Rescue robot flexible joint structure based on multi-field coupling driving and selective locking

Abstract

The invention relates to a rescue robot flexible joint structure based on multi-field coupling driving and selective locking, and belongs to the technical field of rescue robots. The structure aims at solving the technical problems that an existing joint is difficult to give consideration to high flexibility and high rigidity, mode switching is not flexible, and energy consumption is high. According to the core of the technical scheme, the modular design composed of an outer flexible supporting layer, a middle multi-field coupling driving layer and an inner locking supporting layer is adopted, and rapid and accurate joint movement is achieved through cooperation of pneumatic actuation and electric actuation; and a reversible locking mechanism of a magneto-rheological or phase-change material is utilized to keep high rigidity after the action is completed, and continuous energy supply is not needed. The adaptability, operation flexibility and task execution efficiency of the rescue robot in the complex disaster environment are effectively improved, and meanwhile system energy consumption is remarkably reduced.

Description

Technical Field

[0001] This invention belongs to the field of rescue robot technology and relates to a flexible joint structure for rescue robots based on multi-field coupling drive and selective locking. Background Technology

[0002] Disaster relief robots urgently need strong heavy-duty grasping capabilities when dealing with complex disaster environments such as earthquakes and landslides. This places extremely high demands on the flexibility, lightweight design, and reliability of the robot's joint structure. Currently, most rescue robot joints still use a rigid drive method combining traditional motors and gear transmissions. While this method provides strong load-bearing capacity, its inherent problems of large size, high weight, and insufficient flexibility make it difficult for the robot to quickly adapt to complex and changing terrain environments.

[0003] Some studies have explored pneumatic flexible joint solutions, which offer advantages such as good environmental adaptability and lightweight design. However, pneumatic joints suffer from inherent drawbacks, including low energy efficiency, slow response speed, and difficulty in maintaining posture after a movement. Existing technologies mostly focus on a single actuation mode, such as pure pneumatic, hydraulic, or electro-actuated systems. Each single actuation method struggles to balance compliance, load-bearing capacity, and programmable control performance, failing to simultaneously meet the dual requirements of high compliance and high stiffness.

[0004] In complex real-world rescue missions, robots often need to switch between different modes, such as obstacle clearing and heavy object handling. When performing handling tasks, joints require high rigidity to maintain overall stability, but existing joint structures struggle to achieve rapid and reliable dynamic switching between different task modes. Furthermore, maintaining a specific posture after an action often requires a continuous energy supply from a single drive system, leading to excessive energy consumption and limiting the robot's ability to operate for extended periods during rescue missions. These technological shortcomings severely restrict the environmental adaptability and mission execution efficiency of rescue robots in complex disaster sites.

[0005] Figure 3 The schematic diagram of the working principle of a multi-field coupled drive joint illustrates the basic principles of cooperative drive and closed-loop control, highlighting the limitations of existing single drive methods and the necessity of introducing multi-field coupled drive. In summary, there are significant gaps in existing technologies, and there is an urgent need for a novel robot joint structure that can intelligently switch working modes, balance flexible drive and rigidity maintenance, and effectively reduce energy consumption. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a flexible joint structure for rescue robots based on multi-field coupling drive and selective locking. This structure achieves rapid adjustment of joint shape and maintenance of stiffness through a composite drive method combining pneumatic, electro-actuated, and magnetorheological or phase-change locking. It can perform multi-mode tasks such as precise obstacle grasping and high-load transport in complex disaster environments, thereby improving the adaptability and execution efficiency of rescue robots.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A flexible joint structure for a rescue robot based on multi-field coupling drive and selective locking, comprising: The outer flexible support layer 1, the middle multi-field coupling driving layer 2, and the inner locking support layer 3; The outer flexible support layer 1 is made of a flexible matrix composed of a flexible polymer film and embedded fibers, providing an overall deformation basis and external protection for the joint; The middle multi-field coupling drive layer 2 integrates a micro-pneumatic cavity and an electro-actuation unit, which realizes rapid bending motion and fine angle adjustment of the joint through the synergistic effect of air pressure and electric field; The inner locking support layer 3 is embedded with magnetorheological material or reversible curable resin and is equipped with a magnetorheological locking coil 6 or a local heating unit 7. Selective locking is triggered by an external magnetic field or temperature adjustment to achieve high rigidity retention after the action is completed.

