A multi-modal sensing tendon system based on distributed magnetic induction and a measurement method thereof

Abstract

The application discloses a multi-modal perception tendon rope system based on distributed magnetic induction and a measuring method thereof, and belongs to the field of sensors, which comprises a flexible tendon rope body, a tension force perception module and a displacement and speed perception module connected and driven by the flexible tendon rope body; the tension force perception module is arranged at the tail end of the flexible tendon rope body, and is used for measuring the tension force of the flexible tendon rope body; the displacement and speed perception module is arranged at the middle section of the transmission path of the flexible tendon rope body, and is used for measuring the displacement and moving speed of the flexible tendon rope body; and a signal processing and data output unit is used for receiving and processing the output signals of the tension force perception module and the displacement and speed perception module to calculate the tension force, displacement and moving speed of the tendon rope.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology, and in particular relates to a multimodal sensing tendon ligament system based on distributed magnetic induction and its measurement method. Background Technology

[0002] In robotics, wearable exoskeletons, prostheses, remote operating systems, and advanced human-computer interaction devices, chord actuation systems are widely used due to their advantages such as flexible structure, long transmission distance, and light weight. To achieve precise closed-loop control and safe physical interaction, it is crucial to acquire real-time and accurate operating parameters of the chords, such as tension, displacement, and velocity.

[0003] Traditional tension force sensors typically employ strain gauge-type force sensors or piezoelectric sensors, which are bulky and often require external mounting on the tendon chords, making tight integration with the chords difficult. Traditional displacement and velocity sensors, such as encoders, laser displacement gauges, or ultrasonic sensors, also suffer from problems such as large size, the need for contact measurement, or susceptibility to environmental interference, making miniaturization and non-contact integration within or on the surface of the tendon chords difficult.

[0004] In existing technologies, multiple sensors are typically installed independently to acquire different parameters. These solutions either cannot measure the elasticity and stretching of the chord itself, are bulky, or are susceptible to environmental contamination and mechanical wear. This not only increases the complexity, size, and cost of the system but may also affect the flexibility and dynamic response of the chord. Integrating multiple independent sensors into a single chord drive system would significantly increase the overall system size, weight, and wiring complexity, contradicting the trend towards lightweight and compact chord drive systems. Therefore, developing a solution that is highly integrated with the chord, possesses multimodal sensing capabilities, and minimizes the size of the sensor components as much as possible is a current technological challenge. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a multimodal sensing tendon cord system and its measurement method based on distributed magnetic induction, thereby resolving the issues present in the prior art.

[0006] To achieve the above objectives, the present invention provides a multimodal sensing tendon chord system based on distributed magnetic induction, comprising:

[0007] The flexible tendon cable body is used to connect and drive the tension sensing module and the displacement and velocity sensing module;

[0008] The tension sensing module is located at the end of the flexible tendon rope body and is used to measure the tension of the flexible tendon rope body.

[0009] The displacement and velocity sensing module is located in the middle of the transmission path of the flexible tendon cable body, and is used to measure the displacement and movement speed of the flexible tendon cable body.

[0010] The signal processing and data output unit is used to receive and process the output signals of the tension sensing module and the displacement and velocity sensing module, and to calculate the tension, displacement and movement speed of the tendon rope.

[0011] Optionally, the tension sensing module includes: a first main frame, an elastic deformation component, a first magnet, and a first Hall unit;

[0012] The first main frame is used to fix the elastic deformation component and the first magnet;

[0013] One end of the elastic deformation member is fixed to the external support structure of the first main frame and connected to the end of the flexible tendon rope body, while the other end is a free deformation end.

[0014] The first magnet is fixed to the free deformation end of the elastic deformation member to achieve displacement amplification;

[0015] The first Hall unit is fixed on the first main frame and is arranged in a non-contact manner opposite to the first magnet, and is used to detect the change in magnetic field caused by the displacement of the first magnet due to the deformation of the elastic deformation component.

[0016] Optionally, the elastic deformation member is a thin cantilever beam structure made of spring steel.

