Mobile robot based on tensegrity structure and control method thereof

Abstract

The invention discloses a mobile robot based on a tensegrity structure and a control method thereof, and belongs to the technical field of mobile robots, and the mobile robot is composed of the tensegrity structure and a driving system. The tensegrity structure comprises four groups of spatial two-rod tensegrity units and a four-rod tensegrity unit. Each group of spatial two-rod stretch-draw integral units is formed by connecting two planar two-rod stretch-draw integral units in parallel, the two planar two-rod stretch-draw integral units are connected with each other through a transverse connecting rod piece, and each group of two-rod stretch-draw integral units are connected end to end in pairs. The four-rod stretch-draw integral unit is connected with the spatial two-rod stretch-draw integral unit through a connecting mechanism. The driving system is realized by at least four motors, two of the motors are used for synchronously or differentially winding and unwinding four main sliding cables to drive the robot to generate integral stretching and bending deformation, so that multi-mode movement such as earthworm type wriggling and inchworm type arching is realized; the other two motors independently control the four steering driving cables, the curvature of the four-rod tensioning overall unit located in the middle of the robot is accurately adjusted, and then flexible steering of the robot is achieved. The structure has the remarkable advantages of light weight, high impact resistance, high load mass ratio and low energy consumption, and shows excellent adaptability and maneuverability in detection, inspection and rescue tasks in a multi-terrain environment, especially in narrow spaces such as pipelines and ruins.

Description

Technical Field

[0001] This invention relates to the field of mobile robot technology, and in particular to a robot configuration based on a tensioned integral structure that possesses multi-mode movement and autonomous steering capabilities. Background Technology

[0002] Currently, robotics technology research has matured significantly and is widely applied in many fields such as aerospace and industrial production, undoubtedly bringing great convenience to humankind. However, the traditional rigid robots widely used today have only limited degrees of freedom, poor deformation capabilities, and difficulty in achieving flexible maneuvering in space.

[0003] A tensioned monolithic structure is a stable spatial structure with self-stress balance, consisting of a set of discontinuous compression members and a set of continuous tension cables. Due to its inherent lightweight, high stiffness-to-mass ratio, excellent impact resistance, and large deformation capacity, this structure shows great potential in the field of robotics, especially in the design of mobile robots adapted to complex terrains.

[0004] Currently, research on tensioned monolithic mobile robots has made some progress. In existing technologies, there exists a typical planar serial tensioned monolithic robot, which uses two motors to drive two sliding cables, controlling the coordinated deformation of multiple two-bar modules to achieve multi-mode movement such as creeping, arching, and rolling. However, such robots typically employ a planar configuration, restricting their motion to a two-dimensional plane.

[0005] The lack of effective steering capability greatly limits its mobility and application range in real three-dimensional environments.

[0006] To endow robots with steering capabilities, existing technologies often employ the introduction of additional wheel mechanisms or servo motors. However, this not only increases the complexity and weight of the structure but also deviates from the fundamental principle that tensioned integral structures are driven purely by shape changes. On the other hand, although some spherical or spatial tensioned integral robots capable of three-dimensional motion exist, their drive systems often require a large number of actuators, resulting in complex control systems, high energy consumption, and difficulty in achieving precise directional movement and steering control.

[0007] Therefore, there is an urgent need in this field for a new type of tensioning integral mobile robot that can break through the limitations of planar motion and achieve flexible and controllable three-dimensional spatial turning while retaining the advantages of fewer actuators and high energy efficiency, so as to truly adapt to the operation tasks in complex unstructured environments such as pipelines and ruins. Summary of the Invention

[0008] The purpose of this invention is to provide a mobile robot based on a tensioned integral structure and its control method, so as to solve the technical problems of existing planar serial tensioned integral robots lacking steering ability, and existing solutions introducing additional complex mechanisms that lead to structural redundancy and control complexity.