[0008] Furthermore, the micro-pneumatic cavity in the middle multi-field coupling drive layer 2 is connected to a pneumatic interface 9 and a pneumatic actuator 13, and the driving force is generated by adjusting the pressure difference between the inside and outside of the cavity; The electro-actuated unit is made of an electroactive polymer or a dielectric elastomer and is connected to an electrical interface 10. It generates electro-induced compressive stress by applying voltage to establish an electric field.

[0009] Furthermore, the pneumatic equivalent torque generated by the pneumatic actuator 13 Satisfying the formula:

[0010] in, For input air pressure, External air pressure, A This is the equivalent area of ​​the air cavity under pressure. r The lever arm is the distance from the point of action of the pneumatic drive cavity to the axis of joint rotation. The electro-induced equivalent torque generated by the electro-actuation unit Satisfying the formula:

[0011] in, The vacuum permittivity, The relative permittivity, V To apply voltage, To drive the effective area, For geometric lever arm, d The thickness is the dielectric layer thickness.

[0012] Furthermore, the inner locking support layer 3 is also provided with a locking band 4 and a crease line 5; The locking band 4 is arranged along the key parts of the structure to limit strain transmission and assist in attitude locking; The crease lines 5 are distributed on the surface of the flexible support layer, providing a guide path for joint movement.

[0013] Furthermore, it also includes a temperature and strain sensor 8, a control programming microcomputer 20, and a signal receiving antenna 19; The temperature and strain sensor 8 monitors the temperature distribution and deformation inside the joint in real time. The control programming microcomputer 20 receives sensor feedback signals and integrates pneumatic, electro-actuated and lock-up signals for multi-mode coordinated control; The signal receiving antenna 19 enables wireless communication with an external control center.

[0014] Furthermore, the control programming microcomputer 20 controls the joint angle through closed-loop feedback. With equivalent stiffness k Its control objective satisfies:

[0015] And simultaneously satisfy the following constraints: , ,

[0016] in, For equivalent rotational inertia, For viscous damping, It is a neutral angle. For external disturbance torque, It is the equivalent stiffness, and it is the locking engagement degree. The function, This represents the foundation stiffness when it is not locked. The stiffness contributed to locking. Indicates the degree of lock participation. This is the upper limit of the gas source pressure. This is the upper limit of the driving voltage. This represents the upper limit of the permissible temperature.

[0017] A control method for flexible joints of a rescue robot based on multi-field coupling drive and selective locking, applied to the aforementioned flexible joint structure, the method comprising the following steps: Receive control commands and complete system status self-check; According to the target perspective With target stiffness k * Select the drive path, initiate the coordinated operation of pneumatic drive and electro-actuator, and perform state estimation and error calculation through sensor feedback fusion; the angle error , The stiffness error is the estimated value of the joint angle. , This is the estimated equivalent stiffness. Based on angle error With stiffness error Perform closed-loop adjustment to drive the joint movement to the target pose; Determine the task requirements; if posture maintenance is required, trigger the selective locking mechanism; otherwise, maintain compliant drive. After locking, it enters a low-power sustain state until a new task instruction is received.

[0018] Furthermore, the step of triggering the selective locking mechanism specifically includes: Determine the target stiffness level based on task requirements and external torque distribution; select either a magnetorheological locking path or a phase transition locking path. If the magnetorheological locking path is selected, a current is applied to the magnetorheological locking coil 6 to generate a controllable magnetic field, which causes the magnetic particles inside the magnetorheological material to form a chain structure to improve the shear yield strength. If the phase change lock-in path is selected, the reversible curing resin will undergo a phase change by heating through the local heating unit 7, thereby increasing the viscoelastic modulus of the material. After locking is completed, strength and pose are checked. If the standard is not met, compensation is performed and locking is re-locked.

[0019] Furthermore, the method also includes a multi-mode task switching step: Assess operational load requirements through sensor fusion; Switch between fine-grabbing mode, high-load mode and standby mode; Among them, the fine grasping mode prioritizes electro-actuation for small-angle fine adjustment and triggers local locking; the high-load mode fully triggers the locking mechanism after the pneumatic and electro-actuation are driven in place; the standby mode cuts off the drive and selects the locking maintenance or relaxation state according to the scenario to reduce energy consumption.

