Flexible arm driving wire tension detection device

Abstract

The application discloses a flexible arm driving wire tension detection device, which comprises a shell, a force adding module, a tension detection module, a guide module and a control module. The force adding module comprises N force adding units, the tension detection module comprises N tension detection units, and the guide module comprises a fixing disc, a transition disc and N centering units. The flexible arm is fixed by the fixing disc, the N driving wires are guided to be connected to the N centering units one by one by the transition disc, the secondary alignment and constraint of the movement path of the driving wire are completed by the centering units, so that the influence of the driving wire inclination and other factors on the bending angle of the flexible arm is reduced, then the N tension detection units are connected to the N driving wires one by one, the tension is applied by the force adding units, and finally the tension detection units are used for detection. The application has the advantages of compact structure, convenient operation, high testing precision and the like, can be suitable for the driving wire performance detection of flexible arms with different structural forms, and provides an effective means for the reliability evaluation and service life prediction of the flexible arm.

Description

Technical Field

[0001] This invention relates to the field of continuous robots, and more particularly to a flexible arm drive wire tension detection device. Background Technology

[0002] Flexible arms are widely used in robot end effectors, flexible actuators, and lightweight structures. Their actuation typically involves using a drive wire (such as a steel wire rope or Kevlar rope) to achieve pose changes. In practical applications, the drive wire and its connectors, guiding and locking components, and the arm structure are prone to fatigue damage, loosening, or breakage under repeated loads, thus affecting the reliability and service life of the flexible arm.

[0003] Existing methods for detecting the tension of flexible arm drive wires mainly include:

[0004] 1. Perform cyclic loading tests using a general-purpose tensile testing machine;

[0005] 2. A simple reciprocating loading mechanism was used for testing.

[0006] However, these tests have many shortcomings, including:

[0007] 1. The drive wire is prone to slippage during the return or reverse force phase, resulting in inconsistent loading conditions and affecting the accuracy of cycle counting and life determination.

[0008] 2. The lack of effective alignment and constraint in the drive wire path can easily lead to off-center loading, abnormal friction, or local stress concentration, resulting in large fluctuations in test results.

[0009] 3. The force transmission link and force measurement arrangement are unreasonable, making it difficult to stably obtain force data and record it synchronously with the number of cycles;

[0010] 4. Long-term reciprocating motion and friction may lead to dust entering key components and sensor installation locations, potentially causing jamming, wear, or signal drift, affecting test repeatability.

[0011] Therefore, it is necessary to provide a flexible arm drive wire tension detection device with a well-defined structure, easy implementation, capable of counting and measuring force during the cyclic loading process of the drive wire, limiting slippage during the return phase, and having centering and dust protection capabilities, so as to improve the stability and repeatability of the testing process. Summary of the Invention

[0012] The technical problem to be solved by the present invention is to provide a flexible arm drive wire tension detection device to address the deficiencies mentioned in the background art.

[0013] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0014] A flexible arm driven wire tension detection device includes a housing, a force application module, a tension detection module, a guide module, and a control module;

[0015] The housing is hollow and has N through holes for introducing the drive wires of the flexible arm to be tested, where N is the number of drive wires of the flexible arm to be tested.

[0016] The force-adding module is housed within the casing and contains N force-adding units;

[0017] The force-applying unit includes a base plate, a first bearing, a second bearing, a first bearing housing, a second bearing housing, a lead screw, a lead screw motor, a slide rail, and a slide table;

[0018] The slide rail is mounted on the base plate; the slide table is mounted on the slide rail and can slide freely along the slide rail, and the slide table is provided with a threaded through hole parallel to the slide rail for cooperating with the lead screw;

[0019] The outer ring of the first bearing is fixed to the substrate by the first bearing seat, and the outer ring of the second bearing is fixed to the substrate by the second bearing seat.

[0020] The two ends of the lead screw are coaxially fixed to the inner rings of the first bearing and the second bearing, respectively, and the lead screw is threadedly connected to the slide table.

