Reconfigurable motion platform and mobile robot with multiple motion modes in pipeline curved surface environment

Abstract

The invention provides a reconfigurable motion platform and a mobile robot with multiple motion modes in a pipeline curved surface environment, the reconfigurable motion platform comprises six connecting rods, and the six connecting rods are sequentially connected end to end through six revolute pairs to form a single-loop closed chain space 6R mechanism; among the six revolute pairs, the axis extension lines of three adjacent revolute pairs intersect at a first virtual point, the axis extension lines of the other three adjacent revolute pairs intersect at a second virtual point, the first virtual point and the second virtual point form a virtual reference line, and the plane where the perpendicular bisector of the virtual reference line is located forms a vertical bisector of the space 6R mechanism. Wherein the six revolute pairs comprise at least three driving revolute pairs, and each driving revolute pair is provided with a first actuating unit, so that the space 6R mechanism is switched between different configurations.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of pipeline robot, and particularly relates to a reconfigurable motion platform and a mobile robot with multiple motion modes in a pipeline curved surface environment. BACKGROUND

[0002] As a long-distance transportation channel for oil and gas, water and other media, the detection and maintenance of pipelines urgently need robots to replace human work.

[0003] Currently, there are two types of mobile robots suitable for pipeline curved surfaces: one is a support robot that relies on an unfolding mechanism to abut the pipe wall, but mechanical interference and jamming easily occur in curved pipes and variable diameter sections; the other is a traditional mobile device, and the rigid vehicle body and fixed wheel system are difficult to adapt to the continuously changing curved surface, which easily leads to wheel suspension, skidding and motion instability. The common defects of these two types of technology are that they are fixed in shape and lack dynamic adaptability, and cannot always maintain stable adhesion and reliable motion in a changing curvature environment.

[0004] Therefore, there is an urgent need for a core motion mechanism that can actively adjust its own configuration to adapt to different pipeline curves. SUMMARY

[0005] Therefore, the embodiments of the present disclosure provide a reconfigurable motion platform and a mobile robot with multiple motion modes in a pipeline curved surface environment, which at least partially solve the above technical problems.

[0006] The embodiments of the present disclosure provide a reconfigurable motion platform, comprising: six connecting rods, the six connecting rods are sequentially connected through six rotating pairs, and a single ring closed chain spatial 6R mechanism is formed; among the six rotating pairs, the axis extension lines of three adjacent rotating pairs intersect at a first virtual point, and the axis extension lines of the other three adjacent rotating pairs intersect at a second virtual point, the connecting line of the first virtual point and the second virtual point forms a virtual reference line, and the plane where the perpendicular bisector of the virtual reference line is located forms the perpendicular bisector surface of the spatial 6R mechanism; wherein the six rotating pairs include at least three driving rotating pairs, each driving rotating pair is configured with a first actuating unit, so that the spatial 6R mechanism is switched between different configurations.

[0007] According to an embodiment of the present disclosure, the spatial 6R mechanism is configured to switch between at least two of the first configuration, the second configuration and the third configuration; when the spatial 6R mechanism is in the first configuration, the portions of the spatial 6R mechanism located on both sides of the virtual reference line are bent and gathered around the virtual reference line; when the spatial 6R mechanism is in the second configuration, the portions of the spatial 6R mechanism located on one side of the perpendicular bisector are curved relative to the portions located on the other side of the perpendicular bisector; and when the spatial 6R mechanism is in the third configuration, the portions of the spatial 6R mechanism located on both sides of the perpendicular bisector are curved relative to the perpendicular bisector and mirror-symmetric.

[0008] According to an embodiment of the present disclosure, the six revolute pairs include three active revolute pairs and three passive revolute pairs, the three active revolute pairs are sequentially arranged along a closed loop and located on both sides of the perpendicular bisector, and the three passive revolute pairs are respectively arranged opposite to the three active revolute pairs; or, the six revolute pairs are all active revolute pairs.

[0009] According to an embodiment of the present disclosure, the first actuating unit configured for the active revolute pair includes a servo motor, an output shaft of the servo motor defines an axis of the active revolute pair, and a housing and the output shaft of the servo motor are respectively connected to two adjacent connecting rods.

[0010] According to an embodiment of the present disclosure, the passive revolute pair includes a sleeve and a shaft-shaped member penetrating the sleeve, the shaft-shaped member defines an axis of the passive revolute pair, and the sleeve and the shaft-shaped member are respectively connected to two adjacent connecting rods.

[0011] According to an embodiment of the present disclosure, the connecting rod includes a main body configured as a frame structure, at least two connecting portions arranged at two opposite ends of the main body and configured as arc structures, and the at least two connecting portions are respectively connected to two revolute pairs.

[0012] The present disclosure further provides a mobile robot having multiple motion modes in a pipe curved surface environment, including a reconfigurable motion platform, six connecting rods of the reconfigurable motion platform including two first connecting rods arranged opposite to each other, the first connecting rods being parallel to a virtual reference line of a spatial 6R mechanism, four second connecting rods divided by a perpendicular bisector of the spatial 6R mechanism into two groups, two second connecting rods in each group being sequentially arranged between two first connecting rods, the second connecting rods being at an angle with the virtual reference line, and the mobile robot further including four wheeled chains each arranged on a second connecting rod, and each wheeled chain being configured with traveling wheels.

[0013] According to an embodiment of the present disclosure, the wheeled chain includes: a mounting portion pivotally connected to the second link; an actuating portion configured to output torque to the travel wheel; and a lifting portion disposed between the mounting portion and the actuating portion, configured to adjust the vertical distance between the travel wheel and the second link.

