Automatic assembling device for infusion apparatus production

Abstract

The invention relates to the field of medical instrument automatic production equipment, and discloses an automatic assembly device for infusion apparatus production, which is used for assembling a flexible hose and a to-be-assembled component, and comprises a conveying unit which is configured to apply distributed axial driving force along the length direction of the flexible hose so as to drive the flexible hose to move along a preset path; the guiding actuator is arranged at the tail end of the preset path and is configured to guide the port part of the flexible hose and generate a force feedback signal corresponding to the axial force borne by the port part during assembly; and the assembling platform is configured to fixedly clamp the to-be-assembled component and is in physical contact with the to-be-assembled component when the port part is in physical contact with the to-be-assembled component. By establishing a closed-loop control logic triggered by an event, the reliability of the assembly process is fundamentally improved, it is ensured that each time of assembly is carried out under a controlled mechanical condition, and hose buckling, deflection or insertion failure caused by time sequence or positioning errors in a traditional open-loop system is effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of automated production equipment for medical devices, specifically an automated assembly device for the production of infusion sets. Background Technology

[0002] In the automated production of disposable medical consumables, the assembly of infusion sets is a complex process involving multiple precision steps. Among them, reliably connecting the highly flexible, slender tubing made of medical-grade PVC or TPE to rigid plastic components such as drip chambers, flow regulators, or puncture needle hubs is a core technological bottleneck in the entire automated process.

[0003] Existing automation solutions typically rely on pneumatic blowing, conveyor belt transport, or mechanical gripper pushing to move and position the tubing. However, the effectiveness of these methods is limited by the inherent physical characteristics of the infusion tubing itself. The tubing's flexibility, bendability, and susceptibility to static electricity make it highly prone to unintended tangling, blockage, or vibration in the transport channel, resulting in significant uncertainty in the spatial position and orientation of its end upon arrival at the assembly station. This positioning inaccuracy is amplified dramatically in the final assembly stage. When the system attempts to force a poorly positioned tubing end into the narrow orifice of a flow regulator or onto the tapered interface of a drip chamber, simple axial thrust easily encounters resistance. At this point, the flexible tubing wall cannot withstand the concentrated stress, leading to buckling, deflection, or scratching by the sharp edges of hard components. This not only directly causes assembly failure and product scrap but also potentially generates tiny plastic particles due to scratching, posing a potential threat to the quality and safety of the final product.

[0004] Furthermore, existing devices based on rigid mechanical designs often exhibit low tolerance for variations in process parameters. Even subtle differences in diameter, wall thickness, or material hardness between different production batches and specifications of infusion tubing can necessitate cumbersome mechanical adjustments and readjustments to the entire system, severely impacting the flexibility and overall efficiency of the production line. Therefore, the industry urgently needs a technological solution that can fundamentally change the way flexible tubing is handled to address these challenges. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an automated assembly device for infusion set production, which solves the problems of inaccurate assembly positioning, easy bending damage to the hose, and low assembly reliability caused by the inherent characteristics of flexible hoses in existing technologies.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an automated assembly device for infusion set production, used to assemble flexible tubing with components to be assembled, comprising: A delivery unit is configured to apply a distributed axial driving force along the length of the flexible hose to drive the flexible hose to move along a predetermined path. A guide actuator, located at the end of a predetermined path, is configured to guide the port portion of a flexible hose and generate a force feedback signal corresponding to the axial force applied to the port portion during assembly. The assembly platform is configured to hold the component to be assembled in a fixed position, and generates a contact signal when the port part makes physical contact with the component to be assembled. The control system is electrically connected to the conveying unit, the guide actuator, and the assembly platform. When it receives a contact signal, it performs closed-loop control on the conveying unit based on the force feedback signal.

[0007] Preferably, the conveying unit includes a conveying pipe, which is a hollow structure. Multiple annular drive components are arrayed at equal intervals along the axial direction on its inner wall. The pipe wall of the conveying pipe has openings corresponding to the annular drive components, so that a part of the annular drive components is exposed to the outside. A rotating shaft parallel to the conveying pipe is provided outside the conveying pipe. The rotating shaft is driven to rotate by a servo motor. A gear corresponding to the annular drive component is fixedly connected to the outer wall of the rotating shaft. The rotation of the gear drives the annular drive component to rotate.

