CN113733149A - Soft finger manipulator for sensing hardness of fruits and detection method - Google Patents
Soft finger manipulator for sensing hardness of fruits and detection method Download PDFInfo
- Publication number
- CN113733149A CN113733149A CN202111026386.XA CN202111026386A CN113733149A CN 113733149 A CN113733149 A CN 113733149A CN 202111026386 A CN202111026386 A CN 202111026386A CN 113733149 A CN113733149 A CN 113733149A
- Authority
- CN
- China
- Prior art keywords
- fruit
- soft
- manipulator
- soft finger
- hardness
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 235000013399 edible fruits Nutrition 0.000 title claims abstract description 136
- 238000001514 detection method Methods 0.000 title claims abstract description 26
- 238000000034 method Methods 0.000 claims abstract description 15
- 238000005452 bending Methods 0.000 claims description 51
- 230000008447 perception Effects 0.000 claims description 11
- 230000008878 coupling Effects 0.000 claims description 8
- 238000010168 coupling process Methods 0.000 claims description 8
- 238000005859 coupling reaction Methods 0.000 claims description 8
- 238000002474 experimental method Methods 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 210000001624 hip Anatomy 0.000 claims description 4
- 239000012528 membrane Substances 0.000 claims description 4
- 238000013329 compounding Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 claims description 3
- 239000002245 particle Substances 0.000 claims description 3
- 230000008569 process Effects 0.000 abstract description 6
- 239000010408 film Substances 0.000 description 39
- 210000003205 muscle Anatomy 0.000 description 7
- 239000010409 thin film Substances 0.000 description 7
- 210000000078 claw Anatomy 0.000 description 5
- 101100491335 Caenorhabditis elegans mat-2 gene Proteins 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012636 effector Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000007542 hardness measurement Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J15/00—Gripping heads and other end effectors
- B25J15/08—Gripping heads and other end effectors having finger members
- B25J15/12—Gripping heads and other end effectors having finger members with flexible finger members
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J15/00—Gripping heads and other end effectors
- B25J15/02—Gripping heads and other end effectors servo-actuated
- B25J15/0206—Gripping heads and other end effectors servo-actuated comprising articulated grippers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J19/00—Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators
- B25J19/02—Sensing devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N19/00—Investigating materials by mechanical methods
Landscapes
- Engineering & Computer Science (AREA)
- Robotics (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Manipulator (AREA)
Abstract
The invention discloses a soft finger manipulator for sensing fruit hardness and a detection method. The soft finger mechanical arms are integrally and symmetrically arranged, a plurality of mechanical soft fingers are circumferentially arranged on the mechanical arm driving module at intervals, each mechanical soft finger is hinged with the mechanical arm driving module through a fixed sliding rod and a connecting rod, and the plurality of mechanical soft fingers are electrically connected with a terminal through a signal collector; placing fruit between a plurality of soft fingers of machinery, manipulator drive module's start-up, manipulator drive module drives a plurality of soft pointss of machinery simultaneously and carries out the gripping of fruit after drawing close to. The detection method is used for implementing the soft finger mechanical arm to grasp the fruit, the soft finger mechanical arm grasps the fruit, acquires a sensing signal and sends the sensing signal to the signal collector, the signal collector processes the sensing signal to obtain a voltage signal, the voltage signal is sent to the terminal, and the terminal calculates to obtain the hardness of the fruit. The fruit hardness sensing device can stably grab fruits, can sense the hardness information of the fruits, and has a good application prospect.
Description
Technical Field
The invention relates to a soft-finger manipulator for sensing fruit hardness, in particular to a soft-finger manipulator for sensing fruit hardness and a detection method.
Background
The fruit yield of China is at the forefront of the world, but the fruit quality is not high due to the lack of fruit detection and grading equipment, and the market competitiveness in the international market is lacked. In the picking, storing and transporting links of fruits, due to the lack of detection means for hardness and maturity without damage, no matter whether soft or hard fruits are mixed to be transported, stored and circulated, the soft and mature fruits are easy to be extruded and deformed, and are easy to rot as the fruits are further matured and softened, so that the loss rate of fruit circulation is very high.
