Modular reconfigurable underactuated manipulator and motion control method thereof

Abstract

The application relates to the technical field of robots, and discloses a modular reconfigurable under-actuated manipulator and a motion control method thereof. The manipulator comprises an end operating hand, a flexible body and a cover. The end operating hands are symmetrically arranged at the two ends of the flexible body. The cover is fixedly connected with the end operating hands and the flexible body. The cover internally contains a power supply, a driving component and a control board. The driving component is in transmission connection with the end operating hands and the flexible body respectively. The manipulator is integrated with a sensing system and a communication module. The end operating hands have the dual functions of grabbing objects and connecting modules. Through the modular reconfigurable design, the manipulator can not only be used as an independent operation terminal to complete single grabbing and carrying work, but also can be connected with multiple modules through the end operating hands to form a complex mechanical arm or a mobile operation system. In combination with the adjustable bending and rigidity characteristics of the flexible body, the manipulator can adapt to different work scenes such as narrow spaces and multi-task switching.

Description

Technical Field

[0001] This invention relates to the field of robotics, specifically to a modular, reconfigurable underactuated manipulator and its motion control method. Background Technology

[0002] Existing robotic arm technology continues to develop in the fields of industrial automation and special operations. Traditional fully actuated robotic arms achieve high-precision control by configuring an independent actuator for each degree of freedom, but they suffer from problems such as complex structure, large weight, high cost, high energy consumption, and cumbersome control algorithms, which limit their application in mobile platforms and space-constrained scenarios. Underactuated robotic arms simplify the structure and control difficulty by reducing the number of actuators and introducing passive components such as springs and linkages, thereby reducing manufacturing costs and energy consumption. However, existing underactuated solutions mostly focus on single-arm grasping functions and lack multimodal motion capabilities, making it difficult to adapt to the needs of movement, obstacle crossing, and multi-tasking in unstructured environments. Modular reconfigurable robotic arms enable multi-module combination and functional reconfiguration through standardized interfaces. While existing modular designs enhance system adaptability and task flexibility, they rely on dedicated connection devices and complex docking mechanisms, resulting in cumbersome inter-module connection processes, high alignment accuracy requirements, insufficient connection strength, and long reconfiguration times. Some studies have applied the underactuated concept to the design of modular manipulators to simplify connection mechanisms, but these still suffer from problems such as limited functionality, weak sensing capabilities, lack of bidirectional motion capabilities, and difficulties in multi-module collaborative control. In particular, existing solutions cannot achieve the dual functions of end-effector grasping and rapid inter-module connection and locking within the same mechanism, nor do they solve key issues such as indiscriminate bidirectional movement of modules, environmental perception, and multi-degree-of-freedom coordinated control under underactuated conditions. Consequently, they fail to meet the practical application requirements of rapid deployment, flexible reconfiguration, and efficient collaboration.

[0003] To address these issues, those skilled in the art have proposed a modular, reconfigurable underactuated manipulator and its motion control method. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a modular, reconfigurable underactuated manipulator and its motion control method, solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a modular, reconfigurable, underactuated manipulator, comprising an end effector, a flexible body, and a cover. The end effector is symmetrically disposed at both ends of the flexible body. The cover is fixedly connected to the end effector and the flexible body. The cover houses a power supply, a drive component, and a control board. The drive component is connected to the end effector and the flexible body via transmission. The manipulator integrates a sensing system and a communication module. The end effector simultaneously possesses the dual functions of grasping objects and connecting modules. The flexible body can perform bending, stiffness adjustment, and propulsion movements. The manipulator can achieve one-to-one or one-to-many connections between modules through the end effector to complete reconfiguration.