[0021] The lead screw motor is on the base plate, and its output shaft is coaxially fixed to one end of the lead screw, which is used to drive the slide table to slide on the slide rail.

[0022] The base plates of the N force-applying units are all fixed inside the housing;

[0023] The tension detection module includes N tension detection units, which are arranged one-to-one on the slides of the N force-applying units;

[0024] The tension detection unit includes a mounting box, a pressure sensor, a drive wire locker, a locking stud, a locking nut, a slider, an adjusting bolt, and an adjusting nut.

[0025] The mounting box is a hollow cuboid, comprising an upper plate, a lower plate, and first to fourth side plates connected end to end. The first side plate has a through hole in its center for the drive wire locking device to pass through, and the third side plate has a through hole in its center for installing the adjusting nut. The inner walls of the upper and lower plates are respectively provided with a first sliding groove and a second sliding groove for cooperating with the slider. The first sliding groove and the second sliding groove are both parallel to the axis of the through hole in the center of the first side plate.

[0026] The slider is installed in the first slide groove and the second slide groove, and can slide freely in the mounting box along the first slide groove and the second slide groove. The slider is provided with a mounting hole for fixing the drive wire locker. The mounting hole and the through hole in the center of the first side plate are coaxial.

[0027] The pressure sensor is a strain gauge pressure sensor, with a through hole in the center of the strain gauge for the locking stud to pass through. The strain gauge of the pressure sensor is fixed to the outer wall of the first side plate by bolts. The through hole in the center of the strain gauge of the pressure sensor and the through hole in the center of the first side plate are coaxial.

[0028] The locking stud is a hollow stud with openings at both ends; the drive wire lock is fixed in the mounting hole of the slider and is used to lock or release the drive wire connected therein, with one end near the first side plate being coaxially connected to one end of the locking stud; the other end of the locking stud passes through the through hole in the center of the first side plate and the through hole in the center of the strain gauge of the pressure sensor in sequence, and is then threadedly connected to the locking nut, so that the strain gauge of the pressure sensor and the drive wire lock are fixedly connected.

[0029] The adjusting nut is fixed in the through hole in the center of the third side plate; the adjusting bolt and the adjusting nut are threadedly connected, and the stud of the adjusting bolt passes through the adjusting nut and extends into the installation and abuts against the end of the drive wire lock that is away from the first side plate, which is used to adjust the initial stress of the strain gauge of the pressure sensor.

[0030] The lower plate of the mounting box is fixed on the slide table of the force-applying unit corresponding to its tension detection unit, and the axis of the drive wire lock is parallel to the slide rail of the force-applying unit corresponding to its tension detection unit.

[0031] The guiding module includes a fixed disk, a transition disk, and N centering units;

[0032] The fixing plate is used to fix one end of the shell of the flexible arm to be tested, and N through holes are evenly arranged on it in the circumferential direction, corresponding one-to-one with the drive wire of the flexible arm.

[0033] One end of the transition disk is fixedly connected to the fixed disk, and the other end is fixedly connected to the housing. It has N channels for guiding the dispersion of the drive wire. One end of each of the N channels corresponds to one of the N through holes on the fixed disk, and the other end corresponds to one of the N through holes on the housing.

[0034] The N centering units are arranged one-to-one on the slides of the N force-applying units, and are used to connect the drive wires passing through the N channels of the transition plate to the N tension detection units one-to-one.

[0035] The centering unit includes an adjusting plate, a guide bolt, and a guide nut. The adjusting plate is fixed to the slide of the force-applying unit corresponding to its centering unit and has a slot for engaging with the stud of the guide bolt. The slot is perpendicular to and coplanar with the axis of the drive wire locking device of the tension detection unit corresponding to its centering unit. The guide bolt has a through hole along its axis for the drive wire to pass through. The stud of the guide bolt passes through the slot and is threadedly connected to the guide nut. The axis of the guide bolt is perpendicular to and coplanar with the slot. The guide nut is used to adjust the position of the guide bolt on the slot.

