Multi-mode sensing tendon rope system based on distributed magnetic induction and measuring method thereof

Abstract

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

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sensors, and particularly relates to a multi-modal sensing tendon system based on distributed magnetic induction and a measurement method thereof. BACKGROUND

[0002] In the field of robotics, wearable exoskeletons, prosthetics, teleoperation systems, and advanced human-machine interaction devices, tendon-driven systems are widely used due to their flexible structure, long transmission distance, and light weight. In order to achieve precise closed-loop control and safe physical interaction, it is crucial to obtain real-time and accurate operational state parameters of the tendon, such as tension, displacement, and speed.

[0003] Traditional tension sensors usually use strain gauge force sensors or piezoelectric sensors, which are bulky and often need to be installed externally on the tendon, making it difficult to achieve close integration with the tendon. Traditional displacement and speed sensors, such as encoders, laser displacement meters, or ultrasonic sensors, also have problems such as large size, the need for contact measurement, or susceptibility to environmental interference, making it difficult to achieve miniaturization and non-contact integration inside or on the surface of the tendon.

[0004] In the prior art, multiple sensors are often needed to be installed independently to obtain different parameters. These solutions either cannot measure the elastic expansion of the tendon body, or are bulky, or are susceptible to environmental pollution and mechanical wear. This not only increases the complexity, size, and cost of the system, but also may affect the flexibility and dynamic response of the tendon. Integrating multiple independent sensors into a tendon-driven system can significantly increase the overall size, weight, and wiring complexity of the system, which contradicts the trend of lightweight and compact development of tendon-driven systems. Therefore, developing a solution that can be highly integrated with the tendon, has multi-modal sensing capability, and the sensor part is as small as possible, is a challenge faced by current technology. SUMMARY

[0005] To solve the above technical problems, the present application provides a multi-modal sensing tendon system based on distributed magnetic induction and a measurement method thereof to solve the problems existing in the prior art.

[0006] To achieve the above purpose, the present application provides a multi-modal sensing tendon system based on distributed magnetic induction, comprising: a flexible tendon body for connecting and driving a tension sensing module and a displacement and speed sensing module; a tension sensing module arranged at the end of the flexible tendon body for measuring the tension of the flexible tendon body; a displacement and speed sensing module arranged in the middle of the transmission path of the flexible tendon body for measuring the displacement and speed of the flexible tendon body; A signal processing and data output unit is configured to receive and process output signals of the tension sensing module and the displacement and speed sensing module, and calculate the tension of the tendon, the displacement and the moving speed.

[0007] Optionally, the tension sensing module comprises a first main frame, an elastic deformation member, a first magnet and a first Hall unit. The first main frame is configured to fix the elastic deformation member and the first magnet. One end of the elastic deformation member is fixed to an external support structure of the first main frame and connected to the end of the flexible tendon body, and the other end is a free deformation end. The first magnet is fixed to the free deformation end of the elastic deformation member, and is configured to realize displacement amplification. The first Hall unit is fixed to the first main frame and is configured to detect the change of the magnetic field caused by the displacement of the first magnet due to the deformation of the elastic deformation member.

[0008] Optionally, the elastic deformation member is a thin cantilever beam structure made of spring steel.

[0009] Optionally, the displacement and speed sensing module comprises a second main frame, a second magnet and a second Hall unit. The second main frame is provided with a channel for the flexible tendon body and the second magnet to pass through. The second Hall unit is fixed to the outside of the second main frame and is configured to detect the change of the magnetic field caused by the relative displacement between the second magnet and the second magnetic field sensing element when the flexible tendon body moves.

[0010] Optionally, the second magnet is a permanent magnet ring, which is sleeved and fixed to the position of the flexible tendon body located in the middle section of the transmission path, and the second magnet moves together with the flexible tendon body.

[0011] Optionally, the signal processing and data output unit is connected with the first Hall unit and the second Hall unit, and comprises a tension calculation unit, a displacement calculation unit, a speed calculation unit and a data output unit. The tension calculation unit is configured to calculate the real-time tension based on the magnetic field data obtained by the first Hall unit. The displacement calculation unit is configured to calculate the real-time displacement based on the magnetic field data obtained by the second Hall unit. The speed calculation unit is configured to perform time difference operation on the displacement to obtain the real-time moving speed. The data output unit is configured to output the tension, displacement and moving speed to an upper controller through a communication interface.

[0012] Optionally, the first and second Hall units are tri-axial Hall sensors.

[0013] The application also provides a measurement method of a multi-modal sensing tendon system based on distributed magnetic induction, for implementing the system, the method comprising the following steps: Based on the first Hall unit in the tension force sensing module, first magnetic field data caused by the position change of the first magnet due to the tension force of the tendon is collected; Based on the second Hall unit in the displacement and speed sensing module, second magnetic field data caused by the position change of the second magnet due to the movement of the tendon is collected; The first magnetic field data is input into a preset tension force calibration model, and the real-time tension force of the flexible tendon body is calculated; The second magnetic field data is input into a preset displacement calibration model, and the real-time displacement of the flexible tendon body is calculated; The real-time displacement is subjected to time difference processing, and the real-time movement speed of the flexible tendon body is obtained; The tension force, displacement and movement speed are finally output synchronously.

