Magnetic type omni-directional moving spherical robot based on line driving

Abstract

The invention discloses a line-driven magnetic type omni-directional moving spherical robot, and relates to the technical field of moving robots. The device comprises a magnetic outer spherical shell, an internal mass block assembly, a linear driving assembly, a detection assembly and a control unit, the internal mass block assembly is composed of an upper electromagnet, a lower side weight and a spring connecting the upper electromagnet and the lower side weight, the linear driving assembly comprises at least three sets of driving motors and high-strength steel wire ropes which are distributed in the circumferential direction, and the detection assembly comprises double gradienters. In the working process, the electromagnet is electrified to attract the outer spherical shell to fix the mass block, rope winding / unwinding actions of the driving motor in different directions are matched with deformation of the spring, the mass block tilts to achieve mass center deviation, and the outer spherical shell is pushed to roll; after the gradienter detects that the posture is reset, the electromagnet is powered off and repeated. According to the invention, the transmission structure is simplified, the motion response speed and omnidirectional flexibility are improved, and the device can be widely applied to scenes such as complex terrain detection and indoor inspection.

Description

Technical Field

[0001] This invention relates to the field of mobile robot technology, specifically to a line-driven magnetic omnidirectional mobile spherical robot, which is particularly suitable for scenarios such as indoor inspection, complex terrain exploration, educational demonstrations, and operations in confined spaces. It belongs to the field of structural design and control technology for omnidirectional mobile robots. Background Technology

[0002] Spherical robots, with their unique advantages such as impact resistance due to their enclosed structure, flexible omnidirectional movement, and strong environmental adaptability, have broad application prospects in special operations and civilian inspection fields. Currently, the mainstream driving methods for spherical robots mainly include three types: friction-driven, center-of-gravity offset-driven, and line-driven. However, existing technologies still have many shortcomings:

[0003] Friction-driven spherical robots rely on the friction between the internal drive wheels and the outer spherical shell to transmit power. Although they can achieve omnidirectional movement, they are susceptible to slippage due to factors such as the roughness of the contact surface and changes in load, which leads to a decrease in motion accuracy. In addition, the internal wheel system is complex, containing multiple drive motors, reducers and guiding mechanisms, which not only increases the overall weight and size, but also increases maintenance costs.

[0004] Center-of-gravity offset spherical robots adjust the position of their internal center of gravity through mechanical links, counterweights, and other structures, and use gravitational torque to drive the outer spherical shell to roll. However, traditional structures mostly use hydraulic or pneumatic drives, which have slow response speeds and are difficult to achieve high-frequency center-of-gravity adjustments, resulting in insufficient motion flexibility. At the same time, the mechanical wear of the linkage mechanism is severe, and jamming problems are likely to occur after long-term use.

[0005] Wire-driven spherical robots move their internal components by retracting and extending steel wire ropes. The structure is relatively simple, but traditional designs lack a stable fixation-reset mechanism. The tension control of the steel wire ropes is not precise and is prone to slack or overstretching, resulting in poor motion smoothness. Moreover, most wire-driven structures can only achieve unidirectional or bidirectional motion, which is difficult to meet the actual needs of omnidirectional movement.

[0006] Therefore, designing a spherical robot with a simplified structure, fast response, stable motion, and omnidirectional flexibility has become the key to solving the pain points of existing technologies. Summary of the Invention

[0007] This invention aims to provide a line-driven magnetic omnidirectional spherical robot. Through a cyclic mechanism of "magnetic fixation - line-driven tilting - spring reset", it solves the problems of complex transmission, slow response, and poor motion stability of traditional spherical robots, and achieves a simplified structure, fast response, and omnidirectional flexible movement effect.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A line-driven magnetic omnidirectional mobile spherical robot includes a magnetic outer shell, an internal mass block assembly, a line-driven assembly, a detection assembly, and a control unit. The components work together to achieve omnidirectional movement.

[0010] The magnetic outer shell is made of high-strength magnetic alloy material to form a complete spherical structure with a smooth curved inner wall to ensure stable adsorption by the electromagnet. The surface of the outer shell is treated with anti-slip material to increase the coefficient of friction with the ground and prevent slippage during rolling. The outer shell is divided into upper and lower hemispheres, which can be detachably connected by buckles to facilitate the installation and maintenance of internal components.