The hardness of the fruit refers to the strength of the pressure resistance of fruit pulp, and can be used as an important index for judging the quality of the fruit. The current fruit hardness detection method mainly comprises sampling detection, fixing a fruit sample, pressing the fruit sample into the fruit by using a texture analyzer or a hardness tester, and obtaining the hardness information of the fruit through destructive experiments. The fruit hardness can be detected nondestructively, and the method has important practical significance for storage and circulation of picked fruits, evaluation of the optimal edible period and product classification. At present, the nondestructive detection method of the hardness of the fruit mainly comprises an acoustic detection method and an optical detection method, signals of the acoustic detection method are easily interfered by environmental noise, and some modes of knocking still cause damage to the fruit. The hardness of the fruit is mainly related to the physical structure of the fruit, so that the optical detection is greatly influenced by the environment, the price of detection equipment is high, the detection conditions are harsh, the detection method is complex, and the fruit hardness detection method cannot be well popularized.
The film pressure sensor is subjected to different pressures, and the sensor presents different resistance values due to a special film resistance structure in the sensor. Different pressure sizes act on the pressure sensor, corresponding electric signals can be generated in the access detection circuit, and corresponding pressure values can be obtained on the terminal after the signals are processed by the signal acquisition device.
When the film angle sensor deforms, due to the special sheet resistor structure inside the sensor, the angle sensor can present different resistance values when different bending angles occur. When the angle sensor is bent to different angles, corresponding electric signals can be generated when the angle sensor is connected into the detection circuit, and after the signals are processed by the acquisition device, corresponding bending angle values can be obtained on the terminal.
Disclosure of Invention
In order to solve the problems in the background art, the invention provides a soft finger manipulator for sensing the hardness of fruits and a detection method. The soft finger manipulator drives the connecting rod to open and close through the rotation of the motor. When the soft finger manipulator is closed, the mechanical soft finger can be attached to the fruit shape curve to be bent and deformed, the non-slip pad on the mechanical soft finger can be tightly attached to the fruit, and the fruit is not easy to slip. The pressure value and the bending angle value of the working face can be obtained through the pressure sensor and the bending angle sensor implanted in the flexible soft finger, data are input into a formula in the terminal, and then the hardness of the fruit is obtained through calculation. The soft finger manipulator can be used for grabbing in a fruit picking and transferring feeding link, the flexible mechanical claw can reduce damage to fruits, and meanwhile, the fruit hardness information acquired through the sensor can guide the fruit to be conveyed in a grading mode. This soft manipulator that indicates simple structure, nondestructive test, it is with low costs, can realize simultaneously that the stability of fruit snatchs and the perception of fruit hardness, have great realistic meaning and application prospect.
The technical scheme adopted by the invention is as follows:
soft finger manipulator capable of sensing hardness of fruits
The soft finger manipulator is integrally and symmetrically arranged and comprises a plurality of mechanical soft fingers, a fixed sliding rod, a connecting rod and a manipulator driving module, wherein the plurality of mechanical soft fingers are arranged on the manipulator driving module at equal intervals along the circumference, each mechanical soft finger is hinged with the manipulator driving module through the fixed sliding rod and the connecting rod, and the plurality of mechanical soft fingers are electrically connected with a terminal through a signal collector; placing fruit between a plurality of mechanical soft fingers, manipulator drive module's start, carry out the gripping of fruit after manipulator drive module drives a plurality of mechanical soft sensing simultaneously and draws close, gather perception signal and send perception signal for signal collection ware after a plurality of mechanical soft fingers carry out the gripping to fruit, signal collection ware obtains voltage signal after handling perception signal, voltage signal sends for the terminal, obtains fruit hardness after the terminal calculation, realizes perception fruit hardness.
The plurality of mechanical soft fingers have the same structure, and each mechanical soft finger structure specifically comprises:
the device comprises a flexible soft finger, a soft finger base, a film pressure sensor, a film angle sensor and an anti-skid pad;
the flexible soft finger is fixedly arranged on the soft finger base, and the soft finger base is hinged with the manipulator driving module through a fixed sliding rod and a connecting rod; the flexible soft finger is close to one side face of the center of the manipulator driving module and serves as a working face, the working face is formed by compounding multiple layers, a film angle sensor, a film pressure sensor and an anti-slip mat are sequentially arranged in a stacking mode in the direction pointing to the center of the manipulator driving module, and the film angle sensor and the film pressure sensor are connected with the terminal through signal collectors.
