CN112692848A - Flexible pneumatic arm and tail end control system - Google Patents
Flexible pneumatic arm and tail end control system Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J11/00—Manipulators not otherwise provided for
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B10/00—Other methods or instruments for diagnosis, e.g. instruments for taking a cell sample, for biopsy, for vaccination diagnosis; Sex determination; Ovulation-period determination; Throat striking implements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J18/00—Arms
Abstract
The embodiment of the application discloses a flexible pneumatic arm and a tail end control system, which are used for realizing flexible contact with a target point and further reducing contact damage to the target point. The flexible pneumatic arm of the embodiment of the application comprises: a pneumatic arm body and a channel cover; the pneumatic arm body is provided with a plurality of air chambers which are linearly arranged along the pneumatic arm body, and gaps exist between adjacent air chambers; the air chamber is made of flexible materials; the pneumatic arm body or the channel cover is provided with an inflation channel which is communicated with each air chamber; the channel cover is used for being matched with the pneumatic arm body to seal the inflation channel; one end of the pneumatic arm body is provided with an inflation inlet which is communicated with the inflation channel.
Description
Technical Field
The embodiment of the application relates to the technical field of intelligent equipment, in particular to a flexible pneumatic arm and a tail end control system.
Background
In the prior art, in order to avoid infection risk caused by pharyngeal swab collection work to medical personnel, the pharyngeal swab collection work of target personnel can be replaced by manual work through the mechanical arm, and then infection risk caused to medical personnel is avoided.
However, the tail ends of the robot arms are rigid mechanisms, and the tail ends of the robot arms of the rigid mechanisms easily injure the pharynx when collecting swabs of target people.
Disclosure of Invention
The embodiment of the application provides a flexible pneumatic arm and a tail end control system, which are used for realizing flexible contact with a target point and further reducing contact damage to the target point.
The present application provides in a first aspect a flexible pneumatic arm comprising: a pneumatic arm body and a channel cover;
the pneumatic arm body is provided with a plurality of air chambers which are linearly arranged along the pneumatic arm body, and gaps exist between adjacent air chambers; the air chamber is made of flexible materials;
the pneumatic arm body or the channel cover is provided with an inflation channel which is communicated with each air chamber;
the channel cover is used for being matched with the pneumatic arm body to seal the inflation channel;
one end of the pneumatic arm body is provided with an inflation inlet which is communicated with the inflation channel.
Optionally, the material stiffness of the channel cover is greater than the material stiffness of the plenum.
Optionally, the other end of the pneumatic arm body has an adapter for mounting a gripping mechanism.
Optionally, the method further comprises: a restraint tube;
the pneumatic arm body is sleeved in the restraint pipe, and the restraint pipe is used for limiting the inflation and expansion degree of part of or all of the air chambers.
Optionally, a force sensing sensor is also included;
the force sensing sensor is arranged on the channel cover and used for generating a deformation signal based on the deformation quantity of the channel cover.
Optionally, the force sensing sensor is one or more of a fiber grating sensor, a bending sensor, or a pressure sensor.
Optionally, the pneumatic arm body is provided with 12 air chambers, each air chamber has a wall thickness of 1.5 mm, and the pneumatic arm body has a length of 80 mm.
Optionally, the channel cover, the pneumatic arm body, and the plenum are formed by one of a deposition fabrication method, a soft lithography method, a lost wax casting method, or a composite 3D printing method.
A second aspect of the present application provides a tip end control system, comprising: the flexible pneumatic arm, air supply, pneumatic valve and control circuit of claims 1-8; the air source is communicated with the input end of the pneumatic valve, and the output end of the pneumatic valve is communicated with the inflation inlet of the flexible pneumatic arm;
the pneumatic valve is also electrically connected with the control circuit, the control circuit controls the output end of the pneumatic valve to output the gas of the gas source, the gas enters each gas chamber through the inflation channel communicated with the inflation port, and after each gas chamber is inflated, the flexible pneumatic arm bends towards the direction of the channel cover;
the control circuit also controls the output end of the pneumatic valve to lock the gas entering the gas chamber, so that the flexible pneumatic arm keeps bending towards the channel cover;
the control circuit further controls a pressure relief hole of the pneumatic valve to relieve the pressure of the output end of the pneumatic valve, so that the gas of each gas chamber can be recovered to the posture before the flexible pneumatic arm bends towards the channel cover from the pressure relief hole.