[0036] The control module is electrically connected to the lead screw motors of the N force-applying units and the pressure sensors of the N tension detection units, respectively, and is used to control the operation of the lead screw motors of the N force-applying units and read the sensing data of the pressure sensors of the N tension detection units.

[0037] As a further optimization of the flexible arm drive wire tension detection device of the present invention, the pressure sensor adopts a strain gauge pressure sensor of model RML340.

[0038] As a further optimization of the flexible arm drive wire tension detection device of the present invention, a Bowden tube for protecting the drive wire is provided between the end of the N channels of the transition plate away from the fixed plate and the guide nut of the corresponding tension detection unit.

[0039] As a further optimization of the flexible arm drive wire tension detection device of the present invention, the Bowden tube is made of polytetrafluoroethylene.

[0040] As a further optimization of the flexible arm drive wire tension detection device of the present invention, the drive wire locking device adopts an M6 copper tension head wire locking device.

[0041] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0042] This invention restricts the slippage of the drive wire during the return phase by using a drive wire locker, constrains the drive wire path by using an alignment unit to reduce the impact of off-center load, achieves synchronous acquisition of force data and cycle count by arranging force sensors in series in the force link, and provides dust protection for key mechanisms and sensors by using a mounting box, which facilitates assembly, maintenance and repeatability testing. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0044] Figure 2 This is a schematic diagram of the tension detection unit in this invention;

[0045] Figure 3 This is a cross-sectional view of the structure in which the transition disk and the fixed disk cooperate in this invention.

[0046] Figure 4 This is a schematic diagram of the structure of the centering unit in this invention;

[0047] Figure 5 A schematic diagram of the flexible arm housing type adapted for the flexible arm drive wire tension detection device.

[0048] In the figure, 1-housing, 2-force application unit, 3-tension detection unit, 4-centering unit, 5-fixed plate, 6-transition plate, 7-mounting box, 8-strain gauge of pressure sensor, 9-drive wire locking device, 10-locking stud, 11-slider, 12-adjusting bolt, 13-adjusting nut, 14-adjusting plate, 15-guide bolt, 16-guide nut. Detailed Implementation

[0049] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings:

[0050] This invention can be implemented in many different forms and should not be considered limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully express the scope of the invention to those skilled in the art. In the drawings, components are enlarged for clarity.

[0051] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, and / or parts, these elements, components, and / or parts are not limited by these terms. These terms are merely used to distinguish elements, components, and / or parts from one another. Therefore, the first element, component, and / or part discussed below may be a second element, component, or part without departing from the teachings of this invention.

[0052] In the description of this invention, it should be understood that the terms "horizontal," "vertical," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and should not be construed as limiting this invention; the terms "installation," "connection," "fixing," etc., should be interpreted broadly, for example, they can refer to a fixed connection, a detachable connection, or an integral connection, they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components; for those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0053] In the description of this application, unless otherwise expressly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly, for example, as a fixed connection, an integral connection, or a detachable connection; as a mechanical connection or an electrical connection; as a direct connection or an indirect connection through an intermediate medium, or as communication between two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] like Figure 1 As shown, the present invention discloses a flexible arm drive wire tension detection device, including a housing, a force application module, a tension detection module, a guide module and a control module;

[0055] The housing is hollow and has N through holes for introducing the drive wires of the flexible arm to be tested, where N is the number of drive wires of the flexible arm to be tested.

[0056] The force-adding module is housed within the casing and contains N force-adding units;

[0057] The force-applying unit includes a base plate, a first bearing, a second bearing, a first bearing housing, a second bearing housing, a lead screw, a lead screw motor, a slide rail, and a slide table;

[0058] The slide rail is mounted on the base plate; the slide table is mounted on the slide rail and can slide freely along the slide rail, and the slide table is provided with a threaded through hole parallel to the slide rail for cooperating with the lead screw;

[0059] The outer ring of the first bearing is fixed to the substrate by the first bearing seat, and the outer ring of the second bearing is fixed to the substrate by the second bearing seat.