[0020] Furthermore, the system power in the low-power maintenance state satisfy:

[0021] in, To maintain power for sensing and control, I For driving current, R Equivalent resistance Q This represents the gas volumetric flow rate. This refers to the air pressure difference.

[0022] The beneficial effects of this invention are as follows: This invention fundamentally overcomes the reliance of existing technologies on a single driving method through an innovative combination of multi-field coupling drive and selective locking. This design cleverly integrates the advantages of pneumatic drive's large stroke and rapid response with the fine adjustment capability of electric field drive, enabling the joint to not only achieve large-amplitude, rapid movements but also to perform high-precision attitude fine-tuning. Its overall response speed is significantly superior to that of a single pneumatic joint.

[0023] In terms of energy saving, this invention has achieved a breakthrough. Thanks to the unique locking mechanism of magnetorheological or phase change materials, the joints can maintain a high stiffness state without continuously consuming a large amount of energy after completing the movement and locking the shape. This characteristic greatly reduces the overall energy consumption of rescue robots during long-term operations, effectively extending their mission endurance.

[0024] Figure 4 The schematic diagram of selective locking and stiffness maintenance clearly illustrates the working logic of the aforementioned low-energy maintenance state. This system possesses a high degree of intelligent adaptability, capable of programmably and autonomously switching between various modes such as delicate grasping, high-load handling, and standby, according to different task requirements. This flexibility ensures that the robot can both gently handle delicate objects and stably undertake heavy-load support tasks in complex and ever-changing post-disaster environments.

[0025] Figure 5 The schematic diagram of the multi-mode task switching workflow of the rescue robot further illustrates its excellent task adaptability. From a structural design perspective, this invention adopts a modular and lightweight concept, making the joint structure not only robust and reliable, but also easy to expand to multi-joint robot systems to adapt to the specific needs of different rescue scenarios.

[0026] This invention achieves synergistic optimization in improving the flexibility, reliability, and energy efficiency of rescue robot joints, ultimately significantly enhancing the robot's task execution efficiency and overall adaptability in complex disaster environments.

[0027] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a structural diagram of a single component of the device of the present invention; Figure 2 An exploded view of a single component of the device of the present invention; Figure 3 A schematic diagram illustrating the working principle of a multi-field coupling driven joint; Figure 4 This is a schematic diagram of the selective locking and stiffness maintenance process; Figure 5 A schematic diagram illustrating the workflow for switching between multiple mission modes for rescue robots.

[0029] Reference numerals: 1. Outer flexible support layer; 2. Middle multi-field coupling drive layer; 3. Inner locking support layer; 4. Locking band; 5. Crease line; 6. Magnetorheological locking coil; 7. Local heating unit; 8. Temperature and strain sensor; 9. Pneumatic interface; 10. Electrical interface; 11. Mechanical buckle groove; 12. Connecting base; 13. Pneumatic actuator; 14. Control computer protective cover; 15. Servo motor; 16. Mechanical gripper; 17. Rotation unit; 18. Fixed flange; 19. Signal receiving antenna; 20. Control programming microcomputer. Detailed Implementation

[0030] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0031] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0032] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0033] This invention provides a programmable flexible joint structure for disaster relief robots based on multi-field coupling and selective locking. Structurally, it adopts a multi-layered composite modular design with clearly defined functions for each layer. The outer flexible support layer provides compliance and protection; the middle multi-field coupling drive layer achieves coordinated pneumatic and electro-actuated actuation; and the inner locking support layer, combined with magnetorheological locking coils and local heating units, achieves reversible locking and stiffness maintenance. The overall design is characterized by being detachable, lightweight, and highly reliable. In terms of principle, the system achieves large-stroke motion through pneumatic drive, fine-tunes attitude through electro-actuation, and maintains high stiffness after the action is completed through magnetorheological or phase-change locking. Combined with temperature and strain sensor feedback and a multi-field fusion control strategy, it achieves adaptive adjustment and precise control of the joint. In terms of structural layout, the joint modules adopt a symmetrical distribution and an integrated fixed flange connection scheme to reduce the impact of external disturbances and enhance stability. In terms of software and control, the system relies on a control programming microcomputer as the core unit, integrates an LCD display and a human-machine interface, and realizes mode switching, parameter adjustment and energy consumption optimization through closed-loop feedback and multi-field coupling control algorithms. It can achieve multi-mode collaborative operation from compliant grasping to high-rigidity support in complex post-disaster environments, significantly improving the flexibility, stability and task execution efficiency of rescue robots.