[0017] Optionally, the displacement and velocity sensing module includes: a second main frame, a second magnet, and a second Hall unit;

[0018] The second main frame is provided with a channel for the flexible tendon rope body and the second magnet to pass through;

[0019] The second Hall unit is fixed to the outside of the second main frame and is used to detect the change in magnetic field caused by the relative displacement between the second magnet and the second magnetic field sensing element when the flexible tendon body moves.

[0020] Optionally, the second magnet is a permanent magnet ring, which is sleeved and fixed to the flexible tendon rope body at the position in the middle of the transmission path, and the second magnet moves together with the flexible tendon rope body.

[0021] Optionally, the signal processing and data output unit is connected to the first Hall unit and the second Hall unit, and includes: a tension calculation unit, a displacement calculation unit, a velocity calculation unit and a data output unit;

[0022] The tension force calculation unit is used to calculate the real-time tension force based on the magnetic field data obtained by the first Hall unit.

[0023] The displacement calculation unit is used to calculate the real-time displacement based on the magnetic field data obtained by the second Hall unit.

[0024] The speed calculation unit is used to perform time difference calculation on the displacement to obtain the real-time moving speed;

[0025] The data output unit is used to output the tension force, displacement, and movement speed to the upper-level controller through the communication interface.

[0026] Optionally, the first Hall unit and the second Hall unit are triaxial Hall sensors.

[0027] The present invention also provides a measurement method for a multimodal sensing tendon chord system based on distributed magnetic induction, for implementing the aforementioned system, the method comprising the following steps:

[0028] Based on the first Hall unit in the tension force sensing module, the first magnetic field data generated by the change in position of the first magnet caused by the tension force of the tendon ligament is collected;

[0029] Based on the second Hall unit in the displacement and velocity sensing module, the second magnetic field data generated by the change in position of the second magnet caused by the movement of the tendon ligament is collected.

[0030] The first magnetic field data is input into a preset tension calibration model to calculate the real-time tension of the flexible tendon rope body.

[0031] The second magnetic field data is input into a preset displacement calibration model to calculate the real-time displacement of the flexible tendon body.

[0032] The real-time displacement is processed by time difference to obtain the real-time moving speed of the flexible tendon cable body.

[0033] Finally, the tension force, displacement, and movement speed are output synchronously.

[0034] Compared with the prior art, the present invention has the following advantages and technical effects:

[0035] This invention ingeniously integrates two sensing modules based on non-contact magnetic induction principles—a tension sensing module deployed at the end of the chord and a displacement and velocity sensing module deployed in the middle of the chord—at the system level through an original distributed modular design. These two modules are physically separate, but functionally they work together through signal processing and data output units, successfully solving the problem of synchronously and accurately measuring tension, displacement, and velocity on a single flexible chord. While ensuring measurement accuracy, this significantly improves the system's design freedom, flexibility, and environmental adaptability. This invention provides a high-performance, highly reliable, cost-effective, and easily deployable state-awareness solution for chord-driven systems in cutting-edge fields such as robotics, intelligent prostheses, and wearable devices. Attached Figure Description

[0036] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0037] Figure 1 This is a schematic diagram of the overall system layout according to an embodiment of the present invention;

[0038] Figure 2 This is a cross-sectional view of the internal structure of the tension sensing module according to an embodiment of the present invention;

[0039] Figure 3 This is a cross-sectional view of the internal structure of the displacement and velocity sensing module according to an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the multimodal data processing and output unit performing multimodal data computation according to an embodiment of the present invention;

[0041] Labeling descriptions: 1. Flexible tendon rope body; 2. Tension sensing module; 3. Displacement and velocity sensing module; 4. Signal processing and data output unit; 21. First main frame; 22. Elastic deformation component; 23. First magnet; 24. First Hall unit; 31. Second main frame; 32. Second magnet; 33. Second Hall unit. Detailed Implementation

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0043] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0044] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multimodal sensing chordae system and its measurement method based on distributed magnetic induction. The system adopts a distributed modular design and is based on the principle of non-contact magnetic induction. It can simultaneously, in real time and non-contactly measure the tension, displacement and movement speed of the chordae. Moreover, the sensing part directly related to the chordae has a small size, thereby achieving a high degree of integration with the chordae.

