Multi-degree-of-freedom circular omnidirectional mobile robot chassis

Abstract

The invention discloses a multi-degree-of-freedom circular omnidirectional mobile robot chassis, and relates to the field of mobile robots. The problems that an existing movable chassis is insufficient in steering flexibility, complex in structure and poor in adaptability to the use environment are solved. The chassis comprises a chassis upper cover (D) and a circular disc body (F), and further comprises a plurality of modular steering wheels (A), the modular steering wheels (A) integrate driving and steering functions, the modular steering wheels (A) are installed on the circular disc body (F) in an annular array mode, and wheels (A-22) of the modular steering wheels (A) extend out of the circular disc body (F) and then make contact with the ground. And the chassis upper cover (D) covers the plurality of modular steering wheels (A) on the circular disc body (F). The chassis can move in any direction in a plane, the position of the chassis does not need to be adjusted through multiple times of steering like a traditional chassis, and the positioning accuracy and efficiency are greatly improved. The robot is used for robot movement.

Description

Technical Field

[0001] This invention relates to mobile robot chassis, specifically to a multi-degree-of-freedom circular omnidirectional mobile robot chassis, for use in the field of mobile chassis technology. Background Technology

[0002] In today's fields of automated equipment and robotics applications, mobile chassis are key components, and their performance directly affects the overall efficiency of the equipment. Currently, there are various types of mobile chassis on the market; however, each of them has some problems that urgently need to be solved.

[0003] Traditional mobile chassis mostly employ a fixed steering system with four or more wheels. While this structure performs adequately in normal straight-line driving scenarios, its steering flexibility is extremely limited. For example, in relatively confined working environments such as warehouses and workshops, ordinary chassis often require a large turning radius to complete steering maneuvers. This is not only time-consuming but also risks collisions with surrounding obstacles due to the inability to turn in time, significantly limiting the equipment's working efficiency in such scenarios. Moreover, due to its relatively complex steering structure, which includes numerous links, steering knuckles, and other components, this not only increases the overall weight and cost of the chassis but also raises the probability of malfunctions. Once a component fails, repairs are difficult and costly.

[0004] The patent, with publication number CN118358284A and titled "An Invention Patent for a Multifunctional Omnidirectional Intelligent Mobile Chassis," uses Mecanum wheels as the power source for the mobile chassis. While this allows for relatively flexible movement, such as turning on the spot, providing convenience for certain special work scenarios, the structure of Mecanum wheels is quite unique. The wheels consist of multiple small rollers with a small and complex contact area with the ground. On one hand, it requires extremely high ground flatness; when the ground is uneven, has potholes, or contains debris, the wheels are prone to jamming and slipping, severely affecting the normal operation of the mobile chassis. On the other hand, this complex structure makes cleaning the wheels exceptionally difficult; dust and debris easily become trapped between the rollers, not only affecting the wheel's lifespan but also potentially reducing the mobile chassis's movement accuracy.

[0005] In summary, existing mobile chassis suffer from insufficient steering flexibility, structural complexity, and poor adaptability to the operating environment. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of insufficient steering flexibility, structural complexity, and poor adaptability to the operating environment of existing mobile chassis, and to provide a multi-degree-of-freedom circular omnidirectional mobile robot chassis.

[0007] The technical solution of this invention is:

[0008] A multi-degree-of-freedom circular omnidirectional mobile robot chassis includes a chassis cover and a circular disk. It also includes multiple modular steering wheels, which integrate driving and steering functions. The multiple modular steering wheels are mounted on the circular disk in a circular array, and the wheels of the multiple modular steering wheels extend out of the circular disk and contact the ground. The chassis cover is mounted on the multiple modular steering wheels.

[0009] Furthermore, the modular steering wheel includes a drive power unit, a steering power unit, a steering wheel reduction mechanism, and a wheel. The drive power unit and the steering power unit are arranged symmetrically on the left and right and transmit power to the input end of the steering wheel reduction mechanism. The output end of the steering wheel reduction mechanism is connected to the wheel and drives the wheel to rotate.