[0008] Preferably, the annular drive assembly includes an annular bearing, the outer ring of which is fixedly connected to the inner wall of the conveying pipe, allowing the inner ring of the annular bearing to rotate freely around the central axis of the channel. A second gear is fixedly connected to the side wall of the inner ring of the annular bearing, the tooth end of the second gear passes through an opening in the wall of the conveying pipe and meshes with the tooth end of the first gear. Flexible helical blades are provided on the inner wall of the inner ring of the annular bearing. When the second gear is driven to rotate, the flexible helical blades interact with the outer wall of the flexible hose to generate an axial driving force.

[0009] Preferably, the guide actuator includes a guide cylinder with an annular chamber filled with medical-grade magnetorheological fluid. A guide hole is located at the center of the guide cylinder, the inlet of which is conical and the hole wall is made of an elastic and flexible membrane. An electromagnetic coil is wound around the outer wall of the guide cylinder. When the electromagnetic coil is energized, the magnetorheological fluid in the annular chamber changes from a flowing liquid to a semi-solid with controllable yield strength within milliseconds, thus constraining the end of the flexible hose passing through the guide hole to the geometric center of the guide cylinder.

[0010] Preferably, the guide actuator further includes a current monitoring module. When the flexible hose is subjected to the axial force, in order to maintain the semi-solid state of the magnetorheological fluid, the electromagnetic coil generates current fluctuations. The current monitoring module is used to monitor the current fluctuations and use the current fluctuations as a force feedback signal.

[0011] Preferably, the assembly platform includes a base and a motion platform. The motion platform is connected to the base via a flexible hinge. The motion platform is equipped with a clamp for holding and fixing the component to be assembled. A plurality of piezoelectric ceramic actuators are also provided between the base and the motion platform to drive the motion platform to perform high-frequency micro-amplitude oscillation.

[0012] Preferably, the assembly platform further includes a resonant frequency monitoring module, which is installed in the high-stress area of ​​the flexible hinge to monitor the resonant frequency of the motion platform during the swinging process, and generates a contact signal when a preset offset is detected due to the physical contact between the port of the flexible hose and the component to be assembled.

[0013] Preferably, after receiving a contact signal, the control system controls the power supply current of the electromagnetic coil to reduce the stiffness of the semi-solid formed by the magnetorheological fluid, thereby enabling the flexible hose port to perform flexible adaptive alignment.

[0014] Preferably, the control system performs closed-loop control of the conveying unit, specifically including: adjusting the axial driving force applied by the conveying unit in real time based on the force feedback signal, so that the axial force is maintained within a preset threshold range.

[0015] Preferably, the control system is further configured as follows: Before receiving a contact signal, the control conveying unit operates in a first preset mode; Upon receiving a contact signal, the conveying unit is switched to a second mode based on closed-loop control using force feedback signals.

[0016] This invention provides an automated assembly device for the production of infusion sets. It has the following advantages: 1. This invention fundamentally improves the reliability of the assembly process by establishing an event-triggered closed-loop control logic. Specifically, the device does not blindly execute a preset sequence of actions, but first uses the resonant frequency change of the assembly platform to accurately generate a contact signal, thereby keenly sensing the precise moment when the hose contacts the component to be assembled. Immediately afterwards, the control system responds to this signal and switches to a more refined control mode, guiding subsequent insertion actions based on the force feedback signal generated in real time by the guide actuator. This "sensing first, then complying" collaborative working method ensures that every assembly is performed under controlled mechanical conditions, effectively avoiding hose buckling, deflection, or insertion failure caused by timing or positioning errors in traditional open-loop systems.

[0017] 2. This invention provides comprehensive protection for flexible hoses throughout the entire conveying and assembly process. During the conveying stage, the flexible helical blades of the conveying unit apply a distributed driving force to the entire hose, avoiding stress concentration and deformation risks caused by applying concentrated thrust to a single end. In the critical assembly stage, the guiding actuator uses the force field generated by the magnetorheological fluid to constrain and align the hose ends, completely eliminating surface scratches or contamination that could be caused by mechanical grippers. This series of protective measures ensures that the hose maintains its original physical and cleanliness state.

