancing under any steering posture in the omnidirectional configuration of this invention, and also cannot explain the fundamental reason for the changes in balance margin and dynamic response under different steering postures, the main controller explicitly introduces the aforementioned coupling angle. At the configuration level, a mapping relationship was established from the geometric constraints of the gear and connecting rod to the equivalent driving channel of the inverted pendulum. This method incorporates the traditional coaxial inverted pendulum system and the non-coaxial inverted pendulum system of this invention into the same analytical framework, enabling the dynamic characteristics under any turning posture to be uniformly described and compared within the same state-space model, thus providing a physically meaningful analytical parameter basis for controller design. Based on the above modeling, the main controller further utilizes... The definition compensates for torque. The main controller will... As a core gain factor embodying the "non-coaxial effect", it is introduced into the design of the system drive matrix and feedback gain, enabling the control law to self-adjust with the geometric changes of the steering configuration.

[0078] like Figure 15 As shown, to accurately compensate for the dynamic deviations caused by the aforementioned non-coaxial configuration, this invention further constructs a translational dynamic model based on the omnidirectional configuration in the main controller. The specific modeling process is as follows:

[0079] First, analyze the forces in the wheel's motion according to Newton's second law. The wheel's mass is m, its radius is r, and the forward displacement of the machine's center of mass is... The horizontal displacement of the wheel is given by , where Represents the left and right wheels. Assuming the horizontal component of the force exerted on the wheel by the entire vehicle body, coupling the rotational and translational motions, and eliminating the ground friction term, we obtain the wheel's dynamic equations:

[0080] The robot possesses a gear-linkage synchronous steering mechanism to achieve system wheel steering. To simplify the model, and considering the characteristics of the self-balancing vehicle's dynamics model, the analysis process takes into account the overall horizontal displacement under different wheel angles. Therefore, the robot's horizontal displacement relative to the base coordinate system, y, can be obtained using trigonometric functions.

[0081] ;

[0082] Add the obtained dynamic equations (3) of the left and right wheels together and combine them with the deflection angle. The analytic expression (1) can be simplified to obtain:

[0083] ;

[0084] in Let M be the acceleration of the robot's center of mass. Analyze the horizontal and vertical motions of the robot during its forward motion separately using Newton's second law. Given that M is the mass of the robot body and l is the vertical distance from the robot's center of mass to the center of the wheel, the following forces can be obtained in the horizontal direction:

[0085] ;

[0086] Vertical direction:

[0087] ;

[0088] in and Let be the supporting force exerted by the tires on the robot in the vertical direction. According to the laws of rigid body rotation, the robot's pitch acceleration can be obtained. The relationship between the various forces:

[0089] ;

[0090] in, Let be the moment of inertia of the vehicle body about the center of mass, the pitch axis; Let be the angle between the vehicle body and the vertical direction. Solving equations (5) and (6) simultaneously, we get: (9);

[0092] Since the value remains very small during the robot's normal movement, with a variation range of approximately ±0.1745 rad (radians), the nonlinear term in the formula can be linearized. , Therefore, by linearizing formula (9), we can obtain:

[0093] ;

[0094] Substituting equations (6) and (7) into equation (8), and combining them with equation (10) to linearize the equation, we get:

[0095] ;

[0096] Substitute equations (10) and (11) into each other and eliminate them respectively. and The equilibrium linear dynamic equations of the non-coaxial inverted pendulum system after the wheel turns can then be obtained:

[0097] ;

[0098] ;

[0099] ;

[0100] ;

[0101] ;

[0102] ;

[0103] ;

[0104] ;

[0105] in .

[0106] In this way, even under omnidirectional motion conditions with large turning angles, the geometric weakening of the equivalent drive channel has already been achieved. With compensation, the non-coaxial inverted pendulum system of this invention can still achieve a similar balance margin and dynamic performance to the coaxial configuration. This integrated modeling and control design effectively ensures the robot's attitude robustness during omnidirectional movement mode switching.

[0107] like Figure 16 As shown, this embodiment constructs a composite closed-loop control architecture that includes feedforward compensation and variable parameter state feedback. The system first receives three target commands: speed, body balance, and motor control (including servo steering control). These commands are then differentially compared with real-time data fed back from sensors to calculate the speed error, balance pitch angle error, and servo rotation angle error. The core controller performs state-space calculations on the above error signals based on the current system configuration parameters. Combined with the error compensation signal generated by the feedforward control module, the controller performs superposition calculations to finally synthesize the driving torque commands for the steering servo and the left and right wheels.

[0108] In the execution and feedback phase, the aforementioned torque commands drive the hub motors and CAN servos to move, thereby controlling the robot's posture. Simultaneously, core electronic components, including inertial sensors (IMU), angle sensors, and motor encoders, monitor the robot's physical state in real time, collecting the robot's pitch angle... Spin angle Wheel steering angle and feed rate The feedback signal is transmitted back to the input end to form a complete closed loop, so as to realize real-time correction of the robot's balance posture and accurate tracking of the target trajectory.