[0060] The two ends of the lead screw are coaxially fixed to the inner rings of the first bearing and the second bearing, respectively, and the lead screw is threadedly connected to the slide table.

[0061] The lead screw motor is on the base plate, and its output shaft is coaxially fixed to one end of the lead screw, which is used to drive the slide table to slide on the slide rail.

[0062] The base plates of the N force-applying units are all fixed inside the housing;

[0063] The tension detection module includes N tension detection units, which are arranged one-to-one on the slides of the N force-applying units;

[0064] like Figure 2 As shown, the tension detection unit includes a mounting box, a pressure sensor, a drive wire locker, a locking stud, a locking nut, a slider, an adjusting bolt, and an adjusting nut.

[0065] The mounting box is a hollow cuboid, comprising an upper plate, a lower plate, and first to fourth side plates connected end to end. The first side plate has a through hole in its center for the drive wire locking device to pass through, and the third side plate has a through hole in its center for installing the adjusting nut. The inner walls of the upper and lower plates are respectively provided with a first sliding groove and a second sliding groove for cooperating with the slider. The first sliding groove and the second sliding groove are both parallel to the axis of the through hole in the center of the first side plate.

[0066] The slider is installed in the first slide groove and the second slide groove, and can slide freely in the mounting box along the first slide groove and the second slide groove. The slider is provided with a mounting hole for fixing the drive wire locker. The mounting hole and the through hole in the center of the first side plate are coaxial.

[0067] The pressure sensor is a strain gauge pressure sensor, with a through hole in the center of the strain gauge for the locking stud to pass through. The strain gauge of the pressure sensor is fixed to the outer wall of the first side plate by bolts. The through hole in the center of the strain gauge of the pressure sensor and the through hole in the center of the first side plate are coaxial.

[0068] The locking stud is a hollow stud with openings at both ends; the drive wire lock is fixed in the mounting hole of the slider and is used to lock or release the drive wire connected therein, with one end near the first side plate being coaxially connected to one end of the locking stud; the other end of the locking stud passes through the through hole in the center of the first side plate and the through hole in the center of the strain gauge of the pressure sensor in sequence, and is then threadedly connected to the locking nut, so that the strain gauge of the pressure sensor and the drive wire lock are fixedly connected.

[0069] The adjusting nut is fixed in the through hole in the center of the third side plate; the adjusting bolt and the adjusting nut are threadedly connected, and the stud of the adjusting bolt passes through the adjusting nut and extends into the installation and abuts against the end of the drive wire lock that is away from the first side plate, which is used to adjust the initial stress of the strain gauge of the pressure sensor.

[0070] The lower plate of the mounting box is fixed on the slide table of the force-applying unit corresponding to its tension detection unit, and the axis of the drive wire lock is parallel to the slide rail of the force-applying unit corresponding to its tension detection unit.

[0071] The guiding module includes a fixed disk, a transition disk, and N centering units;

[0072] The fixing plate is used to fix one end of the shell of the flexible arm to be tested, and N through holes are evenly arranged on it in the circumferential direction, corresponding one-to-one with the drive wire of the flexible arm.

[0073] One end of the transition disk is fixedly connected to the fixed disk, and the other end is fixedly connected to the housing. It contains N channels for guiding the dispersion of the drive wires, such as... Figure 3 As shown, one end of each of the N channels corresponds to one of the N through holes on the fixed plate, and the other end corresponds to one of the N through holes on the housing.

[0074] The N centering units are arranged one-to-one on the slides of the N force-applying units, and are used to connect the drive wires passing through the N channels of the transition plate to the N tension detection units one-to-one.