[0018] 3. This invention highly integrates sensing and execution functions. The guide actuator is not only an execution component for achieving precise alignment, but its internal magnetic field changes are also creatively used as a sensor to measure axial force, generating force feedback signals. Similarly, the micro-oscillation of the assembly platform is not only an auxiliary means of reducing friction, but its resonant characteristics are also cleverly utilized as a "tactile" switch to detect physical contact. This design, which integrates multiple functions such as driving, guiding, and sensing within a single component, allows the system to gain a more direct and rapid understanding of the assembly state, thereby achieving a higher level of precision control.

[0019] 4. The structural design of this invention gives it excellent process compatibility and adaptability, enabling it to flexibly cope with physical differences between components of different specifications or batches. The magnetorheological fluid in the guide actuator can naturally adapt to hoses of different outer diameters without the need to replace hardware. More importantly, the closed-loop control system based on force feedback signals can automatically compensate for differences in assembly resistance caused by variations in hose hardness, surface friction coefficient, or component interface dimensional tolerances. The system automatically adjusts the driving force of the conveying unit to achieve the predetermined compliant assembly target, greatly enhancing the flexibility of the production line and its adaptability to fluctuations in incoming materials.

[0020] 5. This invention achieves dynamic optimization of the assembly process through strategic scheduling of deeply coordinated units by the control system. For example, upon receiving a contact signal, the system not only switches the operating mode of the conveying unit but also synchronously instructs the guide actuator to reduce its magnetic field strength, changing its guiding action from "rigid" to "flexible." This subtle mode switch allows the flexible hose's end to undergo final attitude self-correction under the guidance of contact force, achieving intelligent assembly that conforms to physical laws rather than forcibly overcoming them. This ability to adjust system parameters in real time based on process status is key to achieving high-success-rate precision assembly. Attached Figure Description

[0021] Figure 1 This is a perspective view of the present invention; Figure 2 This is a partial structural diagram of the conveying unit in this invention; Figure 3 This is a perspective view of the annular driving component in this invention; Figure 4 This is a schematic diagram of the internal structure of the guide cylinder in this invention; Figure 5 This is a schematic diagram of the assembly platform in this invention.

[0022] Among them, 1. conveying pipe; 2. ring drive assembly; 201. ring bearing; 202. gear two; 3. rotating shaft; 4. gear one; 5. guide cylinder; 501. ring chamber; 502. guide hole; 6. electromagnetic coil; 7. base; 8. motion platform; 9. flexible hinge. Detailed Implementation

[0023] The technical solutions of 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.

[0024] Please see the appendix Figure 1 - Appendix Figure 5 This invention provides an automated assembly device for infusion set production, used to assemble flexible tubing with components to be assembled, including: A delivery unit is configured to apply a distributed axial driving force along the length of the flexible hose to drive the flexible hose to move along a predetermined path. A guide actuator, located at the end of a predetermined path, is configured to guide the port portion of a flexible hose and generate a force feedback signal corresponding to the axial force applied to the port portion during assembly. The assembly platform is configured to hold the component to be assembled in a fixed position, and generates a contact signal when the port part makes physical contact with the component to be assembled. The control system is electrically connected to the conveying unit, the guide actuator, and the assembly platform. When it receives a contact signal, it performs closed-loop control of the conveying unit based on the force feedback signal.

[0025] The core design of this invention lies in constructing a precision electromechanical system capable of intelligent closed-loop control of the entire process of conveying and assembling flexible hoses, thereby solving the assembly reliability problem caused by the characteristics of flexible materials in existing technologies. The automated assembly device is primarily composed of three collaborative core functional units: a conveying unit, a guiding actuator, and an assembly platform. Furthermore, the device includes a control system serving as the system's central hub. This control system electrically connects to and uniformly schedules the aforementioned functional units to execute complex collaborative assembly tasks.