The manipulator driving module comprises a motor fixing platform, a stepping motor, a threaded flange, a lifting platform and a bottom plate;
a bottom plate, a plurality of first connecting plates, the lifting platform and the motor fixing platform are sequentially arranged at intervals from bottom to top, a platform flange through hole is formed in the middle of the lifting platform, a plurality of bosses are radially and outwardly extended from the edge of the lifting platform and are circumferentially arranged at intervals, strip-shaped through groove and strip-shaped through grooves are formed in the lifting platform between the bosses and the platform flange through holes and are radially arranged along the manipulator driving module, a plurality of slide bar clamping grooves are formed in the motor fixing platform, the upper ends of the fixed slide bars are fixedly installed on the motor fixing platform, the upper ends of the fixed slide bars penetrate through the strip-shaped through grooves and are hinged to one side, close to the center of the manipulator driving module, of the bottom surface of the corresponding mechanical soft fingers, the lower ends of the fixed slide bars movably penetrate through the strip-shaped through grooves along the radial direction and are fixedly installed on the bottom plate, and one side, far away from the center of the manipulator driving module, of the bottom surface of the mechanical soft fingers is hinged to the bosses of the lifting platform through connecting rods;
the middle part of bottom plate is opened there is the bottom plate counter bore, and lift platform's middle part fixed mounting has the screw flange, and motor fixed platform's lower fixed surface installs step motor, and step motor's play axle lead screw passes through screw thread coaxial coupling with the screw flange, and the activity is installed in the bottom plate counter bore after the tip of play axle lead screw passes the screw flange.
The non-slip mat is a flexible non-slip mat, and protruding particles are arranged on the surface of the flexible non-slip mat.
The cross-section of flexible soft finger when non-operating condition is isosceles triangle, is provided with the horizontal muscle of a plurality of flexible couplings between two waists, and interval and slope distribution or parallel and interval setting between the horizontal muscle of a plurality of flexible couplings.
The fixed sliding rod close to the lifting platform is arranged into an outward bending shape from bottom to top, so that the lifting platform is limited, and the opening angle range of the flexible soft finger is finally controlled.
Second, a detection method for sensing fruit hardness
The method comprises the following steps:
the method comprises the following steps: the soft-finger manipulator is driven to close by controlling the forward rotation of the stepping motor, and closing force is continuously exerted on the soft-finger manipulator, so that each working surface of the soft-finger manipulator is attached to the surface of a fruit to generate bending deformation; the film pressure sensors and the film angle sensors of all working surfaces respectively acquire pressure and bending angles after bending deformation is generated, the pressure and the bending angles are used as sensing signals and sent to the signal collector, and the signal collector respectively calculates the pressure and the bending angles to respectively obtain pressure voltage of the film pressure sensors and bending voltage of the film angle sensors;
step two: analyzing and processing the pressure voltage and the bending voltage by the terminal to obtain the hardness of the fruit;
step three: and controlling the stepping motor to rotate reversely, driving the soft finger manipulator to open, loosening the fruit by the soft finger manipulator, and detecting the next fruit after taking off the fruit.
In the first step, the signal collector performs voltage conversion according to the pressure collected by the film pressure sensor according to the following formula to obtain the pressure voltage of the film pressure sensor:
Fpressure＝3.29Vpressure -2.061
wherein, FpressurePressure, V, acquired for a diaphragm pressure sensorpressureIs the pressure voltage of the membrane pressure sensor,
the signal collector converts voltage according to the bending angle collected by the film angle sensor according to the following formula to obtain the bending voltage of the film angle sensor:
wherein θ is a bending angle of the film angle sensor; vbendingIs the bending voltage output by the thin film angle sensor.
The second step is specifically as follows:
after the terminal analyzes and processes the pressure voltage and the bending voltage, the hardness of the fruit is obtained according to the following formula:
wherein H is the hardness of the fruit; rho represents the curvature of the fruit obtained in the experiment, and R represents the median of the radius of the fruit of the type; r' represents the radius of a fitting circle after the working surface of the flexible soft finger is deformed; and L is the total length A of the film pressure sensor and is the voltage initial offset compensation coefficient.