[0034] like Figure 1 Structural diagram of a single component of the device of the present invention and Figure 2 An exploded view of a single component of the device of the present invention is shown.

[0035] This invention proposes a programmable flexible joint structure for disaster relief robots based on multi-field coupling and selective locking. The structure comprises an outer flexible support layer 1, a middle multi-field coupling drive layer 2, an inner locking support layer 3, a locking band 4, a crease line 5, a magnetorheological locking coil 6, a local heating unit 7, a temperature and strain sensor 8, a pneumatic interface 9, an electrical interface 10, a mechanical latching groove 11, a connecting base 12, a pneumatic actuator 13, a control computer protective cover 14, a servo motor 15, a mechanical gripper 16, a rotating unit 17, a fixed flange 18, a signal receiving antenna 19, and a control programming microcomputer 20. This structure is installed at the joint positions of the rescue robot's main body and achieves multi-mode collaborative operation through multi-field driving and locking control, adapting to grasping, transporting, and supporting tasks in complex disaster environments.

[0036] The outer flexible support layer is made of high-molecular composite material, possessing excellent flexibility and fatigue resistance, providing the overall deformation basis and external protection for the joint. The middle multi-field coupling drive layer combines micro-pneumatic cavities and electro-actuated units, enabling bending, extension, and fine-tuning of angles through air pressure difference and electric field effects. In different task modes, the control system can adjust the pneumatic and electro-actuated outputs separately, achieving layered control of coarse and fine adjustments. The inner locking support layer, as the core of joint stiffness adjustment, embeds magnetorheological composite material and works in conjunction with magnetorheological locking coils. It triggers local stiffness changes through an external magnetic field, thereby maintaining morphological stability after the movement is completed. Locking bands are arranged along key parts of the structure to limit strain transmission and assist in attitude locking. Crease lines are distributed on the surface of the flexible support layer, providing a guiding path for joint movement, making the stress distribution more uniform and the deformation controllable during bending.

[0037] Magnetorheological locking coils are positioned on the outside of the locking support layer. When the control system applies current, the coils generate a controllable magnetic field that acts on the internal magnetorheological material, causing the magnetic particles to align along the magnetic field direction to form a chain-like structure. This significantly improves the shear yield strength, achieving reversible locking. Local heating units can be triggered independently or work in conjunction with the magnetorheological coils to adjust the material phase through the temperature field, achieving thermally triggered locking or shape retention. Temperature and strain sensors monitor the internal temperature distribution and deformation of the joint in real time, providing status feedback to the control system and enabling closed-loop control through multi-field driving.

[0038] The pneumatic interface connects to an external air source and pneumatic actuator. By adjusting the pressure difference between the inside and outside of the cavity, it achieves large-stroke flexible drive and is the main power source of the system. The electrical interface is responsible for the transmission of electrical signals and energy, forming an integrated control network with the servo motor, control system, and various sensors. Mechanical snap-fit ​​slots are used for quick assembly and disassembly of modules, improving the convenience of maintenance and replacement. The connecting base undertakes the functions of structural connection and force transmission. It is made of lightweight, high-strength alloy material to ensure the stability and accuracy of the system under high load conditions.

[0039] The control computer protective cover provides physical protection and electromagnetic shielding for the core control components. Servo motors are responsible for local rotation and fine-tuning of attitude, providing precise angle adjustment capabilities based on pneumatic drive and electro-actuation. Mechanical grippers are located at the joint ends, used for grasping, transporting, and obstacle clearing tasks in disaster relief. Rotation units are located at key joint connections, achieving multi-degree-of-freedom motion through multiple bearings and torque transmission mechanisms, working in conjunction with flexible support layers to achieve controllable rotation in complex postures. Fixed flanges serve as structural mounting interfaces, connecting the joint modules to the robot body. Signal receiving antennas enable wireless communication with an external control center, ensuring real-time transmission of rescue mission information.