[0026] In the overall layout of the device, these three core functional units are arranged sequentially along the assembly path of the flexible hose, forming a coherent functional chain. The conveying unit is located at the beginning or upstream section of the assembly path, defining a predetermined path for the flexible hose to pass through. The function of this unit is to provide a stable, damage-free axial driving force for the flexible and easily deformable hose.

[0027] The guide actuator is precisely positioned at the end of the predetermined path, directly opposite the outlet of the conveying unit. Its function is to perform final, high-precision orientation alignment and control of the flexible hose end to be assembled. This actuator is a key component connecting the conveying stage and the final assembly stage.

[0028] The assembly platform is located directly below the guide actuator and is configured to securely hold the assembly components, such as flow regulators or drip chambers of infusion sets, awaiting connection to the tubing. This three-dimensional spatial arrangement allows the tubing end aligned by the guide actuator to point vertically downwards, precisely corresponding to the interface of the assembly component on the assembly platform, creating ideal geometry for the final insertion or connection.

[0029] As the "nerve center" of the entire device, the control system's role goes beyond simply issuing action commands. It not only sends action commands to the drive mechanisms of each unit, but more importantly, it continuously receives real-time feedback signals from the guide actuators and assembly platform. By analyzing and processing these signals, the control system can obtain real-time information about key physical states during the assembly process, such as the occurrence of contact events and the magnitude of assembly forces. Based on this information, it dynamically adjusts its control strategy, thereby achieving a high degree of coordination and intelligent linkage between the units.

[0030] The conveying unit includes a conveying pipe 1, which is a hollow structure. Multiple annular drive components 2 are arrayed equidistantly along the axial direction on the inner wall of the conveying pipe 1. An opening corresponding to the annular drive components 2 is opened on the pipe wall of the conveying pipe 1, so that a part of the annular drive components 2 is exposed to the outside. A rotating shaft 3 parallel to the conveying pipe 1 is provided on the outside of the conveying pipe 1. The rotating shaft 3 is driven to rotate by a servo motor. A gear 4 corresponding to the annular drive components 2 is fixedly connected to the outer wall of the rotating shaft 3. The rotation of the gear 4 drives the annular drive components 2 to rotate. The annular drive assembly 2 includes an annular bearing 201. The outer ring of the annular bearing 201 is fixedly connected to the inner wall of the conveying pipe 1, allowing the inner ring of the annular bearing 201 to rotate freely around the central axis of the channel. A gear 202 is fixedly connected to the side wall of the inner ring of the annular bearing 201. The tooth end of the gear 202 passes through the opening on the pipe wall of the conveying pipe 1 and meshes with the tooth end of the gear 4. Flexible helical blades are provided on the inner wall of the inner ring of the annular bearing 201. When the gear 202 is driven to rotate, the flexible helical blades interact with the outer wall of the flexible hose to generate axial driving force.

[0031] The internal structure of the delivery unit reveals its unique driving mechanism. Its main body is a delivery pipe 1 defining a hollow channel. The inner wall of the channel is not a smooth plane, but rather composed of multiple independent annular drive components 2 arranged equidistantly along the axial direction. Each annular drive component 2 contains an annular bearing 201, the inner ring of which can rotate precisely around the central axis of the channel. On the inner wall of the inner ring of each annular bearing 201, several flexible helical blades made of medical-grade silicone or similar elastomers are evenly distributed and fixed. Each blade is not a simple straight piece, but has a precise helix angle. It resembles a small, flexible, upright thread. When the inner ring fixing it rotates, the surface of this "flexible thread" sweeps a helical trajectory in space. When the servo motors drive synchronously, these flexible helical blades make gentle and continuous line contact with the outer wall of the flexible tubing placed within the channel. The helical surface of the blades makes frictional contact with the outer wall of the tubing, and the rotational motion is decomposed by the helix angle into a normal pressure perpendicular to the tube wall and an axial driving force parallel to the tube wall. It is this axial force that propels the hose forward. Through the helical angle design of the blades, the rotational motion is efficiently converted into a pure axial driving force evenly distributed throughout the hose. In traditional end-push methods, the force is concentrated at a single point, making the flexible hose like a rope being pushed, extremely prone to bending. The core innovation of this invention lies in decomposing a concentrated thrust into multiple, minute thrusts distributed along the entire hose. Each set of blades provides only a small portion of the driving force, and their combined effect is that each segment of the hose is evenly "supported" forward, physically avoiding concentrated stress on the hose ends and thus eliminating the risk of buckling during delivery.