[0045] like Figure 1 As shown, this embodiment provides a multimodal sensing tendon chord system and its measurement method based on distributed magnetic induction, including: a flexible tendon chord body 1, a tension sensing module 2, a displacement and velocity sensing module 3, and a signal processing and data output unit 4. The tension sensing module 2 is fixed to the end of the flexible tendon chord body 1, and the displacement and velocity sensing module 3 is fixed at a selected position in the middle of the flexible tendon chord body 1. The two modules are physically separated, work independently, and transmit the data uniformly to the signal processing and data output unit 4.

[0046] The flexible tendon rope body 1 is used to connect the tension sensing module 2 and the displacement and velocity sensing module 3.

[0047] The internal structural cross-sectional view of tension sensing module 2 is shown below. Figure 2 As shown, this module is the terminal of the flexible tendon cord body 1. An elastic deformation member 22 is fixed within its first main frame 21. The end of the flexible tendon cord body 1 is anchored to this elastic deformation member 22. A first magnet 23 is fixed to the free end of the elastic deformation member 22, and a first Hall unit 24 is fixed to the first main frame 21, opposite to the first magnet 23. When the flexible tendon cord body 1 is subjected to tension, the elastic deformation member 22 bends, causing the first magnet 23 to move. The first Hall unit 24 detects the change in magnetic field, and the signal processing and data output unit 4 calculates the tension accordingly.

[0048] Tension sensing module 2 is disposed at the end of the flexible tendon cord body 1 and is used to measure the tension of the flexible tendon cord body 1. This module includes a first main frame 21, an elastic deformation member 22, a first magnet 23, and a first Hall unit 24. The first main frame 21 is used to fix the elastic deformation member 22 and the first magnet 23. One end of the elastic deformation member 22 is fixed to an external support structure, while the other end is freely deformable. The end of the flexible tendon cord body 1 is anchored to the elastic deformation member 22, so that the tension of the flexible tendon cord body 1 can cause elastic deformation of the structure. The first magnet 23 is fixed to the freely deformable end of the elastic deformation member 22 to achieve displacement amplification. The first Hall unit 24 is fixed to the first main frame 21 and is disposed opposite to the first magnet 23 in a non-contact manner, used to detect the change in magnetic field caused by the displacement of the first magnet 23 due to the deformation of the elastic deformation member 22.

[0049] The elastic deformation member 22 is a thin cantilever beam structure made of spring steel. The end of the flexible tendon rope body 1 is anchored near the fixed end of the cantilever beam, so that the tension of the flexible tendon rope body 1 causes the elastic deformation member 22 to bend or tilt. The first magnet 23 is fixed at the free end away from the fixed end, thereby amplifying the displacement caused by the tension.

[0050] The internal structural cross-sectional view of displacement and velocity sensing module 3 is shown below. Figure 3 As shown, the module is fixed to an external support structure, through which the flexible tendon cable body 1 passes. Its second main frame 31 is designed with through holes or channels, allowing the flexible tendon cable body 1 to slide freely within them. A second magnet 32 ​​is firmly fixed to the flexible tendon cable body 1. A second Hall effect unit 33 is fixed inside the second main frame 31, adjacent to the tendon cable channel. When the flexible tendon cable body 1 moves as a whole, it causes the second magnet 32 ​​to move relative to the fixed second Hall effect unit 33. The second Hall effect unit 33 detects the change in magnetic field, and the signal processing and data output unit 4 calculates the displacement accordingly. The displacement data is then processed using time difference analysis to obtain the real-time moving speed of the flexible tendon cable body 1.

[0051] The displacement and velocity sensing module 3 is located in the middle of the transmission path of the flexible tendon cable body 1, and is used to measure the displacement and movement speed of the flexible tendon cable body 1. This module includes a second main frame 31, a second magnet 32, and a second Hall unit 33. The second main frame 31 has a channel through which the flexible tendon cable body 1 passes, with the flexible tendon cable body 1 and the second magnet 32 ​​passing through the middle. The second Hall unit 33 is fixed to the outside and secured to an external support structure with bolts or other fasteners. The second magnet 32 ​​is tightly attached to a position on the flexible tendon cable body 1 in the middle of the transmission path and moves with the flexible tendon cable body 1. The second Hall unit 33 is fixed to the second main frame 31 and maintains a relative position with the second magnet 32, used to detect the change in magnetic field caused by the relative displacement between the second magnet 32 ​​and the second magnetic field sensing element when the flexible tendon cable body 1 moves.