[0040] The control programmable microcomputer is the core control unit of this system. It integrates an LCD screen and a human-machine interface, displaying current task status, joint angles, temperature, and strain data. It communicates with an external PLC to achieve mode switching, task scheduling, and parameter adjustment. During multi-field coupled control, the control programmable microcomputer integrates pneumatic, electro-actuated, and locking signals to achieve automatic switching and precise coordination of multiple modes, thereby enabling high-precision operation, rapid response, and energy-saving control in complex post-disaster environments. During operation, the entire system can quickly switch between compliant, stable, and high-rigidity modes according to different task requirements, balancing flexible grasping with high-load support, significantly improving the environmental adaptability and task execution efficiency of the rescue robot.

[0041] like Figure 3 The schematic diagram of the working principle of the multi-field coupling driven joint is shown. After receiving the cooperative drive command from the controller, the system first completes online self-checks of temperature, pressure, pose, and strain, and then reads the target angle. * Target stiffness k * And the upper limits of air pressure and voltage. After the self-test passes, select the micro-pneumatic cavity and electroactive polymer or dielectric elastomer channel corresponding to the joint, and start the drive according to the strategy of achieving large stroke control through pneumatics and fine-tuning control through electro-actuation. At the same time, enable sensor feedback fusion to obtain state estimation. The fusion result gives the closed-loop error of angle and stiffness: ,

[0042] In the formula, These are joint angle estimates calculated using a combination of vision and IMU. The equivalent stiffness estimate is obtained from small perturbations or force-displacement identification. and They are used for closed-loop adjustment of the outer angle ring and the inner stiffness ring, respectively.

[0043] The pneumatic actuator consists of a flexible cavity and a deformable support diaphragm. When the controller adjusts the input air pressure... At this time, a pressure difference is formed inside and outside the cavity:

[0044] The gas pressure difference acts on the inner wall of the cavity and the membrane surface to generate normal pressure, causing the membrane to flexurally deform at the constraint boundary. The deformation generates displacement driving force through the connecting structure.

[0045] in This represents the equivalent area of ​​the air chamber under pressure. Because there is a distance between the line of action of this driving force and the joint axis of rotation... This generates torque:

[0046] In the formula, The equivalent torque contributed to aerodynamics. This is the lever arm from the point of action of the pneumatic drive cavity to the axis of joint rotation. Changes in air pressure directly determine the degree of bending or rotation of the cavity, thus achieving rapid drive with a large stroke. In multi-field coordination, pneumatic torque mainly provides coarse adjustment energy for the main motion.

[0047] The electro-actuation channel uses a pair of flexible electrodes placed on both sides of a dielectric thin film. When the controller applies a voltage difference V, an electric field is established within the dielectric layer with a thickness of d.

[0048] Electro-induced compressive stress is generated within the medium:

[0049] In the formula and These are the vacuum permittivity and the relative permittivity, respectively. This compressive stress acts on the driving effective area. Forming equivalent effect:

[0050] The coupling member with geometric eccentricity to the joint pivot in the lever arm Converted to torque:

[0051] In the formula, The equivalent torque contributed to electric actuation.

[0052] In this process, when the joint selects the electric field drive path, the control module applies a voltage to the flexible electrode to establish an electric field. The dielectric layer then undergoes coupled deformation of thickness compression and in-plane elongation. This deformation is applied to the rotating unit via the structural coupling, outputting torque. The torque varies with the square of the voltage and is determined by parameters such as electrode spacing, effective area, and geometric lever arm. Changing the voltage adjusts the torque accordingly, thereby controlling the rotational driving force. In multi-field coordination, the electro-actuated torque is used for fine-tuning of the attitude.

[0053] To achieve multi-field coordinated drive, the controller synthesizes the equivalent torque generated by pneumatics and electro-actuation to satisfy: In the formula, , , These are the angle proportional gain, angle differential gain, and stiffness proportional gain, used to simultaneously correct for angle and stiffness errors.

[0054] All executions simultaneously satisfy the safety constraints: In the formula, and These are the air source and the upper limit of the driving voltage, respectively. The upper limit of the allowable temperature is used to prevent overvoltage, overcurrent, and overtemperature.