[0032] The guide actuator includes a guide cylinder 5, within which an annular chamber 501 is formed. The annular chamber 501 is filled with medical-grade magnetorheological fluid. A guide hole 502 is located at the center of the guide cylinder 5. The inlet of the guide hole 502 has a conical structure, and the wall of the guide hole 502 is made of an elastic and flexible membrane. An electromagnetic coil 6 is wound around the outer wall of the guide cylinder 5. When the electromagnetic coil 6 is energized, the magnetorheological fluid in the annular chamber 501 transforms from a flowing liquid state to a semi-solid state with controllable yield strength within milliseconds, constraining the end of the flexible hose passing through the guide hole 502 to the geometric center of the guide cylinder 5. The guide actuator also includes a current monitoring module. When the flexible hose is subjected to axial force, the electromagnetic coil 6 generates current fluctuations to maintain the semi-solid state of the magnetorheological fluid. The current monitoring module monitors these current fluctuations and uses them as a force feedback signal.

[0033] The guide actuator is designed as a precision component integrating sensing capabilities. Its core is a guide cylinder 5 made of non-magnetic material, with a conical guide hole 502 at its center. An annular chamber 501 is formed within the cylinder 5, filled with medical-grade magnetorheological fluid—a smart material whose rheological properties can rapidly change under the influence of a magnetic field. An electromagnetic coil 6 is precisely wound around the outside of the guide cylinder 5, combined with a highly efficient closed magnetic circuit. When the electromagnetic coil 6 is energized, the magnetorheological fluid in the annular chamber 501 transforms from a flowing liquid to a semi-solid state with controllable yield strength within milliseconds. This semi-solid magnetorheological fluid tightly supports the walls of the guide hole 502, suspending and constraining the end of the flexible tube passing through the guide hole 502 to its geometric center, achieving high-precision positioning and guidance.

[0034] More importantly, this guiding actuator also cleverly achieves force sensing. To maintain a specific suspension state, the control system needs to provide a stable current to sustain the magnetic field. When the port of the flexible hose is subjected to an axial reaction force during assembly, this force is transmitted to the semi-solid magnetorheological fluid medium, causing changes in its internal microstructure and stress field, thereby altering the magnetic reluctance of the entire magnetic circuit. To maintain a constant magnetic flux, the closed-loop drive power supply must immediately adjust its output current to compensate for the change in magnetic reluctance. Therefore, by precisely monitoring and acquiring the minute fluctuations of this compensation current, the magnitude of the axial force acting on the port of the flexible hose can be directly and sensitively calculated. This acquired current fluctuation signal constitutes the force feedback signal in this invention.

[0035] The assembly platform includes a base 7 and a motion platform 8. The motion platform 8 is connected to the base 7 via a flexible hinge 9. A fixture for holding and fixing the components to be assembled is mounted on the motion platform 8. Multiple piezoelectric ceramic actuators are also installed between the base 7 and the motion platform 8 to drive the motion platform 8 to perform high-frequency micro-amplitude oscillations. The assembly platform also includes a resonant frequency monitoring module, which is installed in the high-stress area of ​​the flexible hinge 9. This module monitors the resonant frequency of the motion platform 8 during its oscillation and generates a contact signal when a preset offset is detected due to the physical contact between the flexible hose end and the component to be assembled.

[0036] The assembly platform is also a unit integrating actuation and sensing functions. Its structure includes a motion platform 8 connected to the base 7 via a flexible hinge 9. The design of the flexible hinge 9 ensures frictionless and backlash-free movement. The motion platform 8 is equipped with specialized clamps for holding the components to be assembled and is driven by actuators such as piezoelectric ceramics. During assembly, these actuators drive the motion platform 8 to perform high-frequency, micro-amplitude oscillations. This controlled micro-vibration effectively breaks down the static friction between the port of the flexible hose and the interface of the component to be assembled, thereby significantly reducing insertion resistance.

