Tension measuring method and device for flexible structure in flexible equipment and storage medium

Abstract

The invention provides a tension measuring method and device for a flexible structure in flexible equipment and a storage medium, the tension measuring device comprises a shell cover, a shell, a strain plate and an acquisition circuit, the strain plate and the acquisition circuit are arranged in the shell, the upper surface of the strain plate is provided with a protruding part, the lower surface of the strain plate is provided with a strain gauge, and the protruding part is connected with the strain gauge. The flexible structure passes through a channel formed between the shell cover and the strain plate, so that the flexible structure locally generates three-point bending local deformation; the acquisition circuit is used for monitoring an actual strain value and a temperature value of tensile strain generated when the lower surface of the strain plate is pulled when the bending part of the flexible structure tends to be straight to apply an acting force to the protruding part to cause bending deformation of the strain plate, and calculating the bending deformation of the strain plate according to the monitored actual strain value and the temperature value. And performing nonlinear compensation in combination with the calibration experiment result to obtain the actual tension of the flexible structure. By implementing the embodiment of the invention, the tension change of the flexible structure in the working process can be monitored on line.

Description

Technical Field

[0001] The present disclosure relates to the technical field, and in particular to a method, device and storage medium for measuring the tension of a flexible structure in flexible equipment. Background Art

[0002] The flexible structures in flexible equipment will experience tension changes during operation. For example, taking a parachute as an example, the flexible structures such as parachute ropes, radial belts, and slings will experience severe impact dynamic loads during the inflation and deployment process, and the material loads at different positions will be asynchronous and uneven. Due to the lack of practical measurement methods and sensors, the asynchronous and uneven loads of materials in different parts of the parachute have never been quantitatively evaluated.

[0003] In related technologies, in order to ensure that the flexible structure in flexible equipment (such as parachute structure) has sufficient load-bearing reliability, a large safety margin design strategy is usually adopted to ensure that the belt materials in the structure have sufficient load-bearing reliability. However, this design strategy is difficult to adapt to the development requirements of advanced model tasks under the new situation for efficient, highly reliable and lightweight flexible equipment, and it is urgent to reliably measure the stress / strain of key flexible structural components such as ropes / belts under actual working conditions. Summary of the invention

[0004] Embodiments of the present disclosure provide a tension measurement method, a tension measurement device, and a storage medium for a flexible structure in flexible equipment.

[0005] According to a first aspect of an embodiment of the present disclosure, a tension measurement device is provided, which is used to measure the tension of a flexible structure in a flexible device. The tension measurement device includes: a shell cover, a shell, a strain plate, and an acquisition circuit, wherein:

[0006] The shell cover is fixed against the shell body by a plurality of bolts;

[0007] The shell includes a first cavity and a second cavity, and the first cavity is located above the second cavity along the vertical direction;

[0008] The strain plate is arranged in the first cavity, the upper surface of the strain plate is provided with a protrusion, and the lower surface of the strain plate is provided with a strain gauge, wherein the flexible structure passes through a channel formed between the shell cover and the strain plate to locally generate a local deformation of three-point bending in the flexible structure;

[0009] The acquisition circuit is arranged in the second cavity, wherein a threading hole is arranged between the partitions of the first cavity and the second cavity, and the wire of the strain gauge is connected to the acquisition circuit through the threading hole.

[0010] According to a second aspect of an embodiment of the present disclosure, a method for measuring the tension of a flexible structure in a flexible device is provided. The method is performed by the tension measuring device of the first aspect, and the method comprises:

[0011] Acquiring an actual strain value and a temperature value monitored by the bridge circuit, wherein the actual strain value is a strain value of a lower surface of the strain plate being pulled to generate tensile strain when a bending portion of the flexible structure has a tendency to straighten so as to apply a force to the protrusion to cause the strain plate to bend and deform;

[0012] According to the monitored actual strain value and the temperature value, nonlinear compensation is performed in combination with the calibration test result to obtain the actual tension of the flexible structure.

[0013] According to a third aspect of an embodiment of the present disclosure, a storage medium is provided, wherein the storage medium stores instructions, and when the instructions are executed on a tension measurement device, the tension measurement device executes the method described in the second aspect.

[0014] According to a fourth aspect of an embodiment of the present disclosure, there is provided a computer program product, comprising a computer program, wherein when the computer program is executed by the tension measurement device, the steps of the method described in the second aspect are implemented.