[0009] To solve the above problems, the present invention adopts the following technical solution:

[0010] A mobile robot based on a tensioned integral structure and its control method, including the tensioned integral configuration and drive system.

[0011] The tensioning overall configuration includes four sets of spatial two-bar tensioning modules and one four-bar tensioning module. The spatial two-bar tensioning modules are arranged in series, and the four-bar tensioning module is located at a designated position in the series structure and connected to adjacent spatial two-bar modules through a connecting structure. This constitutes a composite tensioning overall configuration with both efficient movement and autonomous steering capabilities, solving the fundamental problem that a single planar configuration cannot turn.

[0012] The drive system includes four motors, eight winding shafts, and eight active sliding ropes. The motors are connected to the winding shafts for controlling the extension and retraction of the active sliding ropes. This drive scheme achieves precise control of complex spatial configuration changes with a few actuators, exhibiting high system integration and low energy consumption.

[0013] Furthermore, each set of spatial two-bar tensioned integral units is composed of two planar two-bar tensioned integral units connected in parallel. The two planar two-bar tensioned integral units are fixedly connected by transverse connecting rods. The end node of the preceding module and the starting node of the following module of each set of spatial two-bar tensioned integral units are the same physical node, which is the common hinge point of the two modules. The rods of the preceding and following modules of the spatial two-bar tensioned integral unit are staggered along the connecting rods at the node position. This design forms a stable and continuous spatial truss kinematic chain, which not only significantly enhances the stiffness and stability of the structure, but also optimizes the force flow transmission path and ensures efficient movement.

[0014] Furthermore, the connecting rods between the planar two-bar tensioning units include a connecting rod body and a connecting rod head. A guide hole for guiding and constraining the active sliding rope is arranged in the middle of the connecting rod head. This structure ensures the precise path and reliable tension of the active sliding rope throughout the robot structure, which is crucial for achieving precise motion control. The connecting rod head and the connecting rod body are connected by a nested circular shaft and circular hole, enabling rapid and precise assembly and reliable connection strength between modules.

[0015] Furthermore, the retractable rods between each set of spatial two-bar tensioning integral units include a first telescopic rod, a second telescopic rod, and a compression spring. The first telescopic rod and the second telescopic rod are connected by a nested circular shaft and a circular hole. The compression spring is fixedly connected to the bottom end of the circular shaft in the first telescopic rod and the bottom end of the circular hole in the second telescopic rod, so that the retractable rods can elastically extend and retract within a preset stroke range. This structure gives the rods the ability to passively adapt to the terrain, effectively absorb and buffer the impact from the ground, and greatly improve the stability and structural durability of the robot when moving on rugged terrain.

[0016] Furthermore, the four-bar tensioning integral unit includes four telescopic bars, an intermediate layer unit, a bottom layer unit, and a top layer unit. The intermediate layer unit is connected to the top layer unit or the bottom layer unit in a spiral circular arrangement via the four telescopic bars. The four telescopic bars are connected to the intermediate layer unit, the top layer unit, and the bottom layer unit using a spherical joint connection. This design makes the module a multi-degree-of-freedom universal joint, capable of flexibly bending and deforming in space in response to the tension of the drive cable. This is the core of achieving the robot's precise steering function.

[0017] Furthermore, the four-bar tensioning unit possesses actively adjustable stiffness characteristics. By adjusting the preload or extension / retraction of the steering drive cable (11), the compression state of the compression spring (4043) within the four telescopic bars (404) can be changed, thereby adjusting the equivalent stiffness of the module in the bending direction. This design enables the robot to maintain sufficient structural stiffness to support the load and maintain posture stability during turning, while also reducing stiffness and enhancing deformation compliance when passing through narrow or flexible environments, achieving rigid-flexible coupled adaptive motion.