[0006] Preferably, the end manipulator is configured as a spherical structure, and each end manipulator includes three gripping fingers; each gripping finger is composed of a gripping finger initial segment, a gripping finger middle segment, and a gripping finger distal segment connected in sequence; the gripping finger initial segment has a guide hole I inside, a guide rod I is installed in the guide hole I, a spring I is sleeved on the guide rod I, one end of the guide rod I is fixedly connected to a gripping finger slider I, and the other end moves in the guide hole I; the gripping finger middle segment has a corresponding guide hole II, a guide rod II is installed in the guide hole II, a spring II is sleeved on the guide rod II, one end of the guide rod II is fixedly connected to a gripping finger slider I, and the other end moves in the guide hole II; the gripping finger initial segment is connected to the gripping finger middle segment through a gripping finger initial segment connecting rod, and the gripping finger middle segment is connected to the gripping finger distal segment through a gripping finger middle segment connecting rod.

[0007] Preferably, the top of the gripper finger has a circular hole, the width ratio of the center plane of the gripper finger is 40°, the inner sides of the gripper finger slider one and gripper finger slider two are both attached with rubber material, the gripper finger slider one and gripper finger slider two are both integrated with pressure feedback modules, and the pressure feedback modules are connected to the control board; when the pressure feedback module detects the set pressure value, the drive component achieves self-locking.

[0008] Preferably, a flexible rod component is provided inside the flexible body, which fixes two helical structures together. Turntables are installed at both ends of the flexible body. A wire pull structure is provided inside the turntable, which forms a transmission connection with the wire-controlled servo. An angle sensor is integrated inside the turntable, and the angle sensor forms a signal connection with the control board.

[0009] Preferably, the driving components include a rotary servo, a wire-controlled servo, a gripper motion motor, and a rotary servo. The rotary servo is connected to the helical structure for controlling the rotation of the helical structure to provide propulsion power. The wire-controlled servo is connected to the wire-pull structure for controlling the bending and steering of the flexible body. The gripper motion motor is connected to a transmission link, which is connected to the initial section of the gripper finger for controlling the closure of the gripper finger. The rotary servo is connected to the end manipulator for adjusting the rotation angle of the end manipulator.

[0010] Preferably, the sensing system includes an ultrasonic sensor, a camera, and an infrared module; the ultrasonic sensor is installed on the cover, the camera is installed in the gap of the upper shell, and the infrared module is installed at both ends of the robotic arm; the ultrasonic sensor, camera, and infrared module are all connected to the communication module, and the communication module transmits sensor data to the control board.

[0011] Preferably, the robotic arm adopts a highly symmetrical structural design with no distinction between the front and rear ends. The rotary servo motor 14 achieves the switching of the robotic arm's movement direction by reversing the rotation direction. Both the front and rear ends of the robotic arm are equipped with ultrasonic sensors, cameras, and infrared modules, which can bidirectionally identify the surrounding environment and adjust the module status.

[0012] Preferably, when the end manipulators serve as collaborative interfaces, the flexible body bending adjustment and the rotational servo motor angle adjustment are used to align the centers of the two end manipulators and keep the angle within the allowable connection range. The gripper motion motor drives the transmission linkage, causing the initial section, middle section and final section of the gripper finger to close sequentially, forming a robust connection structure. After connection, multiple robotic arm modules can move collaboratively.

[0013] A motion control method for a modular, reconfigurable, underactuated manipulator includes the following steps:

[0014] Grasping Control: The servo motor controls the retraction of the cable-driven structure, driving the flexible body to bend and adjust the shape of the manipulator, aligning the end effector with the target object; the rotation servo motor adjusts the rotation angle of the end effector; the gripper's motion motor drives the transmission linkage to move, causing the initial section of the gripper finger to close; after the first gripper finger slider touches the object, it moves inward to compress the first gripper finger, which in turn causes the middle section of the gripper finger to close via the initial gripper finger linkage; after the second gripper finger slider touches the object, it compresses the second gripper finger, which in turn causes the final section of the gripper finger to close via the middle gripper finger linkage; when the pressure feedback module detects that the pressure reaches the set pressure value, the drive components self-lock to maintain a stable grip;