[0109] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A two-wheeled omnidirectional humanoid robot, characterized in that, It includes a head display and sensing component, a main body component, a symmetrical robotic arm component, an electric lifting support frame, and a two-wheeled inverted pendulum omnidirectional moving chassis; The dual-wheeled inverted pendulum omnidirectional moving chassis is located at the bottom of the robot. The main body assembly is fixedly installed at the top center of the dual-wheeled inverted pendulum omnidirectional moving chassis. The robotic arm assembly is symmetrically hinged to both sides of the main body assembly through a shoulder joint drive assembly. The head display and sensing assembly is rotatably connected to the top of the main body assembly through a head pitch-yaw composite drive assembly. The electric lifting support frame is arranged inside the main body assembly and is fixedly connected to the dual-wheeled inverted pendulum omnidirectional moving chassis. The dual-wheel inverted pendulum omnidirectional moving chassis includes a top frame assembly, a rotary actuator assembly, and symmetrical tire assemblies. The rotary actuator assembly is integrated between the top frame assembly and the tire assemblies and includes an active steering drive unit, a synchronous power distribution transmission unit, a synchronous constraint linkage unit, and symmetrical rotary shaft assemblies. The symmetrical rotary shaft assemblies are respectively fixed to the corresponding tire assemblies, and each rotary shaft assembly includes a force-driven end and a driven linkage end. The active steering drive unit is connected to the force-driven ends of the two rotary shaft assemblies through the synchronous power distribution transmission unit, and the two ends of the synchronous constraint linkage unit are respectively connected to the force-driven ends and driven linkage ends of the left and right rotary shaft assemblies.

2. The robot according to claim 1, characterized in that, The main body assembly has a rigid spatial frame structure inside. The upper part of the rigid spatial frame structure has a mounting plate for installing the shoulder drive motor of the robotic arm, and the lower part is fixed to the dual-wheel inverted pendulum omnidirectional moving chassis through bottom fixing parts. The outer shell of the rigid spatial frame structure forms a closed cavity, and the main controller, power management module and communication module are arranged inside.

3. The robot according to claim 2, characterized in that, The robotic arm assembly includes a shoulder assembly, a large arm assembly, and a forearm assembly. The shoulder assembly is equipped with a shoulder rotation drive motor and a shoulder left and right swing motor. The large arm assembly is equipped with an elbow joint rotation motor and a forward and backward swing motor. The forearm assembly has an end gripper fixed at its front end. Each motor is electrically connected to the main controller. The head display and sensing assembly has a human-machine interaction display screen on its front side and a camera assembly on its top. The head pitch-yaw composite drive assembly includes a head yaw drive motor with its output shaft arranged vertically and a head pitch drive motor with its output shaft arranged horizontally.

4. The robot according to claim 1, characterized in that, The electric lifting support frame includes a crank-slider mechanism assembly and a two-section retractable support linkage mechanism symmetrically arranged on both sides of the frame. The crank-slider mechanism assembly includes a lifting support drive motor, a motor mounting bracket, a slide rail mounting bracket, a slider, and a slide rail. The motor mounting bracket and the slide rail mounting bracket are fixedly connected by multiple aluminum columns and are also fixedly connected to a double-wheel inverted pendulum omnidirectional moving chassis. A rocker arm is fixedly connected to the output end of the lifting support drive motor. The rocker arm is hinged to a connecting rod via a rotating shaft. The other end of the connecting rod is hinged to a slider fixing rod. The slider fixing rod is fixedly connected to the slider. The slider is adapted to be installed on a vertical slide rail on the slide rail mounting bracket. The two-section retractable support linkage mechanism includes an end support rod, multiple intermediate rods, and a middle support hinge. The middle support hinge is fixed to the slide rail fixing bracket and corresponds to the middle position of the multiple intermediate rods. One end of the multiple intermediate rods is hinged to a slider fixing long rod, the middle is hinged to the middle support hinge, and the other end is hinged to the end support rod.

5. The robot according to claim 1, characterized in that, The tire assembly includes upper and lower axle brackets and two drive wheels of integrated hub motors. The drive wheels of the integrated hub motors are clamped and fixed by the upper and lower axle brackets. The upper and lower axle brackets are respectively fixedly connected to the force-driven end and the driven linkage end of the corresponding rotating shaft assembly.

6. The robot according to claim 1, characterized in that, The top frame assembly of the dual-wheel inverted pendulum omnidirectional moving chassis consists of a chassis top upper cover plate, a chassis top lower cover plate, at least one top vertical support member, and a middle vertical support member forming a closed structure, with a battery pack, power management circuit, and balance control board arranged inside; the rotary actuator assembly also includes upper and lower mounting plates for the rotary mechanism and front and rear rotary mechanism supports, the upper mounting plate for the rotary mechanism being fixed to the middle vertical support member, and the upper and lower mounting plates being fixedly connected through the front and rear rotary mechanism supports.