[0014] Compared with the prior art, the application has the following advantages and technical effects: The application ingeniously integrates two sensing modules based on the non-contact magnetic induction principle, i.e., the tension force sensing module deployed at the end of the tendon and the displacement and speed sensing module deployed at the middle of the tendon, through a unique distributed modular design. The two modules are physically separated, but functionally work cooperatively through the signal processing and data output unit, successfully solving the problem of synchronously and accurately measuring the tension, displacement and speed on a single flexible tendon. While ensuring the measurement accuracy, the design freedom, flexibility and environmental adaptability of the system are greatly improved. The application provides a state sensing solution with superior performance, high reliability, controllable cost and easy deployment for tendon-driven systems in the fields of robots, intelligent prostheses, wearable devices and the like. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings, which form a part of this application, are intended to provide further understanding of the application and are incorporated herein in their entirety, and the illustrative embodiments thereof and their description serve to explain the application. In the drawings: Figure 1 It is a schematic diagram of the overall layout of the system of the embodiment of the application; Figure 2 It is a sectional view of the internal structure of the tension force sensing module of the embodiment of the application; Figure 3 It is a sectional view of the internal structure of the displacement and speed sensing module of the embodiment of the application; Figure 4 The flowchart of the signal processing and data output unit in the embodiment of the application for multi-modal data solving is shown in the figure. Label description: 1, flexible tendon body; 2, tension sensing module; 3, displacement and speed sensing module; 4, signal processing and data output unit; 21, first main frame; 22, elastic deformation member; 23, first magnet; 24, first Hall unit; 31, second main frame; 32, second magnet; 33, second Hall unit. DETAILED DESCRIPTION

[0016] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0017] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a group of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0018] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a multi-modal sensing tendon system based on distributed magnetic induction and a measuring method thereof. The system adopts a distributed modular design and is based on the principle of non-contact magnetic induction. It can simultaneously, real-time and non-contact measure the tension, displacement and moving speed of the tendon, and the sensing part directly related to the tendon has a small size, thereby realizing high integration with the tendon.

[0019] As shown in Figure 1 The embodiment provides a multi-modal sensing tendon system based on distributed magnetic induction and a measuring method thereof. The system includes a flexible tendon body 1, a tension sensing module 2, a displacement and speed sensing module 3, and a signal processing and data output unit 4. The tension sensing module 2 fixes the end of the flexible tendon body 1, the displacement and speed sensing module 3 is fixed at a selected position in the middle of the flexible tendon body 1, the two modules are physically separated, work independently, and transmit data to the signal processing and data output unit 4.

[0020] The flexible tendon body 1 is used to connect the tension sensing module 2 and the displacement and speed sensing module 3.

[0021] The internal structure of the tension sensing module 2 is shown in Figure 2As 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] A flowchart illustrating signal processing and multimodal output is shown below. Figure 4 As shown, the details are as follows: 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] The first Hall unit 24 and the second Hall unit 33 are triaxial Hall sensors capable of detecting magnetic field components in a three-dimensional space (X, Y, Z).

[0034] The application also provides a matching measurement method, comprising the following steps: based on the first Hall unit 24 in the tension force sensing module 2, collecting first magnetic field data generated due to the position change of the first magnet 23 caused by the tendon tension force; based on the second Hall unit 33 in the displacement and speed sensing module 3, collecting second magnetic field data generated due to the position change of the second magnet 32 caused by the movement of the tendon; inputting the first magnetic field data into a preset tension force calibration model to obtain the real-time tension force of the flexible tendon body; inputting the second magnetic field data into a preset displacement calibration model to obtain the real-time displacement of the flexible tendon body 1; performing time difference processing on the real-time displacement to obtain the real-time movement speed of the flexible tendon body; and finally synchronously outputting the tension force, the displacement and the movement speed.

[0035] The tension force measurement step is to monitor the magnetic field change amount caused by the position change of the first magnet caused by the tendon tension force in real time through the first Hall unit in the tension force sensing module arranged at the end of the flexible tendon body; and input the magnetic field change amount into the signal processing and data output unit to calculate the real-time tendon tension force according to the preset tension force calibration model.

[0036] The displacement measurement step is to monitor the magnetic field change amount caused by the position change of the second magnet caused by the movement of the flexible tendon body in real time through the second Hall unit in the displacement and speed sensing module arranged at the middle section of the flexible tendon body; and input the magnetic field change amount into the signal processing and data output unit to calculate the real-time tendon displacement according to the preset displacement calibration model.