[0015] Connection control: The servo motor controls the retraction of the cable pull structure to adjust the bending of the flexible body, and the rotary servo motor adjusts the rotation angle of the end manipulators to align the centers of the two end manipulators and keep the angle within the allowable connection range; the gripper motion motor drives the transmission linkage, causing the initial, middle and final sections of the gripper fingers to close sequentially to form a firm connection; during the connection process, the two end manipulators are prohibited from rotating relative to each other, and to adjust the docking angle, the existing connection must be disengaged first and then approached again to complete the connection;

[0016] Motion and Cooperative Control: Rotary servos control the rotation of the helical structure to provide propulsion power, and the direction of the manipulator's movement is switched by reversing the direction of the rotary servos; angle sensors feed back the degree of bending of the flexible body to the control board to ensure that the motion posture meets the requirements; after multiple modules are connected, the control board coordinates the various drive components to achieve cooperative movement and handling tasks.

[0017] This invention provides a modular, reconfigurable underactuated manipulator and its motion control method. It offers the following advantages:

[0018] 1. Through modular and reconfigurable design, the robot can function as an independent operating terminal to complete a single grasping and handling task, or it can be flexibly connected between multiple modules with the help of the end effector to form a complex robotic arm or mobile operating system. With the adjustable bending and stiffness characteristics of the flexible body, it can adapt to different working scenarios such as narrow spaces and multi-task switching, effectively solving the problem that existing robot arms have fixed shapes and cannot cope with complex and ever-changing work requirements, thus expanding the overall working range and application scenario coverage.

[0019] 2. This invention achieves dual optimization of functional integration and operational reliability. The end effector has both grasping and connecting functions. Its underactuated structure can passively adapt to the shape deviation of the target object or docking module. With the built-in pressure feedback of the slider and the self-locking mechanism of the drive component, it can not only stably grasp irregular and non-rigid objects, but also ensure the stability of the module connection. At the same time, the sensing system collects environmental information in real time and feeds it back to the control terminal to help avoid operational obstacles and adjust the working posture. It solves the defects of existing manipulators such as single function, poor connection fault tolerance and insufficient grasping reliability, and improves the stability and safety of the operation process.

[0020] 3. This invention reduces the overall structural complexity and weight, and simplifies the control logic; the modular architecture allows each core component to be manufactured, maintained and replaced independently, reducing the risk of overall system failure due to local faults, reducing manufacturing and subsequent maintenance costs, and combined with the headless and tailless symmetrical structure to achieve motion steering by reversing the direction of the servo motor, further simplifying the motion control process, solving the problems of cumbersome control, high cost and difficult maintenance of existing fully driven manipulators, and improving the product's economy and practicality. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall invention.

[0022] Figure 2 This is a schematic diagram of the end effector of the present invention.

[0023] Figure 3 This is a schematic diagram of the grasping finger structure of the end-operated hand of the present invention.

[0024] Figure 4 This is a block diagram of the drive mechatronics and control system of the present invention.

[0025] The components include: 1. End-operated hand; 2. Flexible body; 3. Cover; 4. Gripping finger; 5-1. Gripping finger slider one; 5-2. Gripping finger slider two; 6-1. Guide hole one; 6-2. Guide hole two; 7-1. Guide rod one; 7-2. Guide rod two; 8-1. Spring one; 8-2. Spring two; 9-1. Gripping finger initial section connecting rod; 9-2. Gripping finger middle section connecting rod; 10. Flexible rod component; 11. Helical structure; 12. Turntable; 13. Cable-stayed structure; 14. Rotary servo motor; 15. Cable-stayed servo motor; 16. Gripping hand motion motor; 17. Rotary servo motor; 18. Transmission connecting rod; 19. Gripping finger initial section; 20. Gripping finger middle section; 21. Gripping finger distal section. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see the appendix Figure 1 - Appendix Figure 3 This invention provides a modular reconfigurable underactuated manipulator, including an end effector 1, a flexible body 2, and a cover 3. The end effector 1 is symmetrically arranged at both ends of the flexible body 2. The cover 3 is fixedly connected to the end effector 1 and the flexible body 2. The cover 3 houses a power supply, a drive component, and a control board. The drive component forms a transmission connection with the end effector 1 and the flexible body 2, respectively. The manipulator integrates a sensing system and a communication module. The end effector 1 has the dual functions of grasping objects and connecting between modules. The flexible body 2 can perform bending, stiffness adjustment, and propulsion movements. The manipulator can achieve one-to-one or one-to-many connections between modules through the end effector 1 to complete reconfiguration.