[0014] According to an embodiment of the present disclosure, the lifting part includes a first motor; the main body of the first motor is connected to one of the mounting part and the actuating part, and the output shaft of the first motor is connected to the other of the mounting part and the actuating part, so that the actuating part rotates about the output shaft of the first motor; wherein the rotation plane of the actuating part is perpendicular to the rotation plane of the mounting part.

[0015] According to an embodiment of this disclosure, the actuation unit includes a second motor and a transmission assembly, wherein the output shaft of the second motor transmits torque to the traveling wheel through the transmission assembly.

[0016] According to embodiments of this disclosure, the four aforementioned wheeled branches are configured to adjust the position of the aforementioned travel wheels in response to the configuration of the aforementioned space 6R mechanism, so that the aforementioned mobile robot has different motion modes.

[0017] According to embodiments of this disclosure, in response to the spatial 6R mechanism in the first configuration, the two traveling wheels on each side of the vertical bisecting plane are arranged in a figure-eight shape to give the mobile robot a first motion mode; in response to the spatial 6R mechanism in the second configuration, the centers of the four traveling wheels are located on a common sphere to give the mobile robot a second motion mode; in response to the spatial 6R mechanism in the third configuration, the centers of the four traveling wheels are located on a common reference plane, which is parallel to the virtual reference line and perpendicular to the vertical bisecting plane.

[0018] According to embodiments of this disclosure, the aforementioned travel wheels are configured to be made of magnetic material so that the mobile robot can be adsorbed onto the inner wall of the pipe.

[0019] The reconfigurable motion platform and mobile robot provided in this disclosure are based on a core structure where six links are connected end-to-end via six revolute joints, forming a single-loop closed-chain spatial 6R mechanism. The axes of three adjacent revolute joints intersect at a first virtual point, and the axes of the other three adjacent revolute joints intersect at a second virtual point, thus forming a geometric basis with inherent symmetry and reconfigurability. By driving the active revolute joints, this spatial 6R mechanism can actively switch between various configurations, dynamically adjusting its overall shape to adapt to different working scenarios of the mobile robot. This effectively improves the mobile robot's mobility, motion stability, and overall operational reliability in complex environments. Attached Figure Description

[0020] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0021] Figure 1 A perspective view of a reconfigurable motion platform according to an embodiment of the present disclosure is shown schematically;

[0022] Figure 2 A perspective view of a mobile robot with multiple motion modes in a curved pipe environment according to an embodiment of the present disclosure is schematically shown.

[0023] Figure 3 yes Figure 2 The diagram shows a mobile robot with multiple motion modes in a curved pipe environment, in its first motion mode. It also shows the first configuration of the reconfigurable motion platform.

[0024] Figure 4 yes Figure 3 The diagram shows a mobile robot with multiple motion modes operating in a straight pipe environment within a curved pipe surface environment.

[0025] Figure 5 yes Figure 2 The diagram shows a mobile robot with multiple motion modes in a curved pipe environment, in its second motion mode. It also shows a second configuration of a reconfigurable motion platform.

[0026] Figure 6 yes Figure 5 The diagram shows a mobile robot with multiple motion modes operating in a curved pipe environment.

[0027] Figure 7 yes Figure 2 The diagram shows a mobile robot with multiple motion modes in a curved pipe environment, in its second motion mode. It also shows another second configuration of the reconfigurable motion platform.

[0028] Figure 8 yes Figure 7 The diagram shows a mobile robot with multiple motion modes operating in a curved pipe environment.

[0029] Figure 9 yes Figure 2 The diagram shows a mobile robot with multiple motion modes in a curved pipe environment, in its third motion mode. It also shows the third configuration of the reconfigurable motion platform.

[0030] Figure 10 yes Figure 9The diagram shows a mobile robot with multiple motion modes operating in a U-shaped pipe environment.

[0031] Figure label:

[0032] 100. Reconfigurable motion platform; 110. Linkage; 111. First link; 1111. Arc plate; 1112. End plate; 1113. Rib plate; 1114. Support plate; 112. Second link; 1121. First bracket; 120. Driving revolute joint; 130. Driven revolute joint; 140. First part; 150. Second part;

[0033] 200. Wheeled chain; 210. Mounting part; 220. Lifting part; 221. Second bracket; 230. Actuating part; 231. Pulley; 232. Synchronous belt; 233. Second motor; 234. Third bracket; 240. Traveling wheel;

[0034] 310. Straight pipe; 320. Bend pipe; 330. U-shaped pipe. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0036] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0037] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0038] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0039] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0040] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0041] Pipelines, serving as long-distance transport channels for critical media such as oil, gas, and water, are vital energy infrastructure, and their long-term safe and stable operation is crucial. However, pipelines typically operate underground, overhead, or underwater, with enclosed spaces that may contain hazardous substances or be under high pressure. This presents traditional manual inspection and maintenance methods with severe challenges, including high safety risks, low efficiency, and limited accessibility. Therefore, adopting mobile equipment (such as wheeled robots) to autonomously enter pipelines for inspection, flaw detection, and cleaning has become an inevitable trend in the industry.

[0042] Currently, mobile devices designed for the curved inner walls of pipelines mainly follow two technical routes, but both suffer from inherent defects due to their fixed body structure. The first is the support-type mobile robot, which relies on multiple radially deployable mechanisms to abut against the pipe wall to provide driving force and stability, performing well in straight pipes. However, because its deployed structural dimensions are fixed and occupy a large space, it is prone to mechanical interference and jamming when passing through areas with abrupt changes in pipe geometry or local obstacles, such as bends, tees, valves, or diameter changes, resulting in poor environmental mobility. The second is the traditional wheeled mobile robot, which typically uses a rigid body and fixed wheel system. While simple in structure and mature in control, its fixed form cannot adapt to the continuously changing high curvature surfaces of the pipeline inner wall. When the robot moves from a straight pipe section into a bend or moves on complex curved surfaces, it is difficult to ensure that all driving wheels maintain reliable contact with the wall simultaneously, easily leading to wheel suspension and slippage, resulting in loss of driving force, motion instability, and decreased positioning accuracy.