[0037] The speed calculation step is to perform time difference processing on the continuous displacement data obtained in the displacement measurement step by the signal processing and data output unit to obtain the real-time movement speed of the flexible tendon body.

[0038] Through the above steps, the tension force and displacement sensing functions are decoupled into two independent physical modules through the distributed modular design, and they can be flexibly deployed at the optimal position of the tendon driving chain according to the system requirements, having high design freedom and adaptability. Meanwhile, through the collaborative work of the two distributed modules, a set of system can synchronously output three key state parameters of tension force, displacement and speed, realize multi-modal sensing, and provide a comprehensive data basis for realizing complex control algorithms. In terms of structure, each sensing module is a non-contact magnetic induction, has no mechanical wear, has a long theoretical service life, is not sensitive to dust, oil stains and other harsh environments, has a simple and compact structure, has low invasiveness to the entire tendon driving system, and is easy to realize the lightweight and miniaturization of the system.

[0039] The above embodiments are only preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A multi-modal sensing tendon system based on distributed magnetic induction, characterized by, The application relates to a flexible tendon body (1) for connecting and driving a tension sensing module (2) and a displacement and speed sensing module (3); the tension sensing module (2) is arranged at the end of the flexible tendon body (1), and the tension sensing module (2) is used for measuring the tension of the flexible tendon body (1); the displacement and speed sensing module (3) is arranged in the middle section of a transmission path of the flexible tendon body (1) and is used for measuring the displacement and moving speed of the flexible tendon body (1); a signal processing and data output unit (4) is used for receiving and processing the output signals of the tension sensing module (2) and the displacement and speed sensing module (3) to calculate the tension, displacement and moving speed of the tendon. The tension sensing module (2) comprises 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 for fixing the elastic deformation component (22) and the first magnet (23); one end of the elastic deformation component (22) is fixed to the external support structure of the first main frame (21) and is communicated with the end of the flexible tendon body (1), and the other end is a free deformation end; the first magnet (23) is fixed to the free deformation end of the elastic deformation component (22), and the first magnet (23) is used for realizing displacement amplification; the first Hall unit (24) is fixed to the first main frame (21) and is arranged in a non-contact mode relative to the first magnet (23), and the first Hall unit (24) is used for detecting the magnetic field change caused by the displacement of the first magnet (23) due to the deformation of the elastic deformation component (22). The elastic deformation component (22) is a thin sheet cantilever beam structure made of spring steel. The displacement and speed sensing module (3) comprises 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 body (1) and the second magnet (32) to pass through; the second Hall unit (33) is fixed to the outer side of the second main frame (31) and is used for detecting the magnetic field change caused by the relative displacement between the second magnet (32) and the second magnetic field sensing element when the flexible tendon body (1) moves; the second magnet (32) is a permanent magnet ring, is sleeved and fixed to the position of the flexible tendon body (1) in the middle section of the transmission path, and moves together with the flexible tendon body (1). The signal processing and data output unit (4) is connected with the first Hall unit (24) and the second Hall unit (33), and comprises a tension calculation unit, a displacement calculation unit, a speed calculation unit and a data output unit; the tension calculation unit is used for calculating the real-time tension based on the magnetic field data acquired by the first Hall unit (24); the displacement calculation unit is used for calculating the real-time displacement based on the magnetic field data acquired by the second Hall unit (33).

2. The distributed magnetic induction based multi-modal sensing tendon system of claim 1, wherein, ​ ​ ​ ​ ​ 3. The distributed magnetic induction based multi-modal sensing tendon system of claim 2, wherein, ​ 4. The distributed magnetic induction based multi-modal sensing tendon system of claim 2, wherein, ​ ​ ​ 5. The distributed magnetic induction based multi-modal sensing tendon system of claim 4, wherein, ​ 6. The distributed magnetic induction based multi-modal sensing tendon system of claim 4, wherein, ​ ​ ​ The speed calculation unit is configured to perform time difference operation on the displacement to obtain real-time moving speed; The data output unit is configured to output the tension, displacement and moving speed to an upper controller through a communication interface.

7. The distributed magnetic induction based multi-modal sensing tendon system of claim 6, wherein, The first and second Hall units are three-axis Hall sensors.

8. A measurement method for a multimodal sensing tendon chord system based on distributed magnetic induction, characterized in that, The method for implementing the system according to any one of claims 1-7 comprises the following steps: Based on the first Hall unit (24) in the tension sensing module (2), first magnetic field data caused by the position change of the first magnet (23) due to the tendon tension is collected; Based on the second Hall unit (33) in the displacement and speed sensing module (3), second magnetic field data caused by the position change of the second magnet (32) due to the tendon movement 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 body; The second magnetic field data is input into a preset displacement calibration model to calculate the real-time displacement of the flexible tendon body (1); The real-time displacement is subjected to time difference processing to obtain the real-time moving speed of the flexible tendon body; Finally, the tension, displacement and moving speed are synchronously output.

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