[0018] Furthermore, the bottom of the connection structure between the spatial two-bar tensioning unit and the four-bar tensioning unit is provided with four through holes. The top and bottom units of the four-bar tensioning unit are connected to the connection structure through the four through holes. The outer periphery of the connection mechanism is provided with four protruding connecting parts, each with a connecting hole. The spatial two-bar tensioning unit is connected to the rods of the spatial two-bar tensioning unit through the head of the connecting rod. This connection structure realizes a stable transmission of force and motion between the moving module and the steering module, which is the structural basis for ensuring the overall motion coordination of the robot.

[0019] Furthermore, the ends of the series nodes of the tensioned integral configuration are provided with unidirectional moving wheels, which are nested and connected to the heads of the connecting rods. This mechanism effectively prevents accidental slippage when climbing slopes or crossing obstacles by restricting the robot's movement direction, thus ensuring the reliability of the movement process and the certainty of task execution.

[0020] Furthermore, the drive system motor and winding shaft are fixed in the connecting structure. The motor drives the winding shaft to rotate forward or backward. One end of the active sliding rope is fixed to the winding shaft, and the other end is fixed to the guide hole of the active sliding rope at the head of the connecting rod. The rope passes through the remaining guide holes sequentially throughout the entire mobile robot structure. This layout, which integrates the drive system into the connecting structure, greatly optimizes space utilization and makes the robot structure more compact. At the same time, the rope-through drive method achieves the unification of centralized drive and distributed actuation, simplifying the control logic.

[0021] Furthermore, the mobile robot also integrates an environmental perception and intelligent control system. The system includes environmental information sensors fixedly installed on the central or end connection structure, and a host computer communicatively connected to them. The environmental information sensors are used to collect images or distance information of the robot's surrounding environment in real time; the host computer determines the path status and obstacle characteristics based on the collected environmental information, and decides to execute corresponding linear movement control or steering control steps, thereby enabling the robot to achieve autonomous navigation and adaptive movement in complex environments.

[0022] Furthermore, the control method possesses multi-mode adaptive capabilities: if no obstacles are detected ahead and the path is straight, the robot is controlled to perform earthworm-like worm-like burrowing or inchworm-like arching, using two motors to synchronously or differentially retract four motion drive cables, driving all spatial two-bar tensioned integral modules to deform collaboratively, and combining the alternating locking and releasing of unidirectional moving wheels to achieve efficient and directional movement; if an obstacle that can be overcome is detected, the robot is controlled to use inchworm-like arching mode to overcome the obstacle; if a curved path or obstacle requiring turning is detected, steering control is activated, using two other motors to independently retract four steering drive cables, precisely adjusting the curvature and bending direction of the four-bar tensioned integral modules, achieving flexible and precise steering of the robot, and the steering control and linear movement control are decoupled from each other and do not interfere with each other.

[0023] Based on the above technical solution, the advantages of this invention compared with the prior art are as follows:

[0024] By constructing a composite tensioning overall configuration of "four sets of spatial two-bar modules in series + a central four-bar steering module", the robot has for the first time achieved an organic unity of planar movement and spatial steering with a small number of actuators. This design allows the robot to retain the multi-mode movement capability of a series structure while gaining precise three-dimensional directional control capability through an independent four-bar steering module, fundamentally breaking through the motion limitations of traditional planar tensioning overall robots.

[0025] Specifically, the parallel design and staggered arrangement of the two-bar spatial modules significantly enhance the overall structural rigidity and motion stability; the combination of telescopic rods and compression springs gives the structure excellent passive terrain adaptability; the highly integrated drive system and the rope-through layout enable precise control of complex configuration changes by four motors, demonstrating efficient energy utilization and control logic. Meanwhile, the introduction of a unidirectional movement mechanism ensures the reliability of the movement process.

[0026] This invention successfully resolves the inherent contradiction between steering capability and structural simplification in tensioning robots without significantly increasing system complexity, providing an innovative technical solution for the practical application of robots in complex and unstructured environments such as pipeline inspection and rubble search and rescue. Attached Figure Description

[0027] To clearly illustrate the technical solutions in the implementation of this invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0028] Figure 1 This is a front view of the overall structure of the mobile robot based on the tensioned integral structure of the present invention.

