Fault monitoring system and method for adaptive flexible gripper

Abstract

The application discloses a fault monitoring system and method for adaptive flexible gripper, comprising a workpiece library module, a work station module, a recycling module, a transfer module and a monitoring module; the transfer module comprises a three-dimensional driving mechanism and a flexible gripper; the flexible gripper comprises a supporting part and a clamping part; the supporting part comprises two symmetrical elastic arms and a supporting plate connected with the two elastic arms; the clamping part comprises two symmetrical clamping claws; the clamping claws are cantilever structures, one end of each clamping claw is fixed with the elastic arm, the other end of each clamping claw is provided with a clamping surface, and the two clamping surfaces are oppositely arranged; the monitoring module comprises a camera and a side surface strain gauge arranged on the inner side of the elastic arm. The clamping claws will cause the elastic arms to deform in the process of clamping workpieces and releasing the clamping workpieces; the camera and the side surface strain gauge can detect whether the flexible gripper appears faults when transferring the workpieces between the workpiece library module, the work station module and the recycling module, and manual attendance is not needed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of automation, more particularly, to a fault monitoring system and method for adaptive flexible gripper. BACKGROUND

[0002] Biochemical experiments often have the characteristics of fine operation, clear steps, but tedious process, and it is an urgent demand in the field of biochemistry to realize the automation of the whole experimental process. In the pipeline biochemical experiment, the experimental steps are disassembled into several stations, and the experimental samples and operating devices are switched between the stations through positioning, picking, transferring, installing, disassembling and other operations to complete the whole process automation operation. However, due to the involvement of multi-module and component linkage, in the long-term and continuous experimental process, the cumulative electrical control or mechanical error will cause connection error, at which time the fault needs to be found, located, diagnosed and eliminated in time to ensure the smooth and accurate operation of the biochemical experiment. In the past, the diagnosis and elimination of faults were mainly carried out by manual duty, which greatly consumed manpower and was low in efficiency. SUMMARY

[0003] In view of the above defects or improvement needs of the prior art, the present application provides a fault monitoring system and method for adaptive flexible gripper, which aims to monitor and investigate the fault characteristics that may be caused in the automated biochemical experiment in real time.

[0004] To achieve the above-mentioned purpose, according to one aspect of the present application, a fault monitoring system for adaptive flexible gripper is provided, comprising a workpiece library module, a station module, a recycling module, a transfer module and a monitoring module;

[0005] The transfer module comprises a three-dimensional driving mechanism and a flexible gripper installed on the three-dimensional driving mechanism, the flexible gripper comprises a supporting part and a clamping part, the supporting part comprises two symmetrically arranged elastic arms and a supporting plate connecting the two elastic arms, the clamping part comprises two symmetrically arranged clamping claws, the clamping claws are cantilever structures, the fixed end of the clamping claws is fixed with the elastic arms, the cantilever end is provided with a clamping surface, the two clamping surfaces are oppositely arranged, and the three-dimensional driving mechanism drives the flexible gripper to transfer workpieces between the workpiece library module, the station module and the recycling module in turn;

[0006] The monitoring module comprises cameras arranged in the workpiece library module, the station module and the recycling module respectively, one side of the two elastic arms opposite to each other is an inner side, and the monitoring module further comprises a side surface strain gauge arranged on the inner side of the elastic arm.

[0007] Preferably, the monitoring module further comprises a top surface strain gauge located at the top of the elastic arm.

[0008] Preferably, the elastic arm comprises a thin wall, a first fixing block and a second fixing block, the first fixing block and the second fixing block are arranged on the thin wall in a spaced manner, the first fixing block and the second fixing block divide the thin wall into three thin wall plates arranged side by side along the length direction of the thin wall, and the side surface strain gauge and the top surface strain gauge are fixed on the inner side and the top of the same thin wall plate respectively.

[0009] Preferably, the side surface strain gauge and the top surface strain gauge are both thin film strain gauges, and the geometric specification is double-bridge type.

[0010] Preferably, the system further comprises a positioning module, a judgment module, a diagnosis module and a processing module.

[0011] The positioning module acquires the rotation angle of the flexible gripper in the horizontal direction to determine the current operation of the flexible gripper, or the positioning module simultaneously acquires the rotation angle of the flexible gripper in the horizontal direction and the distance change in the vertical direction to determine the current operation of the flexible gripper.

[0012] The judgment module acquires the shooting result of the camera, the number change of the side surface strain gauge and the top surface strain gauge under the current operation, judges whether a fault occurs, and outputs a diagnosis signal to the diagnosis module if a fault occurs.

[0013] The diagnosis module receives the diagnosis signal, determines the fault type in combination with the shooting result of the camera, the number change of the side surface strain gauge and the top surface strain gauge, and outputs a processing signal to the processing module.

[0014] The processing module alarms according to the processing signal, or drives the three-dimensional driving mechanism to move the flexible gripper to the workpiece library module to take the workpiece again, or corrects the spatial position of the three-dimensional driving mechanism.

[0015] The application also proposes a fault monitoring method for an adaptive flexible gripper, which is based on the foregoing system and comprises the following steps:

[0016] The system starts to work and determines the current operation of the flexible gripper.

[0017] Acquire monitoring parameters under the current operation, and judge whether a fault occurs according to the matching condition of the monitoring parameters and the current operation, wherein the monitoring parameters comprise the shooting result of the camera and the number change of the side surface strain gauge:

[0018] If no fault occurs, the system continues to work,

[0019] If a fault occurs, the system suspends operation, acquires a fault table and a fault parameter under current operation, determines a fault category according to matching of the fault parameter and the fault table, and performs fault processing, wherein the fault parameter includes a shooting result of the camera, a change in a reading of the side strain gauge, and a change in a reading of the top strain gauge.

[0020] Preferably, determining the current operation of the flexible gripper specifically includes: acquiring a rotation angle of the flexible gripper in a horizontal direction, or acquiring a rotation angle of the flexible gripper in a horizontal direction and a distance change in a vertical direction to determine the current operation of the flexible gripper; and the current operation includes picking, mounting, dismounting, and recycling.