[0043] Therefore, the common limitation of existing technologies lies in the static and rigid form of the motion platform, lacking the ability to dynamically self-adjust according to the shape of the pipe surface, thus failing to maintain stable and efficient attachment and motion performance throughout the entire process. Therefore, there is an urgent need for a motion platform that can actively reconstruct its body shape to adapt to different pipe surfaces, in order to improve the overall passability and operational reliability of mobile devices equipped with such a motion platform in complex pipe networks.

[0044] Figure 1 A perspective view of a reconfigurable motion platform according to an embodiment of the present disclosure is shown schematically.

[0045] This disclosure provides a reconfigurable motion platform 100, with reference to... Figure 1 As shown, the mechanism includes six links 110, which are connected end-to-end via six revolute joints to form a single-loop closed-chain spatial 6R mechanism. Among the six revolute joints, the extended axes of three adjacent revolute joints intersect at a first virtual point, and the extended axes of the other three adjacent revolute joints intersect at a second virtual point. The line connecting the first and second virtual points forms a virtual reference line, and the plane containing the perpendicular bisector of the virtual reference line forms the perpendicular bisector of the spatial 6R mechanism. The six revolute joints include at least three active revolute joints 120, each equipped with a first actuation unit to enable the spatial 6R mechanism to switch between different configurations.

[0046] In some illustrative embodiments, reference is made to Figure 1As shown, the reconfigurable motion platform 100 includes six links 110, which are connected end-to-end via six revolute joints to form a single-loop closed-chain spatial 6R mechanism (R stands for Revolute Joint). Specifically, viewed along this closed-loop sequence, the six revolute joints can be divided into two groups. The extended axes of three adjacent revolute joints intersect at a first virtual point (F1), while the extended axes of the other three adjacent revolute joints intersect at a second virtual point (F2). The line connecting the first and second virtual points forms a virtual reference line (F1F2). The perpendicular bisector of this virtual reference line forms the plane of symmetry for the entire mechanism, which can be called the perpendicular bisector (XY plane). This perpendicular bisector divides the mechanism into two parts (specifically, the first part 140 and the second part 150 described below). Furthermore, at least three of the six revolute joints are configured as active revolute joints 120 (i.e., revolute joints that can output controllable torque and motion so that the two connecting rods 110 connected via the revolute joint can produce the expected relative rotation). Each active revolute joint 120 is provided with a first actuation unit. By controlling these first actuation units, the active revolute joint 120 can be driven to rotate precisely, thereby enabling the entire space 6R mechanism to switch and transform between different preset configurations.

[0047] It should be noted that the first virtual point (F1) and the second virtual point (F2) are both virtual geometric points, not actual physical structural components, but conceptual references established to describe the spatial geometric relationship between the rotational axes of the reconfigurable motion platform 100. The aforementioned perpendicular bisector is also a virtual geometric plane (i.e., the XY plane), defined by the line connecting the first and second virtual points, perpendicular to this line, and passing through its midpoint. This perpendicular bisector can be considered as being fixed to the mechanism configuration of the reconfigurable motion platform 100, used to characterize and define the symmetry relationship and attitude reference of the mechanism in space, and is part of the geometric reference system for analyzing the motion and configuration transformations of the reconfigurable motion platform 100.

[0048] In this implementation, based on the aforementioned geometric constraints, the spatial 6R mechanism formed by the reconfigurable motion platform 100 possesses inherent motion laws and coupling characteristics. By driving at least three active rotary joints 120, the entire reconfigurable motion platform 100 can actively and controllably switch between various preset configurations, completing the dynamic reconstruction of its overall form. This makes the reconfigurable motion platform 100 no longer a traditional rigid fixed structure, but capable of actively adjusting its own form in actual use environments, such as according to specific changes in the pipeline environment (e.g., transitioning from a straight pipe section to a curved pipe section or traversing a diameter-changing area).

[0049] According to embodiments of this disclosure, referring to Figure 1As shown, the connecting rod 110 includes a main body and at least two connecting parts. The main body is configured as a frame structure. The at least two connecting parts are located at opposite ends of the main body and are configured as arc-shaped structures. Each of the at least two connecting parts connects to a revolute joint (i.e., an active revolute joint 120 and a driven revolute joint 130, the driven revolute joint being understood as a revolute joint without active driving capability, whose movement is entirely passively determined by the movement of other components (usually driven by the active revolute joint 120).

[0050] In some illustrative embodiments, reference is made to Figure 1 As shown, the connecting rod 110 mainly includes a main body and connecting parts disposed at both ends thereon. The main body constitutes the core load-bearing frame of the connecting rod 110, and is typically constructed as a stable frame structure. Specifically, the main body may include at least two end plates 1112 arranged parallel and spaced apart along the closed-loop extension direction, a support plate 1114 extending along this direction and connected between the two end plates 1112, and triangular stiffening plates 1113 disposed at the connection position between the end plates 1112 and the support plate 1114 to enhance overall rigidity. Furthermore, the connecting parts are configured as arc-shaped structures, specifically at least two arc-shaped plates 1111 fixed to the end plates 1112 at intervals along a direction orthogonal to the closed-loop extension direction. An active rotary joint 120 or a driven rotary joint 130 is installed between the two arc-shaped plates 1111 at each end to form a stable and reliable rotational support.