Optionally, a force sensing sensor is further mounted on the surface of the flexible pneumatic arm;
the force perception sensor is used for perceiving the deformation quantity of the flexible pneumatic arm to correspondingly generate a deformation signal;
the force sensing sensor is electrically connected with the control circuit, and the control circuit is used for controlling the opening degree of the output end of the pneumatic valve according to the deformation signal so as to control the amount of gas filled into each gas chamber of the flexible pneumatic arm by the gas of the gas source.
According to the technical scheme, the embodiment of the application has the following advantages:
the air chamber of flexible pneumatic arm of the embodiment of this application comprises flexible material, when the inflation inlet of flexible pneumatic arm pours into gas into, the air chamber can take place the inflation, again because there are a plurality of air chambers on the pneumatic arm body and be the straight line and arrange, can crowd each other between the inflation air chamber like this, until the crowded back that accounts for in the clearance between the adjacent air chamber, after the inflation inlet has the gas of continuous filling into the air chamber of flexible pneumatic arm, each air chamber of pneumatic arm can continue to take place the inflation, and there is one side of the air chamber of passageway lid contact to expand obstructed, the air chamber can not realize continuing the inflation, force flexible pneumatic arm to bend towards one side at passageway lid place under the air chamber mutual extrusion of continuous inflation. If control the gas volume that gets into in the flexible pneumatic arm from the inflation inlet, then can effectively control flexible pneumatic arm towards the crooked degree in channel cover one side, if install the flexible pneumatic arm of this application embodiment at the end of arm, then can control the arm and carry the flexible pneumatic arm of this application embodiment and realize the flexible contact to the target point, reduce the contact damage to the target point, especially be fit for being used for medical field to replace artifical pharyngeal swab collection work to target person, when avoiding the infection risk that causes medical personnel, also reduce the injury that causes pharyngeal to target person's pharyngeal child collection during operation.
Drawings
FIG. 1 is a schematic view of an embodiment of a pneumatic arm body of a flexible pneumatic arm according to the present application;
FIG. 2 is a schematic view of an embodiment of a flexible pneumatic arm according to the present application;
FIG. 3 is a left side view of the structure of the embodiment of FIG. 2;
FIG. 4 is a cross-sectional view taken along line A-A of the structure of the embodiment of FIG. 3;
FIG. 5 is a schematic view of one embodiment of a flexible pneumatic arm of the present application performing finite element analysis;
FIG. 6 is a schematic view of one embodiment of a flexible pneumatic arm of the present application performing physical testing;
FIG. 7 is a schematic view of one embodiment of a flexible pneumatic arm of the present application undergoing a stiffness test;
FIG. 8 is a schematic view of one embodiment of a flexible pneumatic arm and constraint tube stiffness test of the present application;
FIG. 9 is a schematic view of one embodiment of a flexible pneumatic arm of the present application performing a repeatability test;
fig. 10 is a schematic view of an embodiment of a data recording table in the force calibration test of the flexible pneumatic arm according to the present application.
Detailed Description
The embodiment of the application provides a flexible pneumatic arm and a tail end control system, and the contact damage to a target point is reduced.