[0021] Preferably, determining whether a fault occurs according to matching of the monitoring parameter and the current operation includes:

[0022] When the current operation is picking, if the shooting result is that no workpiece is shot in the workpiece library module, and the change in the reading of the side strain gauge is from 0 to maximum and then to 0 or from 0 to maximum, it is determined that no fault occurs, otherwise it is determined that a fault occurs;

[0023] When the current operation is mounting, if the shooting result is that a workpiece is shot in the work station module, it is determined that no fault occurs, otherwise it is determined that a fault occurs;

[0024] When the current operation is dismounting, if the shooting result is that no workpiece is shot in the work station module, and the change in the reading of the side strain gauge is from 0 to maximum and then to 0 or from 0 to maximum, it is determined that no fault occurs, otherwise it is determined that a fault occurs;

[0025] When the current operation is recycling, if the shooting result is that no workpiece is shot in the recycling module, it is determined that no fault occurs, otherwise it is determined that a fault occurs.

[0026] Preferably, determining the fault category according to matching of the fault parameter under the current operation and the fault table includes:

[0027] When the current operation is picking, if the shooting result is that a workpiece is shot in the workpiece library module, and the change in the reading of the side strain gauge is always 0, the fault category is a position fault, and if the shooting result is that no workpiece is shot in the workpiece library module, and the change in the reading of the side strain gauge is from 0 to maximum and then does not decrease to 0, the fault category is a clamping fault;

[0028] When the current operation is installation, the shooting result is that no workpiece is shot in the station module, and the top surface strain gauge number change is always 0, the failure category is drop failure, the shooting result is that no workpiece is shot in the station module, and the side surface strain gauge number change is always 0 or always the maximum value, the failure category is position failure, the shooting result is that no workpiece is shot in the station module, and the side surface strain gauge number change is 0 increasing to the maximum value and then not decreasing to 0, the failure category is clamping failure;

[0029] When the current operation is installation, the shooting result is that no workpiece is shot in the station module, and the top surface strain gauge number change is always 0, the failure category is drop failure, the shooting result is that no workpiece is shot in the station module, and the side surface strain gauge number change is always 0 or always the maximum value, the failure category is position failure, the shooting result is that no workpiece is shot in the station module, and the side surface strain gauge number change is 0 increasing to the maximum value and then not decreasing to 0, the failure category is clamping failure;

[0030] When the current operation is installation, the shooting result is that no workpiece is shot in the station module, and the top surface strain gauge number change is always 0, the failure category is drop failure, the shooting result is that no workpiece is shot in the station module, and the side surface strain gauge number change is always 0 or always the maximum value, the failure category is position failure, the shooting result is that no workpiece is shot in the station module, and the side surface strain gauge number change is 0 increasing to the maximum value and then not decreasing to 0, the failure category is clamping failure;

[0031] Preferably, the fault processing specifically includes:

[0032] For the position failure, the spatial position of the three-dimensional driving mechanism is corrected;

[0033] For the clamping failure, an alarm is given and manual processing is waited for;

[0034] For the drop failure, the three-dimensional driving mechanism drives the flexible gripper to move to the workpiece library module to take the workpiece again.

[0035] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0036] (1) The position of the flexible gripper can be determined by driving the flexible gripper to move by the three-dimensional driving mechanism, and then the current operation of the flexible gripper is determined, and then whether a failure occurs when the flexible gripper transfers the workpiece between the workpiece library module, the station module and the recycling module can be detected by the camera and the side surface strain gauge, without manual attendance, and when a failure occurs, the type of the failure can be diagnosed in time and corresponding fault processing can be performed by acquiring the failure parameters and the failure table;

[0037] (2) The elastic arm is deformed in the process of clamping / unclamping the workpiece, and the camera, the side strain gauge and the top strain gauge can be used to determine whether the workpiece is captured, whether the flexible clamp jaw is successfully opened, and whether the workpiece is clamped, so as to determine the position and type of fault, and then select to alarm or correct or re-take the workpiece, thereby avoiding direct alarm of the fault and increasing manual operation. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a work flow chart of the fault monitoring system of the present application;

[0039] Figure 2 is a structural schematic diagram of the fault monitoring system of the present application;

[0040] Figure 3 is a structural schematic diagram between the flexible clamp jaw and the monitoring module;

[0041] Figure 4 is a structural perspective view of the flexible clamp jaw;

[0042] Figure 5 is a structural parameter and stress analysis principle schematic diagram of the elastic arm;

[0043] Figure 6 is a signal transmission schematic diagram of the fault monitoring system of the present application;

[0044] Figure 7 is a flow schematic diagram of the fault monitoring method of the present application.

[0045] In the figure, 1 is a workpiece library module; 2 is a work station module; 3 is a recycling module; 4 is a transfer module; 41 is a three-dimensional driving mechanism; 42 is a flexible clamp jaw; 421 is a first support plate; 422 is a second support plate; 423 is an elastic arm; 4231 is a thin-walled plate; 4232 is a first fixed block; 4233 is a second fixed block; 424 is a clamping jaw; 425 is a fixed end; 426 is a cantilever end; 427 is a clamping surface; 428 is a clamping groove; 429 is a round corner; 51 is a camera; 52 is a side strain gauge; and 53 is a top strain gauge. DETAILED DESCRIPTION

[0046] In order to make the objectives, technical solutions and advantages of the present application clearer and more comprehensible, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as there is no conflict.

[0047] As Figure 1As shown, the present invention proposes a fault monitoring system for an adaptive flexible gripper 42, including a workpiece library module 1, a workstation module 2, a recycling module 3, a transfer module 4, and a monitoring module.

[0048] like Figure 2 and Figure 3 As shown, the transfer module 4 includes a three-dimensional driving mechanism 41 and a flexible gripper 42 mounted on the three-dimensional driving mechanism 41. The flexible gripper 42 includes a support part and a clamping part. The support part includes two symmetrically arranged elastic arms 423 and a support plate connecting the two elastic arms 423. The clamping part includes two symmetrically arranged clamping claws 424. The clamping claws 424 are cantilever structures. Their fixed ends are fixed to the elastic arms 423. The cantilever ends are provided with clamping surfaces 427. The two clamping surfaces 427 are arranged opposite to each other. The three-dimensional driving mechanism 41 drives the flexible gripper 42 to transfer workpieces between the workpiece storage module 1, the workstation module 2, and the recycling module 3 in sequence.

[0049] The monitoring module includes cameras 51 respectively installed in the workpiece storage module 1, the workstation module 2, and the recycling module 3. The opposite side of the two elastic arms 423 is the inner side. The monitoring module also includes side strain gauges 52 installed on the inner side of the elastic arms 423.