[0029] Figure 2 This is a schematic diagram of the overall structure of the mobile robot based on the tensioned integral structure of the present invention.

[0030] Figure 3 This is a schematic diagram of the connecting rod structure of the mobile robot based on the tensioned integral structure of the present invention.

[0031] Figure 4 This is a schematic diagram of the four-bar tensioned integral module structure of the mobile robot based on the tensioned integral structure of the present invention.

[0032] Figure 5 This is a schematic diagram of the four-bar telescopic rod structure of the mobile robot based on the tensioned integral structure of the present invention.

[0033] The attached diagram lists the components represented by each number as follows:

[0034] In the diagram: 1. Spatial two-bar tensioning module; 101. Spatial two-bar tensioning module; 2. Connecting rod; 201. Connecting rod head; 202. Connecting rod body; 2011. Guide hole for connecting rod head; 3. Telescopic rods between spatial two-bar tensioning units; 4. Four-bar tensioning module; 401. Top-level unit of four-bar tensioning module; 402. Middle-level unit of four-bar tensioning module; 403. Bottom-level unit of four-bar tensioning module; 404. Four-bar telescopic rod; 4041. First telescopic rod of four-bar telescopic rod; 4042. Second telescopic rod of four-bar telescopic rod; 4043. Compression spring of four-bar telescopic rod; 405. Compression spring of four-bar structure; 5. End connection structure; 6. Middle connection structure; 7. One-way moving wheel; 8. Winding shaft; 9. Motor; 10. Moving drive cable; 11. Steering drive cable. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, but the scope of protection of the present invention is not limited to the following embodiments.

[0036] like Figure 1 and Figure 2 As shown in the figure, this embodiment provides a mobile robot based on a tensioned integral structure and its control method. The core of the robot lies in a modular composite tensioned integral configuration and its integrated drive system. The robot mainly consists of four sets of spatial two-bar tensioned integral modules 1, one four-bar tensioned integral module 4, end connection structure 5, middle connection structure 6, and drive system.

[0037] Spatial Two-Bar Tensioning Integrated Module 1 Figure 2 As shown, each set of spatial two-bar tensioning integral modules 1 is composed of two identical planar two-bar tensioning integral units 101 arranged in parallel in space.

[0038] The telescopic rod 3 adopts a sleeve design, comprising a first telescopic rod and a second telescopic rod. A precision circular shaft at one end of the first telescopic rod is inserted into a precision circular hole in the second telescopic rod, forming a sliding fit. A spring is pre-loaded inside the sleeve, allowing the rod to undergo elastic deformation under pressure, with a maximum compression of up to 50% of its original length.

[0039] Connecting rod 2, as Figure 3 As shown, it includes a connecting rod body 202 and a connecting rod head 201. The connecting rod head 201 has a guide hole 2011 in the middle for guiding the active sliding rope. The connector is connected to the rod body via a precision shaft hole.

[0040] Four sets of spatial two-bar modules are connected in series through a shared node, and adjacent modules share the same connector as a hinge point.

[0041] Four-bar tensioning integrated module 4 Figure 4 As shown, the module includes a top-level unit 401, a middle-level unit 402, a bottom-level unit 403, and four telescopic rods 404. The four rods are arranged in a spiral circular array, with the included angle between the projections of adjacent rods being 90 degrees. Both ends of each rod are connected to a connecting plate via ball joints.

[0042] The connection structure includes an end connection structure 5 and a middle connection structure 6. The middle connection structure 6 has four through holes at its bottom, which are connected to the four-bar module via fasteners; its outer periphery has four protruding connecting parts, which are rotatably connected to the connector of the spatial two-bar module via hinged pins. The end connection structure 5 also has four protruding connecting parts on its outer periphery, which are rotatably connected to the connector of the spatial two-bar module via hinged pins.