Referring to fig. 1 to 4, an embodiment of a flexible pneumatic arm according to the present application includes: a pneumatic arm body 100 and a channel cover 200. The pneumatic arm body 100 is provided with a plurality of air chambers 110, where the plurality of air chambers 110 are two or more air chambers, the plurality of air chambers are linearly arranged along the pneumatic arm body 100, and a gap 130 exists between adjacent air chambers 110. The gas chamber is made of a flexible material, and the gas chamber 110 made of the flexible material can expand when the pressure of the gas is increased, so that the gas chamber 110 is enlarged to force the gas wall of the gas chamber 110 to generate elastic deformation, and when the pressure of the gas in the gas chamber 110 is reduced, the gas wall of the gas chamber 110 gradually recovers the shape of the original gas chamber under the action of the elastic deformation restoring force. Wherein the pneumatic arm body 100 or the channel cover 200 is provided with an inflation channel 120, the inflation channel 120 communicating with each air cell, the inflation channel being for simultaneously inflating each air cell. The channel cover 200 is used for cooperating with the pneumatic arm body 100 to seal the inflation channel 120; one end of the pneumatic arm body 100 is provided with an inflation port 140, the inflation port 140 is communicated with the inflation channel 120, and the inflation port 140 is used for being connected with an external air source. Just as the gas chamber 110 of the flexible pneumatic arm of the present embodiment is made of a flexible material, when the gas is injected through the gas inlet 140 of the flexible pneumatic arm, the gas reaches each of the air cells 110 of the pneumatic arm body 100 through the inflation channel 120, each air cell 110 is expanded when the gas pressure is increased, the air chamber 110 is enlarged to force the air wall of the air chamber 110 to generate elastic deformation, and because the plurality of air chambers 110 on the pneumatic arm body 100 are arranged in a straight line, when the adjacent air cells 110 are expanded to occupy the gap 130, the expanded air cells 110 are displaced from each other, after the gas filling port 140 is filled with gas continuously into the gas chambers 110 of the flexible pneumatic arms, the respective gas chambers 110 of the pneumatic arms are continuously inflated, the side of the gas cell 110 where the channel cover 200 is in contact will be prevented from expanding and will not allow further expansion, forcing the flexible pneumatic arms to bend towards the side where the channel cover 200 is located under the mutual compression of the expanding gas cells 110. If the amount of gas entering the flexible pneumatic arm from the gas charging port 140 is controlled, the degree of bending of the flexible pneumatic arm toward the side of the channel cover 200 can be effectively controlled; if install the flexible pneumatic arm of this application embodiment at the end of arm, then can control the arm and carry the flexible pneumatic arm of this application embodiment and realize the flexible contact to the target point, reduce the contact damage to the target point, be particularly suitable for being used for medical field to replace artifical pharyngeal swab collection work to target personnel, when avoiding the infection risk that leads to the fact medical personnel, also reduce the injury that leads to the fact pharyngeal when gathering work to target personnel's pharyngeal.
Specifically, the material stiffness of the channel cover 200 should be greater than that of the gas chamber 110, and since the flexible pneumatic arm of the embodiment of the present application is bent toward the channel cover side when the gas chamber 110 is expanded, in order to allow the flexible pneumatic arm to be rapidly restored from the bent state to the normal state when the gas chamber 110 is restored from the expanded state to the normal state, the material stiffness of the channel cover 200 is required to be greater than that of the flexible material of the gas chamber 110, and is preferably an elastic material with a shape memory function.
Further, the other end of the pneumatic arm body 100 has an adapter 160, and the adapter 160 is used for installing a gripping mechanism for automatically gripping the target object. The fitting portion 160 may also be provided with a mounting hole 161, and a target object, such as the pharyngeal swab 400, may be directly mounted and fixed through the mounting hole 161, and the mounting hole 161 may be adapted to mount and fix a holding end of the pharyngeal swab 400, as shown in fig. 2 or fig. 4.
Further, the flexible pneumatic arm of the embodiment of the present application may further include: a restraining tube (not shown). The pneumatic arm body 100 of the flexible pneumatic arm is sleeved in the restraint pipe, and the restraint pipe is used for limiting the inflation and expansion degree of part of the air chambers 110 or all the air chambers 110 on the pneumatic arm body 100, so that the number of the air chambers participating in the flexible pneumatic arm to realize bending is controlled. That is, the constraining tube is made of a hard material and is tubular, and the constraining tube is slidably sleeved outside the pneumatic arm body 100. Before the air chamber on the pneumatic arm body 100 is inflated and expanded, the restraint tube is slid to the air chamber needing to restrain the expansion of the air chamber, then the expansion of the air chamber of the flexible pneumatic arm can be limited through the restraint tube, the control of the number of the air chambers on the pneumatic arm body 100 of the flexible pneumatic arm in the bending process can be achieved, the air chambers restrained by the restraint tube can only be expanded to be in contact with the inner wall of the restraint tube during working due to the restraint of the restraint tube in the inflation and expansion process, further the air chambers can not be expanded any more, and the position of the flexible pneumatic arm can not be bent in any direction. When the linear power source for control is used for controlling the sliding of the constraint tube on the pneumatic arm body 100, the flexible pneumatic arm bending process can be controlled by controlling the sliding of the constraint tube.