[0050] like Figure 1 As shown, two gripping jaws 424 close / open, enabling two opposing gripping surfaces 427 to clamp / release the workpiece. A three-dimensional drive mechanism 41 drives the flexible gripper 42 to move back and forth between the workpiece storage module 1, the workstation module 2, and the recycling module 3. This allows for the retrieval of workpieces from the workpiece storage module 1 and their sequential installation onto the workstation in the workstation module 2 according to the specified process. After the operation is complete, the workpiece is removed from the workstation and finally transferred to the recycling module 3 for recycling, achieving automated workpiece retrieval, installation, disassembly, and recycling. The camera 51 uses image capture to determine whether a workpiece at each location has been successfully retrieved / installed / disassembled / recycled. It can be positioned horizontally directly below or above each location, or vertically to the side, depending on the monitoring requirements. However, even if the camera 51 captures a workpiece being retrieved from the workpiece storage module 1, it's possible that it may not be gripped by the flexible gripper 42, or the camera 51 may capture a workpiece being disassembled from the workstation module 2 but not entering the flexible gripper 42, etc. During the clamping / unclamping process, the elastic arm 423 deforms. Therefore, the side strain gauge 52 inside the flexible gripper 42 can be used to monitor whether the flexible gripper 42 has successfully opened. This application combines the camera 51 and the side strain gauge 52 inside the flexible gripper 42. Based on the initial judgment made by the camera 51, and further based on the changes in the readings of the side strain gauge 52 during the workpiece clamping and unclamping process, various fault conditions can be more accurately judged, and the automated transfer process of the flexible gripper 42 can be monitored without manual intervention.

[0051] Specifically, the workpiece library module 1 is used to store workpieces, and the workpieces can be placed at equal intervals. After the flexible gripper 42 takes out a workpiece, the next workpiece is moved to the position of the previous workpiece by using a motor or other driving system, so that the flexible gripper 42 can take out the workpiece again. The three-dimensional driving mechanism 41 includes a three-dimensional moving platform and a rotating table, the rotating table is fixed on the three-dimensional moving platform, and the support part of the flexible gripper 42 is fixed on the rotating table. A Cartesian coordinate system is established with the three-dimensional moving platform as the center, and the transfer of the workpiece is more accurate.

[0052] Specifically, the workpiece module 2 can include n workstations, n is a positive integer, and is selected according to the operation of the workpiece. Correspondingly, a camera 51 needs to be arranged under each workstation to monitor each workstation.

[0053] The recycling module 3 includes a protruding tab fixed relative to the center of the three-dimensional moving platform. When the flexible gripper 42 disassembles the workpiece from the workpiece module 2 and transfers to the recycling module 3, the protruding tab limits the workpiece, and then the flexible gripper 42 horizontally exits away from the workpiece, and the workpiece can naturally fall off.

[0054] Further, the monitoring module further includes a top surface strain gauge 53 located at the top of the elastic arm 423. During the process of clamping the workpiece, the top surface strain gauge 53 shows that the number increases from zero to maximum, which indicates that the number change of the top surface strain gauge is normal, otherwise it is abnormal; during the process of loosening the clamping, the number of the top surface strain gauge 53 will decrease from maximum to zero, which indicates that the number change of the top surface strain gauge is normal, otherwise it is abnormal. The number of the top surface strain gauge 53 can be used to judge whether there is a workpiece in the flexible gripper. In some fault conditions, the number change of the side surface strain gauge 52 is abnormal, but it cannot be further judged that which kind of reason leads to the failure. Therefore, on the basis of monitoring the stress change of the flexible gripper 42 in the horizontal direction by the side surface strain gauge 52, the stress change of the flexible gripper 42 in the vertical direction is monitored by the top surface strain gauge 53 to judge whether there is a workpiece in the flexible gripper 42, so that the abnormal condition can be further analyzed and the specific fault condition can be judged.

[0055] Further, as shown in FIG. 6, the flexible gripper 42 includes a flexible arm 423 and a flexible gripper head 422. The flexible arm 423 is connected to the rotating table of the three-dimensional driving mechanism 41, and the flexible gripper head 422 is connected to the end of the flexible arm 423. Figure 4As shown, the support plate in the flexible gripper 42 includes a first support plate 421 and a second support plate 422 arranged in parallel, and two elastic arms 423 connected between the first support plate 421 and the second support plate 422, the elastic arm 423 includes a thin wall, a first fixed block 4232 and a second fixed block 4233, the first fixed block 4232 and the second fixed block 4233 are arranged on the thin wall in a spaced manner, the first fixed block 4232 is arranged on the side close to the first support plate 421, and the second fixed block 4233 is arranged on the side close to the second support plate 422, the first fixed block 4232 and the second fixed block 4233 divide the thin wall into three thin wall plates 4231 arranged side by side along the length direction of the thin wall, and the side strain gauges 52 and the top strain gauges 53 are fixed on the inner side and the top of the same thin wall plate 4231, respectively.

[0056] The clamping jaw 424 is a cantilever structure, the fixed end 425 of the clamping jaw 424 is connected with the second fixed block 4233, and the thickness of the second fixed block 4233 is greater than the thickness of the thin wall plate 4231. The elastic arm 423 is composed of three thin wall plates 4231, and the first fixed block 4232 and the second fixed block 4233 are thicker on the thin wall, the clamping jaw 424 is fixed on the second fixed block 4233, and the deformation at the connection between the second fixed block 4233 and the thin wall plate 4231 is used to drive the clamping jaw 424 to open, so that the workpiece is clamped. The three thin wall plates 4231 in the structure of the present application use the principle of bistable structure, and the three thin wall plates 4231 are deformed by torque, so that the three thin wall plates 4231 are reversibly switched between the two stable equilibrium states of the non-clamping state and the clamping state. The cantilever end 426 of the clamping jaw 424 is provided with a clamping surface 427, and the clamping surfaces 427 of the two clamping jaws 424 are opposite to each other. When clamping, the flexible gripper 42 moves to the workpiece in the non-clamping state, the workpiece contacts the clamping surface 427 to generate a force and transmit it to the elastic arm 423 to bend inwardly and deform, so that the two clamping jaws 424 move away from each other and are in an open state, the workpiece is clamped by the clamping surface 427 of the clamping jaw 424, and the clamping state is achieved to complete clamping. Similarly, when releasing the clamping, the flexible gripper 42 retreats, the workpiece and the clamping jaw 424 generate extrusion force again, and the force is transmitted to the flexible hinge to bend and deform, the clamping jaw 424 is opened, so that the workpiece is released, and the non-clamping state is returned.