[0010] Furthermore, the drive power unit includes a drive motor and a first motor drive assembly, which is mounted on the drive motor to realize the power drive of the drive motor.

[0011] Preferably, the first motor drive assembly includes a first motor drive unit and a first coaxial mounting assembly, which are coaxially mounted on the drive motor from top to bottom.

[0012] Preferably, the steering power unit includes a steering motor and a second motor drive assembly, the second motor drive assembly being mounted on the steering motor to achieve steering drive of the steering motor.

[0013] Preferably, the second motor drive assembly includes a second motor drive unit and a second coaxial mounting assembly, which are coaxially mounted on the steering motor from top to bottom.

[0014] Furthermore, the steering wheel reduction mechanism is a three-stage reduction mechanism.

[0015] Preferably, the wheels are rubber wheels.

[0016] Furthermore, it also includes a battery assembly mounted on a circular disc.

[0017] Furthermore, it also includes a main control computer, which is mounted on a circular disk.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The present invention has excellent steering performance and flexible movement.

[0020] Traditional mobile chassis lack maneuverability and have a large turning radius, making them extremely inconvenient for operation in confined spaces. In contrast, the circular omnidirectional mobile robot chassis of this invention preferably employs a three-drive, three-motion circular mobile chassis. With six degrees of freedom provided by three modular steering wheels A, it can easily achieve functions such as turning on the spot, efficient turning in confined spaces, and U-turns. The six-degree-of-freedom design gives the chassis omnidirectional mobility, a feature not found in traditional chassis. This chassis can move in any direction within a plane without requiring multiple turns to adjust its position, as is the case with traditional chassis, greatly improving positioning accuracy and efficiency.

[0021] 2. This invention adopts a modular design, with each steering wheel mechanism as an independent module, connected to the chassis body through a standardized interface. The drive motor and steering motor of the steering wheel module are evenly arranged (meaning symmetrically arranged left and right) to reduce the overall size. The steering mechanism adopts an internal meshing method, which has higher integration and smaller size compared to the external meshing structure. The motor driver uses a solution that integrates the magnetic encoder and the driver, further saving space and improving the integration of the steering wheel.

[0022] 3. Existing mobile chassis have complex structures, making maintenance and upgrades difficult. The modular design of this chassis allows maintenance personnel to replace faulty modules quickly, reducing equipment downtime. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 yes Figure 1 A schematic diagram of the overall structure after removing the chassis cover D; Figure 3 yes Figure 1 Exploded view; Figure 4 yes Figure 2 Top view; Figure 5 This is a top view of the circular disk F; Figure 6 This is a schematic diagram of the overall structure of modular steering wheel A; Figure 7 yes Figure 6 The exploded main view of the upper middle section; Figure 8 yes Figure 6 A decomposed 3D diagram of the upper and middle sections; Figure 9 This is a structural schematic diagram of the steering wheel cover A-1; Figure 10 This is a simplified kinematic diagram of the steering wheel reduction mechanism; Figure 11 This is a cross-sectional view of the steering wheel reduction mechanism.

[0024] Among them, A is a modular steering wheel, A1 is the first modular steering wheel, A2 is the second modular steering wheel, A3 is the third modular steering wheel, A-1 is the steering wheel cover, A-1-1 is the first through hole, A-1-2 is the first groove, A-1-3 is the second groove, A-1-4 is the first threaded hole, A-1-5 is the second threaded hole, A-1-6 is the third threaded hole, A-1-7 is the fourth threaded hole, A-2 is the first upper connector, A-3 is the first motor driver, A-3-1 is the first encoder, A-4 is the first lower connector, A-5 is the first magnet, A-6 is the first printed part, A-7 is the drive motor, and A-8 is the second upper connector. Components, A-9, Second motor driver; A-9-1, Second encoder; A-10, Second lower connector; A-11, Second magnet; A-12, Second printed part; A-13, Steering motor; A-14, First driving spur gear; A-15, First driven spur gear; A-16, Second driving spur gear; A-17, Steering spur gear; A-18, Gear ring; A-19, Second driven spur gear; A-20, Third driving bevel gear; A-21, Third driven bevel gear; A-22, Wheel; A-23, Threaded hole; A-24, Lower half of steering wheel housing one; A-25, Lower half of steering wheel housing two; A-26. A. First bolt, B. Battery assembly, B-1. First battery, B-2. Second battery, C. Main control computer, D. Chassis cover, E. Mounting bracket, E-1. First mounting bracket, E-2. Second mounting bracket, F. Circular disc, F-1. First hole, F-2. Second hole, F-3. Third hole. Detailed Implementation