Further, the flexible pneumatic arm of the embodiment of the present application may further include a force sensor 300. The force sensing sensor 300 is disposed on the channel cover 200, for example, the force sensing sensor 300 is adhered to a side of the channel cover 200, which is bent when the channel cover 200 works, the force sensing sensor 300 is used for generating a deformation signal based on a deformation amount of the channel cover 200, so as to realize data monitoring of a bending degree of the flexible pneumatic arm, and the force sensing sensor can establish mapping between the bending degree of the flexible pneumatic arm and a corresponding clamping stress, so as to realize monitoring of a clamping stress of the flexible pneumatic arm. In particular, the force sensing sensor of the embodiments of the present application may be one or more of a fiber grating sensor, a bending sensor, or a pressure sensor.
As shown in fig. 1 to 4, the pneumatic arm body of the present embodiment is preferably provided with 12 air chambers, each air chamber has a wall thickness of 1.5 mm, and the length of the pneumatic arm body is 80 mm, which is a preferred size and structure of the flexible pneumatic arm applied to the end of the mechanical arm for holding a pharyngeal swab to a target person for collecting the pharyngeal swab.
Specifically, the channel cover, the pneumatic arm body, the air chamber, and the constraining tube of the embodiments of the present application can be formed by one of deposition fabrication, soft lithography, lost wax casting, or composite 3D printing.
To the flexible pneumatic arm of the embodiments of the present application, the present application also provides a tip control system, including: the flexible pneumatic arm, air supply, pneumatic valve and control circuit described above. The gas source may be a gas supply device for providing a stable gas pressure to a gas pump or a gas tank, etc., and the pneumatic valve is a flexible pneumatic arm for controlling the input and output of gas from a pipe of the gas source, and the pneumatic valve is preferably a proportional valve ITV 1050-312L. The air source is communicated with the input end of the pneumatic valve, and the output end of the pneumatic valve is communicated with the inflation inlet of the flexible pneumatic arm; the pneumatic valve is also electrically connected with a control circuit, the control circuit controls the output end of the pneumatic valve to output the gas of the gas source, the gas enters the inner cavity 111 of each air chamber 110 through the inflation channel 120 communicated with the inflation port 140, and after each air chamber 110 is inflated, the flexible pneumatic arm bends towards the direction of the channel cover 200; the control circuit also controls the output end of the pneumatic valve to lock the gas entering the gas chamber, so that the flexible pneumatic arm keeps the bent posture towards the direction of the channel cover; the control circuit also controls the pressure relief holes of the pneumatic valve to relieve the pressure of the output end of the pneumatic valve, so that the gas in each air chamber escapes from the pressure relief holes, and the flexible pneumatic arm recovers the posture before bending towards the direction of the channel cover.
Further, when the force sensor 300 is installed on the surface of the flexible pneumatic arm, the force sensor 300 is used for sensing the deformation amount of the flexible pneumatic arm to generate a deformation signal correspondingly. The force sensing sensor is electrically connected with the control circuit, and the control circuit is used for controlling the opening degree of the output end of the pneumatic valve according to the deformation signal so as to control the gas quantity of the gas source filled into each gas chamber of the flexible pneumatic arm and further control the bending degree of the flexible pneumatic arm.
It can be seen that the terminal control system of this application embodiment can be according to the signal of sensor 300 is felt to force, correspond the control pneumatic valve through control circuit, and then the crooked degree of control flexible pneumatic arm, can carry the flexible contact of the flexible pneumatic arm realization to the target point of this application embodiment to the control arm, reduce the contact damage to the target point, especially be fit for being used for medical field to replace artifical pharyngeal swab collection work to the target personnel, when avoiding the infection risk that causes medical personnel, also reduce the injury that causes the pharyngeal when gathering work to the pharyngeal of target personnel.
To verify the performance parameters of the flexible pneumatic arm according to the embodiment of the present application, the following tests are performed for verification, please refer to:
the total number of the flexible pneumatic arms is 12 air chambers, the wall thickness of each air chamber is 1.5 mm, the total width of each air chamber in the cross section of each air chamber is 4.5 mm, and the total length of the micro pneumatic mechanical arm is 80 mm, as shown in figure 2.