[0075] like Figure 4 As shown, the centering unit includes an adjusting plate, a guide bolt, and a guide nut. The adjusting plate is fixed to the slide of the force-applying unit corresponding to its centering unit, and has a strip-shaped through groove for engaging with the stud of the guide bolt. The strip-shaped through groove is perpendicular to and coplanar with the axis of the drive wire locking device of the tension detection unit corresponding to its centering unit. The guide bolt has a through hole along its axis for the drive wire to pass through. The stud of the guide bolt passes through the strip-shaped through groove and is threadedly connected to the guide nut. The axis of the guide bolt is perpendicular to and coplanar with the strip-shaped through groove. The guide nut is used to adjust the position of the guide bolt on the strip-shaped through groove.

[0076] The control module is electrically connected to the lead screw motors of the N force-applying units and the pressure sensors of the N tension detection units, respectively, and is used to control the operation of the lead screw motors of the N force-applying units and read the sensing data of the pressure sensors of the N tension detection units.

[0077] The pressure sensor is preferably a strain gauge pressure sensor of model RML340, and the drive wire locking device is preferably an M6 copper tension head wire locking device.

[0078] A Bowden tube for protecting the drive wire can also be provided between the end of the N channels of the transition plate away from the fixed plate and the guide nut of the corresponding tension detection unit. The Bowden tube is preferably made of polytetrafluoroethylene.

[0079] The following example illustrates the use of this invention by measuring a flexible arm with three drive wires, where N is 3:

[0080] like Figure 5 As shown, the relevant components of the flexible arm under test are fixed to the fixed plate with set screws. The three drive wires of the flexible arm under test pass through the three through holes of the transition plate and are connected to the through holes of the guide bolts of the three centering units, and then connected to the corresponding tension detection units. When connected to the tension detection units, the locking studs of the tension detection units are inserted into the drive wire lockers and locked. The centering units are adjusted to make the drive wires connected to the tension detection units and the drive wire lockers coaxial.

[0081] Then, by adjusting the adjusting nut, the initial stress of the pressure sensor is made to be 0. After that, the tension can be applied to the drive wire by driving the lead screw motor of the corresponding force-applying unit, and the tension value can be obtained by reading the data from the pressure sensor.

[0082] During long-term experiments or when switching between flexible arms of different specifications, the transition and fixing plates can be disassembled and replaced; the installation and testing of the arm body can be completed by selecting a transition and fixing plate that is compatible with the size of the flexible arm housing.