[0025] Specific implementation method one: Combining Figures 1 to 11 This embodiment describes a multi-degree-of-freedom circular omnidirectional mobile robot chassis, including a chassis cover D and a circular disk F. It also includes multiple modular steering wheels A, which integrate drive and steering functions. The multiple modular steering wheels A are mounted on the circular disk F in a circular array, and the wheels A-22 of the multiple modular steering wheels A extend out of the circular disk F and contact the ground. The chassis cover D covers the multiple modular steering wheels A.

[0026] In this embodiment, the modular steering wheels A are preferably three in number. That is, the present invention preferably adopts a three-drive, three-rotor design, using three modular steering wheel mechanisms as the power source, and these three steering wheel mechanisms are evenly arranged on a circular disc. This layout fundamentally changes the traditional chassis drive mode, giving the chassis unique motion characteristics. All three steering wheels can contact the ground, ensuring stable movement. Furthermore, the three multi-wheel modules have a unified electrical control interface, are independent of each other, and are easy to maintain in case of failure. Damaged modules can be replaced immediately, thus ensuring the normal movement of the mobile chassis.

[0027] Specific Implementation Method Two: Combining Figures 2 to 11 This embodiment describes a modular steering wheel A that includes a drive power unit, a steering power unit, a steering wheel reduction mechanism, and a wheel A-22. The drive power unit and the steering power unit are arranged symmetrically on the left and right sides and transmit power to the input end of the steering wheel reduction mechanism. The output end of the steering wheel reduction mechanism is connected to the wheel A-22, driving the wheel A-22 to rotate.

[0028] Each steering wheel module in this embodiment integrates two degrees of freedom: drive and steering. The three steering wheel modules give the chassis a total of six degrees of freedom. This design enables the chassis to achieve flexible omnidirectional movement, including turning on the spot, efficient turning in confined spaces, and U-turns, greatly improving the chassis's maneuverability in complex spatial environments.

[0029] The steering wheel structure is designed using a vertical design. In this design, the drive motor and steering motor are fixed, facilitating electrical wiring. The drive motor and steering motor are arranged symmetrically from left to right, resulting in higher space utilization and integration compared to the traditional arrangement where the drive motor is in the center and the steering motor is off-center.

[0030] Specific implementation method three: Combining Figures 7 to 8 This embodiment describes a drive power unit that includes a drive motor A-7 and a first motor drive assembly. The first motor drive assembly is mounted on the drive motor A-7 to provide power to the drive motor A-7. This configuration provides a controllable and powerful forward / reverse drive force to the steering wheel, ensuring sufficient power for the robot chassis to move.

[0031] Specific implementation method four: Combination Figures 7 to 8 This embodiment describes a first motor drive assembly comprising a first motor drive unit and a first coaxial mounting assembly, which are coaxially mounted on a drive motor A-7 from top to bottom. The first motor drive assembly includes a first motor driver A-3 and a first upper connector A-2. A first encoder A-3-1 is mounted on the first motor driver A-3, which is embedded within the first upper connector A-2. The first coaxial mounting assembly includes a first magnet A-5, a first printed piece A-6 (specifically, an auxiliary mounting printed piece connecting the magnet and the motor shaft), and a first lower connector A-4. The first magnet A-5 is coaxially mounted on the shaft of the drive motor A-7 via the first printed piece A-6. The first lower connector A-4 is mounted on the first magnet A-5 and the first printed piece A-6 and then connected to the first motor driver A-3.