[0037] Another core function of this assembly platform lies in its "tactile" sensing capability. Before the flexible hose contacts the assembly, the motion platform 8 and its clamps constitute a vibration system with specific physical properties, thus possessing a measurable inherent resonant frequency. The control system determines this reference resonant frequency through rapid frequency sweeping before assembly. The instant the flexible hose's port makes its first physical contact with the assembly component, it is equivalent to introducing a tiny additional mass and damping into this vibration system. This disturbance immediately causes a frequency shift in its resonant frequency that can be accurately captured by a highly sensitive sensor (such as a piezoelectric film). This identified frequency shift signal serves as a zero-delay logic trigger signal, constituting the contact signal in this invention, precisely announcing the occurrence of the physical contact event to the control system.

[0038] After receiving the contact signal, the control system controls the power supply current of the electromagnetic coil 6 to reduce the stiffness of the semi-solid formed by the magnetorheological fluid, thereby enabling the flexible hose port to perform flexible adaptive alignment.

[0039] The control system performs closed-loop control of the conveying unit, specifically including: adjusting the axial driving force applied by the conveying unit in real time based on the force feedback signal so that the axial force is maintained within a preset threshold range.

[0040] The control system is further configured as follows: Before receiving a contact signal, the control conveying unit operates in a first preset mode; Upon receiving a contact signal, the conveying unit is switched to a second mode based on closed-loop control using force feedback signals.

[0041] A complete assembly cycle begins with the preparation and approach phases. First, the control system command transmission unit starts in a preset "rapid approach" mode. In this mode, the servo motor drives the inner ring of the ring bearing 201 to rotate synchronously at a high speed, driving the flexible hose to advance quickly and straight along the predetermined path through its flexible helical blades. At the same time, the control system applies a high initial current to the electromagnetic coil 6 of the guide actuator, causing the magnetorheological fluid inside to rapidly transform into a semi-solid with controllable yield strength, precisely pre-aligning the port of the approaching flexible hose.

[0042] As the end of the flexible hose approaches the component to be assembled, the control system switches the delivery unit to a lower "probe speed" mode to ensure a gentle initial contact. During this phase, the piezoelectric actuators of the assembly platform begin driving its motion platform 8 to perform a rapid resonant frequency sweep to monitor the reference resonant frequency of its vibration system in real time. When the end of the flexible hose makes its first physical contact with the component held on the motion platform 8, even a very slight touch will cause a momentary, identifiable shift in the platform's resonant frequency due to the introduction of additional system mass and damping. The resonant frequency monitoring module on the platform captures this frequency shift and immediately generates a contact signal, sending this precise "tactile" event information to the control system.

[0043] Upon receiving the contact signal, the control system executes a preset, multi-task parallel collaborative mode switching command, marking the transition of the device from the open-loop positioning stage to the closed-loop precision assembly stage. On one hand, the system command guides the actuator to moderately reduce the supply current to its electromagnetic coil 6. This reduces the stiffness of the magnetorheological fluid, transforming it from a rigid guide to a flexible adaptive state. This allows the flexible hose's port to undergo minor posture self-correction under subsequent assembly forces, better conforming to the geometry of the component interface to be assembled.

[0044] On the other hand, the control system simultaneously instructs the conveying unit to completely switch its operating mode from speed control to force feedback control mode, and instructs the assembly platform to enter a preset "drag-reducing oscillation" mode, vibrating continuously at a specific frequency and amplitude. At this point, the final force-controlled compliant assembly stage officially begins. In this stage, the movement of the conveying unit's push hose is entirely dominated by the real-time force feedback signal from the guide actuator. The force control algorithm within the control system continuously compares this signal with a preset safety force threshold and adjusts the output torque of the servo motor in real time to ensure that the axial force applied to the port of the flexible hose is always precisely maintained below this threshold, thereby achieving compliant insertion without the risk of overload with the assistance of continuous micro-vibration drag reduction.