[0055] In the stage of sensor feedback fusion reaching the target determination, the small-angle dynamics of the joint can be simplified as follows: In the formula, For equivalent rotational inertia, For viscous damping, It is a neutral angle. External disturbance torque; For equivalent stiffness, Indicates the degree of participation in locking ( Not locked 1 is fully locked). When the following conditions are met: Then it is judged as meeting the standard. In the formula, and This refers to the allowable range for angle and stiffness.

[0056] In the branch regarding locking, if the task requires attitude stiffness maintenance, selective locking is triggered and a check is performed. As the locking process rises to increase If the task only requires compliant following, locking is not triggered, and a small amount of cooperative drive is maintained. After locking is completed, it enters a low-power maintenance state, with an approximate power consumption of: In the formula, To maintain power for necessary sensing and control, The driving power for pneumatic and electric actuation. For driving current, The gas volumetric flow rate is represented by this relationship, indicating that after locking, attitude and stiffness can be maintained without continuous high-power drive. Subsequently, the system enters subsequent tasks according to the task schedule. If it is necessary to readjust the attitude or stiffness, the lock is first released, and then it returns to multi-field cooperative drive, repeating the closed-loop process of aerodynamic approximation, electro-actuated fine-tuning, and sensor fusion correction.

[0057] like Figure 4 The selective locking and stiffness maintenance process is illustrated in the diagram. Figure 4 This demonstrates the complete workflow of a multi-field coupled flexible joint achieving high stiffness maintenance and low energy consumption during task execution. When the system receives a locking request or detects an over-threshold load, the controller first determines the required target stiffness level and holding time parameters based on task requirements and external torque distribution. Subsequently, the system enters the locking path selection stage, automatically determining whether to use magnetorheological locking or phase change locking based on material properties and current environmental conditions to achieve adjustable and reversible stiffness control.

[0058] When a magnetorheological locking path is selected, the system first uses ring-shaped or radially arranged magnetorheological locking coils to generate a controllable magnetic field around the locking cavity. The direction of the magnetic field is guided by the magnetic circuit design to the magnetorheological composite layer embedded in the flexible joint structure. As the current increases, the magnetic field strength increases, and magnetic particles (such as carbonyl-iron particles) rapidly form chain-like or columnar structures along the direction of the magnetic field lines in the rheological matrix. These chain-like structures can resist slippage when subjected to shear loads, thereby causing the shear yield strength of the region to increase sharply, achieving high-stiffness directional locking in the local area. When a phase change locking path is selected, the control module injects heat into the inner locking support layer, so that the material temperature reaches its curing or phase change temperature range. At this temperature, the internal cross-linking or crystalline structure rearrangement of the material causes its viscoelastic modulus to increase rapidly and significantly. The material changes from a deformable state to a semi-rigid or rigid state, thereby maintaining its shape without the application of external force.

[0059] After the locking phase is completed, the system enters the strength and pose verification stage. Multi-sensor fusion is used to detect and correct attitude deviations and stiffness errors in real time after locking. If the detection results fail to meet the set standards, minor corrections and compensation are performed to re-verify the locking effect. If the verification results pass, the system transitions to the de-excitation or low-power maintenance stage. At this point, the external magnetic field is stopped or the system gradually cools down, maintaining the locking state stable under low-energy conditions, thereby significantly reducing energy consumption.

[0060] Upon completion of the task or a change in the environment, the system enters the unlocking determination phase, judging whether the unlocking conditions are met based on instructions from the host computer and real-time feedback from sensors. If the conditions are met, the magnetic field is removed or the system is cooled and reset, allowing the magnetorheological material to return to its flow state or the phase change layer to soften again, and the joint returns from a high-stiffness mode to a compliant and controllable state. Subsequently, the system enters the compliant drive recovery phase, achieving attitude reconstruction through coordinated pneumatic and electro-actuated control, providing the ability for continuous programmable drive for the next stage of the task.

[0061] Figure 4 The process follows a main thread of lock-up triggering—path selection—strength verification—low-power maintenance—conditional unlocking. The system dynamically switches between magnetorheological and phase-change lock-up mechanisms, achieving comprehensive performance of adaptive stiffness, controllable energy consumption, and reversible attitude. This mechanism ensures that the joint maintains stable shape and response accuracy under high load support and delicate operation tasks, further enhancing the structural reliability and operational continuity of this invention in complex post-disaster rescue environments.