[0015] According to the technical solution disclosed in the present invention, a three-point bending and pulling conversion device is used for measuring the tension of a flexible structure, which can have the characteristics of high precision, small size, and adjustable range. In addition, when measuring the tension of a flexible structure, the present invention takes into account the nonlinear compensation of the measurement caused by temperature and materials, etc., which can improve the measurement accuracy. The present invention adopts an integrated design solution, which does not require external power supply and data collection, and is convenient to integrate with the flexible structure and fold into the umbrella tube, so that the tension change of the parachute rope / belt structure during operation can be realized online.

[0016] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present disclosure will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0018] Figure 1 It is a structural schematic diagram of the tension measurement device provided in an embodiment of the present disclosure.

[0019] Figure 2 It is a schematic diagram of the appearance structure of the tension measurement device provided in an embodiment of the present disclosure.

[0020] Figure 3 Schematic diagram of the structure of the strain plate provided in the embodiment of the present disclosure.

[0021] Figure 4It is a flow chart of the tension measurement method of the flexible structure in the flexible equipment provided by the embodiment of the present disclosure.

[0022] Figure 5 It is a flow chart of the tension measurement method of the flexible structure in the flexible equipment provided by the embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] Embodiments of the present disclosure are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present disclosure, and should not be construed as limiting the present disclosure.

[0024] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present disclosure. The singular forms "a", "an" and "the" used in the embodiments of the present disclosure and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0025] In the embodiments of the present disclosure, "multiple" refers to two or more. In some embodiments, "at least one of A, B", "A and / or B", "A in one case, B in another case", "in response to one case A, in response to another case B", etc., may include the following technical solutions according to the situation: in some embodiments A (execute A independently of B); in some embodiments B (execute B independently of A); in some embodiments, select execution from A and B (A and B are selectively executed); in some embodiments A and B (both A and B are executed). When there are more branches such as A, B, C, etc., it is similar to the above.

[0026] In some embodiments, the recording method of "A or B" may include the following technical solutions according to the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). When there are more branches such as A, B, C, etc., the above is also similar.

[0027] It should be noted that the flexible structure in the flexible equipment will experience tension changes during operation. For example, taking the flexible equipment as a parachute, the flexible structures such as the parachute rope, radial belt, and sling will experience severe impact dynamic loads during the inflation and deployment process, and the material loads at different positions will show the characteristics of asynchronous and uneven force. Due to the lack of practical measurement methods and sensors, the asynchronous and uneven loads of materials in different parts of the parachute have never been quantitatively evaluated.

[0028] In related technologies, in order to ensure that the flexible structure in flexible equipment (such as parachute structure) has sufficient load-bearing reliability, a large safety margin design strategy is usually adopted to ensure that the belt materials in the structure have sufficient load-bearing reliability. However, this design strategy is difficult to adapt to the development requirements of advanced model tasks under the new situation for efficient, highly reliable and lightweight flexible equipment, and it is urgent to reliably measure the stress / strain of key flexible structural components such as ropes / belts under actual working conditions.

[0029] Based on this, the embodiment of the present disclosure provides a tension measurement method, device and storage medium of a flexible structure in a flexible equipment, wherein the tension measurement device includes: a shell cover, a shell, a strain plate and an acquisition circuit, wherein the strain plate and the acquisition circuit are arranged on the shell, the upper surface of the strain plate is provided with a protrusion, the lower surface of the strain plate is provided with a strain gauge, the flexible structure passes through the channel formed between the shell cover and the strain plate to make the flexible structure locally deformed by three-point bending; the acquisition circuit is electrically connected to the strain gauge, and the acquisition circuit can be used to monitor the actual strain value and temperature value of the lower surface of the strain plate when there is a tendency to straighten the bending part of the flexible structure to apply a force to the protrusion to cause the strain plate to bend and deform. The tension measurement method can be performed by the above-mentioned tension measurement device, and the method can include the following steps: obtaining the monitored actual strain value and temperature value, and performing nonlinear compensation based on the monitored actual strain value and temperature value combined with the calibration experiment results to obtain the actual tension of the flexible structure, so as to realize online monitoring of the tension change of the flexible structure during operation.

[0030] The following describes a method, device, and storage medium for measuring the tension of a flexible structure in flexible equipment according to an embodiment of the present disclosure with reference to the accompanying drawings.