[0032] This configuration enables precise servo control of the drive motor A-7, ensuring its compact structure and stable reliability. It guarantees that the first magnetic encoder A-3-1 can read the precise position and speed information of the drive motor A-7 without any deviation, thus forming a high-performance closed-loop control system.

[0033] In addition, the first encoder A-3-1 and the first magnet A-5 must be kept strictly coaxial, and the air gap (distance) between them must be kept stable to avoid control inaccuracy, motor vibration or efficiency reduction, thus ensuring high-precision movement of the chassis.

[0034] Specific Implementation Method Five: Combining Figures 7 to 8 This embodiment describes a steering power unit that includes a steering motor A-13 and a second motor drive assembly. The second motor drive assembly is mounted on the steering motor A-13 to drive the steering motor A-13 in steering. This configuration facilitates precise control of the wheel steering angle, thereby enabling omnidirectional movement of the robot.

[0035] Specific Implementation Method Six: Combination Figures 7 to 8 This embodiment describes a second motor drive assembly that includes a second motor drive unit and a second coaxial mounting assembly, which are coaxially mounted on the steering motor A-13 from top to bottom.

[0036] The second motor drive assembly includes a second motor driver A-9 and a second upper connector A-8. A second encoder A-9-1 is mounted on the second motor driver A-9, which is installed within the second upper connector A-8. The second coaxial mounting assembly includes a second magnet A-11, a second printed piece A-12, and a second lower connector A-10. The second magnet A-11 is coaxially mounted on the shaft of the steering motor A-13 via the second printed piece A-12. The second lower connector A-10 is mounted on the second magnet A-11 and the second printed piece A-12 and then connected to the second motor drive assembly.

[0037] To further improve the integration of the steering wheel structure, this embodiment uses an integrated magnetic encoder and driver for the motor driver. The motor driver is mounted directly above the motor, and a specially designed connecting device secures the driver and motor. This fixing method ensures that the motor shaft is always directly aligned with the magnetic encoder on the motor driver, guaranteeing that the encoder can accurately acquire key information such as the motor shaft's position and speed, providing a reliable data foundation for precise motor control. The power and communication cables of the motor driver are systematically led out through openings in the upper housing of the steering wheel and neatly connected to the power supply and controller of the mobile chassis. This wiring method not only ensures the safety and stability of the wiring, preventing malfunctions caused by wiring vibration or friction during chassis operation, but also makes the wiring layout inside the chassis more organized, facilitating later maintenance and repair.

[0038] Specific implementation method seven: Combining Figures 10 to 11 This embodiment describes a three-stage reduction mechanism for the steering wheel. The steering wheel reduction mechanism includes a three-stage drive reduction mechanism and a steering transmission mechanism, with the steering transmission mechanism connected to the three-stage drive reduction mechanism.

[0039] The three-stage drive reduction mechanism includes a first driving spur gear A-14, a first driven spur gear A-15, a second driving spur gear A-16, a second driven spur gear A-19, a third driving bevel gear A-20, and a third driven bevel gear A-21. The first driving spur gear A-14 is connected to the output shaft of the drive motor A-7. The first driven spur gear A-15 meshes with the driving spur gear A-14. The second driving spur gear A-16 is coaxially arranged with the first driven spur gear A-15. The second driven spur gear A-19 meshes with the second driving spur gear A-16. The third driving bevel gear A-20 meshes with the second driven spur gear A-19. The third driving bevel gear A-20 and the third driven bevel gear A-21 mesh. The wheel A-22 is mounted on the gear shaft of the third driven bevel gear A-21.

[0040] In this embodiment, the drive mechanism is designed with a three-stage reduction gear to drive the wheels and provide sufficient torque power for the mobile chassis.

[0041] The steering transmission mechanism includes a steering spur gear A-17 and a gear ring A-18. The steering spur gear A-17 is connected to the output shaft of the steering motor A-13. The gear ring A-18 is grooved, and the upper opening of the gear ring A-18 meshes with the steering spur gear A-17. The steering spur gear A-17 drives the gear ring A-18 to rotate as a whole, and the gear ring A-18 drives the wheel A-22 on it to steer as a whole.