[0057] During the opening process of the clamping jaw 424, the thin-walled plate 4231 is thin and easy to produce bending deformation, which is equivalent to a flexible hinge; the first fixed block 4232 and the second fixed block 4233 are thicker than the thin-walled plate 4231 and can be regarded as rigid bodies, so they are equivalent to rigid links; in theoretical analysis, it is idealized to consider only the bending deformation of the thin-walled plate 4231. The stress and strain trends of the three thin-walled plates 4231 are the same, so the side strain gauge 52 and the top strain gauge 53 can be fixed on any one of the thin-walled plates 4231 at the same time. Preferably, they can be fixed on the thin-walled plate 4231 in the middle, because the strain of the thin-walled plate 4231 in the middle is the largest, the sensitivity is also the largest, and the effect is the best when observing the change of the readings of the side strain gauge 52 and the top strain gauge 53.

[0058] In some embodiments, the clamping of the workpiece is realized directly by the friction between the clamping surface 427 of the clamping jaw 424 and the workpiece. During the clamping process, if the reading of the side strain gauge 52 increases from zero to the maximum and remains unchanged, it indicates that the reading change of the side strain gauge 52 is normal, otherwise it is abnormal; during the process of releasing the clamping, if the reading of the side strain gauge 52 decreases from the maximum to zero, it indicates that the reading change of the side strain gauge 52 is normal, otherwise it is abnormal.

[0059] In other embodiments, a clamping groove 428 is formed in the clamping surface 427 of the clamping jaw 424, and the shape of the clamping groove 428 is adapted to the shape of the workpiece, so that the workpiece can be better positioned in the flexible clamping jaw 42, facilitating precise operation between the workpiece library module 1, the work station module 2 and the recycling module 3, and reducing errors. Due to the existence of the clamping groove 428, during the clamping process, if the reading of the side strain gauge 52 increases from zero to the maximum and then decreases to zero, it indicates that the reading change of the side strain gauge 52 is normal; otherwise it is abnormal. During the process of releasing the clamping, if the reading of the side strain gauge 52 increases from zero to the maximum and then decreases to zero, it indicates that the reading change of the side strain gauge 52 is normal; otherwise it is abnormal.

[0060] Further, in the process of clamping and unclamping the workpiece by the flexible jaw 42, the clamping jaw 424 is automatically opened by horizontally approaching or leaving the workpiece, so that the thin-walled plate 4231 of the elastic arm 423 is deformed, thereby switching between the clamped state and the unclamped state. The flexible jaw 42 has no external driving force. In order to make the flexible jaw 42 better complete the repeated clamping and unclamping actions between the modules, a corresponding workpiece groove can be arranged in the workpiece library module 1, and a corresponding work groove can be arranged in the work station module 2. The workpiece can be stored in the workpiece groove in the vertical direction or vertically installed in the work groove. The workpiece is limited in the vertical direction by the workpiece groove and the work groove, so that the flexible jaw 42 can better approach the workpiece in the horizontal direction for clamping or exit to unclamp. In addition, the clamping jaw 424 also has a clamping groove 428 for limiting the workpiece in the vertical direction, so that the clamped workpiece is separated from the workpiece groove, installed in the work groove, and separated from the work groove in the vertical direction, thereby completing the picking, installation and disassembly. The clamped workpiece includes microneedles, glass slides, PCR tubes and the like, and the shapes of the clamping groove 428, the workpiece groove and the work groove are adapted to the shape of the clamped workpiece.

[0061] Further, a fillet 429 is arranged between the clamping surface 427 and the end surface of the cantilever end 426 of the flexible jaw 42. The clamping groove 428 has openings on the clamping surface 427 and the arc surface where the fillet 429 is located. During clamping and unclamping, the fillet 429 can make the clamping jaw 424 better open under force when the workpiece enters and exits the clamping groove 428. The openings facilitate clamping and releasing of the workpiece.

[0062] Further, the thickness of the thin-walled plate 4231 is h, and 0.1mm≤h≤1mm. Since the flexible jaw 42 of the present application is used to clamp precise devices such as microneedles, glass slides, PCR tubes and the like used in the biochemical field, the deformation of the thin-walled plate 4231 within this thickness range can meet the clamping requirements and clamping accuracy of such precise devices.

[0063] Preferably, the side strain gauge 52 and the top strain gauge 53 are both thin-film strain gauges. Since the thickness of the thin-walled plate 4231 is within 0.1mm-1mm, the strain position of the thin-walled plate 4231 is very small during the opening process of the flexible jaw 42. The existence of the base material and the adhesive in the commonly used foil strain gauge makes it too thick, which affects its sensing characteristics when applied to small size structures. Therefore, using thin-film strain gauges on the side and top of the thin-walled plate 4231 can better measure the bending deformation of the thin-walled plate 4231.

[0064] Preferably, since the system of the present application is applied in room temperature without large temperature difference and harsh temperature environment, the side strain gauge 52 and the top strain gauge 53 select constantan material as the strain base, which can effectively reduce the cost.

[0065] Preferably, since the thin-walled plate 4231 of the present application is thin, the thin-walled plate 4231 produces bending deformation when the flexible jaw 42 is opened, which is a typical bending beam, therefore, the geometric specifications of the side strain gauges 52 and the top strain gauges 53 can adopt a double-bridge type to better measure the deformation of the thin-walled plate 4231.

[0066] Further, referring to Figure 5 , Figure 5 Fig. (a) is a schematic diagram of force analysis when the flexible jaw 42 is transformed from the clamping state to the unclamping state, Figure 5 Fig. (b) shows the parameters of the thin-walled plate 4231, and the structural parameters of the elastic arm 423 satisfy the following conditions:

[0067]

[0068] wherein L is the effective arm, l is half of the length of the elastic arm 423, b is the width of the thin-walled plate 4231, R is the rotation radius of the clamping end relative to the torsion center of the thin-walled plate 4231, w is the displacement of the clamping end relative to the initial state when the clamping end is in the clamping state, E is the elastic modulus of the thin-walled material, and F is the force of the clamping end on the precision device.

[0069] Specifically, the torque M that makes the thin-walled plate 4231 produce bending deformation is M = FL, wherein F is the force when the workpiece is taken, and the direction is affected by the circular arc geometric parameters; therefore, the maximum stress σ of the thin-walled plate 4231 can be calculated as follows: max , and the rotation angle θ is:

[0070]

[0071] wherein E is the elastic modulus of the thin-walled material, W is the bending modulus of the thin-walled plate section, / is the inertia moment of the thin-walled plate section, b is the width of the thin-walled plate, h is the thickness of the thin-walled plate, and l is half of the length of the elastic arm.