[0028] Specifically, the basic configuration is formed by symmetrically arranging the end manipulators 1 at both ends of the flexible body 2. The end manipulators 1 and the flexible body 2 are fixedly connected by the cover 3, which also houses the power supply, drive components, and control board to form a centralized control hub. The drive components are connected to the end manipulators 1 and the flexible body 2 to achieve power distribution. The end manipulators 1 adopt a dual-function design, enabling them to grasp objects and connect mechanically between modules. The flexible body 2 achieves bending deformation, active stiffness adjustment, and helical propulsion through its internal flexible mechanism. The manipulator obtains environmental information through the sensing system and communication module and transmits it to the control board for decision-making. Based on the underactuated principle, it completes complex movements with fewer drive components than the system's degrees of freedom. The docking and locking mechanism of the end manipulators 1 enables one-to-one or one-to-many connection and reconfiguration between modules. Thus, while maintaining the simplicity of the drive system, the degrees of freedom and functions are expanded through module combination, and different forms are reconfigured to adapt to various task requirements such as grasping, handling, and crawling.

[0029] The end manipulator 1 is configured as a spherical structure, and each end manipulator 1 contains three grasping fingers 4; each grasping finger 4 is composed of a grasping finger initial segment 19, a grasping finger middle segment 20 and a grasping finger distal segment 21 connected in sequence.

[0030] The initial segment 19 of the gripper has a guide hole 6-1 inside, and a guide rod 7-1 is installed inside the guide hole 6-1. A spring 8-1 is sleeved on the guide rod 7-1. One end of the guide rod 7-1 is fixedly connected to the gripper slider 5-1 inside the gripper, and the other end moves within the guide hole 6-1. The middle segment 20 of the gripper has a guide hole 6-2 inside, and a guide rod 7-2 is installed inside the guide hole 6-2. A spring 8-2 is sleeved on the guide rod 7-2. One end of the guide rod 7-2 is fixedly connected to the gripper slider 5-2 inside the gripper, and the other end moves within the guide hole 6-2.

[0031] Specifically, the end-operated hand 1 is based on the underactuated adaptive gripping principle, adopts a spherical structure, and has three gripping fingers 4 evenly distributed on its surface to achieve omnidirectional gripping capability. Each gripping finger 4 is connected in sequence by a gripping finger initial segment 19, a gripping finger middle segment 20, and a gripping finger distal segment 21 to form a multi-segment finger structure to increase contact points and gripping stability. The guide holes 6-1 and 6-2 respectively opened in the gripping finger initial segment 19 and the gripping finger middle segment 20 inside the gripping finger 4 form a sliding pair with the guide rod 7-1 and the guide rod 7-2. The springs 8-1 and 8-2 sleeved on the guide rod 7-1 and the guide rod 7-2 provide elastic restoring force and adaptive buffering. One end of the guide rod 7-1 and the guide rod 7-2 is fixed to the gripping finger sliding pair. Block 5-1 and the gripper slider 5-2 move along the axis of guide rods 7-1 and 7-2, forming a two-stage linear drive input. The initial segment link 9-1 and the middle segment link 9-2 of the gripper finger respectively convert the linear motion of the slider into the rotational motion of the middle segment 20 and the end segment 21 of the gripper finger, realizing the sequential linkage of multiple joints under a single drive input. When the gripper slider 5-1 contacts the object, it compresses the spring 8-1 and the spring 8-2 and slides into the gripper finger 4. Through the mechanical transmission chain, it sequentially drives the middle segment 20 and the end segment 21 of the gripper finger to close, forming an envelope-type adaptive gripping of the object. This underactuated mechanism controls more degrees of freedom with fewer motors, reducing system complexity and improving gripping flexibility.