[0051] In this implementation, the aforementioned connecting rod 110 is configured as a composite mechanical component with a specific functional configuration, integrating a frame-like main body and a dedicated arc-shaped connection interface (i.e., a connecting part). This satisfies the specific geometric constraints, motion relationships, and installation requirements of the aforementioned spatial 6R mechanism. The main body provides a stable mechanical framework, while the arc-shaped connecting part provides the necessary space, interface, and degrees of freedom for the installation and movement of the revolute joint, thus ensuring both overall structural strength and the coordination of the mechanism's motion.

[0052] It should be noted that the aforementioned link 110 refers to the rigid connecting member constituting the aforementioned spatial 6R mechanism. Its core function is to transmit motion and force between two adjacent revolute joints, and it is not a rod-shaped or bar-shaped structure with a uniform cross-section as traditionally understood. Based on this, in addition to the above-described embodiments, the structure of the link 110 can be adaptively designed according to specific needs.

[0053] For example, in other embodiments, the main body of the connecting rod 110 may be constructed as a plate-shaped monolithic structure integrally formed or welded from one or more plates, with its two ends forming the arc-shaped connecting parts by bending or welding, thereby achieving lightweighting and simplified manufacturing process.

[0054] Alternatively, the main body of the connecting rod 110 may adopt a lightweight truss structure based on topology optimization or an internally reinforced shell structure, thereby further reducing the weight while meeting the requirements for stiffness and strength, and its connection part still maintains an arc design to accommodate the installation of the rotating pair.

[0055] According to embodiments of this disclosure, referring to Figure 1 As shown, the six rotary joints include three driving rotary joints 120 and three driven rotary joints 130. The three driving rotary joints 120 are arranged sequentially along the closed loop and located on both sides of the perpendicular bisector plane. The three driven rotary joints 130 are each arranged opposite to one driving rotary joint 120.

[0056] According to embodiments of this disclosure, referring to Figure 1 As shown, the first actuation unit configured in the active rotary joint 120 includes a servo motor, the output shaft of which defines the axis of the active rotary joint 120. The servo motor housing and output shaft are each connected to two adjacent connecting rods 110.

[0057] According to embodiments of this disclosure, referring to Figure 1 As shown, the driven rotary joint 130 includes a kit and a shaft member passing through the kit, the shaft member defining the axis of the driven rotary joint 130. The kit and the shaft member are each connected to two adjacent connecting rods 110.

[0058] In some illustrative embodiments, reference is made to Figure 1 As shown, the six revolute joints of the aforementioned spatial 6R mechanism include three active revolute joints 120 and three driven revolute joints 130. Specifically, the three active revolute joints 120 are arranged sequentially along the closed loop of the spatial 6R mechanism and distributed on both sides of the vertical bisecting plane (i.e., the XY plane). That is, the vertical bisecting plane passes through two opposing connecting rods 110 (such as the first connecting rod 111 described below, which will be specifically described in the following embodiments), such that one active revolute joint 120 and two active revolute joints 120 are distributed on both sides of the connecting rod 110, respectively. Furthermore, each of the three driven revolute joints 130 is arranged opposite to one active revolute joint 120, thereby forming a symmetrical and coupled kinematic constraint relationship as a whole. In this way, when at least one active revolute joint 120 outputs torque to the connected connecting rod 110, the opposite driven revolute joint 130 can cause the connecting rod 110 on the opposite side to perform a synchronous follow-up action.

[0059] In some illustrative embodiments, reference is made to Figure 1As shown, the first actuation unit configured in each active rotary joint 120 includes, but is not limited to, a servo motor. Specifically, the outer housing of the servo motor is, but is not limited to, constructed as a generally cubic structure, with its output shaft extending from one side of the housing. The axis of this output shaft can be understood as the axis of the active rotary joint 120. Thus, during installation, the servo motor's housing and its output shaft are respectively fixed to two adjacent connecting rods 110, thereby integrating the servo motor into a spatial 6R mechanism. In this way, rotation of the output shaft relative to the housing can directly drive relative rotation of the adjacent connecting rods 110.

[0060] Correspondingly, the driven rotary joint 130 includes a generally cubic-shaped outer assembly and a shaft-shaped component passing through the assembly. The axis of the shaft-shaped component can be understood as the axis of the driven rotary joint 130. The assembly and the shaft-shaped component are respectively connected to two adjacent connecting rods 110, so that the two connecting rods 110 can rotate relative to each other around the axis, realizing the passive transmission of motion.

[0061] In this implementation, by designing both the first actuation unit (servo motor) and the driven rotary joint 130 (i.e., the bushing assembly formed by the kit and the shaft member) into a compact cubic shape, it not only facilitates modular installation and reliable fixation between the arc-shaped connection parts of the connecting rod 110, but also helps to optimize the structural layout and space utilization of the entire reconfigurable motion platform 100, thereby ensuring the accuracy and overall stability of the mechanism's movement. It should be understood that the embodiments of this disclosure are not limited thereto.

[0062] For example, the driving rotary joint 120 may also adopt other rotary actuators; and / or, the driven rotary joint 130 may also adopt bushing and shaft fit and other arbitrary structures that can meet the requirements of rotation and assembly.