[0042] In the steering mechanism design of this embodiment, the present invention adopts an internal meshing method. Compared with the traditional external meshing structure, the internal meshing method can not only achieve a larger reduction ratio, but also allow for higher integration of the steering wheel structure. When using the same motor, the internal meshing structure is smaller in size, which helps in the rational layout within limited chassis space.

[0043] Specific implementation method eight: Combination Figure 6 , Figures 10 to 11 In this embodiment, wheel A-22 is a rubber wheel. This configuration means the wheel of the present invention uses a common rubber wheel. Compared to special wheels such as Mecanum wheels, common rubber wheels have greater friction with the ground, making them less prone to slipping. They have lower requirements for ground flatness and offer significant advantages in cleaning. The smooth surface of common rubber wheels prevents dust and debris from adhering, making cleaning easier and faster. This effectively solves the problem of long-term stable operation of the chassis in different environments.

[0044] Specific Implementation Method Nine: Combining Figures 2 to 4 This embodiment further includes a battery assembly B, which is mounted on a circular disk F. The battery assembly B includes a battery and a mounting base E, with the battery mounted on the circular disk F via the mounting base E. This configuration provides a stable and reliable power supply to the entire mobile robot chassis, serving as the energy source for all electronic devices and the power system.

[0045] Specific Implementation Method Ten: Combining Figures 2 to 4 This embodiment also includes a main control computer C, which is mounted on the circular chassis F. With this configuration, the main control computer C is used to control the entire chassis.

[0046] Combination Figures 1 to 11 Explanation of the working principle of this invention:

[0047] This embodiment includes three modular steering wheels A, two batteries, one main control computer C, a circular disk F, and a chassis cover D. The first battery B-1 and the second battery B-2 are connected to the circular disk F via the first mounting bracket E-1 and the second mounting bracket E-2, respectively, and are bolted together through the second hole F-2. The three modular steering wheels are: the first modular steering wheel A1, the second modular steering wheel A2, and the third modular steering wheel A3, each bolted to the first hole F-1 of the circular disk F via eight evenly distributed threaded holes A-23. The steering wheel modules are arranged in an evenly distributed manner. The main control computer C is bolted to the circular disk F through the third hole F-3. The chassis cover D is bolted together via the first threaded hole A-1-4, the second threaded hole A-1-5, the third threaded hole A-1-6, and the fourth threaded hole A-1-7 on the steering wheel cover A-1. All the above connections use bolts.

[0048] The isometric view of a single modular steering wheel A is as follows Figure 3 As shown. The motor power cable and control signal cable are led out from the first through hole A-1-1 of the steering wheel cover A-1. The first motor driver A-3 and the second motor driver A-9 are connected to the steering wheel cover A-1 through the first upper connector A-2 and the second upper connector A-8, respectively, leaving space for terminal wiring. The motor drivers are positioned through the first groove A-1-2 and the second groove A-1-3, respectively, and the connection method is bolt connection.

[0049] The first magnet A-5 and the second magnet A-11 are connected to the motor shaft via the first printed part A-6 and the second printed part A-12. The fit between the first printed part A-6 and the second printed part A-12 and the magnets and motor shaft is an interference fit. The connection is secured with glue, ensuring concentricity between the magnets and the shaft. The first motor driver A-3 and the second motor driver A-9 are connected to the first lower connector A-4, the second lower connector A-10, the drive motor A-7, and the steering motor A-13, respectively, thus ensuring concentricity between the first magnet A-5 and the second magnet A-11 and the first magnetic encoder A-3-1 and the second encoder A-9-1, respectively. In this way, the components in the modular steering wheel A are connected and assembled using bolts, ensuring concentricity of the motor shaft, magnets, and magnetic encoders. The steering wheel cover is connected to the lower half of the steering wheel housing, A-24 and A-25, via bolts.