[0045] When the displacement encoder reading of the conveying unit reaches the preset assembly depth, or when the force feedback signal exhibits the force value curve characteristic of complete assembly, the control system determines that the assembly task is complete. Immediately, the system issues a reset command to all units: the conveying unit stops driving, the magnetic field of the guide actuator is completely removed, and the oscillation of the assembly platform also stops. All components of the device return to their initial state, ready to enter the next work cycle.

[0046] To achieve a highly coordinated and automated assembly process among the aforementioned units, embodiments of the present invention provide a structurally complete and logically rigorous control system. The specific implementation of this control system will be described from two levels: hardware architecture and core control methods.

[0047] In this embodiment, the hardware architecture of the control system uses an industrial PC or a high-performance programmable logic controller (PLC) as the main controller. This main controller serves as the computational and decision-making core of the entire device, responsible for running the main control program and coordinating all lower-level components. It communicates with a dedicated motion controller via a high-speed bus. This motion controller is directly responsible for parsing low-level motion commands and sending pulses to the servo motors within the conveying unit to achieve precise drive.

[0048] In addition, the control system includes a high-precision programmable DC power supply specifically designed to power the electromagnetic coil 6 of the guide actuator. This power supply receives digital commands from the main controller and can quickly and accurately adjust its output current. Simultaneously, a high-speed data acquisition module is integrated into the system, with its inputs connected to a current monitoring module for monitoring force feedback signals and a resonant frequency monitoring module for monitoring contact signals. This data acquisition module is responsible for converting the acquired analog or frequency signals into digital quantities that can be processed by the main controller in real time.

[0049] At the control method level, the core of the control system in this embodiment lies in its event-triggered state-switching control logic. The core of this logic is to divide the entire assembly process into two distinct control stages, using the contact signal generated by the assembly platform as the sole and explicit trigger for switching between these two stages. Before receiving the contact signal, the system operates in a first preset mode, namely the position control mode. In this mode, the main controller sends displacement- or velocity-based commands to the motion controller of the conveying unit, with the goal of quickly and accurately delivering the port of the flexible hose to the predetermined position.

[0050] Once the contact signal (i.e., a defined resonant frequency shift) is captured by the data acquisition module and sent to the main controller, the main controller immediately executes an interrupt service routine, seamlessly switching the entire system to the second mode, namely the force feedback closed-loop control mode. In this mode, the behavior of the control system undergoes a fundamental change: the main controller no longer sends preset speed commands to the conveying unit, but instead initiates a force control algorithm (such as a PID control algorithm), the input of which is the real-time force feedback signal from the guide actuator.

[0051] This force control algorithm continuously compares real-time force feedback values ​​with a preset force threshold within a safe range, and dynamically calculates the required adjustment of drive torque or speed for the delivery unit based on the deviation between the two. This calculation result is sent to the motion controller in real time for execution, ensuring that the axial force applied to the port of the flexible hose is always smoothly maintained within the set safety threshold throughout the entire insertion process, achieving an intelligent shift from "position-based advancement" to "force-based advancement." This closed-loop control method, triggered by "tactile" events and guided by "force" signals, forms the technological cornerstone of this invention for achieving highly reliable and compliant assembly.

[0052] 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. An automated assembly device for manufacturing infusion sets, used to assemble flexible tubing with components to be assembled, characterized in that, include: A delivery unit is configured to apply a distributed axial driving force along the length of the flexible hose to drive the flexible hose to move along a predetermined path. A guide actuator, located at the end of a predetermined path, is configured to guide the port portion of a flexible hose and generate a force feedback signal corresponding to the axial force applied to the port portion during assembly. The assembly platform is configured to hold the component to be assembled in a fixed position, and generates a contact signal when the port part makes physical contact with the component to be assembled. The control system is electrically connected to the conveying unit, the guide actuator, and the assembly platform. When it receives a contact signal, it performs closed-loop control on the conveying unit based on the force feedback signal.