[0032] The gripper 4 has a circular hole at its top, and the width of the gripper 4 at its center plane is 40°. Both gripper slider 1 (5-1) and gripper slider 2 (5-2) have rubber coatings on their inner sides. Both gripper sliders 1 (5-1) and 2 (5-2) integrate pressure feedback modules, which are connected to the control board. When the pressure feedback module detects a set pressure value, the drive component self-locks. The flexible body 2 has a flexible rod component 10 inside, which fixes two spiral structures 11 together. Turntables 12 are installed at both ends of the flexible body 2. Each turntable 12 has a wire pull structure 13 inside, which is connected to a wire-controlled servo motor 15. An angle sensor is integrated inside the turntable 12, and the angle sensor is connected to the control board.

[0033] Specifically, the circular hole at the top of the gripper 4 is used to reduce weight and increase structural flexibility. The 40° aspect ratio of the center plane width of the gripper 4 optimizes the matching relationship between the gripping space and structural strength. The rubber material attached to the inner side of the gripper slider 1 5-1 and gripper slider 2 5-2 improves the gripping friction and adaptability to the object surface. The pressure feedback module integrated inside the slider monitors the contact force in real time and transmits the signal to the control board. When the pressure value detected by the pressure feedback module reaches the set threshold, the motor is triggered to self-lock, realizing gripping force maintenance and overload protection. The flexible rod component 10 set inside the flexible body 2 fixes the two spiral structures 11 to form a deformable skeleton. The turntables 12 installed at both ends of the flexible body 2 have built-in wire pull structures 13. The wire pull structures 13 pull the flexible rod component 10 under the drive of the wire control servo motor 15 to produce bending deformation. The angle sensor integrated inside the turntable 12 measures the bending angle in real time and feeds the signal back to the control board, forming a closed-loop control of bending motion, thereby realizing precise attitude adjustment and stiffness sensing of the flexible body 2.

[0034] The drive components include a rotary servo motor 14, a wire-controlled servo motor 15, a gripper motion motor 16, and a rotary servo motor 17. The rotary servo motor 14 is connected to the helical structure 11 and is used to control the rotation of the helical structure 11 to provide propulsion power. The wire-controlled servo motor 15 is connected to the wire-pull structure 13 and is used to control the bending and steering of the flexible body 2. The gripper motion motor 16 is connected to the transmission link 18 and the transmission link 18 is connected to the initial segment 19 of the gripper finger and is used to control the closing of the gripper finger 4. The rotary servo motor 17 is connected to the end manipulator 1 and is used to adjust the rotation angle of the end manipulator 1.

[0035] Specifically, the rotary servo motor 14 is connected to the helical structure 11 to convert rotational motion into linear propulsion, providing forward or backward power for the manipulator; the servo motor 15 is connected to the wire-pull structure 13 to convert rotational motion into traction force, driving the flexible body 2 to bend and deform to achieve steering and attitude adjustment; the gripper motor 16 is connected to the gripper finger section 19 through the transmission link 18, converting the motor's rotational motion into the closing action of the gripper finger 4 to complete gripping or locking; the rotary servo motor 17 is connected to the end manipulator 1 to achieve precise adjustment of the overall rotation angle of the end manipulator 1 to align with the target; each drive component independently controls different functional modules, which are uniformly coordinated through the control board. Under the underactuated architecture, four drive units realize multiple degrees of freedom of motion such as propulsion, bending, gripping, and rotation, reducing system complexity and improving modular reconfigurability.

[0036] The sensing system includes ultrasonic sensors, cameras, and infrared modules; the ultrasonic sensors are installed at three locations on the cover, the cameras are installed in the gaps of the upper shell, and the infrared modules are installed at both ends of the robotic arm; the ultrasonic sensors, cameras, and infrared modules are all connected to the communication module, which transmits sensor data to the control board.