[0031] Figure 1 : is a schematic diagram of the structure of the tension measurement device provided in the embodiment of the present disclosure. In some embodiments, the tension measurement device can be used to measure the tension of a flexible structure in a flexible device. In some embodiments, the flexible device can be a parachute. Exemplarily, the parachute can be an aerospace parachute. In some embodiments, the flexible structure can include at least one of the following: parachute ropes; radial straps; slings, etc. Exemplarily, the flexible structure can be parachute ropes. Exemplarily, the flexible structure can be radial straps of a parachute. Exemplarily, the flexible structure can be a sling of a parachute.

[0032] like Figure 1 As shown, the tension measurement device may include a shell cover 101, a shell 102, a strain plate 103 and an acquisition circuit 104. The shell cover 101 is fixed against the shell 102. For example, the shell cover 101 may be fixed against the shell 102 by a plurality of bolts, for example, Figure 2As shown, the shell cover 101 can be fixed against the housing 102 by six bolts 101 a , and the six bolts 101 a can include four bolts respectively located at the corners of the shell cover 101 , and a bolt in the middle.

[0033] In some embodiments, a gap may be left at the portion of the inner surface of the shell cover 101 that contacts the flexible structure 10, and the edge of the shell cover 101 may be set to be an arc shape. Figure 1 As shown, there are gaps on the left and right sides of the inner surface of the shell cover 101 that contact the flexible structure 10, and the edge of the shell cover 101 is designed to be arc-shaped, so that the flexible structure 10 can transition smoothly on it while preventing damage to the parachute rope.

[0034] like Figure 1 As shown, the housing 102 may include a first cavity 102a and a second cavity 102b, and the first cavity 102a may be located above the second cavity 102b along a vertical direction. The strain plate 103 may be disposed in the first cavity 102a, and a protrusion 103a is disposed on the upper surface of the strain plate 103, and a strain gauge ( Figure 1 ), wherein the flexible structure 10 passes through the channel formed between the shell cover 101 and the strain plate 103 to locally generate a local deformation of three-point bending in the flexible structure 10. Exemplarily, there is a gap between the lower surface of the strain plate 103 (or the strain gauge) and the partition of the first cavity 102a, so that when the flexible structure 10 locally generates a local deformation of three-point bending, the strain plate is strained toward the partition.

[0035] For example, Figure 3 As shown, the upper surface of the strain plate 103 may be provided with a protrusion 103a, and the portion of the protrusion 103a in contact with the flexible structure 10 may be set in an arc shape, so that the flexible structure 10 can smoothly transition on the protrusion 103a and prevent damage to the parachute rope. Figure 3 As shown, the length of the strain plate 103 can be 60 mm, the width can be 40 mm, and the height can be 7 mm. It can be understood that the length of the strain plate 103 is only an example, that is, the length of the strain plate 103 can also adopt other values, and the present disclosure does not limit this.

[0036] like Figure 1 As shown, the acquisition circuit 104 can be arranged in the second cavity 102b, wherein a threading hole ( Figure 1 Not shown), strain gauge ( Figure 1 The wires (not shown) are passed through the threading holes ( Figure 1The plurality of holes are connected to the acquisition circuit 104. For example, the number of the threading holes may be one or more, which may be determined according to actual conditions.

[0037] In some embodiments, the tension measurement device may further include a clamp, which can clamp the flexible structure between the shell cover and the strain plate. Figure 1 As shown, the clamp 105 can be disposed on the inner surface of the shell cover 101, and the clamp 105 can clamp the flexible structure 10 between the shell cover 101 and the strain plate 103, so that the flexible structure 10 passing through the channel formed between the shell cover 101 and the strain plate 103 is fixed within an effective range.

[0038] In some embodiments, the tension measurement device may further include an input / output interface, which may be used to connect the acquisition circuit to interact with an external device. Figure 1 As shown, the input-output interface 106 can be arranged on the side of the tension measurement device, and the input-output interface 106 can be connected to the acquisition circuit 104. The input-output interface 106 is used to connect the acquisition circuit 104 to interact with external devices. Exemplarily, the data collected by the acquisition circuit 104 and / or the measured tension are transmitted to the external device through the input-output interface 106, so that the external device can use the data collected by the acquisition circuit 104 and / or the measured tension for research and analysis. Exemplarily, the external device can use the data collected by the acquisition circuit 104 and / or the measured tension to measure and evaluate the reliability and verify the structural safety of the flexible equipment, and can also use the data collected by the acquisition circuit 104 and / or the measured tension to improve the flexible structure design method, so as to improve the refinement and lightweight design capabilities of the flexible equipment from the two aspects of theoretical design and structural measurement.