[0072]

[0073] Finally, the rotation angle is equivalent to the displacement w of the clamping end relative to the initial state when the clamping end is in the clamping state, which is:

[0074]

[0075] wherein R is the rotation radius of the clamping end relative to the torsion center of the thin-walled plate.

[0076] Combining the above formula, the structural parameters of the elastic arm satisfy the following conditions:

[0077]

[0078] In the calculation, the displacement w of the clamping end in the clamping state relative to the initial state, the elastic modulus E of the thin-walled material, and the force F of the clamping end on the precision device can be determined according to the clamping requirements and the material, the structural parameter relationship of the elastic arm is obtained, and the best parameters are selected by using simulation analysis.

[0079] Further, the thickness of the second fixed block 4233 is h', and h' / h>3. In order to ensure that the first fixed block 4232 and the second fixed block 4233 can be regarded as rigid bodies during deformation, and the deformation mainly occurs on the thin-walled plate 4231. In order to facilitate processing, the first fixed block 4232 and the second fixed block 4233 can be integrally formed.

[0080] Optionally, the flexible clamping jaw 42 can be integrally formed with the support part and the clamping part, or the support part and the clamping part can be detachably connected, so that different shapes of the clamping part can be switched according to different clamping objects and application scenarios.

[0081] Further, as shown in Figure 6 The system further comprises a positioning module, a judgment module, a diagnosis module and a processing module;

[0082] The positioning module obtains the rotation angle of the flexible clamping jaw 42 in the horizontal direction to determine the current operation of the flexible clamping jaw 42, or the positioning module simultaneously obtains the rotation angle of the flexible clamping jaw 42 in the horizontal direction and the distance change in the vertical direction to determine the current operation of the flexible clamping jaw 42;

[0083] The judgment module obtains the shooting result of the camera 51, the indication change of the side strain gauge 52 and the top strain gauge 53 under the current operation, judges whether a fault occurs, and outputs a diagnosis signal to the diagnosis module if a fault occurs;

[0084] The diagnosis module determines the fault type according to the diagnosis signal and outputs a processing signal to the processing module;

[0085] The processing module alarms according to the processing signal, or drives the three-dimensional driving mechanism 41 to drive the flexible clamping jaw 42 to move to the workpiece library module 1 to take the workpiece again, or corrects the spatial position of the three-dimensional driving mechanism 41.

[0086] The application also proposes a fault monitoring method for an adaptive flexible clamping jaw, which is based on the foregoing fault monitoring system, and the method comprises:

[0087] S1, the system starts working and determines the current operation of the flexible clamping jaw 42;

[0088] S2, obtaining monitoring parameters under the current operation, judging whether a fault occurs according to the matching of the monitoring parameters and the current operation, the monitoring parameters comprising the shooting result of the camera, the indication change of the side strain gauge 52:

[0089] If no fault occurs, the system continues to work;

[0090] If a fault occurs, the system suspends work, acquires the fault table and the fault parameters under the current operation, determines the fault category according to the matching condition of the fault parameters under the current operation and the fault table, and performs fault processing. The fault parameters include the shooting result of the camera, the indication change of the side strain gauge 52, and the indication change of the top strain gauge 53.

[0091] Further, the determination of the current operation of the flexible gripper 42 in S1 specifically includes: acquiring the rotation angle of the flexible gripper 42 in the horizontal direction, or acquiring the rotation angle of the flexible gripper 42 in the horizontal direction and the distance change in the vertical direction, to determine the current operation of the flexible gripper 42; the current operation includes: picking, installing, dismounting, and recycling.

[0092] Specifically, as shown in Figure 1 and Figure 2 , during the system operation, the four steps of picking, installing, dismounting, and recycling are performed in sequence, and a Cartesian coordinate system is established with the three-dimensional moving platform as the center when the workpiece is transferred. For example, when the flexible gripper 42 is located in the workpiece library module 1, the rotation angle of the flexible gripper 42 on the three-dimensional driving mechanism 41 is set to 0°, at the work station module 2, the rotation angle of the flexible gripper 42 is set to 90° (assuming that there is only one work station in the work station module 2), and at the recycling module 3, the rotation angle of the flexible gripper 42 is set to 180°. As can be seen, the rotation angle of the flexible gripper 42 is related to the positions of the modules. When the positions of the workpiece library module 1, the positions of the work stations in the work station module 2, and the position of the recycling module 3 are fixed, the positioning module can accurately determine whether the flexible gripper 42 is located in the workpiece library module 1, in a certain work station in the work station module 2, or in the recycling module 3 according to the rotation angle of the flexible gripper 42. When it is determined that the flexible gripper 42 is located in the workpiece library module 1, it can be determined that the current operation of the flexible gripper 42 is picking, and when it is determined that the flexible gripper 42 is located in the recycling module 3, it can be determined that the current operation of the flexible gripper 42 is recycling. In these two cases, the current operation of the flexible gripper 42 only needs to acquire the rotation angle in the horizontal direction.

[0093] Since the installation and dismounting of the workpiece are performed at the station module 2, only the rotation angle of the flexible gripper 42 can determine that the flexible gripper 42 is located at the station module 2, and cannot further determine the current operation of the flexible gripper 42. Therefore, the distance change in the vertical direction also needs to be obtained: when installing, the flexible gripper 42 first brings the workpiece to be located directly below or above the station, and then is lifted or lowered in the vertical direction, so as to install the workpiece in the station; when dismounting, the flexible gripper 42 directly approaches the workpiece in the station in the horizontal direction to clamp the workpiece, and then is lifted or lowered in the vertical direction, so as to dismount the workpiece from the station. As can be seen, the flexible gripper 42 first moves in the vertical direction when installing and first moves in the horizontal direction when dismounting, so that the current operation of the flexible gripper 42 can be determined to be installation or dismounting by combining the rotation angle in the horizontal direction and the distance change in the vertical direction.