[0037] Specifically, ultrasonic sensors installed at three points on the cover enable accurate ranging and obstacle avoidance warnings for obstacles at medium to long distances in front. Cameras installed in the gaps of the upper shell acquire visual images and spatial pose information of target objects. Infrared modules installed at both ends of the robotic arm perform close-range environmental perception and temperature field detection. The three types of sensors cover different perception ranges to form a complementary perception network. The ultrasonic sensors, cameras, and infrared modules are all connected to the communication module. The communication module collects and transmits multi-source heterogeneous sensor data to the control board. The control board performs synchronization, filtering, feature extraction, and fusion processing on the data to construct a three-dimensional environmental map and identify graspable targets, connectable interfaces, and obstacle distribution. This provides real-time environmental information for the robotic arm's autonomous navigation, precise grasping decisions, and inter-module collaborative reconstruction.

[0038] The robotic arm adopts a highly symmetrical structural design with no distinction between the front and rear ends. The rotary servo motor 14 switches the movement direction of the robotic arm by reversing the rotation direction. Both ends of the robotic arm are equipped with ultrasonic sensors, cameras, and infrared modules, which can bidirectionally identify the surrounding environment and adjust the module status. When the end manipulator 1 acts as a collaborative interface, the flexible body 2 bends and the servo motor 17 adjusts the angle to align the centers of the two end manipulators 1 and keep the angle within the allowable connection range. The gripper motor 16 drives the transmission link 18, which in turn causes the initial section 19, middle section 20, and distal section 21 of the gripper finger to close sequentially, forming a strong connection structure. After connection, multiple robotic arm modules can move collaboratively.

[0039] Specifically, a highly symmetrical structural design eliminates the distinction between the front and rear directions, allowing the rotary servo motor 14 to switch motion directions simply by reversing its rotation direction. Both ends are equipped with ultrasonic sensors, cameras, and infrared modules, forming a two-way environmental perception capability, enabling indiscriminate forward and backward movement and two-way target recognition. When the end manipulator 1 serves as the interface for inter-module collaboration, the control system coordinates the bending adjustment of the flexible body 2 with the angle adjustment of the servo motor 17 to align the central axes of the two end manipulators 1 to be connected and ensure that their relative angles are within the allowable connection range. Subsequently, the gripper motor 16 drives the transmission linkage 18 to move, causing the initial section 19, middle section 20, and final section 21 of the gripper finger to close sequentially, forming a multi-point contact rigid locking structure. This achieves a firm mechanical connection between modules. After connection, multiple robotic arm modules are uniformly scheduled through the control board, sharing perception data and coordinating the actions of each drive component to complete collaborative movement and collaborative transport tasks.

[0040] A motion control method for a modular, reconfigurable, underactuated manipulator includes the following steps:

[0041] Grasping Control: The servo motor 15 controls the retraction of the wire-pull structure 13, driving the flexible body 2 to bend and adjust the shape of the manipulator, aligning the end manipulator 1 with the target object; the rotation servo motor 17 adjusts the rotation angle of the end manipulator 1; the gripper motion motor 16 drives the transmission link 18 to move, causing the initial section 19 of the gripper finger to close; after the gripper finger slider 5-1 touches the object, it moves inward toward the gripper finger 4 to compress the spring 8-1, which in turn causes the middle section 20 of the gripper finger to close via the initial section link 9-1; after the gripper finger slider 5-2 touches the object, it compresses the spring 8-2 inward toward the gripper finger 4, which in turn causes the distal section 21 of the gripper finger to close via the middle section link 9-2; when the pressure feedback module detects that the pressure reaches the set value, the drive components self-lock to maintain a stable grip.