[0052] The second magnet 32 ​​is a permanent magnet ring, which is sleeved and fixed on the flexible tendon rope body 1, and the magnet ring is magnetized in the thickness direction.

[0053] A flowchart illustrating signal processing and multimodal output is shown below. Figure 4 As shown, the details are as follows:

[0054] Data acquisition: The signal processing and data output unit 4 acquires raw magnetic field vector data in parallel from the first Hall unit 24 of the tension sensing module 2 and the second Hall unit 33 of the displacement and velocity sensing module 3 via the IIC communication bus.

[0055] Tension force calculation: The magnetic field data acquired from the first Hall element 24 is input into a preset "tension force calibration model". This model is a function pre-established through experimental calibration. The real-time tension force is calculated using this model.

[0056] Displacement calculation: The magnetic field data obtained from the second Hall unit 33 is input into the preset "displacement calibration model" to calculate the real-time tendon chord displacement.

[0057] Speed ​​Calculation: The calculated displacement data stream is sent to a processing module. This module first filters the displacement data to eliminate noise, and then performs time-difference operations on the filtered data to obtain the real-time movement speed.

[0058] Data Output: Finally, the signal processing and data output unit 4 outputs the three calculated parameters (tension force, displacement, and moving speed) to the upper-level controller or user through the communication interface.

[0059] The signal processing and data output unit 4 is connected to the first Hall unit 24 and the second Hall unit 33. It is used to receive and process the output signals of the two modules, and calculate the tension, displacement and movement speed of the tendon rope according to the preset algorithm model.

[0060] The first Hall unit 24 and the second Hall unit 33 are triaxial Hall sensors that can detect magnetic field components in three-dimensional space (X, Y, Z).

[0061] The present invention also provides a corresponding measurement method, comprising the following steps: based on the first Hall unit 24 in the tension force sensing module 2, acquiring first magnetic field data generated by the position change of the first magnet 23 caused by the tension of the tendon ligament; based on the second Hall unit 33 in the displacement and velocity sensing module 3, acquiring second magnetic field data generated by the position change of the second magnet 32 ​​caused by the movement of the tendon ligament; inputting the first magnetic field data into a preset tension force calibration model to calculate the real-time tension of the flexible tendon ligament body; inputting the second magnetic field data into a preset displacement calibration model to calculate the real-time displacement of the flexible tendon ligament body 1; performing time difference processing on the real-time displacement to obtain the real-time moving speed of the flexible tendon ligament body; and finally synchronously outputting the tension force, displacement, and moving speed.

[0062] The tension measurement step involves using a first Hall element in the tension sensing module deployed at the end of the flexible tendon ligament to monitor in real time the change in the magnetic field caused by the change in the position of the first magnet due to the tension of the tendon ligament; inputting this change in the magnetic field into the signal processing and data output unit, and calculating the real-time tension of the tendon ligament based on the preset tension calibration model.

[0063] The displacement measurement step involves using a second Hall element in the displacement and velocity sensing module deployed in the middle section of the flexible tendon chord to monitor in real time the change in the magnetic field caused by the positional change of the second magnet due to the movement of the flexible tendon chord body. This change in magnetic field is then input into the signal processing and data output unit, which calculates the real-time tendon chord displacement based on a preset displacement calibration model.

[0064] In the velocity calculation step, the signal processing and data output unit performs time difference processing on the continuous displacement data obtained in the displacement measurement step to obtain the real-time moving velocity of the flexible tendon cable body.

[0065] Through the above steps, this invention decouples tension force and displacement sensing functions into two independent physical modules using a distributed modular design. These modules can be flexibly deployed at optimal positions within the chord drive chain according to system requirements, offering extremely high design freedom and adaptability. Simultaneously, through the collaborative work of the two distributed modules, a single system can synchronously output three key state parameters: tension force, displacement, and velocity, achieving multimodal sensing and providing a comprehensive data foundation for complex control algorithms. Structurally, each sensing module is a non-contact magnetic induction type, exhibiting no mechanical wear, a long theoretical lifespan, and insensitivity to harsh environments such as dust and oil. Its simple and compact structure minimizes intrusion into the entire chord drive system, facilitating system lightweighting and miniaturization.