[0062] like Figure 5 The diagram illustrates the multi-mode task switching workflow of the rescue robot. Figure 5 The complete operational workflow of the robot in complex post-disaster scenarios is presented. The system first receives input of various parameter information from the host computer or operating platform regarding the task and environment, and initiates perception fusion and pattern determination. Through various information such as vision and pose detection, pressure and temperature sensing, and load and strain monitoring, the system assesses the operational load requirements in real time and selects between three modes: fine grasping, high load, and standby, thereby achieving unified scheduling of tasks, environment, and resources.

[0063] When a graspable target is detected or fine manipulation is required, the system switches to a fine grasping mode: electro-actuation performs small-angle fine adjustments to approximate the desired pose, followed by selective locking (magnetorheological locking or phase transition locking) at the end effector or key joints to improve local stiffness and disturbance rejection; the controller performs stability assessment based on slip criteria and attitude error, and if the assessment is not met, it returns to the fine-tuning stage, and if the assessment is met, it returns to the mode determination to proceed to the next task. This mode achieves a transition from compliant to stable, and is adapted to fine operations such as grasping and obstacle removal.

[0064] For applications requiring load-bearing and support, the system enters a high-load mode: after reaching its position under multi-field coupling drive, all joints are fully locked, establishing a high-rigidity support link to perform the transport and support task; during the process, parameters such as load, temperature rise, and pressure are continuously monitored. If limits are exceeded, safety adjustments are triggered, including cooling and intermittent cooling or partial unlocking and relocking, until the system returns to a safe range; if the parameters are normal, the task is completed and the system returns to the mode determination state. This mode ensures load-bearing capacity and dimensional stability through global locking, balancing safety and efficiency.

[0065] When there is no immediate task or when waiting for instructions, the system enters standby mode: it cuts off pneumatic and electric actuation drives, selects a locking state or releases as needed according to the scenario, and maintains the posture or releases the joint in a low-energy manner; during this period, only the necessary monitoring loops are retained, and it returns to the perception fusion and pattern determination stage after receiving a new task.

[0066] Figure 5 The process is based on multi-field coupling drive—selective locking—online monitoring—mode loop, which realizes rapid, repeatable and stable switching between grasping and carrying, taking into account mobility, operability and energy efficiency, and demonstrating the reliability and mission adaptability of the invention in complex rescue missions.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A flexible joint structure for a rescue robot based on multi-field coupling drive and selective locking, characterized in that: include: The outer flexible support layer (1), the middle multi-field coupling driving layer (2), and the inner locking support layer (3) are: The outer flexible support layer (1) is made of a flexible polymer film and a flexible matrix composed of embedded fibers, providing an overall deformation basis and external protection for the joint; The middle multi-field coupling drive layer (2) integrates a micro-pneumatic cavity and an electric actuator unit, which realizes rapid bending motion and fine angle adjustment of the joint through the synergistic effect of air pressure and electric field; The inner locking support layer (3) is embedded with magnetorheological material or reversible curable resin and is equipped with magnetorheological locking coil (6) or local heating unit (7). Selective locking is triggered by external magnetic field or temperature adjustment to achieve high rigidity retention after the action is completed.

2. The flexible joint structure of the rescue robot based on multi-field coupling drive and selective locking according to claim 1, characterized in that: The micro-pneumatic cavity in the middle multi-field coupling drive layer (2) is connected to a pneumatic interface (9) and a pneumatic actuator (13), and the driving force is generated by adjusting the pressure difference between the inside and outside of the cavity; The electro-actuated unit is made of an electroactive polymer or a dielectric elastomer and is connected to an electrical interface (10). It generates electro-induced compressive stress by applying voltage to establish an electric field.

3. The flexible joint structure of the rescue robot based on multi-field coupling drive and selective locking according to claim 2, characterized in that: The pneumatic equivalent torque generated by the pneumatic actuator (13) Satisfying the formula: in, For input air pressure, External air pressure, A This is the equivalent area of ​​the air cavity under pressure. r The lever arm is the distance from the point of action of the pneumatic drive cavity to the axis of joint rotation. The electro-induced equivalent torque generated by the electro-actuation unit Satisfying the formula: in, The vacuum permittivity, The relative permittivity, V To apply voltage, To drive the effective area, For geometric lever arm, d The thickness is the dielectric layer thickness.