[0042] Connection control: The wire-controlled servo motor 15 controls the retraction of the wire-pull structure 13 to adjust the bending of the flexible body 2; the rotation servo motor 17 adjusts the rotation angle of the end manipulator 1 so that the centers of the two end manipulators 1 are aligned and the angle is within the allowable connection range; the gripper motion motor 16 drives the transmission link 18, which drives the initial section 19, the middle section 20, and the final section 21 of the gripper fingers to close sequentially to form a firm connection; during the connection process, the two end manipulators 1 are prohibited from rotating relative to each other. To adjust the docking angle, the existing connection must be disengaged first and then approached again to complete the connection.

[0043] Motion and Cooperative Control: Rotary servo motor 14 controls the rotation of helical structure 11 to provide propulsion power, and the direction of manipulator movement is switched by reversing the direction of rotary servo motor 14; Angle sensor feeds back the degree of bending of flexible body 2 to control board to ensure that the motion posture meets the requirements; After multiple modules are connected, control board coordinates each drive component to realize cooperative movement and handling tasks.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular, reconfigurable, underactuated manipulator, characterized in that, The robot includes an end manipulator (1), a flexible body (2), and a cover (3). The end manipulator (1) is symmetrically arranged at both ends of the flexible body (2). The cover (3) is fixedly connected to the end manipulator (1) and the flexible body (2). The cover (3) contains a power supply, a drive component, and a control board. The drive component forms a transmission connection with the end manipulator (1) and the flexible body (2) respectively. The robot integrates a sensing system and a communication module. The end manipulator (1) has the dual functions of grasping objects and connecting between modules. The flexible body (2) can perform bending, stiffness adjustment, and propulsion actions. The robot can achieve one-to-one or one-to-many connections between modules through the end manipulator (1) to complete reconstruction. The end manipulator (1) is configured as a spherical structure. Each end manipulator (1) contains three grasping fingers (4). Each grasping finger (4) is composed of a grasping finger tip (19), a grasping finger middle section (20), and a grasping finger tip (21) connected in sequence. The drive components include a rotary servo (14), a wire-controlled servo (15), a gripper motion motor (16), and a rotary servo (17). The rotary servo (14) is connected to the helical structure (11) to control the rotation of the helical structure (11) to provide propulsion power. The wire-controlled servo (15) is connected to the wire-pull structure (13) to control the bending and turning of the flexible body (2). The gripper motion motor (16) is connected to the transmission link (18), and the transmission link (18) is connected to the initial segment (19) of the gripper finger to control the closing of the gripper finger (4). The rotary servo (17) is connected to the end manipulator (1) to adjust the rotation angle of the end manipulator (1). When the end manipulator (1) serves as the collaborative interface, the flexible body (2) bends and the servo motor (17) adjusts the angle so that the centers of the two end manipulators (1) are aligned and the angle is within the allowable connection range. The gripper motor (16) drives the transmission link (18) to drive the initial section (19), middle section (20) and final section (21) of the gripper finger to close in sequence, forming a solid connection structure. After connection, multiple manipulator modules can move in coordination.

2. The modular reconfigurable underactuated manipulator according to claim 1, characterized in that, The grasping finger (4) has a guide hole (6-1) inside the initial section (19) of the grasping finger (4). A guide rod (7-1) is installed inside the guide hole (6-1). A spring (8-1) is sleeved on the guide rod (7-1). One end of the guide rod (7-1) is fixedly connected to the grasping finger slider (5-1), and the other end moves in the guide hole (6-1). The middle section (20) of the grasping finger has a corresponding guide hole (6-2). (6-2) The guide rod two (7-2) is installed in the inner part. The spring two (8-2) is sleeved on the guide rod two (7-2). One end of the guide rod two (7-2) is fixedly connected to the finger slider two (5-2), and the other end moves in the guide hole two (6-2). The finger initial section (19) is connected to the finger middle section (20) through the finger initial section connecting rod (9-1), and the finger middle section (20) is connected to the finger end section (21) through the finger middle end connecting rod (9-2).