[0043] The drive system is integrated within the connecting structure, comprising four motors 9 and eight winding shafts 8. The motors are preferably micro stepper motors, driving the winding shafts via gear sets. The eight active sliding ropes are functionally divided as follows:

[0044] Four moving drive cables 10 run through all the two-bar modules in the space;

[0045] Four steering drive cables 11, with independent control of the four-bar module.

[0046] The rope is made of high-performance polyethylene fiber material, which has high strength and low elongation.

[0047] A one-way moving wheel 7 is installed at the hinge point of the robot unit and nested with the head of the connecting rod. This mechanism adopts a ratchet structure, which only allows rotation in one direction, effectively preventing the robot from sliding backward.

[0048] Work process:

[0049] The robot's movement is achieved entirely through the coordinated control of four motors. Its operation can be broken down according to the motion mode as follows: The mobile robot integrates environmental information sensors and a host computer. The environmental information sensors include, but are not limited to, cameras, radar, or infrared detectors (fixedly mounted on the central connecting structure 6 or the end connecting structure), used to collect images or distance information of the environment in front of and around the robot in real time. The host computer receives the sensor information and uses a built-in algorithm to determine whether there are obstacles ahead, the direction of channel curvature, or terrain features.

[0050] 1. Implementation of linear movement: If there are no obstacles and the path is straight, it enters the normal linear movement mode and performs earthworm-like worm-like undulation or inchworm-like arching.

[0051] Drive configuration: The two motors of the motion drive system (defined as motor M1 and motor M2) drive two sets of motion drive cables respectively. Motor M1 synchronously retracts and extends the two motion drive cables located on the upper side of the robot (i.e., the "upper contour") through a transmission mechanism. Motor M2 synchronously retracts and extends the two motion drive cables located on the lower side of the robot (i.e., the "lower contour").

[0052] (1) Worm-like movement: Contraction phase: M1 and M2 simultaneously shorten the motion drive cable, causing the robot body to contract evenly. During this process, the one-way motion wheel at the rear of the body is blocked by the ground, and its ratchet mechanism is locked to prevent the robot from sliding backward; while the one-way wheel at the front of the body can roll freely, allowing the front end to retract freely backward. During this phase, the robot's center of gravity is relatively stable at the rear due to the body contraction. Extension phase: M1 and M2 simultaneously release the motion drive cable, and the robot body extends forward under the action of internal elastic force. At this time, the one-way wheel at the front of the body contacts the ground and is blocked, turning into a locked state, providing a fulcrum; the one-way wheel at the rear rolls freely, allowing the rear end to move forward. During this phase, the robot's effective support point moves forward, pushing the overall center of gravity forward. Through the alternation of "rear wheel lock - front wheel free" and "front wheel lock - rear wheel free", the extension and retraction cycle of the body is converted into a net forward displacement.

[0053] Applicable Scenarios and Beneficial Effects: This mode is particularly suitable for internal inspection of long, straight pipes with limited cross-sectional dimensions, penetrating inspections in narrow gaps in ruins, and any occasion requiring stable, low-profile propulsion. Its uniform radial expansion and contraction can adapt to pipe walls slightly larger than the fuselage diameter. The movement is smooth and continuous with minimal disturbance to the internal structure. The synchronous drive strategy control logic is simple and reliable, with efficient energy transfer; combined with the absolute unidirectional constraint provided by the one-way wheels, it enables slip-free, precise displacement accumulation even on smooth pipe walls or in inclined environments, greatly improving the determinism and reliability of movement within confined spaces.