[0011] The internal mass block assembly is the core of the robot's center of gravity adjustment, including a support frame, electromagnet, weight, and spring. The support frame is made of lightweight aluminum alloy and serves for fixation and load-bearing. The electromagnet is fixed to the upper part of the support frame and generates strong magnetism when energized, allowing it to quickly adhere to the inner wall of the magnetic outer spherical shell. The weight is a high-density metal block, movably connected to the lower part of the support frame, used to adjust the overall center of gravity position. The spring connects the electromagnet and the weight, keeping them coaxial and horizontal in their natural state; it can elastically deform under force and drive the assembly to reset after unloading. The bottom of the support frame also has three circumferentially distributed bullseye wheels that roll in contact with the inner wall of the outer spherical shell, reducing frictional resistance during movement.

[0012] The line drive assembly is used to drive the internal mass block assembly to tilt. It includes three sets of drive units evenly distributed circumferentially, each set corresponding to a direction of movement, and omnidirectional movement is achieved through combined control. Each drive unit consists of a servo drive motor, a winding device, a high-strength steel wire rope, rollers, and a mounting hole. The drive motor is coaxially connected to the winding device and is used to control the winding and unwinding of the steel wire rope. The high-strength steel wire rope is made of stainless steel wire with a low elastic modulus. One end is fixed to the mounting hole, and the other end is guided by the rollers and wound around the winding device. The winding device is equipped with a tension adjustment mechanism to prevent the steel wire rope from being overstretched or slack.

[0013] The detection components include an upper level and a lower level, both of which are high-precision digital levels used to detect the attitude of the internal components in real time. The upper level is fixed to the lower part of the electromagnet and is used to detect whether the electromagnet is in a horizontal state; the lower level is fixed inside the weight and is used to detect whether the weight has returned to a horizontal position. The detection data is transmitted to the control unit in real time.

[0014] The control unit, the core of the robot's control system, includes an industrial computer, a drive circuit board, and a lithium battery, integrated and installed in the middle of the support frame. The industrial computer stores motion control algorithms and receives attitude detection signals from the level indicator. Based on a preset motion trajectory, it controls the on / off state of the electromagnets and the forward / reverse rotation and speed of each drive motor. The drive circuit board converts the control signals from the industrial computer into drive current, providing stable power to the electromagnets and motors. The lithium battery powers the entire system and supports a rechargeable design to ensure battery life.

[0015] Taking forward motion as an example, the motion control process of this invention is as follows:

[0016] (1) During the adsorption and fixation stage, after the control unit is started, the upper level first detects the attitude of the electromagnet. When the electromagnet is detected to be in a horizontal state, the industrial control computer sends a signal to control the electromagnet to be energized. The electromagnet generates strong magnetism and quickly adsorbs onto the inner wall of the magnetic outer spherical shell, so that the internal mass block assembly and the outer spherical shell remain relatively fixed.

[0017] (2) During the wire-driven center of mass offset stage, according to the preset command for forward movement, the industrial control computer controls the corresponding front drive motor to rotate forward, and the winding device tightens the high-strength steel wire rope; at the same time, it controls the drive motors on the left and right sides to rotate in reverse, and the winding device loosens the steel wire rope. Under the tension of the steel wire rope, the support frame tilts forward, the front spring is compressed and shortened, and the rear spring is stretched, which drives the lower weight block to tilt forward, the robot's overall center of mass shifts forward, and the resulting gravitational torque pushes the outer spherical shell to roll forward.

[0018] (3) During the attitude reset stage, when the outer spherical shell rolls until the weight returns to a horizontal state, the lower level instrument detects a horizontal signal and transmits it to the industrial control computer. The industrial control computer immediately controls the electromagnet to de-energize, releasing the electromagnet from its attraction and fixation to the outer spherical shell. Subsequently, it controls all drive motors to reverse and reset, the wire rope to relax, and the spring to return to its natural state under the action of elastic force, driving the upper electromagnet back to the horizontal position.

[0019] (4) During the cyclical motion phase, after the upper level instrument detects that the electromagnet has returned to a horizontal position, it sends a signal to the industrial control computer. The industrial control computer then controls the electromagnet to be energized again to attract the outer spherical shell, thus entering the next motion cycle. By repeating the above cycle at high frequency, the robot's continuous forward movement is achieved.

[0020] (5) When it is necessary to turn, rotate or change speed, the control unit can change the direction and magnitude of the center of gravity offset by adjusting the rope winding and unwinding logic and speed of the drive motors in different directions. This will enable the corresponding motion state switching.

[0021] The beneficial effects of this invention are:

[0022] (1) The structure is simplified and efficient. It adopts a combination structure of "electromagnet + spring + line drive" to replace the complex wheel system or center of gravity offset linkage mechanism of traditional friction drive, which reduces the number of internal transmission parts, reduces the overall weight and maintenance cost, and facilitates assembly and debugging.