[0094] Further, in S2, whether a fault occurs is determined according to the matching of the monitoring parameter and the current operation, including:

[0095] When the current operation is taking, if the shooting result is that no workpiece is shot in the workpiece library module 1, the change of the indication of the side strain gauge 52 is from 0 to maximum and then to 0 again or from 0 to maximum, it is determined that no fault occurs, otherwise it is determined that a fault occurs;

[0096] When the current operation is installing, if the shooting result is that a workpiece is shot in the station module 2, it is determined that no fault occurs, otherwise it is determined that a fault occurs;

[0097] When the current operation is dismounting, if the shooting result is that no workpiece is shot in the station module 2, the change of the indication of the side strain gauge 52 is from 0 to maximum and then to 0 again or from 0 to maximum, it is determined that no fault occurs, otherwise it is determined that a fault occurs;

[0098] When the current operation is recycling, if the shooting result is that no workpiece is shot in the recycling module 3, it is determined that no fault occurs, otherwise it is determined that a fault occurs.

[0099] Table 1 is a successful matching table of the monitoring parameter and the current operation. If the successful matching is achieved, it indicates that the current operation is successfully performed without fault, otherwise it is considered that a fault occurs.

[0100] Table 1: Successful matching table of monitoring parameter and current operation

[0101]

[0102] Specifically, the camera 51 at each module can take a photo when the flexible gripper 42 performs an operation or after the operation is completed to monitor whether the workpiece is successfully picked up / installed / dismantled / recycled. If yes, it is determined that no fault occurs, otherwise, it is determined that a fault occurs.

[0103] When picking up, if the camera 51 does not capture the workpiece in the workpiece library module 1, and the clamping surface 427 is provided with a clamping groove 428, the side strain gauge 52 shows a change from 0 to maximum and then to 0, indicating that the workpiece is successfully picked up. Or, if the clamping surface 427 is not provided with a clamping groove 428, the side strain gauge 52 shows a change from 0 to maximum, indicating that the workpiece is successfully picked up. Otherwise, it is considered that a fault occurs, and a diagnostic signal is output to the diagnostic module.

[0104] When installing, if the camera 51 captures the workpiece in the work station module 2, it is directly considered that the installation is successful, otherwise, it is considered that a fault occurs, and a diagnostic signal is output to the diagnostic module.

[0105] When dismantling, if the camera 51 does not capture the workpiece in the work station module 2, and the clamping surface 427 is provided with a clamping groove 428, the side strain gauge 52 shows a change from 0 to maximum and then to 0, indicating that the workpiece is successfully dismantled. Or, if the clamping surface 427 is not provided with a clamping groove 428, the side strain gauge 52 shows a change from 0 to maximum, indicating that the workpiece is successfully dismantled. Otherwise, it is considered that a fault occurs, and a diagnostic signal is output to the diagnostic module.

[0106] When recycling, if the camera 51 does not capture the workpiece in the flexible gripper 42 at the recycling module 33, it is directly considered that the installation is successful, otherwise, it is considered that a fault occurs, and a diagnostic signal is output to the diagnostic module.

[0107] When the diagnostic module receives the diagnostic signal, it is considered that the current operation has a fault. At this time, the diagnostic module can determine the fault type according to the camera 51 shooting result, the side strain gauge 52 and the top strain gauge 53 under the current operation, and output a corresponding processing signal to the processing module. The processing signal includes three types: an alarm signal, a signal for driving the flexible gripper 42 to the workpiece library module 1 to pick up the workpiece again, and a signal for correcting the spatial position of the three-dimensional driving mechanism 41.

[0108] Further, referring to Table 2, the fault type is determined according to the matching of the fault parameters under the current operation and the fault table to perform corresponding fault processing. The determination of the fault type includes:

[0109] When the current operation is picking, the shooting result is that the workpiece is shot in the workpiece library module, and the reading of the side strain gauge 52 is constantly 0, so the fault type is position fault, the shooting result is that the workpiece is not shot in the workpiece library module, and the reading of the side strain gauge 52 is increased from 0 to the maximum and then is not decreased to 0, so the fault type is clamping fault;

[0110] When the current operation is installing, the shooting result is that the workpiece is not shot in the work station module 2, and the reading of the top strain gauge 53 is constantly 0, so the fault type is dropping fault, the shooting result is that the workpiece is not shot in the work station module 2, and the reading of the side strain gauge 52 is constantly 0 or the maximum, so the fault type is position fault, the shooting result is that the workpiece is not shot in the work station module 2, and the reading of the side strain gauge 52 is increased from 0 to the maximum and then is not decreased to 0, so the fault type is clamping fault;

[0111] When the current operation is picking, the shooting result is that the workpiece is shot in the workpiece library module, and the reading of the side strain gauge 52 is constantly 0, so the fault type is position fault, the shooting result is that the workpiece is not shot in the workpiece library module, and the reading of the side strain gauge 52 is increased from 0 to the maximum and then is not decreased to 0, so the fault type is clamping fault;

[0112] When the current operation is picking, the shooting result is that the workpiece is shot in the workpiece library module, and the reading of the side strain gauge 52 is constantly 0, so the fault type is position fault, the shooting result is that the workpiece is not shot in the workpiece library module, and the reading of the side strain gauge 52 is increased from 0 to the maximum and then is not decreased to 0, so the fault type is clamping fault;

[0113] Further, the fault processing specifically includes:

[0114] For the position fault, the spatial position of the three-dimensional driving mechanism 41 is corrected;

[0115] For the clamping fault, an alarm is given and manual processing is waited;

[0116] For the dropping fault, the three-dimensional driving mechanism 41 drives the flexible gripper 42 to move to the workpiece library module to pick the workpiece again.

[0117] Table 2 Fault type and corresponding fault processing table

[0118]

[0119]

[0120] Specifically, when taking out the workpiece, if the clamping surface 427 is provided with the clamping groove 428, there are two types of faults: the camera 51 still captures the workpiece in the workpiece library module 1, and the indication of the side surface strain gauge 52 is always 0, which indicates that the fault type is a position fault, i.e., the flexible clamping jaw 42 is mispositioned, and the corresponding processing signal is to correct the spatial position of the three-dimensional driving mechanism 41; the camera 51 does not capture the workpiece in the workpiece library module 1, and the indication of the side surface strain gauge 52 changes from 0 to the maximum and then does not decrease to 0, which indicates that the fault type is a clamping fault, i.e., the workpiece is not clamped at the clamping groove 428 of the flexible clamping jaw 42, and the corresponding processing signal is an alarm signal, waiting for manual processing.