7. The robot according to claim 6, characterized in that, The active steering drive unit is an active gear rotary drive motor, the synchronous power distribution transmission unit is an active pinion, the force-driven end is a driven large gear, the driven linkage end is a lower gear rotating plate, and the synchronous constraint linkage unit is a synchronous connecting rod; the rotating shaft assembly also includes a rotating shaft, upper and lower bearing seats, upper and lower angular contact bearings, upper and lower bushings, a lower gear rotating plate, a support bushing between the gear and the rotating plate, and a fastening nut; the lower bearing seat is fixedly mounted on the lower mounting plate of the rotating mechanism, and the inner hole of the lower bearing seat mates with the outer ring of the lower angular contact bearing. The rotating shaft is arranged vertically and its lower end mates with the inner ring of the lower angular contact bearing. From bottom to top, the rotating shaft is fitted with a lower bushing, a lower gear rotating plate, a support bushing between the gear and the rotating plate, and a driven large gear. The lower gear rotating plate and the driven large gear are circumferentially fitted with the rotating shaft via a keyway. The upper part of the rotating shaft is fitted with an upper bushing, an upper angular contact bearing, and an upper bearing seat. The outer ring of the upper angular contact bearing mates with the inner ring of the upper bearing seat. The upper bearing seat is fixedly connected to the upper mounting plate of the rotating mechanism. The upper end of the rotating shaft is fixedly connected to the upper mounting plate of the rotating mechanism via a fastening nut.

8. A control method for the robot according to any one of claims 1-7, characterized in that, The robot employs a composite closed-loop control architecture combining feedforward compensation and variable parameter state feedback, and runs a unified dynamics control algorithm based on a non-coaxial inverted pendulum model; the specific steps include: S1: For a non-coaxial inverted pendulum system with actively steerable wheels, based on the geometric positional relationship between the fuselage center of mass, the wheel steering axle center, and the wheel contact point, a unified mapping relationship from the steering configuration to the equivalent drive channel of the inverted pendulum is constructed, and the influence of wheel steering attitude change on the balance control channel is characterized as configuration parameters. S2: Real-time calculation of the geometric deviation angle between the actual movement direction of the wheels and the pitch control direction of the fuselage, and defining the geometric deviation angle as the coupling angle. The driving torque is compensated by the coupling angle. At the same time, one or two of the coupling angle and the configuration parameters are introduced into at least one of the system driving matrix, control gain, feedforward compensation term and feedback adjustment term to compensate for the driving torque projection attenuation problem during omnidirectional steering, suppress the dynamic parameter drift caused by wheel steering, and ensure the attitude stability of the robot during the configuration change process. S3: By receiving the robot speed control target command, posture balance control target command and the robot drive actuator motion control target command, compare and calculate them one by one with the real-time robot status data fed back by the synchronously collected inertial sensors, angle sensors and motor encoders to obtain the error signals of each control dimension. S4: Based on the error signal, a driving torque command is dynamically generated by combining feedforward compensation and variable parameter state feedback algorithms. The driving torque command drives the actions of each actuator to achieve system attitude correction and omnidirectional trajectory tracking. The driving torque command includes at least one of the following: the speed command and torque command of the drive wheels, and the position command and angle command of the chassis steering actuator.

9. The control method according to claim 8, characterized in that, In the aforementioned feedforward compensation and variable parameter state feedback composite closed-loop control architecture, the feedforward compensation term pre-calculates the compensation torque based on the coupling angle and configuration parameters to offset the projection attenuation of the driving torque during omnidirectional steering; the variable parameter state feedback term dynamically adjusts the control gain and output based on the real-time error signal to correct the robot's posture deviation in real time; the control parameters of both are dynamically and adaptively adjusted according to the wheel steering configuration, so that the non-coaxial inverted pendulum system maintains a balance margin and dynamic response characteristics similar to those of the coaxial configuration in omnidirectional motion modes such as forward, lateral, and oblique movements.

10. The control method according to claim 8, characterized in that, In step S2, the coupling angle is the angle between the wheel motion direction axis Zr and the fuselage pitch control axis Zc, and its analytical expression is: ;in, This represents the geometric offset distance from the fuselage's center of gravity to the center of the wheel steering axle. This indicates the structural outer distance from the wheel steering axle to the wheel's center of gravity. The wheel steering angle is the dynamic parameter drift caused by the dynamic change in the geometric relationship between the fuselage center of mass, steering shaft and wheel contact point during wheel steering, resulting in the drift of at least one of the following parameters: inverted pendulum equivalent driving parameter, moment of inertia and torque transmission coefficient.

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