[0039] In some embodiments, the tension measurement device may further include a power module, which is disposed in the second cavity and is used to supply power to the acquisition circuit. Figure 1 As shown, the power module 107 can be arranged in the second cavity 102b. For example, the power module 107 can be located above the acquisition circuit 104 in the vertical direction, or the power module 107 can also be located below the acquisition circuit 104 in the vertical direction. The power module 107 can supply power to the acquisition circuit 104. For example, the power module 107 can be a battery, such as a storage battery or a lithium battery. For example, the power module 107 can also be a new energy battery such as a solar cell, which is not limited in this disclosure and will not be described in detail.

[0040] In some embodiments, the acquisition circuit may include but is not limited to an acceleration sensor. Among them, when the flexible structure is in the initial state in the flexible equipment, the tension measurement device can operate in a low-power operation mode to collect and judge the acceleration only through the acceleration sensor. The tension measurement device can wake up the acquisition circuit when it determines that the flexible equipment is in a free fall state based on the acceleration data collected by the acceleration sensor. In some embodiments, the flexible equipment is a parachute, then the flexible structure in the initial state in the flexible equipment can be understood as the flexible structure is processed and folded inside the umbrella tube; the flexible equipment in a free fall state can be understood as the umbrella tube of the parachute is in an airdrop state.

[0041] For example, taking the flexible equipment as a parachute, an acceleration sensor can be designed in the acquisition circuit. When the parachute is processed and folded inside the umbrella tube, in order to increase the standby time, the tension measurement device is in a low-power operation mode, and only the acceleration is collected and judged in real time. The tension measurement device determines that the sum of the accelerations in the three directions of the acceleration sensor is less than the set threshold based on the acceleration data collected by the acceleration sensor, and then it can be determined that the umbrella tube is in an airdrop state (i.e., in a free fall state). The tension measurement device can wake up the acquisition circuit and start collecting the strain value of the strain plate. After a period of free fall, the parachute opens, and the deformation of the flexible structure (such as the parachute rope) on the parachute when it is stressed is collected online.

[0042] In some embodiments, the acquisition circuit may include, but is not limited to: a bridge circuit and a processor connected to the bridge circuit. The bridge circuit is used to monitor the actual strain value and temperature value of the lower surface of the strain plate when there is a tendency for the bending part of the flexible structure to straighten so as to apply a force to the protrusion to cause the strain plate to bend and deform. The processor is used to perform nonlinear compensation based on the monitored actual strain value and temperature value in combination with the calibration experiment results to obtain the actual tension of the flexible structure.

[0043] In some embodiments, the bridge circuit may be a Wheatstone bridge circuit. Exemplarily, the bridge circuit may adopt a quarter bridge, half bridge, or full bridge acquisition scheme of a Wheatstone bridge. Exemplarily, taking a flexible device as a parachute as an example, since the flexible structure (such as the parachute rope) on the parachute is bent under the restriction of the strain plate structure, when the flexible structure (such as the parachute rope) is pulled during the working process, the bent part has a tendency to straighten, which will apply a force to the top of the strain plate (i.e., the protrusion) to cause it to bend and deform, then the back (or lower surface) of the strain plate is pulled, generating tensile strain, and the strain gauge value and the nearby temperature value are monitored by the bridge circuit, and the actual tension of the flexible structure (such as the parachute rope) can be converted after nonlinear compensation combined with the calibration results.

[0044] In some embodiments, the processor can be used to: determine the corresponding first compensation coefficient value from the temperature calibration experiment results according to the reference temperature point; determine the strain value generated by the mechanical force deformation according to the actual strain value, the first compensation coefficient value, the reference temperature point and the temperature value; determine the corresponding multiple second compensation coefficient values ​​from the force calibration experiment results according to the reference temperature point, and the multiple second compensation coefficient values ​​are the nonlinear relationship coefficients between the force and strain of the flexible structure; determine the cubic function of the tension of the flexible structure according to the strain value generated by the mechanical force deformation and the multiple second compensation coefficient values, and solve the cubic function to obtain the actual tension of the flexible structure. Exemplarily, the above calibration results may include but are not limited to the temperature calibration experiment results and the force calibration experiment results; Exemplarily, the temperature calibration experiment results may include but are not limited to the mapping information between the reference temperature point and the first compensation coefficient value, such as different reference temperature points correspond to different first compensation coefficient values. The force calibration experiment results may include but are not limited to the mapping information between the reference temperature point and the multiple second compensation coefficient values, such as different reference temperature points correspond to different multiple second compensation coefficient values.