[0050] A simplified kinematic diagram of the steering wheel module's reduction mechanism is shown below. Figure 10 As shown, drive motor A-7 and rotary motor A-13 are evenly arranged. The drive motors drive the wheels through a three-stage reduction mechanism. The first driving spur gear A-14 is connected and positioned to drive motor A-7 via a positioning bolt, and meshes with the first driven spur gear A-15 to form the first-stage reduction mechanism. In this embodiment, the reduction ratio is 2:1. The first driven spur gear A-15 is connected and positioned to the second driving spur gear A-16 via a positioning bolt. The second driving spur gear A-16 meshes with the second driven spur gear to form the second-stage reduction mechanism. In this embodiment, the reduction ratio is 1:1. The third driving bevel gear A-20 is a bevel gear, connected and positioned to the second driven spur gear A-19 via a positioning bolt, and meshes with the third driven bevel gear A-21 to form the third-stage reduction mechanism. In this embodiment, the reduction ratio is 1:1 and the transmission direction is changed.

[0051] The third driven bevel gear A-21 is connected to wheel A-22 via a positioning bolt. The final drive motor A-7 drives the wheel through a three-stage reduction mechanism, providing a sufficient reduction ratio to generate enough torque to move the chassis. The steering motor achieves steering through a single-stage reduction mechanism, and the steering spur gear A-17 is connected to the steering motor A-13 via a positioning bolt. The gear ring A-18 engages with the steering spur gear A-17; in this embodiment, the reduction ratio is 4.8:1, providing the torque required for steering. The gear ring A-18 is connected to the steering mechanism via the first bolt A-26, thereby achieving the steering movement of wheel A-22.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-degree-of-freedom circular omnidirectional mobile robot chassis, comprising a chassis cover (D) and a circular disk (F), characterized in that: It also includes multiple modular steering wheels (A), which integrate drive and steering functions. The multiple modular steering wheels (A) are mounted on a circular disc (F) in a ring array, and the wheels (A-22) of the multiple modular steering wheels (A) extend out of the circular disc (F) and contact the ground. The chassis cover (D) is mounted on the multiple modular steering wheels (A).

2. The multi-degree-of-freedom circular omnidirectional mobile robot chassis according to claim 1, characterized in that: The modular steering wheel (A) includes a drive power unit, a steering power unit, a steering wheel reduction mechanism, and a wheel (A-22). The drive power unit and the steering power unit are arranged symmetrically on the left and right and transmit power to the input end of the steering wheel reduction mechanism. The output end of the steering wheel reduction mechanism is connected to the wheel (A-22) to drive the wheel (A-22) to rotate.

3. The multi-degree-of-freedom circular omnidirectional mobile robot chassis according to claim 2, characterized in that: The drive power unit includes a drive motor (A-7) and a first motor drive assembly. The first motor drive assembly is mounted on the drive motor (A-7) to realize the power drive of the drive motor (A-7).

4. The multi-degree-of-freedom circular omnidirectional mobile robot chassis according to claim 3, characterized in that: The first motor drive assembly includes a first motor drive unit and a first coaxial mounting assembly, which are coaxially mounted on the drive motor (A-7) from top to bottom.

5. The multi-degree-of-freedom circular omnidirectional mobile robot chassis according to claim 4, characterized in that: The steering power unit includes a steering motor (A-13) and a second motor drive assembly. The second motor drive assembly is mounted on the steering motor (A-13) to drive the steering motor (A-13) in steering.

6. The multi-degree-of-freedom circular omnidirectional mobile robot chassis according to claim 5, characterized in that: The second motor drive assembly includes a second motor drive unit and a second coaxial mounting assembly, which are coaxially mounted on the steering motor (A-13) from top to bottom.

7. The multi-degree-of-freedom circular omnidirectional mobile robot chassis according to claim 6, characterized in that: The steering wheel reduction mechanism is a three-stage reduction mechanism.

8. The multi-degree-of-freedom circular omnidirectional mobile robot chassis according to claim 7, characterized in that: The wheels (A-22) are rubber wheels.

9. A multi-degree-of-freedom circular omnidirectional mobile robot chassis according to claim 7, characterized in that: It also includes a battery assembly (B), which is mounted on a circular disc (F).

10. A multi-degree-of-freedom circular omnidirectional mobile robot chassis according to claim 7, characterized in that: It also includes a main control computer (C), which is mounted on a circular disk (F).

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