[0023] (2) Fast motion response: The high-frequency switching of the electromagnet and the fast rope winding and unwinding action of the servo motor realize the high-frequency adjustment of the center of mass. The motion response speed is improved compared with the traditional center of mass offset type robot, and it can quickly realize acceleration, deceleration and turning switching.

[0024] (3) It is flexible and stable in all directions. The three sets of drive units distributed in the circumference support the movement adjustment in any direction. With the closed-loop control of the dual level, it can accurately control the center of gravity offset and avoid the tipping problem caused by excessive tilting. The design of the bullseye wheel reduces the friction between the internal components and the outer spherical shell, and improves the smoothness of the movement.

[0025] (4) It has strong environmental adaptability. The closed spherical structure is impact-resistant and collision-proof, and can adapt to complex terrain with uneven surfaces. The anti-slip treatment on the outer shell surface and the stable center of gravity control inside ensure stable movement on smooth or rough ground, and it is applicable to a wide range of scenarios. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural diagram of one embodiment of the present invention;

[0027] Figure 2 for Figure 1 A schematic diagram of the internal core components in the implementation method;

[0028] Figure 3 for Figure 1 A schematic diagram of the specific structure of the internal core components in the implementation method.

[0029] In the diagram: 1-Magnetic outer spherical shell, 2-Internal mass block, 3-Electromagnet, 4-High-strength steel wire rope, 5-Hole seat, 6-Bullseye wheel, 7-Upper level, 8-Roller, 9-Spring, 10-Drive motor, 11-Control circuit board, 12-Lower level, 13-Industrial computer, 14-Power battery. Detailed Implementation

[0030] The technical solution of the present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0031] like Figures 1 to 3 As shown, the line-driven magnetic omnidirectional mobile spherical robot of the present invention includes a magnetic outer spherical shell 1 and an internal mass block 2, a line drive assembly, a detection assembly, and a control unit installed inside it.

[0032] The magnetic outer shell 1 is made of high-strength magnetic alloy material to form a complete spherical structure with an anti-slip surface and a smooth curved inner wall to provide a stable adsorption surface for the electromagnet 3. The magnetic outer shell 1 can be disassembled into upper and lower hemispheres, which are fixed by a snap-fit ​​structure to facilitate the installation and maintenance of internal components.

[0033] The internal mass block 2 includes an electromagnet 3, a weight, and a spring 9. The electromagnet 3 is fixed to the upper part of the internal mass block 2 and can be quickly attracted to the inner wall of the magnetic outer spherical shell 1 after being energized. The weight is set at the lower part of the internal mass block 2 and is used to adjust the overall center of gravity of the robot. The spring 9 is connected between the electromagnet 3 and the weight. In its natural state, it keeps the two coaxial and horizontal. After being subjected to force, it can elastically deform and drive the components to reset after unloading. The bottom of the internal mass block 2 is provided with a bullseye wheel 6, which contacts the inner wall of the magnetic outer spherical shell 1 to reduce frictional resistance during movement.

[0034] The line drive assembly includes three sets of drive units evenly distributed circumferentially. Each set of drive units consists of a drive motor 10, a high-strength steel wire rope 4, a roller 8, and a hole seat 5. The drive motor 10 is fixed to the support structure of the internal mass block 2. One end of the high-strength steel wire rope 4 is connected to the hole seat 5, and after being guided by the roller 8 in the middle, it enters the interior of the weight block below the internal mass block 2. The other end is wound around the winding structure of the drive motor 10. The forward and reverse rotation of the drive motor 10 realizes the winding and unwinding of the high-strength steel wire rope 4, thereby causing the internal mass block 2 to tilt.

[0035] The detection assembly includes an upper level 7 and a lower level 12. The upper level 7 is fixed to the top of the electromagnet 3 and is used to detect the horizontal attitude of the electromagnet 3. The lower level 12 is fixed to the side of the weight and is used to detect the horizontal attitude of the weight. The detection data of the two are transmitted to the control unit in real time.

[0036] The control unit consists of a control circuit board 11, an industrial computer 13, and a power battery 14. The power battery 14 provides a stable power supply for the entire system. The control circuit board 11 is used to convert the control signals of the industrial computer 13 into drive current, control the on / off state of the electromagnet 3 and the operation of the drive motor 10. The industrial computer 13 has a pre-stored motion control algorithm, which adjusts the speed and direction of the drive motor 10 according to the detection signals of the upper level 7 and the lower level 12.

[0037] The motion control scheme for the above-mentioned robot mechanism is as follows:

[0038] (1) At the initial moment, the upper level 7 detects the attitude of the electromagnet 3. When the electromagnet 3 is detected to be in a horizontal state, the industrial control computer 13 sends a signal to control the electromagnet 3 to be energized through the control circuit board 11, so that it is attracted to the inner wall of the magnetic outer spherical shell 1, so that the internal mass block 2 and the outer spherical shell remain relatively fixed.