4. The flexible joint structure of the rescue robot based on multi-field coupling drive and selective locking according to claim 1, characterized in that: The inner locking support layer (3) is also provided with a locking band (4) and a crease line (5); The locking band (4) is arranged along the key parts of the structure to limit strain transmission and assist in attitude locking; The crease lines (5) are distributed on the surface of the flexible support layer, providing a guide path for joint movement.

5. The flexible joint structure of the rescue robot based on multi-field coupling drive and selective locking according to claim 1, characterized in that: It also includes temperature and strain sensors (8), a control programming microcomputer (20), and a signal receiving antenna (19); The temperature and strain sensor (8) monitors the temperature distribution and deformation inside the joint in real time; The control programming microcomputer (20) receives sensor feedback signals and integrates pneumatic, electro-actuated and lock-up signals for multi-mode coordinated control; The signal receiving antenna (19) enables wireless communication with the external control center.

6. The flexible joint structure of the rescue robot based on multi-field coupling drive and selective locking according to claim 5, characterized in that: The control programming microcomputer (20) controls the joint angle through closed-loop feedback. With equivalent stiffness k Its control objective satisfies: And simultaneously satisfy the following constraints: ， ， in, For equivalent rotational inertia, For viscous damping, It is a neutral angle. For external disturbance torque, It is the equivalent stiffness, and it is the locking engagement degree. The function, This represents the foundation stiffness when it is not locked. The stiffness contributed to locking. Indicates the degree of lock participation. This is the upper limit of the gas source pressure. This is the upper limit of the driving voltage. This represents the upper limit of the permissible temperature.

7. A flexible joint control method for a rescue robot based on multi-field coupling drive and selective locking, applied to the flexible joint structure as described in any one of claims 1 to 6, characterized in that: The method includes the following steps: Receive control commands and complete system status self-check; According to the target perspective With target stiffness k * Select the drive path, initiate the coordinated operation of pneumatic drive and electro-actuator, and perform state estimation and error calculation through sensor feedback fusion; the angle error , The stiffness error is the estimated value of the joint angle. , This is the estimated equivalent stiffness. Based on angle error With stiffness error Perform closed-loop adjustment to drive the joint movement to the target pose; Determine the task requirements; if posture maintenance is required, trigger the selective locking mechanism; otherwise, maintain compliant drive. After locking, it enters a low-power sustain state until a new task instruction is received.

8. The flexible joint control method for rescue robots based on multi-field coupling drive and selective locking according to claim 7, characterized in that: The steps for triggering the selective locking mechanism specifically include: Determine the target stiffness level based on task requirements and external torque distribution; select either a magnetorheological locking path or a phase transition locking path. If the magnetorheological locking path is selected, a current is applied to the magnetorheological locking coil (6) to generate a controllable magnetic field, so that the magnetic particles inside the magnetorheological material form a chain structure to improve the shear yield strength. If the phase change lock-in path is selected, the reversible curing resin is heated by the local heating unit (7) to cause a phase change and improve the viscoelastic modulus of the material. After locking is completed, strength and pose are checked. If the standard is not met, compensation is performed and locking is re-locked.

9. The flexible joint control method for rescue robots based on multi-field coupling drive and selective locking according to claim 7, characterized in that: The method also includes a multi-mode task switching step: Assess operational load requirements through sensor fusion; Switch between fine-grabbing mode, high-load mode and standby mode; Among them, the fine grasping mode prioritizes electro-actuation for small-angle fine adjustment and triggers local locking; the high-load mode fully triggers the locking mechanism after the pneumatic and electro-actuation are driven in place; the standby mode cuts off the drive and selects the locking maintenance or relaxation state according to the scenario to reduce energy consumption.

10. The flexible joint control method for rescue robots based on multi-field coupling drive and selective locking according to claim 9, characterized in that: System power in the low power maintenance state satisfy: in, To maintain power for sensing and control, I For driving current, R Equivalent resistance Q This represents the gas volumetric flow rate. This refers to the air pressure difference.

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