[0121] If the clamping surface 427 is not provided with the clamping groove 428, there is one type of fault: the camera 51 still captures the workpiece in the workpiece library module 1, and the indication of the side surface strain gauge 52 is always 0, which indicates that the fault type is a position fault, i.e., the flexible clamping jaw 42 is mispositioned, and the corresponding processing signal is to correct the spatial position of the three-dimensional driving mechanism 41.

[0122] When installing the workpiece, if the clamping surface 427 is provided with the clamping groove 428, there are three types of faults: the camera 51 does not capture the workpiece at the work station, and the indication of the top surface strain gauge 53 is always 0, which indicates that the fault type is a falling fault, i.e., the workpiece falls off, and the corresponding processing signal is to make the three-dimensional driving mechanism 41 drive the flexible clamping jaw 42 to move to the workpiece library module 1 to take out the workpiece again; the camera 51 does not capture the workpiece at the work station, and the indication of the side surface strain gauge 52 is always 0, which indicates that the fault type is a position fault, i.e., the flexible clamping jaw 42 is mispositioned, and the corresponding processing signal is to correct the spatial position of the three-dimensional driving mechanism 41; the camera 51 does not capture the workpiece at the work station, and the indication of the side surface strain gauge 52 changes from 0 to the maximum and then does not decrease to 0, which indicates that the fault type is a clamping fault, i.e., the workpiece is clamped on the flexible clamping jaw 42, and the corresponding processing signal is an alarm signal, waiting for manual processing.

[0123] If the clamping surface 427 is not provided with the clamping groove 428, there are two types of faults: the camera 51 does not capture the workpiece at the work station, and the indication of the top surface strain gauge 53 is always 0, which indicates that the fault type is a falling fault, i.e., the workpiece falls off, and the corresponding processing signal is to make the three-dimensional driving mechanism 41 drive the flexible clamping jaw 42 to move to the workpiece library module 1 to take out the workpiece again; the camera 51 still captures the workpiece in the workpiece library module 1, and the indication of the side surface strain gauge 52 is always the maximum value, which indicates that the fault type is a position fault, i.e., the flexible clamping jaw 42 is mispositioned, and the corresponding processing signal is to correct the spatial position of the three-dimensional driving mechanism 41.

[0124] When disassembling, if the clamping surface 427 is provided with the clamping groove 428, there are three types of faults: the camera 51 does not capture the workpiece at the work station, and the reading of the top surface strain gauge 53 is always 0, indicating that the fault type is a falling fault, i.e., the workpiece falls, and the corresponding processing signal is to move the flexible gripper 42 driven by the three-dimensional driving mechanism 41 to the workpiece library module 1 to take the workpiece again; the camera 51 still captures the workpiece at the work station, and the reading of the side surface strain gauge 52 is always 0, indicating that the fault type is a position fault, i.e., the flexible gripper 42 is mispositioned, and the corresponding processing signal is to correct the spatial position of the three-dimensional driving mechanism 41; the camera 51 does not capture the workpiece at the work station, and the reading of the side surface strain gauge 52 changes from 0 to the maximum and then does not decrease to 0, indicating that the fault type is a clamping fault, i.e., the workpiece is not clamped in the clamping groove 428 of the flexible gripper 42, at this time, if the flexible gripper 42 is located at the last work station in the work station module 2, no processing signal needs to be output, and the system can continue to work, otherwise, the corresponding processing signal is an alarm signal, waiting for manual processing.

[0125] When disassembling, if the clamping surface 427 is provided with the clamping groove 428, there are three types of faults: the camera 51 does not capture the workpiece at the work station, and the reading of the top surface strain gauge 53 is always 0, indicating that the fault type is a falling fault, i.e., the workpiece falls, and the corresponding processing signal is to move the flexible gripper 42 driven by the three-dimensional driving mechanism 41 to the workpiece library module 1 to take the workpiece again; the camera 51 does not capture the workpiece at the work station, and the reading of the side surface strain gauge 52 changes from 0 to the maximum and then does not decrease to 0, indicating that the fault type is a clamping fault, i.e., the workpiece is not clamped in the clamping groove 428 of the flexible gripper 42, at this time, if the flexible gripper 42 is located at the last work station in the work station module 2, no processing signal needs to be output, and the system can continue to work, otherwise, the corresponding processing signal is an alarm signal, waiting for manual processing.

[0126] When recycling, if the clamping surface 427 is provided with the clamping groove 428, there is one type of fault: the camera 51 still captures the workpiece in the flexible gripper 42 at the recycling module 3, and the reading of the top surface strain gauge 53 is always positive, indicating that the fault type is a clamping fault, i.e., the workpiece is still on the flexible gripper 42, and the corresponding processing signal is an alarm signal, waiting for manual processing.

[0127] When recycling, if the clamping surface 427 is provided with the clamping groove 428, there is one type of fault: the camera 51 still captures the workpiece in the flexible gripper 42 at the recycling module 3, and the reading of the top surface strain gauge 53 is always 0, indicating that the fault type is a clamping fault, i.e., the workpiece is still on the flexible gripper 42, and the corresponding processing signal is an alarm signal, waiting for manual processing.

[0128] When recycling, if the clamping surface 427 is provided with the clamping groove 428, there is one type of fault: the camera 51 still captures the workpiece in the flexible gripper 42 at the recycling module 3, and the reading of the top surface strain gauge 53 is always positive, indicating that the fault type is a clamping fault, i.e., the workpiece is still on the flexible gripper 42, and the corresponding processing signal is an alarm signal, waiting for manual processing.

[0129] In the working process of the system, the automatic fault monitoring and processing can be realized without manual attendance by determining the current operation of the flexible clamping jaw 42, judging whether a fault occurs, determining the fault type if a fault occurs, and finally processing the fault. Moreover, different fault types can be determined according to the shooting result of the camera 51, the indication change of the side strain gauge 52, and the indication change of the top strain gauge 53 under the current operation, the system can self-correct or re-take the part of the fault for processing, and the fault that cannot be processed can be selected to alarm and wait for manual processing. Compared with the alarm as soon as the fault occurs, the fault monitoring is more automatic, and the manual operation amount can be greatly reduced.