[0063] In addition, in other embodiments, the spatial 6R mechanism can also be configured such that all six revolute joints are active revolute joints 120. Compared to the aforementioned implementation with three active joints and three driven joints (i.e., the mechanism's motion is mainly driven by three active joints, with the remaining driven joints moving passively), in this fully active configuration, the relative motion between any adjacent links 110 is directly driven by the corresponding active revolute joint 120. This means that configuration changes of the mechanism can be achieved through the coordinated and synchronous driving of at least two or even all of the active revolute joints 120, thereby providing higher degrees of freedom and adjustment accuracy in motion control.

[0064] Figure 2 A perspective view of a mobile robot with multiple motion modes in a curved pipe environment according to an embodiment of the present disclosure is shown schematically.

[0065] This disclosure also provides a mobile robot with multiple motion modes in a curved pipe environment, specifically a wheeled robot, as shown in the reference. Figure 2As shown, the mobile robot includes a reconfigurable motion platform 100 and four wheeled links 200. The reconfigurable motion platform 100 has six links 110, including two first links 111 and four second links 112. The two first links 111 are positioned opposite each other, with their extension directions parallel to the virtual reference line of the spatial 6R mechanism. The four second links 112 are divided into two groups by the perpendicular bisector of the spatial 6R mechanism. Two second links 112 in each group are sequentially positioned between the two first links 111, with their extension directions forming an angle with the virtual reference line.

[0066] In some illustrative embodiments, reference is made to Figure 2 As shown, the mobile robot includes the aforementioned reconfigurable motion platform 100 and four wheeled links 200. The six links 110 of the reconfigurable motion platform 100 have a clear geometric relationship in spatial layout. The two first links 111 are parallel to each other and opposite to each other, and their extension direction is parallel to the virtual reference line (i.e., the F1F2 line) defined by the spatial 6R mechanism. The four second links 112 are symmetrically distributed in the coordinate system jointly established by the virtual reference line and the perpendicular bisector plane (XY plane).

[0067] Specifically, the perpendicular bisector divides the four second links 112 into two groups, with each group containing two second links 112 sequentially connected to two first links 111. Topologically, this forms a single-chain closed-loop structure: "two second links 112 - one first link 111 - two second links 112 - one first link 111," with all the links 110 together forming a spatial hexagonal closed loop, constituting the main framework of the aforementioned spatial 6R mechanism. The extension direction of each second link 112 forms a specific spatial angle with the virtual reference line, allowing the spatial 6R mechanism to generate different motion branches. Furthermore, each second link 112 is equipped with a wheel-type branch 200, which is pivotally connected to the corresponding second link 112.

[0068] Based on the above layout, any configurational change of the reconfigurable motion platform 100 itself can be directly and synchronously transmitted to all four wheeled branches 200 through the change in the pose of the second link 112, thereby transforming it into a coordinated adjustment of the spatial pose of each traveling wheel 240. Ultimately, this enables the mobile robot to dynamically adapt to pipe surface environments with different curvatures and orientations, such as straight pipes 310 and curved pipes 320, achieving stable and reliable motion and operation.

[0069] According to embodiments of this disclosure, referring to Figure 2As shown, the wheel chain 200 includes a mounting portion 210, an actuating portion 230, and a lifting portion 220. The mounting portion 210 is pivotally connected to the second link 112. The actuating portion 230 is configured to output torque to the travel wheel 240. The lifting portion 220 is disposed between the mounting portion 210 and the actuating portion 230 and is configured to adjust the vertical distance between the travel wheel 240 and the second link 112.

[0070] According to embodiments of this disclosure, referring to Figure 2 As shown, the lifting unit 220 includes a first motor. The main body of the first motor is connected to one of the mounting unit 210 and the actuating unit 230, and the output shaft of the first motor is connected to the other of the mounting unit 210 and the actuating unit 230, so that the actuating unit 230 rotates about the output shaft of the first motor. The plane of rotation of the actuating unit 230 is perpendicular to the plane of rotation of the mounting unit 210.

[0071] According to embodiments of this disclosure, referring to Figure 2 As shown, the actuation unit 230 includes a second motor 233 and a transmission assembly. The output shaft of the second motor 233 transmits torque to the traveling wheel 240 through the transmission assembly.

[0072] According to embodiments of this disclosure, referring to Figure 2 As shown, the travel wheel 240 is configured to be made of magnetic material so that the mobile robot can be adsorbed onto the inner wall of the pipe.

[0073] In some illustrative embodiments, reference is made to Figure 2 As shown, the aforementioned wheeled support chain 200 mainly comprises three functional modules: a mounting section 210, a lifting section 220, and an actuation section 230. The mounting section 210 is pivotally connected to the second link 112, enabling the wheeled support chain 200 to rotate relative to the reconfigurable motion platform 100. The lifting section 220 is located between the mounting section 210 and the actuation section 230, and its function is to actively adjust the vertical distance between the traveling wheel 240 and the second link 112 to adapt to changes in the curvature of the pipe wall. The actuation section 230 outputs driving torque to the traveling wheel 240, serving as the direct power source for the robot's movement.

[0074] Specifically, refer to Figure 2As shown, the second link 112 is provided with a first bracket 1121 protruding in the direction away from the space 6R mechanism. The first bracket 1121 can be configured as a U-shaped or other mounting structure with outward convex features, and its interior defines a rotation axis perpendicular to the direction of the virtual reference line (F1F2). The mounting part 210 includes a second bracket 221 with an L-shaped cross-section, which is rotatably mounted on the first bracket 1121 and can rotate about the aforementioned rotation axis. The lifting part 220 includes a first motor, the housing of which is connected to the second bracket 221 (mounting part 210) and a third bracket 234 (belonging to the actuation part 230) with a similar structure, thereby driving the third bracket 234 and the actuation part 230 integrated thereon and the travel wheel 240 as a whole to swing relative to the second bracket 221. If the oscillation of the second bracket 221 around the rotation axis is considered as the "translation angle" adjustment of the mechanism in the lateral direction, then the oscillation of the third bracket 234, together with the actuator 230, relative to the second bracket 221 can correspond to the "pitch angle" adjustment in the vertical direction. Furthermore, the third bracket 234 can be regarded as the mounting base of the actuator 230, on which the second motor 233, transmission components, and travel wheel 240 are integrated, thus forming a complete drive unit.