[0045] It should be noted that due to the influence of factors such as temperature and material properties in the actual environment, the actual output value of the strain has a nonlinear effect, of which the nonlinear part is mainly composed of the nonlinearity caused by temperature changes and the nonlinearity of the resistance change after the strain gauge is deformed. Based on this, the specific nonlinear compensation scheme is as follows:

[0046] The actual output strain value (i.e. the actual strain value output by the above bridge circuit) ε m It can be obtained by the following formula (1):

[0047] ε m =ε 0 +ε t (1)

[0048] Among them, ε 0 represents the strain caused by mechanical deformation, ε t Represents the strain caused by temperature effect.

[0049] It should be noted that ε t It can be decomposed into the strain ε caused by the change in resistance of the strain gauge due to the temperature change ΔT α and the strain ε caused by the difference in expansion coefficient β during thermal deformation β ,Right now:

[0050] ε t =ε α +ε β (2)

[0051] The change in resistance ΔR of the strain gauge caused by the temperature change ΔT α It can be expressed as:

[0052] ΔR α =R 0 α 0 ΔT (3)

[0053] Among them, R 0 The temperature is T 0 The resistance value, α 0 The temperature is T 0 The resistance temperature coefficient of the strained metal wire at the time, ΔT is the temperature change value. Exemplarily, the temperature is T 0 It can be understood as the reference temperature point mentioned above; ΔT can be understood as the difference between the temperature value T collected when measuring the actual tension of the flexible structure and the reference temperature point T 0 The difference between .

[0054] According to the Wheatstone bridge principle, ε α It can be expressed as:

[0055]

[0056] Among them, K 0 is the strain gauge sensitivity coefficient.

[0057] When it is necessary to explain, the strain ε caused by thermal deformation β Due to the inconsistent thermal deformation of the resistance wire and the specimen, when the two are pasted together, the additional deformation Δl can be expressed as:

[0058] Δl=l g -l s =(β g -β s ) 0 ΔT (5)

[0059] Among them, l g is the length of the specimen after thermal deformation at the pasting point after the temperature changes ΔT, l s is the length of the strain resistance wire after thermal deformation after temperature change ΔT, β g is the thermal expansion coefficient of the specimen, β s is the thermal expansion coefficient of the resistance wire, l 0 The temperature is T 0 The length of the resistance wire and the test piece at the bonding point.

[0060] Then ε β It can be expressed as:

[0061]

[0062] Substituting formula (4) and (6) into formula (2), we can get ε t It is expressed as:

[0063]

[0064] make When the tension measuring device is determined, G T Approximately a constant, the G T This is the first compensation coefficient value mentioned above, which can be obtained by calibration. Different reference temperature points T 0 Corresponding to different first compensation coefficient values ​​G T . According to the reference temperature point T 0 Determine the corresponding first compensation coefficient value G from the temperature calibration experiment results T , according to the first compensation coefficient value G T The strain ε caused by the temperature effect can be calculated by the temperature change ΔT t .

[0065] The strain ε caused by mechanical deformation is 0 It can be expressed as:

[0066]

[0067] Due to the nonlinear relationship between the deformation of the strain gauge resistance wire and the change in resistance, ε0 can be expressed as a cubic function of the tensile force F of the flexible structure:

[0068] ε 0 =aF 3 +bF 2 +cF+d (9)

[0069] It can be seen from formula (9) that when the deformation is small, the relationship between force and strain is approximately linear, and when the deformation is large, the nonlinear effect is obvious. When the tension measurement device is determined, the specific values ​​of a, b, c, and d can be obtained through calibration. The a, b, c, and d are the above-mentioned multiple second compensation coefficient values. Different reference temperature points correspond to different second compensation coefficient values. The corresponding multiple second compensation coefficient values ​​are determined from the force calibration test results according to the reference temperature point, and the cubic function expression is determined according to the multiple second compensation coefficient values. For the specific measured ε 0 , the flexible structure tension F is solved by iteration through numerical methods (such as Newton's method, or bisection method, etc.).