[0130] Those skilled in the art will easily understand that the above description is only the preferred embodiment of the present application, and is not used to limit the present application, and any modification, equivalent replacement, and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A fault monitoring system for adaptive flexible grippers, characterized by, The system comprises a workpiece library module, a work station module, a recycling module, a transfer module and a monitoring module. The transfer module comprises a three-dimensional driving mechanism and a flexible gripper installed on the three-dimensional driving mechanism, the flexible gripper comprises a supporting part and a clamping part, the supporting part comprises two symmetrically arranged elastic arms and a supporting plate connecting the two elastic arms, the clamping part comprises two symmetrically arranged clamping claws, the clamping claws are cantilever structures, the fixed end of the clamping claws is fixed with the elastic arms, the cantilever end is provided with a clamping surface, the two clamping surfaces are oppositely arranged, and the three-dimensional driving mechanism drives the flexible gripper to transfer workpieces between the workpiece library module, the work station module and the recycling module. The monitoring module comprises cameras arranged in the workpiece library module, the work station module and the recycling module respectively, one side of the two elastic arms opposite to each other is an inner side, and the monitoring module further comprises side surface strain gauges arranged on the inner side of the elastic arms.

2. The system of claim 1, wherein, The monitoring module further comprises top surface strain gauges located at the top of the elastic arms.

3. The system of claim 2, wherein, The elastic arm comprises a thin wall, a first fixed block and a second fixed block, the first fixed block and the second fixed block are arranged on the thin wall in a spaced manner, the first fixed block and the second fixed block divide the thin wall into three thin wall plates arranged side by side along the length direction of the thin wall, and the side surface strain gauges and the top surface strain gauges are fixed on the inner side and the top of the same thin wall plate respectively.

4. The system of claim 3, wherein, The side surface strain gauges and the top surface strain gauges are both thin film strain gauges, and the geometric specification is double-bridge type.

5. The system of claim 2, wherein, The system further comprises a positioning module, a judging module, a diagnosing module and a processing module. The positioning module obtains the rotation angle of the flexible gripper in the horizontal direction to determine the current operation of the flexible gripper, or the positioning module simultaneously obtains the rotation angle of the flexible gripper in the horizontal direction and the distance change of the flexible gripper in the vertical direction to determine the current operation of the flexible gripper. The judging module obtains the shooting result of the camera, the number change of the side surface strain gauges and the top surface strain gauges under the current operation, judges whether a fault occurs, and outputs a diagnosis signal to the diagnosing module if a fault occurs. The diagnosing module receives the diagnosis signal, determines the fault type in combination with the shooting result of the camera, the number change of the side surface strain gauges and the top surface strain gauges, and outputs a processing signal to the processing module. The processing module alarms according to the processing signal, or drives the three-dimensional driving mechanism to drive the flexible gripper to move to the workpiece library module to take the workpiece again, or corrects the spatial position of the three-dimensional driving mechanism.

6. A method for failure monitoring of a self-adapting flexible gripper, characterized in that, Based on the system according to any one of claims 2-5, the method comprises: The system starts to work and determines the current operation of the flexible gripper. The monitoring parameters under the current operation are obtained, and whether a fault occurs is judged according to the matching condition of the monitoring parameters and the current operation, the monitoring parameters comprising the shooting result of the camera, the number change of the side surface strain gauges and the top surface strain gauges: If no fault occurs, the system continues to work; If a fault occurs, the system suspends operation, acquires a fault table and a fault parameter under current operation, determines a fault type according to matching of the fault parameter under current operation and the fault table, and performs fault processing, wherein the fault parameter comprises a shooting result of the camera, a change in a reading of the side strain gauge, and a change in a reading of the top strain gauge.

7. The method of claim 6, wherein, The current operation of the flexible gripper is determined by acquiring a rotation angle of the flexible gripper in a horizontal direction, or by acquiring a rotation angle of the flexible gripper in a horizontal direction and a distance change of the flexible gripper in a vertical direction; and the current operation comprises picking, mounting, dismounting, and recycling.

8. The method of claim 7, wherein, According to matching of the monitoring parameter and the current operation, it is determined whether a fault occurs, comprising: when the current operation is picking, if the shooting result is that no workpiece is shot in the workpiece library module, or the change in the reading of the side strain gauge is from 0 to maximum and then to 0, or from 0 to maximum, it is determined that no fault occurs, otherwise, it is determined that a fault occurs; when the current operation is mounting, if the shooting result is that a workpiece is shot in the work station module, it is determined that no fault occurs, otherwise, it is determined that a fault occurs; when the current operation is dismounting, if the shooting result is that no workpiece is shot in the work station module, or the change in the reading of the side strain gauge is from 0 to maximum and then to 0, or from 0 to maximum, it is determined that no fault occurs, otherwise, it is determined that a fault occurs; when the current operation is recycling, if the shooting result is that no workpiece is shot in the recycling module, it is determined that no fault occurs, otherwise, it is determined that a fault occurs.

9. The method of claim 8, wherein, According to matching of the fault parameter under current operation and the fault table, a fault type is determined, comprising: when the current operation is picking, if the shooting result is that a workpiece is shot in the workpiece library module, and the change in the reading of the side strain gauge is always 0, the fault type is a position fault, or if the shooting result is that no workpiece is shot in the workpiece library module, and the change in the reading of the side strain gauge is from 0 to maximum and then does not decrease to 0, the fault type is a clamping fault; when the current operation is mounting, if the shooting result is that no workpiece is shot in the work station module, and the change in the reading of the top strain gauge is always 0, the fault type is a falling fault, or if the shooting result is that no workpiece is shot in the work station module, and the change in the reading of the side strain gauge is always 0 or a maximum value, the fault type is a position fault, or if the shooting result is that no workpiece is shot in the work station module, and the change in the reading of the side strain gauge is from 0 to maximum and then does not decrease to 0, the fault type is a clamping fault; When the current operation is dismounting, the shooting result is that no workpiece is shot in the work station module, the change of the top surface strain gauge is always 0, the fault type is falling fault, the shooting result is that a workpiece is shot in the work station module, the change of the side surface strain gauge is always 0, the fault type is position fault, the shooting result is that no workpiece is shot in the work station module, the change of the side surface strain gauge is from 0 to maximum and then does not decrease to 0, meanwhile the flexible gripper is located in the last work station in the work station module, the fault type is clamping fault; When the current operation is recycling, the shooting result is that the flexible gripper has a workpiece in the recycling module, and the change of the top surface strain gauge is always 0 or always positive, the fault type is clamping fault.

10. The method of claim 9, wherein, The fault processing specifically includes: For the position fault, the spatial position of the three-dimensional driving mechanism is corrected; For the clamping fault, an alarm is given and waits for manual processing; For the falling fault, the three-dimensional driving mechanism drives the flexible gripper to move to the workpiece library module to take the workpiece again.

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