2. The automated assembly device for infusion set production according to claim 1, characterized in that, The conveying unit includes a conveying pipe (1), which is a hollow structure. Multiple annular drive components (2) are arranged equidistantly along the axial direction on its inner wall. An opening corresponding to the annular drive component (2) is opened on the pipe wall of the conveying pipe (1), so that a part of the annular drive component (2) is exposed to the outside. A rotating shaft (3) parallel to the conveying pipe (1) is provided on the outside of the conveying pipe (1). The rotating shaft (3) is driven to rotate by a servo motor. A gear (4) corresponding to the annular drive component (2) is fixedly connected to the outer wall of the rotating shaft (3). The annular drive component (2) is driven to rotate by the rotation of the gear (4).

3. The automated assembly device for infusion set production according to claim 2, characterized in that, The annular drive assembly (2) includes an annular bearing (201). The outer ring of the annular bearing (201) is fixedly connected to the inner wall of the conveying pipe (1), allowing the inner ring of the annular bearing (201) to rotate freely around the central axis of the channel. A gear two (202) is fixedly connected to the side wall of the inner ring of the annular bearing (201). The tooth end of the gear two (202) passes through the opening on the pipe wall of the conveying pipe (1) and meshes with the tooth end of the gear one (4). The inner wall of the inner ring of the annular bearing (201) is provided with flexible helical blades. When the gear two (202) is driven to rotate, the flexible helical blades interact with the outer wall of the flexible hose to generate axial driving force.

4. The automated assembly device for infusion set production according to claim 1, characterized in that, The guide actuator includes a guide cylinder (5), an annular chamber (501) is provided in the cylinder body of the guide cylinder (5), the annular chamber (501) is filled with medical grade magnetorheological fluid, a guide hole (502) is provided in the center of the guide cylinder (5), the inlet of the guide hole (502) is a conical structure, and the hole wall of the guide hole (502) is made of a membrane with elasticity and flexibility. An electromagnetic coil (6) is wound around the outer cylinder wall of the guide cylinder (5). When the electromagnetic coil (6) is energized, the magnetorheological fluid in the annular chamber (501) will change from a flowing liquid state to a semi-solid state with controllable yield strength in milliseconds, constraining the end of the flexible hose passing through the guide hole (502) to the geometric center of the guide cylinder (5).

5. The automated assembly device for infusion set production according to claim 4, characterized in that, The guide actuator also includes a current monitoring module. When the flexible hose is subjected to the axial force, in order to maintain the semi-solid state of the magnetorheological fluid, the electromagnetic coil (6) generates current fluctuations. The current monitoring module is used to monitor the current fluctuations and use the current fluctuations as force feedback signals.

6. The automated assembly device for infusion set production according to claim 1, characterized in that, The assembly platform includes a base (7) and a motion platform (8). The motion platform (8) is connected to the base (7) via a flexible hinge (9). The motion platform (8) is equipped with a clamp for holding and fixing the components to be assembled. A plurality of piezoelectric ceramic actuators are also provided between the base (7) and the motion platform (8) for driving the motion platform (8) to perform high-frequency micro-amplitude oscillation.

7. An automated assembly device for infusion set production according to claim 6, characterized in that, The assembly platform also includes a resonant frequency monitoring module, which is installed in the high-stress area of ​​the flexible hinge (9) to monitor the resonant frequency of the motion platform (8) during the swinging process, and generates a contact signal when the resonant frequency is detected to have shifted due to the physical contact between the port of the flexible hose and the component to be assembled.

8. The automated assembly device for infusion set production according to claim 5, characterized in that, After receiving the contact signal, the control system controls the power supply current of the electromagnetic coil (6) to reduce the stiffness of the semi-solid formed by the magnetorheological fluid, thereby enabling the port of the flexible hose to be flexibly and adaptively aligned.

9. An automated assembly device for infusion set production according to claim 1, characterized in that, The control system performs closed-loop control of the conveying unit, specifically including: adjusting the axial driving force applied by the conveying unit in real time based on the force feedback signal so that the axial force is maintained within a preset threshold range.

10. An automated assembly device for infusion set production according to claim 1, characterized in that, The control system is further configured as follows: Before receiving a contact signal, the control conveying unit operates in a first preset mode; Upon receiving a contact signal, the conveying unit is switched to a second mode based on closed-loop control using force feedback signals.

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