1. Finite element analysis:
finite element analysis of ABAQUS (DassaultSystem, MA) allows mechanical analysis of complex models to verify the feasibility of the flexible pneumatic arm described above. In simulation, various shore hardnesses are selected for material characteristics to carry out simulation experiments. The material properties in ABAQUS can not be directly input into Shore hardness, and the conversion formula of Shore hardness s to Young modulus E is as follows:
since the material of the air chamber is flexible and the rubber-like material is chosen to be generally incompressible, we set the poisson's ratio to 0.49. The part of the upper surface of the channel cover provided with the flexible pneumatic arm, which is bonded with the air chamber, is made of non-stretchable fiber cloth material, the elastic module is 6.5GPa, and the Poisson ratio is 0.2. The contact between the side walls of the air chamber is arranged to be frictionless. The grid is divided using tetrahedrons, the grid size being 1 mm. Finite element analysis calculations were performed after all settings were completed.
The results of finite element analysis in Abaqus of a flexible pneumatic arm with shore 50 are shown in fig. 5, fig. 5(a) shows deformation of shore 50 under different air pressures, and fig. 5(b) shows a curve of bending angle of the flexible pneumatic arm with air pressure P.
Herein, the bending angle γ is defined as shown in fig. 5(a), and θ is the bending angle of each joint (air cell). The curve of the bending angle at different air pressures is shown in FIG. 5 (b). The positive correlation between the bending angle theta and the air pressure is found from simulation experiments.
Using the linear fit in origin, the linear equation of the relationship between the bending angle θ DEG and the air pressure P kPa is shown as formula (2)
α＝0.02785P+0.65931 (2)
The correlation coefficient R of the straight line fit equation was 0.9846 and the standard deviation S was 0.5172. The correlation coefficient is a statistical index used for reflecting the degree of closeness of correlation between variables. The linear correlation coefficient R is calculated as:
where Cov (P, α) is the covariance of P and α, Var [ P ] is the variance of P, and Var [ α ] is the variance of α.
2. Fabrication of flexible pneumatic arm in actual testing:
the structure of the inner cavity of the air chamber of the flexible pneumatic arm is complex, and the traditional machining mode is difficult to machine. The processing techniques that can be used are deposition manufacturing techniques (SDM), soft lithography, lost wax casting, composite 3D printing techniques. Because the 3D photocuring printer has high resolution, the performance of each printed flexible pneumatic arm has better consistency and repeatability. The 3D photo-curing printer (Objet500 connect 3system, Stratasys, Minnesota, UnitedStates) used in this experiment can print soft gum materials.
The air chamber of the flexible pneumatic arm and the channel cover of the flexible pneumatic arm are glued together using glue after the 3D printing is completed. The pneumatic valve used is a proportional valve ITV 1050-312L. The flexible pneumatic arm with shore 50 hardness was tested and the results are shown in fig. 6, where fig. 6(a) shows the deformation of shore 50 hardness under different air pressures, and fig. 6(b) shows the curve of bending angle versus air pressure, and the gravity direction is perpendicular to the paper surface.
When the air pressure is 0, the bending angle is 0, and the relationship between the bending angle and the air pressure is plotted, so that the bending angle and the air pressure are approximately in direct proportion.
Using the linear fit in origin, a linear equation of the relationship between joint angle θ [ ° ] and air pressure P [ kPa ] is fitted as equation (4).
θ＝0.02915P-0.13307 (4)
The correlation coefficient R of the linear fit equation for the three shore hardness flexible pneumatic arms is 0.99926, and the standard deviation S is 0.11753.
In actual use, the bending degree of the flexible pneumatic arm can be predicted by the formula (4), which is approximately similar to the result of finite element analysis, but has a certain deviation, and the reason for this may be that the 3D printing precision is not enough or the model simulation calculation method needs further research.