[0066] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A multimodal sensing tendon chord system based on distributed magnetic induction, characterized in that, include: The flexible tendon rope body (1) is used to connect and drive the tension sensing module (2) and the displacement and velocity sensing module (3). The tension sensing module (2) is located at the end of the flexible tendon rope body (1) and is used to measure the tension of the flexible tendon rope body (1). The displacement and velocity sensing module (3) is set in the middle of the transmission path of the flexible tendon rope body (1) to measure the displacement and movement speed of the flexible tendon rope body (1). The signal processing and data output unit (4) is used to receive and process the output signals of the tension force sensing module (2) and the displacement and velocity sensing module (3) to calculate the tension force, displacement and movement speed of the tendon rope; The tension sensing module (2) includes: a first main frame (21), an elastic deformation component (22), a first magnet (23), and a first Hall unit (24); The first main frame (21) is used to fix the elastic deformation member (22) and the first magnet (23). One end of the fixed elastic deformation member (22) is fixed to the external support structure of the first main frame (21) and connected to the end of the flexible tendon rope body (1), while the other end is a free deformation end; The first magnet (23) is fixed to the free deformation end of the elastic deformation member (22), and the first magnet (23) is used to realize displacement amplification; The first Hall unit (24) is fixed on the first main frame (21) and is disposed opposite to the first magnet (23) in a non-contact manner. The first Hall unit (24) is used to detect the change in magnetic field caused by the displacement of the first magnet (23) due to the deformation of the elastic deformation member (22). The fixed elastic deformation member (22) is a thin cantilever beam structure made of spring steel; The displacement and velocity sensing module (3) includes: a second main frame (31), a second magnet (32), and a second Hall unit (33). The second main frame (31) is provided with a channel for the flexible tendon rope body (1) and the second magnet (32) to pass through. The second Hall unit (33) is fixed to the outside of the second main frame (31). The second Hall unit (33) is used to detect the change in magnetic field caused by the relative displacement between the second magnet (32) and the second magnetic field sensing element when the flexible tendon body (1) moves.

2. The multimodal sensing tendon tract system based on distributed magnetic induction according to claim 1, characterized in that, The second magnet (32) is a permanent magnet ring, which is sleeved and fixed to the flexible tendon rope body (1) at the middle of the transmission path. The second magnet (32) moves together with the flexible tendon rope body (1).

3. The multimodal sensing tendon tract system based on distributed magnetic induction according to claim 1, characterized in that, The signal processing and data output unit (4) is connected to the first Hall unit (24) and the second Hall unit (33). The signal processing and data output unit (4) includes: a tension calculation unit, a displacement calculation unit, a velocity calculation unit and a data output unit. The tension force calculation unit is used to calculate the real-time tension force based on the magnetic field data obtained by the first Hall unit (24); The displacement calculation unit is used to calculate the real-time displacement based on the magnetic field data obtained by the second Hall unit (33); The speed calculation unit is used to perform time difference calculation on the displacement to obtain the real-time moving speed; The data output unit is used to output the tension force, displacement, and movement speed to the upper-level controller through the communication interface.

4. The multimodal sensing tendon tract system based on distributed magnetic induction according to claim 3, characterized in that, The first Hall unit (24) and the second Hall unit (33) are triaxial Hall sensors.

5. A measurement method for a multimodal sensing tendon chord system based on distributed magnetic induction, characterized in that, For implementing the system as described in any one of claims 1-4, the method comprises the following steps: Based on the first Hall unit (24) in the tension sensing module (2), the first magnetic field data generated by the position change of the first magnet (23) caused by the tendon tension is collected; Based on the second Hall unit (33) in the displacement and velocity sensing module (3), the second magnetic field data generated by the position change of the second magnet (32) caused by the movement of the tendon rope is collected; The first magnetic field data is input into a preset tension calibration model to calculate the real-time tension of the flexible tendon rope body. The second magnetic field data is input into a preset displacement calibration model to calculate the real-time displacement of the flexible tendon rope body (1). The real-time displacement is processed by time difference to obtain the real-time moving speed of the flexible tendon cable body. Finally, the tension force, displacement, and movement speed are output synchronously.

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