[0054] (2) Inchworm-like arching: If a protruding obstacle is detected and its height is surmountable, the robot is controlled to use an inchworm-like arching mode to overcome the obstacle. Arching phase: Motor M1 shortens the upper moving drive cable, while motor M2 releases the lower moving drive cable, causing the robot body to arch upward. In this posture, the one-way moving wheels at both ends are in contact with the ground and are locked, anchoring the robot body in place. Extension and forward movement: While the body is in an arched state, the motor is controlled to slowly extend the front end of the body forward. Since the rear one-way wheel is locked, the extension of the front end will inevitably push the front connecting mechanism and the front one-way wheel forward (at this time, the front wheel rolls freely) until a new position is reached. Retraction and reset: After the front end is locked, the body is controlled to retract, pulling the rear end forward (the rear end wheel rolls freely), restoring the initial arched posture, and completing one forward step. By using the alternating locking and releasing of the front and rear one-way wheels, the stepping obstacle-crossing movement of "anchoring the rear end and moving the front end" or "anchoring the front end and pulling the rear end" can be realized.

[0055] Applicable Scenarios and Beneficial Effects: This mode is specifically designed for overcoming discrete obstacles, crossing ditches, or navigating variable cross-section passages with constraints in the vertical direction. Examples include traversing rubble, crossing small drainage ditches, or transitioning from a large-diameter pipe to a small-diameter pipe. By actively arching the fuselage, ground clearance at critical points is significantly increased, avoiding the risk of belly collision or jamming. Differential drive combined with an alternating head-tail locking strategy achieves a inchworm-like "anchor-extend-traction" gait, providing powerful obstacle-crossing capabilities and stable stepping movement on discontinuous terrain. The unidirectional wheels provide solid support during the anchoring phase, ensuring the force and stability of the movement.

[0056] 2. Implementation of Steering Motion: Decoupling of Steering and Movement. If a curve in the path ahead is detected or obstacle avoidance is required, the steering control step is initiated. Motors S1 and S2 adjust the curvature of the four-bar tensioning module 4, causing the robot to bend in the target direction. When a turn is needed (e.g., a left turn), motors S1 and S2 execute specific commands, causing the four-bar module to bend to the left. This bend changes the orientation of the robot's front half. Subsequently, regardless of the movement mode, the unidirectional movement wheels provide the necessary unidirectional constraint and driving force in the new direction of movement, ensuring the robot moves effectively in the new direction.

[0057] Applicable Scenarios and Beneficial Effects: Steering is an essential capability for robots to autonomously explore paths, avoid obstacles, and navigate around targets in complex maze-like environments (such as underground pipe networks and the interiors of building ruins). It allows robots to adjust their direction without relying entirely on forward or backward movement. An independent steering module achieves decoupled control of movement and steering motion, making direction adjustment flexible, fast, and precise. Compared to solutions that rely on the overall torsional deformation of the robot body, this invention achieves steering through the bending of local flexible units, resulting in lower energy consumption and less interference with the robot's gait. This ensures high propulsion efficiency even during turns, greatly expanding the robot's workspace and task complexity handling capabilities.

[0058] Implementation of stiffness adjustment function: The stiffness of the four-bar tensioning integral module (4) can be adjusted in two ways:

[0059] (1) Adjustment via steering drive cable: The steering drive cable (11) works in conjunction with the compression spring (4043) within the four telescopic rods (404). When the steering drive cable (11) is tightened, the four telescopic rods (404) are compressed and contracted, and the compression spring (4043) is further compressed, increasing the overall structural stiffness; when the steering drive cable (11) is released, the rods extend under the restoring force of the compression springs, reducing the structural stiffness. This method allows for real-time adjustment of local stiffness during steering to adapt to different steering radii or ground reaction forces.

[0060] (2) Preload Adjustment: In the initialization or static state, the basic stiffness level of the four-bar module can be set by adjusting the initial preload of the steering drive cable (11), so that it has different resistance to deformation in subsequent movements. This function enables the robot to switch between "high stiffness steering" and "compliant steering" in complex terrain. For example, when the load is heavy or a fast turn is required, the stiffness can be increased to maintain motion accuracy; when crossing flexible pipes or vulnerable environments, the stiffness can be reduced to avoid damage to the environment, while enhancing the robot's passability and safety. This stiffness adjustment mechanism is decoupled from the steering control, and the stiffness parameters can be adjusted independently without affecting the steering posture.