3. Rigidity test:
in order to obtain performance parameters of the flexible pneumatic arm, the tail end force of the flexible pneumatic arm is tested, the model of a used dynamometer is SF-50, the measuring range is-50N, and the resolution ratio is 0.01N. One end of the flexible pneumatic arm is fixed on the bracket, the end force of the flexible pneumatic arm starts to become larger gradually along with the increase of the air pressure of the air chamber, and the fingertip force curve is drawn as shown in figure 7.
It is found from fig. 7 that the tip fingertip force of the same flexible pneumatic arm with shore hardness is approximately positively correlated with the air pressure, while the smaller the shore hardness, the larger the fingertip force at the same pressure. The equation for linear fitting the relationship between the terminal force FN and the gas pressure P kPa is (5).
F＝0.000352P-0.0031 (5)
The equations of the relationship between the terminal force F [ N ] and the air pressure P [ kPa ] are respectively fitted by a binomial formula:
F＝3.89×10-7P2+2.55×10-4P+1.42×10-4 (6)
in order to further intuitively know the rigidity of the flexible pneumatic arm, a standard weight is hung at the tail end of the flexible pneumatic arm to perform a bending degree test, and fig. 8(a), (b) and (c) are experimental results of the constraint pipes respectively constraining the air chambers with the number of 0, 4 and 6. From the experimental results in fig. 8, it can be seen that the stiffness of the tip can be significantly changed by changing the number of confinement tubes to the air cells.
4. And (3) testing repeatability precision:
the method is characterized in that 1 mm coordinate paper is attached to a flat wood board, a metal wire with the diameter of about 0.2 mm is fixed at the tail end of a flexible pneumatic arm, a camera is fixed at a position about 20 cm above the coordinate paper, the side face of the flexible pneumatic arm is not in contact with the coordinate paper surface, no friction is guaranteed between the coordinate paper and the flexible pneumatic arm, and the distance between the tail end metal wire and the paper surface is about 2 mm. During testing, the camera is fixed for shooting, the gravity direction is vertical to the paper surface, the influence of gravity on an experimental result is also eliminated, the experimental method is that air pressure is sequentially set to be 50kPa, 0kPa, 50kPa, 100kPa, 150kPa, 200kPa and 250kPa, after each air pressure stays for more than 10 seconds, a shooting button of the camera is pressed, 10 groups of experiments are carried out totally, and finally reading is carried out uniformly. Please refer to the data presentation in fig. 9.
And analyzing the measured repeatability data, drawing the coordinate points of the ten-time measurement data under each air pressure on a coordinate paper, and enclosing all the coordinate points by adopting a minimum circle enclosing method, wherein the radius of a minimum enclosing circle is used as a minimum repetition error. The maximum error of the repeatability of the flexible pneumatic arm end is about +/-0.8 mm when the repeatability is measured at 250 kPa. The flexible pneumatic arm has better control precision.
5. Force perception:
the force sensing system for the tail end contact of the flexible pneumatic arm mainly comprises a sensing module, a circuit processing module, an AD conversion module and a signal processing module. The sensing module is mainly a strain gauge and is responsible for measuring the strain of the flexible pneumatic arm caused by contact force and converting the strain into the change of the resistance value of the strain gauge. The circuit processing module is a bridge + amplification module, and the change of the resistance value is converted into the change of the voltage value through a bridge circuit and is amplified. The AD conversion is to perform AD (analog-digital) conversion on the voltage output by the circuit processing module for the signal processing module to read. The signal processing module is mainly an upper computer, processes the digitized voltage signal, and converts the digitized voltage signal into the force change according to an earlier calibration experiment by using a software program.
6. Force calibration experiment:
because the strain gauge can only detect the strain amount of the flexible pneumatic arm, the real force value cannot be known. Therefore, a corresponding relationship between the force and the strain (voltage) needs to be established through a force calibration experiment, and the magnitude of the force is obtained by calculating the change of the voltage in the application. The force calibration experiment can be used for electrifying the strain gauge circuit and connecting the output end to the positive electrode and the negative electrode of a multimeter pen, an electronic balance with the resolution ratio of 0.01g is arranged below the flexible pneumatic arm and the throat swab, the flexible pneumatic arm is controlled to move through a program, the tail end of the throat swab contacts the electronic balance, the reaction force enables the flexible pneumatic finger to generate bending strain, the readings of the multimeter and the readings on the electronic balance are respectively read, and the recorded data are shown in a table of fig. 10. The relationship between the pressure difference and the force is obtained by linear fitting, and the relationship is written into a program of the signal processing module. Alternative alternatives: the sensing module can be replaced by other flexible sensors, such as a fiber grating sensor, a bending sensor, a pressure sensor and the like, and the AD conversion module can be replaced by a singlechip development board.