3. The modular reconfigurable underactuated manipulator according to claim 2, characterized in that, The top of the gripper (4) has a circular hole. The width of the gripper (4) at its center plane is 40°. The inner sides of the gripper slider 1 (5-1) and gripper slider 2 (5-2) are both covered with rubber material. The gripper slider 1 (5-1) and gripper slider 2 (5-2) are both integrated with pressure feedback modules. The pressure feedback modules are connected to the control board. When the pressure feedback module detects the set pressure value, the drive component self-locks.

4. The modular reconfigurable underactuated manipulator according to claim 1, characterized in that, The flexible body (2) is provided with a flexible rod component (10) inside, which fixes two spiral structures (11) together. Turntables (12) are installed at both ends of the flexible body (2). A wire pull structure (13) is provided inside the turntable (12). The wire pull structure (13) is connected to the wire-controlled servo motor (15) for transmission. An angle sensor is integrated inside the turntable (12). The angle sensor is connected to the control board for signal transmission.

5. The modular reconfigurable underactuated manipulator according to claim 1, characterized in that, The sensing system includes an ultrasonic sensor, a camera, and an infrared module; the ultrasonic sensor is installed on the cover (3), the camera is installed in the gap of the upper shell, and the infrared module is installed at both ends of the robot arm; the ultrasonic sensor, camera, and infrared module are all connected to the communication module, and the communication module transmits the sensor data to the control board.

6. The modular reconfigurable underactuated manipulator according to claim 1, characterized in that, The robotic arm adopts a highly symmetrical structural design with no distinction between the front and rear ends. The rotating servo motor (14) achieves the switching of the robotic arm's movement direction by reversing the rotation direction. Both the front and rear ends of the robotic arm are equipped with ultrasonic sensors, cameras, and infrared modules, which can bidirectionally identify the surrounding environment and adjust the module status.

7. A motion control method for a modular, reconfigurable, underactuated manipulator, characterized in that, The modular, reconfigurable, underactuated manipulator according to any one of claims 1-6 comprises the following steps: Grasping control: The wire-controlled servo motor (15) controls the wire pull structure (13) to retract, driving the flexible body (2) to bend to adjust the shape of the manipulator, so that the end manipulator (1) is aligned with the target object; the rotation servo motor (17) adjusts the rotation angle of the end manipulator (1); the gripper motion motor (16) drives the transmission link (18) to move, causing the initial section of the gripper finger (19) to close; after the gripper finger slider one (5-1) touches the object, it moves towards the inside of the gripper finger (4) to compress the first spring (8-1), which drives the middle section of the gripper finger (20) to close through the link (9-1) of the initial section of the gripper finger; after the gripper finger slider two (5-2) touches the object, it compresses the second spring (8-2) towards the inside of the gripper finger (4), which drives the end section of the gripper finger (21) to close through the link (9-2) of the middle section of the gripper finger; when the pressure feedback module detects that the pressure reaches the set pressure value, the drive component self-locks to maintain a stable grip; Connection control: The wire-controlled servo motor (15) controls the wire pull structure (13) to retract and adjust the flexible body (2) to bend, and the rotation servo motor (17) adjusts the rotation angle of the end manipulator (1) so that the centers of the two end manipulators (1) are aligned and the angle is within the allowable connection range; the gripper motor (16) drives the transmission link (18) to drive the initial section (19), middle section (20) and end section (21) of the gripper finger to close in sequence to form a firm connection; during the connection process, the two end manipulators (1) are prohibited from rotating relative to each other. To adjust the docking angle, the existing connection must be broken first and then approached again to complete the connection; Motion and Cooperative Control: The rotary servo (14) controls the rotation of the helical structure (11) to provide propulsion power. The direction of the manipulator's movement is switched by reversing the direction of the rotary servo (14); the angle sensor feeds back the degree of bending of the flexible body (2) to the control board to ensure that the motion posture meets the requirements; after multiple modules are connected, the control board coordinates each drive component to realize cooperative movement and handling tasks.

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