[0061] 3. Composite Motion and Reliability Assurance: Movement and steering control are highly coordinated, enabling movement along complex paths. Telescopic links ensure the body passively adapts to terrain undulations, maintaining effective contact between multiple unidirectional wheels and the ground. The unidirectional movement wheels actively convert internal body deformation into effective interaction with the ground, rather than passively relying on sliding friction. This provides more reliable and efficient driving force and completely prevents accidental slippage on slopes or when traversing obstacles, making it one of the core mechanisms of this invention for achieving controllable and directional movement.

[0062] An environmental information sensor, a host computer, and four motors 9 constitute a closed-loop control system. The host computer generates motion commands based on real-time environmental information, and drives the corresponding motors to extend and retract the motion drive cable 10 and the steering drive cable 11 through the motor controller, enabling the robot to move, turn, and overcome obstacles autonomously in complex environments.

[0063] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A mobile robot based on a tensioned integral structure and its control method, characterized in that, include: The tensioning overall configuration includes four sets of spatial two-bar tensioning modules and one four-bar tensioning module. The spatial two-bar tensioning modules are arranged in series, and the four-bar tensioning module is located at a designated position in the series structure and connected to adjacent spatial two-bar modules through a connecting structure. The drive system includes four motors, eight winding shafts, and eight active sliding ropes. The motors are driven by the winding shafts and are used to control the winding and unwinding of the active sliding ropes.

2. The mobile robot based on a tensioned integral structure and its control method according to claim 1, characterized in that, Each set of spatial two-bar tensioning integral units (1) is composed of two planar two-bar tensioning integral units (101) connected in parallel. The two planar two-bar tensioning integral units (101) are fixedly connected by transverse connecting rods (2). The end node of the first module and the starting node of the second module of each set of spatial two-bar tensioning integral units (101) are the same physical node. The node is the common hinge point of the two modules. The rods of the first and second modules of the spatial two-bar tensioning integral unit (1) are arranged alternately along the connecting rods at the node position. The two-bar spatial tensioning integral units (1) are connected end to end in pairs.

3. A mobile robot based on a tensioned integral structure and its control method according to claim 2, characterized in that, The connecting rod (2) between the two planar tensioning integral units (101) includes a connecting rod body (202) and a connecting rod head (201). The middle part of the connecting rod head (202) is provided with a guide hole (2011) for guiding and constraining the active sliding rope. The connecting rod head (201) and the connecting rod body (202) are connected by a circular shaft and a circular hole.

4. A mobile robot based on a tensioned integral structure and its control method according to claim 2, characterized in that, The telescopic rod (3) between each set of spatial two-rod tensioning integral units (1) includes a first telescopic rod, a second telescopic rod, and a compression spring. The first telescopic rod and the second telescopic rod are connected by a nested circular shaft and a circular hole. The compression spring is fixedly connected to the bottom end of the circular shaft in the first telescopic rod and the bottom end of the circular hole in the second telescopic rod, so that the telescopic rod can elastically expand and contract within a preset stroke range.

5. A mobile robot based on a tensioned integral structure and its control method according to claim 1, characterized in that, The four-bar tensioning unit comprises four telescopic rods (404), a four-bar structural compression spring (405), an intermediate layer unit (402), a bottom layer unit (403), and a top layer unit (401). The intermediate layer unit (402) is connected to the top layer unit (401) or the bottom layer unit (403) in a spiral circular arrangement via the four telescopic rods (404). The four telescopic rods (404) are connected to the intermediate layer unit (402), the top layer unit (401), and the bottom layer unit (403) using a spherical joint connection, which provides greater flexibility. The four telescopic rods (404) include a first telescopic rod, a second telescopic rod, and... The compression spring of the four telescopic rods is connected to the first telescopic rod and the second telescopic rod of the four telescopic rods by nesting a circular shaft and a circular hole. The compression spring of the four telescopic rods is fixedly connected to the bottom end of the circular shaft in the first telescopic rod and the bottom end of the circular hole in the second telescopic rod, so that the four telescopic rods can elastically extend and retract within a preset stroke range. The four-bar tensioning unit has adjustable stiffness characteristics. By adjusting the tension on the steering drive cable (11) or the extension and retraction state of the four telescopic rods (404), the overall stiffness of the four-bar tensioning unit can be changed, thereby adapting to the steering requirements under different terrain or load conditions.