[0070] By implementing the embodiments of the present disclosure, a three-point bending and tension conversion device is used for flexible structure tension measurement, which can have the characteristics of high precision, small size, and adjustable range. In addition, when measuring the tension of the flexible structure, the present disclosure takes into account the nonlinear compensation of the measurement caused by temperature and materials, etc., which can improve the measurement accuracy. The present disclosure can improve the endurance of the tension measurement device and achieve a long-term standby function by running at low power for a long time and automatically waking up when conditions are met. The present disclosure adopts an integrated design solution, which does not require external power supply and data collection, and is convenient for integration with the flexible structure and then folding into the umbrella tube, so that online monitoring of the tension changes of the parachute rope / belt structure during operation can be achieved.

[0071] Figure 4 is a flow chart of a tension measurement method for a flexible structure in a flexible device provided by an embodiment of the present disclosure. It should be noted that the tension measurement method can be performed by the tension measurement device described in any of the above embodiments. The function and structure of the tension measurement device can refer to the description of the above embodiments and will not be repeated here. Figure 4 As shown, the tension measurement method may include but is not limited to the following steps.

[0072] In step 401, the actual strain value and temperature value monitored by the bridge circuit are obtained.

[0073] The actual strain value may be a strain value when the lower surface of the strain plate is pulled to generate tensile strain when a bending portion of the flexible structure tends to straighten and a force is applied to the protrusion to cause the strain plate to bend and deform.

[0074] Exemplarily, the bridge circuit can be a Wheatstone bridge circuit. Exemplarily, the bridge circuit can adopt a quarter bridge, half bridge, or full bridge acquisition scheme of a Wheatstone bridge. Exemplarily, taking a flexible equipment as a parachute as an example, since the flexible structure (such as the parachute rope) on the parachute is bent under the restriction of the strain plate structure, when the flexible structure (such as the parachute rope) is pulled during the working process, the bent part has a tendency to straighten, which will apply a force to the top of the strain plate (i.e., the protrusion) to cause it to bend and deform, then the back (or lower surface) of the strain plate is pulled, generating tensile strain, and the strain gauge value and nearby temperature value can be monitored through the bridge circuit.

[0075] In step 402, nonlinear compensation is performed based on the monitored actual strain value and temperature value in combination with the calibration test results to obtain the actual tension of the flexible structure.

[0076] In some embodiments, a corresponding first compensation coefficient value can be determined from the temperature calibration experiment results according to a reference temperature point; a strain value caused by mechanical force deformation can be determined according to the actual strain value, the first compensation coefficient value, the reference temperature point and the temperature value; a corresponding plurality of second compensation coefficient values ​​can be determined from the force calibration experiment results according to the reference temperature point, and the plurality of second compensation coefficient values ​​are nonlinear relationship coefficients between the force and strain of the flexible structure; a cubic function of the tension of the flexible structure can be determined according to the strain value caused by the mechanical force deformation and the plurality of second compensation coefficient values, and the cubic function can be solved to obtain the actual tension of the flexible structure.

[0077] For example, Figure 5 As shown, the actual strain value ε output by the bridge circuit is obtained. m and temperature value T. According to the reference temperature point t 0 Determine the corresponding first compensation coefficient value G from the temperature calibration experiment results T , according to the actual strain value ε m , the first compensation coefficient value G T , reference temperature point T 0 and temperature value T, and then put them into the above formula (8) to calculate the strain value ε caused by mechanical deformation alone 0 =ε m -G T (TT 0 ). According to the reference temperature point T 0 The corresponding multiple second compensation coefficient values ​​(i.e., specific values ​​of a, b, c, d) are determined from the force calibration test results, and the strain value ε generated by the mechanical force deformation is calculated. 0 The cubic function of the tension of the flexible structure (as expressed in the above formula 9) is determined by the multiple second compensation coefficient values ​​(i.e., the specific values ​​of a, b, c, d), and a numerical method (such as Newton's method or bisection method, etc.) is used to solve the cubic function to obtain the actual tension F of the flexible structure.