[0075] Based on this, to clarify the geometric relationships between the directions of motion, the initial configuration of the spatial 6R mechanism can be used as a reference. For example... Figure 2 As shown, when the spatial 6R mechanism is in this initial configuration, all links 110 are approximately coplanar, forming a virtual first reference plane. At this time, the axes of all active rotary joints 120 and driven rotary joints 130 are located within this first reference plane. The axis of pivoting of the mounting part 210 relative to the second link 112 is designed to be perpendicular to this first reference plane. Therefore, the rotation plane (such as the translation angle mentioned above) realized by the mounting part 210 and the plane (such as the pitch angle mentioned above) in which the lifting part 220 drives the actuating part 230 to swing are spatially orthogonal to each other, thereby enabling the wheeled chain 200 to have the ability to independently adjust its attitude in two vertical directions.

[0076] In some illustrative embodiments, reference is made to Figure 2 As shown, the transmission assembly included in the actuation unit 230 includes, but is not limited to, a transmission form using a synchronous belt 232, specifically comprising two pulleys 231 and a synchronous belt 232 sleeved thereon. One pulley 231 is coaxially arranged with the output shaft of the second motor 233, and the other pulley 231 is coaxial with the axle of the traveling wheel 240, thereby achieving torque transmission. It should be understood that the above transmission form is merely an example; in the embodiments of this disclosure, the transmission assembly may also employ a gear set or other transmission structures with equivalent functions.

[0077] In addition, the travel wheel 240 is preferably made of magnetic materials such as permanent magnets to generate a reliable adsorption force on the inner wall of the ferromagnetic pipe, thereby enabling the pipe-moving robot to be stably adsorbed on the inner wall of the pipe during operation.

[0078] Figure 3 yes Figure 2 The diagram shows a mobile robot with multiple motion modes in a curved pipe environment, in its first motion mode, and also shows the first configuration of the reconfigurable motion platform. Figure 4 yes Figure 3 The diagram shows a mobile robot with multiple motion modes operating in a straight pipe environment within a curved pipe surface.

[0079] Figure 5 yes Figure 2 The diagram shows a mobile robot with multiple motion modes in a curved pipe environment, in its second motion mode. It also shows a second configuration of a reconfigurable motion platform. Figure 6 yes Figure 5 The diagram shows a mobile robot with multiple motion modes operating in a curved pipe environment.

[0080] Figure 7 yes Figure 2 The diagram shows a mobile robot with multiple motion modes in a curved pipe environment, in its second motion mode. It also shows another second configuration of the reconfigurable motion platform. Figure 8 yes Figure 7 The diagram shows a mobile robot with multiple motion modes operating in a curved pipe environment.

[0081] Figure 9 yes Figure 2 The diagram shows a mobile robot with multiple motion modes in a pipe surface environment, in its third motion mode. It also shows the third configuration of the reconfigurable motion platform. Figure 10 yes Figure 9 The diagram shows a mobile robot with multiple motion modes operating in a U-shaped pipe environment.

[0082] According to embodiments of this disclosure, four wheeled branches 200 are configured in response to a space 6R mechanism configuration, adjusting the position of the travel wheels 240 to enable the mobile robot to have different motion modes.

[0083] According to embodiments of this disclosure, referring to Figures 3 to 10As shown, the spatial 6R mechanism is configured to switch between at least two of a first configuration, a second configuration, and a third configuration. In the first configuration, the portions of the spatial 6R mechanism located on either side of the virtual reference line (F1F2) bend and converge around the virtual reference line. In the second configuration, the portion of the spatial 6R mechanism located on one side of the perpendicular bisector is warped relative to the portion located on the other side of the perpendicular bisector. In the third configuration, the portions of the spatial 6R mechanism located on either side of the perpendicular bisector are curved and mirror-symmetrical relative to the perpendicular bisector.

[0084] Correspondingly, continue to refer to Figures 3 to 10 As shown, in response to the spatial 6R mechanism in the first configuration, the two travel wheels 240 on each side of the perpendicular bisector are arranged in a V-shape to give the mobile robot a first motion mode. In response to the spatial 6R mechanism in the second configuration, the centers of the four travel wheels 240 are located on a common sphere to give the mobile robot a second motion mode. In response to the spatial 6R mechanism in the third configuration, the centers of the four travel wheels 240 are located on a common reference plane, which is parallel to the virtual reference line and perpendicular to the perpendicular bisector.

[0085] According to embodiments of this disclosure, referring to Figures 3 to 10 As shown, the spatial 6R mechanism can actively switch to a variety of different stable configurations, including the first configuration, the second configuration and the third configuration, and each configuration directly corresponds to a motion mode of a mobile robot to adapt to different pipe surface environments.

[0086] like Figure 3 and Figure 4 As shown, when the spatial 6R mechanism is in the first configuration, the portions located on both sides of the virtual reference line (i.e., F1F2) bend and converge towards the reference line, making the spatial 6R mechanism as a whole present a radially contracted folded shape. In this configuration, the four wheeled branches 200 produce coordinated pose changes as the shape of the reconfigurable motion platform 100 is adjusted, ultimately causing the two traveling wheels 240 on each side of the vertical bisecting plane to be arranged in a stable figure-eight shape, thus forming the first motion mode.