The above description of the present application with reference to specific embodiments is not intended to limit the present application to these embodiments. For those skilled in the art to which the present application pertains, several changes and substitutions may be made without departing from the spirit of the present application, and these changes and substitutions should be considered to fall within the scope of the present application.
Claims (10)
1. A flexible pneumatic arm, comprising: a pneumatic arm body and a channel cover;
the pneumatic arm body is provided with a plurality of air chambers which are linearly arranged along the pneumatic arm body, and gaps exist between adjacent air chambers; the air chamber is made of flexible materials;
the pneumatic arm body or the channel cover is provided with an inflation channel which is communicated with each air chamber;
the channel cover is used for being matched with the pneumatic arm body to seal the inflation channel;
one end of the pneumatic arm body is provided with an inflation inlet which is communicated with the inflation channel.
2. The flexible pneumatic arm according to claim 1, wherein the channel cover is of a material stiffness greater than that of the plenum.
3. The flexible pneumatic arm of claim 2, wherein the other end of the pneumatic arm body has an adapter for mounting a gripper mechanism.
4. The flexible pneumatic arm according to claim 2, further comprising: a restraint tube;
the pneumatic arm body is sleeved in the restraint pipe, and the restraint pipe is used for limiting the inflation and expansion degree of part of or all of the air chambers.
5. The flexible pneumatic arm according to claim 4, further comprising a force sensing sensor;
the force sensing sensor is arranged on the channel cover and used for generating a deformation signal based on the deformation quantity of the channel cover.
6. The flexible pneumatic arm according to claim 5, wherein the force sensing sensor is one or more of a fiber grating sensor, a bending sensor, or a pressure sensor.
7. The flexible pneumatic arm according to claim 2, wherein the pneumatic arm body is provided with 12 air chambers, each air chamber having a wall thickness of 1.5 mm, the pneumatic arm body being 80 mm long.
8. The flexible pneumatic arm of any one of claims 1 to 7, wherein the channel cover, the pneumatic arm body, and the plenum are formed by one of deposition fabrication, soft lithography, lost wax casting, or composite 3D printing.
9. A tip control system, comprising: the flexible pneumatic arm, air supply, pneumatic valve and control circuit of claims 1-8; the air source is communicated with the input end of the pneumatic valve, and the output end of the pneumatic valve is communicated with the inflation inlet of the flexible pneumatic arm;
the pneumatic valve is also electrically connected with the control circuit, the control circuit controls the output end of the pneumatic valve to output the gas of the gas source, the gas enters each gas chamber through the inflation channel communicated with the inflation port, and after each gas chamber is inflated, the flexible pneumatic arm bends towards the direction of the channel cover;
the control circuit also controls the output end of the pneumatic valve to lock the gas entering the gas chamber, so that the flexible pneumatic arm keeps bending towards the channel cover;
the control circuit further controls a pressure relief hole of the pneumatic valve to relieve the pressure of the output end of the pneumatic valve, so that the gas of each gas chamber can be recovered to the posture before the flexible pneumatic arm bends towards the channel cover from the pressure relief hole.
10. The tip control system according to claim 9, wherein a surface of the flexible pneumatic arm is mounted with a force sensing sensor;
the force perception sensor is used for perceiving the deformation quantity of the flexible pneumatic arm to correspondingly generate a deformation signal;
the force sensing sensor is electrically connected with the control circuit, and the control circuit is used for controlling the opening degree of the output end of the pneumatic valve according to the deformation signal so as to control the amount of gas filled into each gas chamber of the flexible pneumatic arm by the gas of the gas source.
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| CN202011584765.6A CN112692848A (en) | 2020-12-28 | 2020-12-28 | Flexible pneumatic arm and tail end control system |
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| CN202011584765.6A CN112692848A (en) | 2020-12-28 | 2020-12-28 | Flexible pneumatic arm and tail end control system |
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