[0078] In some embodiments, when the flexible structure is in the initial state in the flexible equipment, the tension measurement device operates in a low-power operation mode to collect and judge the acceleration only through the acceleration sensor; when the flexible equipment is determined to be in a free fall state according to the acceleration data collected by the acceleration sensor, the collection circuit is awakened. In some embodiments, the flexible equipment is a parachute, and the flexible structure in the initial state in the flexible equipment can be understood as the flexible structure being processed and folded inside the parachute tube; the flexible equipment being in a free fall state can be understood as the parachute tube being in an airdrop state.

[0079] For example, taking the flexible equipment as a parachute, an acceleration sensor can be designed in the acquisition circuit. When the parachute is processed and folded inside the umbrella tube, in order to increase the standby time, the tension measurement device is in a low-power operation mode, and only the acceleration is collected and judged in real time. The tension measurement device determines that the sum of the accelerations in the three directions of the acceleration sensor is less than the set threshold based on the acceleration data collected by the acceleration sensor, and then it can be determined that the umbrella tube is in an airdrop state (i.e., in a free fall state). The tension measurement device can wake up the acquisition circuit and start collecting the strain value of the strain plate. After a period of free fall, the parachute opens, and the deformation of the flexible structure (such as the parachute rope) on the parachute when it is stressed is collected online.

[0080] In the above embodiment, a three-point bending type tension conversion device is used for flexible structure tension measurement, which can have the characteristics of high precision, small size, and adjustable range. In addition, when measuring the tension of the flexible structure, the present disclosure takes into account the nonlinear compensation of the measurement caused by temperature and materials, etc., which can improve the measurement accuracy. The present disclosure can improve the endurance of the tension measurement device and realize the function of long-term standby by running at low power consumption for a long time and automatically waking up when the conditions are met. The present disclosure adopts an integrated design solution, which does not require external power supply and data collection, and is convenient to integrate with the flexible structure and then fold into the umbrella tube, so as to realize online monitoring of the tension changes of the parachute rope / belt structure during operation.

[0081] The tension measurement device proposed in the embodiments of the present disclosure may include: at least one processor; a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method described in any of the above embodiments. In some embodiments, the tension measurement device may also include a wireless communication module, for example, to communicate and interact with an external device through WiFi, or mobile data (such as 3G, 4G, 5G, 6G, etc.), or NFC (near field communication), or Bluetooth (BT), for example, to transmit data collected by the tension measurement device (such as actual strain value and temperature value) and / or measured tension and other data to an external device.

[0082] The embodiment of the present disclosure also provides a storage medium, which stores instructions. When the instructions are executed on the tension measurement device, the tension measurement device executes the method described in any of the above embodiments; illustratively, the instructions can be executed by a processor of the tension measurement device to complete the above method. For example, the storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0083] The embodiments of the present disclosure further provide a computer program product, including a computer program, which implements the steps of the method described in any of the above embodiments when executed by a tension measurement device.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0085] In the description of the present disclosure, it is necessary to understand that the terms "length", "width", "thickness", "up", "down", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0086] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0087] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0088] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present disclosure includes additional implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present disclosure belong.

[0089] It should be understood that the various parts of the present disclosure can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0090] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0091] In addition, each functional unit in each embodiment of the present disclosure may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0092] The storage medium mentioned above may be a read-only memory, a disk or an optical disk, etc. Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present disclosure. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present disclosure.

Claims

1. A tension measuring device, characterized in that: The tension measuring device is used to measure the tension of the flexible structure in the flexible equipment, and the tension measuring device includes: a shell cover, a shell, a strain plate and a collection circuit, wherein: The shell cover is fixed against the shell body by a plurality of bolts; The housing comprises a first cavity and a second cavity, wherein the first cavity is located above the second cavity along a vertical direction; The strain plate is disposed in the first cavity, a protrusion is disposed on the upper surface of the strain plate, and a strain gauge is disposed on the lower surface of the strain plate, wherein the flexible structure passes through a channel formed between the shell cover and the strain plate to locally generate a local deformation of three-point bending of the flexible structure; The acquisition circuit is arranged in the second cavity, wherein a threading hole is arranged between the partitions of the first cavity and the second cavity, and the wire of the strain gauge is connected to the acquisition circuit through the threading hole.

2. The tension measuring device according to claim 1, characterized in that: The acquisition circuit includes: a bridge circuit and a processor connected to the bridge circuit, wherein: The bridge circuit is used to monitor the actual strain value and temperature value of the lower surface of the strain plate when the bending portion of the flexible structure has a tendency to straighten so as to apply a force to the protrusion to cause the strain plate to bend and deform; The processor is used to perform nonlinear compensation according to the monitored actual strain value and the temperature value in combination with the calibration experiment result to obtain the actual tension of the flexible structure.