[0039] (2) According to the preset motion direction, the industrial control computer 13 controls the drive motor 10 in the corresponding direction to rotate forward to retract the rope, and the other drive motors 10 to rotate in reverse to release the rope. The high-strength steel wire rope 4 generates a tension difference, which drives the internal mass block 2 to tilt in the target direction. The spring 9 deforms to shift the weight block, and the robot's center of mass changes, thereby pushing the magnetic outer spherical shell 1 to roll.

[0040] (3) When the magnetic outer shell 1 rolls to the point where the weight returns to a horizontal state, the lower level 12 detects the horizontal signal and transmits it to the industrial control computer 13. The industrial control computer 13 controls the electromagnet 3 to be de-energized, releasing the adsorption and fixation with the magnetic outer shell 1. Then the drive motor 10 reverses and resets, the high-strength steel wire rope 4 is relaxed, and the spring 9 rebounds and drives the electromagnet 3 back to the horizontal position.

[0041] (4) Repeat the above steps and adjust the rope feeding and releasing logic and speed of the drive motor 10 in different directions to realize the robot's omnidirectional movements such as straight line, turning, rotation and acceleration and deceleration.

Claims

1. A line-driven magnetic omnidirectional spherical robot, characterized in that, include: Magnetic outer spherical shell (1), internal mass block assembly, wire drive assembly, detection assembly and control unit; The magnetic outer spherical shell (1) is made of magnetic material, and its inner wall forms a smooth curved surface for the electromagnet (3) to be attracted. The internal mass block assembly includes a support frame, an electromagnet (3) disposed on the upper part of the support frame, a weight disposed on the lower part of the support frame, and a spring (9) connecting the electromagnet (3) and the weight. The line drive assembly includes at least three sets of drive units evenly distributed along the circumference. Each set of drive units includes a drive motor (10), a reel driven by the drive motor (10), a high-strength steel wire rope (4), and a hole seat (5). One end of the high-strength steel wire rope (4) is fixed to the hole seat (5), and its rope body is guided by a guide roller (8), while the other end is wound around the reel. The detection assembly includes an upper level (7) for detecting the horizontal orientation of the electromagnet (3) and a lower level (12) for detecting the horizontal orientation of the weight. The control unit includes an industrial computer (13) and a control circuit board (11). The industrial computer (13) is connected to the upper level (7) and the lower level (12) respectively. The control circuit board (11) is connected to the industrial computer (13) and is used to control the on / off state of the electromagnet (3) and the operation of each of the drive motors (10).

2. The line-driven magnetic omnidirectional spherical robot according to claim 1, characterized in that: The bottom of the support frame of the internal mass block assembly is provided with at least three bullseye wheels (6) distributed circumferentially, and the bullseye wheels (6) are in rolling contact with the inner wall of the magnetic outer spherical shell (1).

3. The line-driven magnetic omnidirectional spherical robot according to claim 1, characterized in that: The high-strength steel wire rope (4) is made of stainless steel with low elastic modulus; the drive motor (10) is a servo motor, and its winding mechanism is equipped with a tension adjustment mechanism.

4. A motion control method for controlling a line-driven magnetic omnidirectional spherical robot as described in any one of claims 1 to 3, characterized in that, Includes the following iterative steps: (1) Initial adsorption step: The attitude of the electromagnet (3) is detected by the upper level (7). When the electromagnet (3) is detected to be in a horizontal state, the control unit controls the electromagnet (3) to be energized so that it is adsorbed and fixed to the inner wall of the magnetic outer shell (1). (2) Center of mass offset driving step: According to the target motion direction, the control unit controls the drive motor (10) in the corresponding direction to wind up its high-strength steel wire rope (4), and controls the drive motor (10) in the other directions to release its high-strength steel wire rope (4), so that the internal mass block assembly tilts as a whole towards the target direction, the spring (9) deforms, the position of the weight block shifts, the robot's center of mass changes and drives the magnetic outer spherical shell (1) to roll; (3) Reset step: The posture of the weight is detected by the lower level (12). When the weight is detected to be restored to a horizontal state, the control unit controls the electromagnet (3) to be de-energized and released from adsorption, and controls all drive motors (10) to reverse to release the tension of the wire rope. The spring (9) drives the electromagnet (3) to restore the horizontal posture under the action of elastic restoring force. (4) By repeating steps (1) to (3) and adjusting the rope-reeling logic and speed of different drive motors (10), the robot can move in all directions.

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