[0087] By adjusting the degree of convergence of the mechanism, the opening angle of the "eight"-shaped wheel assembly can be changed, allowing all the traveling wheels 240 to conform to the inner walls of pipes of different diameters and maintain uniform contact pressure. In the straight pipe 310, this symmetrical "eight"-shaped support not only provides good radial constraint, effectively suppressing possible lateral slippage of the robot, but also maintains full wheel adhesion through slight adaptive adjustments to the wheel assembly posture when the pipe has slight bends or local deformations. This enables the mobile robot to achieve efficient and stable linear motion in straight pipe sections, while reserving the necessary configuration transformation space for entering curved pipe sections.

[0088] Compared to traditional rigid wheeled robots, which often struggle to adapt to changes in pipe diameter or slight curvature fluctuations due to their fixed wheel configuration, leading to individual wheels becoming suspended or slipping, this mobile robot achieves continuous and reliable grounding of all wheels in a straight pipe environment 310 through the first configuration of its reconfigurable motion platform 100 and its corresponding figure-eight adaptive wheel arrangement. This significantly improves the mobile robot's stability, driving efficiency, and overall passability in straight pipe sections.

[0089] like Figures 5 to 8 As shown, in the second configuration, the portion of the spatial 6R mechanism located on one side of the perpendicular bisector plane undergoes controllable spatial warping deformation relative to the other side. In this configuration, the centers of the four traveling wheels 240 are dynamically maintained on a common spherical surface, forming a second motion mode. Wherein, Figure 5 and Figure 6 This demonstrates a warping shape applicable to a certain steering bend (i.e., the upward warping shape of the first part 140), and Figure 7 and Figure 8 This demonstrates the corresponding form for adapting to bends with opposite directions or different curvature radii (i.e., the form of the second part 150 that curves upwards).

[0090] In this second configuration, the direction and degree of warping deformation of the spatial 6R mechanism can actively match the curvature change of the bend along its extension direction. When the mobile robot enters the bend, the spatial 6R mechanism can adjust the orientation and amplitude of the warping in real time, ensuring that the contact points of the four traveling wheels 240 always dynamically fall on a virtual sphere conformal to the inner wall surface of the bend. This means that regardless of whether the curvature of the bend is constant or continuously changing, each wheel can maintain reliable contact with the pipe wall, thereby providing continuous and uniform driving force throughout the entire stroke.

[0091] Compared to traditional robots with rigid chassis or fixed wheel layouts, which often experience issues like inner wheels being suspended in the air and outer wheels being overloaded when navigating bends due to their fixed geometry, leading to traction loss, unstable movement, or even jamming, this mobile robot features a second configuration of its reconfigurable motion platform 100 and its corresponding spherical adaptive wheel arrangement. This ensures that all drive wheels are always in optimal contact within bends, significantly improving the robot's motion continuity, directional control accuracy, and overall passage efficiency in bends.

[0092] like Figure 9 and Figure 10As shown, when the spatial 6R mechanism switches to the third configuration, the portions located on both sides of the vertical bisecting plane will undergo symmetrical bending deformation relative to the vertical bisecting plane, forming an inverted U-shaped structure similar to bending around a line (Z) perpendicular to the vertical bisecting plane (XY plane). It can also have a certain spatial twisting deformation (which can be understood as, under the premise of maintaining the overall configuration as a mirror symmetry about the vertical bisecting plane (XY plane), some links or local structures of the motion platform can be reconstructed, and their instantaneous motion direction or deformation trajectory is not strictly in a plane perpendicular or parallel to the symmetry plane, but generates a composite bending or torsional component in three-dimensional space), thus forming a mirror symmetrical spatial configuration. At this time, the wheel centers of the four traveling wheels 240 are all located in a common reference plane; this reference plane is parallel to the virtual reference line and perpendicular to the vertical bisecting plane, forming the third motion mode (which can be regarded as a line-symmetric Bricard motion, that is, maintaining radial symmetry with a certain straight line in the vertical bisecting plane).

[0093] This third configuration (and the resulting third motion mode) is specifically designed to handle symmetrical pipe sections with large curvature and sharp turns, such as U-shaped pipes 330. Traditional rigid structure robots, due to their fixed shape, are prone to internal collisions or misalignment of the front and rear wheel sets in such pipe sections, leading to motion instability. The third configuration of the spatial 6R mechanism drives the reconfigurable motion platform 100 to actively converge in the pipe extension direction by causing the connecting rods 110 on both sides of the perpendicular bisector to bend synchronously and symmetrically. This not only effectively reduces the lateral space occupied by the robot in the turning section, but also significantly reduces the longitudinal span of its beginning and end ends in the pipe extension direction, thereby fundamentally reducing the risk of jamming due to structural interference in U-shaped bends.

[0094] Based on the above mechanism, the mobile robot can pass through the U-shaped pipe 330 in a more compact and coordinated overall posture. During this process, all drive wheels can maintain balanced ground force and continuous adhesion contact, thereby ensuring that the robot can still achieve smooth, continuous and controllable movement in complex pipe sections with sudden changes in direction and sharp curvature.

[0095] In summary, through the active switching of the spatial 6R mechanism between the three configurations and the coordinated response of the wheeled branch 200, the aforementioned mobile robot can adaptively match the optimal motion mode in different scenarios such as straight pipes 310, curved pipes 320, and U-shaped pipes 330. In this way, from the perspective of geometric fit and mechanical balance, the system solves the inherent defects of traditional rigid structures that are prone to slippage and suspension in curved pipes, and the inherent defects of supported structures that are prone to mechanical interference in variable diameter sections. This significantly improves the robot's passability, motion stability, and operational reliability in complex pipe networks.