3. The tension measuring device according to claim 2, characterized in that: The processor is used to: Determining a corresponding first compensation coefficient value from a temperature calibration experiment result according to a reference temperature point; Determine the strain value caused by mechanical force deformation according to the actual strain value, the first compensation coefficient value, the reference temperature point and the temperature value; Determine a plurality of corresponding second compensation coefficient values ​​from the force calibration test results according to the reference temperature point, wherein the plurality of second compensation coefficient values ​​are coefficients of a nonlinear relationship between the force and strain of the flexible structure; A cubic function of the tension of the flexible structure is determined according to the strain value generated by the mechanical force deformation and the multiple second compensation coefficient values, and the cubic function is solved to obtain the actual tension of the flexible structure.

4. The tension measuring device according to any one of claims 1 to 3, characterized in that: Also includes: A power supply module is disposed in the second cavity and is used to supply power to the acquisition circuit.

5. The tension measuring device according to claim 4, characterized in that: The acquisition circuit includes an acceleration sensor, wherein: When the flexible structure is in an initial state in the flexible equipment, the tension measurement device operates in a low power consumption operation mode to collect and judge the acceleration only through the acceleration sensor; When the tension measurement device determines that the flexible equipment is in a free fall state according to the acceleration data collected by the acceleration sensor, the collection circuit is awakened.

6. The tension measuring device according to claim 1, characterized in that: Also includes: A clamper clamps the flexible structure between the housing cover and the strain plate.

7. The tension measuring device according to claim 1, characterized in that: A gap is left in the portion where the inner surface of the shell cover contacts the flexible structure, and the edge of the shell cover is configured to be in an arc shape; and / or The portion where the protrusion contacts the flexible structure is in an arc shape.

8. The tension measuring device according to claim 1, characterized in that: Also includes: The input and output interface is used to connect the acquisition circuit to interact with external devices.

9. The tension measuring device according to claim 1, characterized in that: The flexible equipment is a parachute; the flexible structure comprises at least one of the following: parachute ropes, radial belts, and slings.

10. A method for measuring the tension of a flexible structure in a flexible device, characterized in that: The method is performed by a tension measuring device according to any one of claims 1 to 9, and the method comprises: Acquiring an actual strain value and a temperature value monitored by the bridge circuit, wherein the actual strain value is a strain value of a lower surface of the strain plate being pulled to generate tensile strain when a bending portion of the flexible structure has a tendency to straighten so as to apply a force to the protrusion to cause the strain plate to bend and deform; According to the monitored actual strain value and the temperature value, nonlinear compensation is performed in combination with the calibration test result to obtain the actual tension of the flexible structure.

11. The method according to claim 10, characterized in that The nonlinear compensation is performed based on the monitored actual strain value and the temperature value in combination with the calibration test result to obtain the actual tension of the flexible structure, including: Determining a corresponding first compensation coefficient value from a temperature calibration experiment result according to a reference temperature point; Determine the strain value caused by mechanical force deformation according to the actual strain value, the first compensation coefficient value, the reference temperature point and the temperature value; Determine a plurality of corresponding second compensation coefficient values ​​from the force calibration test results according to the reference temperature point, wherein the plurality of second compensation coefficient values ​​are coefficients of a nonlinear relationship between the force and strain of the flexible structure; A cubic function of the tension of the flexible structure is determined according to the strain value generated by the mechanical force deformation and the multiple second compensation coefficient values, and the cubic function is solved to obtain the actual tension of the flexible structure.

12. The method according to claim 10 or 11, characterized in that The method further comprises: When the flexible structure is in an initial state in the flexible equipment, the tension measurement device operates in a low power consumption operation mode to collect and judge the acceleration only through the acceleration sensor; When it is determined that the flexible equipment is in a free fall state according to the acceleration data collected by the acceleration sensor, the collection circuit is awakened.

13. A storage medium storing instructions, characterized in that: When the instruction is executed on a tensile force measuring device, the tensile force measuring device is caused to execute the method according to any one of claims 10 to 12.

14. A computer program product comprising a computer program, characterized in that The computer program implements the steps of the method according to any one of claims 10 to 12 when executed by the tension measuring device.

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