6. A mobile robot based on a tensioned integral structure and its control method according to claim 1, characterized in that, The bottom of the central connection structure (6) between the spatial two-bar tensioning integral unit (1) and the four-bar tensioning integral unit (4) is provided with four through holes. The top unit (401) and the bottom unit (403) of the four-bar tensioning integral unit are connected to the central connection structure (6) through the four through holes. The central connection mechanism (6) has four protruding connecting parts on its outer periphery. The protruding connecting parts are provided with connecting holes. The spatial two-bar tensioning integral unit (1) is connected to the rods of the spatial two-bar tensioning integral unit (1) through the head (201) of the connecting rod.

7. A mobile robot based on a tensioned integral structure and its control method according to claim 1, characterized in that, The ends of the series nodes of the tensioning integral configuration are provided with unidirectional moving wheels (7), which are nested and connected with the head (201) of the connecting rod to restrict the robot's movement direction.

8. A mobile robot based on a tensioned integral structure and its control method according to claim 1, characterized in that, The drive system motor (9) and winding shaft (8) are fixed in the middle connection structure (6) and the end connection structure (5). The motor (9) drives the winding shaft (8) to rotate forward or backward. One end of the drive cable is fixed to the winding shaft, and the other end is fixed to the guide hole (2011) of the head (201) of the connecting rod. The cable passes through the remaining guide holes (2011) and passes through the entire mobile robot structure in sequence.

9. A mobile robot based on a tensioned integral structure and its control method according to claim 1, characterized in that, An environmental information sensor fixedly installed on the middle connecting structure (6) or the end connecting structure (5) collects surrounding environmental information in real time and transmits it to the host computer; the host computer judges the path status and obstacle characteristics based on the environmental information and decides to execute the corresponding linear movement control step or the steering control step.

10. A mobile robot based on a tensioned integral structure and its control method according to claim 1, characterized in that, If no obstacles are detected ahead and the path is straight, the robot is controlled to perform earthworm-like undulation or inchworm-like arching. By controlling two motors to synchronously or differentially retract four moving drive cables (10), the four sets of spatial two-bar tensioning integral modules (1) are deformed in coordination, driving the robot to perform earthworm-like undulation or inchworm-like arching. Among them, earthworm-like undulation is achieved by synchronously retracting and extending the moving drive cables (10) through the two motors, and unidirectional propulsion is achieved by alternating locking and releasing of the unidirectional moving wheels (7). If an obstacle that can be overcome is detected, the robot is controlled to use the inchworm-like arching mode to overcome the obstacle. The inchworm-like arching is achieved by controlling the two motors to synchronously or differentially retract and extend the four moving drive cables (10), so that the four sets of spatial two-bar tensioning integral modules (1) deform in coordination, driving the robot to perform earthworm-like undulation or inchworm-like arching. The differential retraction and extension of the mobile drive cable (10) by the motors realizes the arching and extension of the robot body, and the alternating locking of the one-way moving wheel (7) realizes the step-by-step obstacle-crossing movement; if a curved path or obstacle that needs to be turned is detected, the turning control step is initiated to adjust the robot's direction. By controlling the independent retraction and extension of the four turning drive cables (11) by the other two motors, the curvature and bending direction of the four-bar tensioning overall module (4) are precisely adjusted to realize the spatial turning of the robot; wherein, the turning control is decoupled from the linear movement control, and after turning, the one-way moving wheel (7) provides a one-way constraint in the new movement direction to ensure movement along the set direction.

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