[0096] It should be noted that the above embodiments establish a correspondence between the configuration of the reconfigurable motion platform and the motion mode of the mobile robot, aiming to link configuration changes with actual use scenarios, thereby intuitively and clearly illustrating the advantages of each configuration in the corresponding scenario. This description is illustrative and not restrictive. In addition to the aforementioned mobile robot equipped with wheeled branches, the above-mentioned reconfigurable motion platform can also be applied to other equipment that needs to move or operate in enclosed or confined spaces.

[0097] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this application is not limited thereto. Any changes or substitutions made within the spirit and principles of this disclosure should be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A reconfigurable motion platform, characterized in that, include: Six links, which are connected end to end by six revolute joints, form a single-loop closed-chain spatial 6R mechanism. In the six revolute joints, the extended axes of three adjacent revolute joints intersect at a first virtual point, and the extended axes of the other three adjacent revolute joints intersect at a second virtual point. The line connecting the first virtual point and the second virtual point forms a virtual reference line, and the plane containing the perpendicular bisector of the virtual reference line constitutes the perpendicular bisector of the spatial 6R mechanism. The six revolute joints include at least three active revolute joints, and each active revolute joint is equipped with a first actuation unit to enable the space 6R mechanism to switch between different configurations.

2. The reconfigurable motion platform according to claim 1, characterized in that, The space 6R mechanism is configured to switch between at least two of the first, second, and third configurations; When the space 6R mechanism is in the first configuration, the portions of the space 6R mechanism located on both sides of the virtual reference line bend and converge around the virtual reference line; When the space 6R mechanism is in the second configuration, the portion of the space 6R mechanism located on one side of the vertical bisecting plane is warped relative to the portion located on the other side of the vertical bisecting plane. When the space 6R mechanism is in the third configuration, the portion of the space 6R mechanism located on both sides of the vertical bisecting plane is curved and mirror-symmetrical relative to the vertical bisecting plane.

3. The reconfigurable motion platform according to claim 1, characterized in that, The six revolute joints include three active revolute joints and three passive revolute joints. The three active revolute joints are arranged sequentially along the closed loop and located on both sides of the perpendicular bisector plane. Each of the three passive revolute joints is arranged opposite to one of the active revolute joints. Alternatively, all six revolute joints may be active revolute joints.

4. The reconfigurable motion platform according to claim 3, characterized in that, The first actuation unit of the active rotary joint includes a servo motor, the output shaft of which defines the axis of the active rotary joint; The servo motor's housing and output shaft are each connected to one of the two adjacent connecting rods.

5. The reconfigurable motion platform according to claim 4, characterized in that, The driven rotary joint includes a kit and a shaft member passing through the kit, the shaft member defining the axis of the driven rotary joint; The kit and the shaft are each connected to the two adjacent connecting rods.

6. The reconfigurable motion platform according to claim 3, characterized in that, The link includes: The main body is configured as a frame structure; At least two connecting portions are provided at opposite ends of the main body and are configured as arc-shaped structures; At least two of the connecting parts are each connected to a rotating pair.

7. A mobile robot with multiple motion modes in a curved pipe environment, characterized in that, include: The reconfigurable motion platform as described in any one of claims 1 to 6, wherein the six links of the reconfigurable motion platform comprise: Two first links are arranged opposite each other, and the extension direction of the first links is parallel to the virtual reference line of the spatial 6R mechanism; The four second links are divided into two groups by the perpendicular bisector of the spatial 6R mechanism. In each group, two second links are sequentially arranged between two first links. The extension direction of the second links forms an angle with the virtual reference line. The mobile robot also includes: Four wheeled chains are each mounted on a second link, and each wheeled chain is equipped with a travel wheel.

8. The mobile robot according to claim 7, characterized in that, The wheeled branch includes: The mounting part is pivotally connected to the second link; The actuator is configured to output torque to the traveling wheel; A lifting section is disposed between the mounting section and the actuating section and is configured to adjust the vertical distance between the travel wheel and the second link.

9. The mobile robot according to claim 8, characterized in that, The lifting unit includes a first motor; The main body of the first motor is connected to one of the mounting part and the actuating part, and the output shaft of the first motor is connected to the other of the mounting part and the actuating part, so that the actuating part rotates around the output shaft of the first motor; The rotation plane of the actuating part is perpendicular to the rotation plane of the mounting part.

10. The mobile robot according to claim 8, characterized in that, The actuation unit includes a second motor and a transmission assembly, wherein the output shaft of the second motor transmits torque to the traveling wheel through the transmission assembly.

11. The mobile robot according to any one of claims 7 to 10, characterized in that, The four wheeled branches are configured to adjust the position of the travel wheels in response to the configuration of the space 6R mechanism, so that the mobile robot has different motion modes.

12. The mobile robot according to claim 11, characterized in that, In response to the spatial 6R mechanism in the first configuration, the two travel wheels on each side of the vertical bisecting plane are arranged in a figure-eight pattern to give the mobile robot a first motion mode. In response to the space 6R mechanism in the second configuration, the centers of the four traveling wheels are located on a common sphere, so that the mobile robot has a second motion mode; In response to the spatial 6R mechanism in the third configuration, the centers of the four traveling wheels are located on a common reference plane, which is parallel to the virtual reference line and perpendicular to the vertical bisecting plane.

13. The mobile robot according to any one of claims 7 to 10, characterized in that, The travel wheels are configured to be made of magnetic material so that the mobile robot can be adsorbed onto the inner wall of the pipe.

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