[0083] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0084] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flexible arm driven wire tension detection device, characterized in that, It includes a housing, a force-applying module, a tension detection module, a guiding module, and a control module; The housing is hollow and has N through holes for introducing the drive wires of the flexible arm to be tested, where N is the number of drive wires of the flexible arm to be tested. The force-adding module is housed within the casing and contains N force-adding units; The force-applying unit includes a base plate, a first bearing, a second bearing, a first bearing housing, a second bearing housing, a lead screw, a lead screw motor, a slide rail, and a slide table; The slide rail is mounted on the base plate; the slide table is mounted on the slide rail and can slide freely along the slide rail, and the slide table is provided with a threaded through hole parallel to the slide rail for cooperating with the lead screw; The outer ring of the first bearing is fixed to the substrate by the first bearing seat, and the outer ring of the second bearing is fixed to the substrate by the second bearing seat. The two ends of the lead screw are coaxially fixed to the inner rings of the first bearing and the second bearing, respectively, and the lead screw is threadedly connected to the slide table. The lead screw motor is on the base plate, and its output shaft is coaxially fixed to one end of the lead screw, which is used to drive the slide table to slide on the slide rail. The base plates of the N force-applying units are all fixed inside the housing; The tension detection module includes N tension detection units, which are arranged one-to-one on the slides of the N force-applying units; The tension detection unit includes a mounting box, a pressure sensor, a drive wire locker, a locking stud, a locking nut, a slider, an adjusting bolt, and an adjusting nut. The mounting box is a hollow cuboid, comprising an upper plate, a lower plate, and first to fourth side plates connected end to end. The first side plate has a through hole in its center for the drive wire locking device to pass through, and the third side plate has a through hole in its center for installing the adjusting nut. The inner walls of the upper and lower plates are respectively provided with a first sliding groove and a second sliding groove for cooperating with the slider. The first sliding groove and the second sliding groove are both parallel to the axis of the through hole in the center of the first side plate. The slider is installed in the first slide groove and the second slide groove, and can slide freely in the mounting box along the first slide groove and the second slide groove. The slider is provided with a mounting hole for fixing the drive wire locker. The mounting hole and the through hole in the center of the first side plate are coaxial. The pressure sensor is a strain gauge pressure sensor, with a through hole in the center of the strain gauge for the locking stud to pass through. The strain gauge of the pressure sensor is fixed to the outer wall of the first side plate by bolts. The through hole in the center of the strain gauge of the pressure sensor and the through hole in the center of the first side plate are coaxial. The locking stud is a hollow stud with openings at both ends; the drive wire lock is fixed in the mounting hole of the slider and is used to lock or release the drive wire connected therein, with one end near the first side plate being coaxially connected to one end of the locking stud; the other end of the locking stud passes through the through hole in the center of the first side plate and the through hole in the center of the strain gauge of the pressure sensor in sequence, and is then threadedly connected to the locking nut, so that the strain gauge of the pressure sensor and the drive wire lock are fixedly connected. The adjusting nut is fixed in the through hole in the center of the third side plate; the adjusting bolt and the adjusting nut are threadedly connected, and the stud of the adjusting bolt passes through the adjusting nut and extends into the installation and abuts against the end of the drive wire lock that is away from the first side plate, which is used to adjust the initial stress of the strain gauge of the pressure sensor. The lower plate of the mounting box is fixed on the slide table of the force-applying unit corresponding to its tension detection unit, and the axis of the drive wire lock is parallel to the slide rail of the force-applying unit corresponding to its tension detection unit. The guiding module includes a fixed disk, a transition disk, and N centering units; The fixing plate is used to fix one end of the shell of the flexible arm to be tested, and N through holes are evenly arranged on it in the circumferential direction, corresponding one-to-one with the drive wire of the flexible arm. One end of the transition disk is fixedly connected to the fixed disk, and the other end is fixedly connected to the housing. It has N channels for guiding the dispersion of the drive wire. One end of each of the N channels corresponds to one of the N through holes on the fixed disk, and the other end corresponds to one of the N through holes on the housing. The N centering units are arranged one-to-one on the slides of the N force-applying units, and are used to connect the drive wires passing through the N channels of the transition plate to the N tension detection units one-to-one. The centering unit includes an adjusting plate, a guide bolt, and a guide nut. The adjusting plate is fixed to the slide of the force-applying unit corresponding to its centering unit and has a slot for engaging with the stud of the guide bolt. The slot is perpendicular to and coplanar with the axis of the drive wire locking device of the tension detection unit corresponding to its centering unit. The guide bolt has a through hole along its axis for the drive wire to pass through. The stud of the guide bolt passes through the slot and is threadedly connected to the guide nut. The axis of the guide bolt is perpendicular to and coplanar with the slot. The guide nut is used to adjust the position of the guide bolt on the slot. The control module is electrically connected to the lead screw motors of the N force-applying units and the pressure sensors of the N tension detection units, respectively, and is used to control the operation of the lead screw motors of the N force-applying units and read the sensing data of the pressure sensors of the N tension detection units.

2. The flexible arm drive wire tension detection device according to claim 1, characterized in that, The pressure sensor is a strain gauge pressure sensor of model RML340.

3. The flexible arm drive wire tension detection device according to claim 1, characterized in that, Bowden tubes for protecting the drive wire are provided between the end of each of the N channels of the transition plate furthest from the fixed plate and the guide nut of the corresponding tension detection unit.

4. The flexible arm drive wire tension detection device according to claim 3, characterized in that, The Bowden tube is made of polytetrafluoroethylene.

5. The flexible arm drive wire tension detection device according to claim 1, characterized in that, The drive wire locking device uses an M6 copper tension head wire locking device.

Images