The invention has the beneficial effects that:
the flexible finger manipulator is a flexible claw, and due to the special soft structure of the flexible claw, the flexible claw can be attached to the surface of the fruit according to the shape and the size of the fruit when the fruit is grabbed. And the non-slip mat with the protruding particles is attached to the contact surface of the soft fingers, so that the fruit can be stably grabbed, and meanwhile, the fruit cannot be squeezed and damaged.
The soft finger manipulator is a pressure feedback manipulator, and the threshold design of the pressure of the contact surface is adopted in the grabbing process, so that the situation that the power overload of a motor is caused by the difference of fruit shapes and sizes during grabbing can be avoided, and the fruits can be well protected.
According to the invention, the film pressure sensor and the angle sensor are buried under the contact surface of the soft finger manipulator, so that the fruit can be stably grabbed, and the hardness information of the fruit can be sensed, thereby achieving two purposes. The method is simple, efficient and practical, and has good application prospect.
Drawings
FIG. 1 is an assembled perspective view of the present invention;
FIG. 2 is an exploded view of the soft finger of the present invention;
FIG. 3 is a schematic view of the fruit grasping of the present invention;
FIG. 4 is a schematic view of the motor mounting of the present invention;
FIG. 5 is a schematic view of the motor driven lift platform of the present invention;
FIG. 6 is a schematic view of a linkage connection of the present invention;
FIG. 7 is a schematic view of a hardness testing system of the present invention;
FIG. 8 is a schematic diagram of the soft finger variation to achieve stiffness perception of the present invention;
FIG. 9 is a graph of partial experimental data for the soft fingers to sense fruit firmness in accordance with the present invention;
figure 10 is a schematic view of a three finger soft finger robot of the present invention.
In the figure: 1. the flexible soft finger, 1a, connect horizontal muscle, 2, slipmat, 3, soft finger base, 4, fixed platform, 5, fixed slide bar, 6, the connecting rod, 7, step motor, 8, the screw flange, 9, lift platform, 9b, platform flange through-hole, 9c, the bar leads to the groove, 10, play axle lead screw, 11, the bottom plate, 11b, the bottom plate counter bore, 11c, the bottom plate square groove, 12, the gasket, 13, fixed pin pole, 14, film pressure sensor, 15, film angle sensor, 16, fruit, 17, signal collector, 18, terminal.
Detailed Description
The invention is further described with reference to the following figures and specific embodiments.
As shown in fig. 1, the soft finger manipulator is symmetrically arranged integrally and comprises a plurality of mechanical soft fingers, a fixed slide bar 5, a connecting rod 6 and a manipulator driving module, wherein the plurality of mechanical soft fingers are arranged on the manipulator driving module at equal intervals along the circumference, each mechanical soft finger is hinged with the manipulator driving module through the fixed slide bar 5 and the connecting rod 6, and the plurality of mechanical soft fingers are electrically connected with a terminal 18 through a signal collector 17; as shown in fig. 3, 7 and 8, a fruit 16 is placed between a plurality of mechanical soft fingers, the manipulator driving module is started, the manipulator driving module simultaneously drives the mechanical soft fingers to grab the fruit 16 after the mechanical soft fingers are inwardly closed, the mechanical soft fingers grab the fruit 16 and collect sensing signals and send the sensing signals to the signal collector 17, the signal collector 17 processes the sensing signals to obtain voltage signals, the voltage signals are sent to the terminal 18, the terminal 18 obtains the hardness of the fruit after calculation, and the terminal 18 is a computer to realize the sensing of the hardness of the fruit.
The structure of a plurality of mechanical soft fingers is the same, and each mechanical soft finger structure specifically is:
as shown in fig. 2, fig. 2 shows the distribution of the film pressure sensors 14 and the film angle sensors 15 in the non-slip mat 2 in detail, the sensors can more accurately acquire the captured force and deformation information by adopting an embedding mode, and the flexible soft finger 1 is integrally formed. The device comprises a flexible soft finger 1, a soft finger base 3, a film pressure sensor 14, a film angle sensor 15 and an anti-skid pad 2;
the bottom surface of the flexible soft finger 1 is fixedly arranged on a soft finger base 3, and the bottom surface of the soft finger base 3 is hinged with a manipulator driving module through a fixed sliding rod 5 and a connecting rod 6; one side face, close to the center of the manipulator driving module, of the flexible soft finger 1 serves as a working face, the working face is formed by compounding multiple layers, the thin film angle sensor 15, the thin film pressure sensor 14 and the non-slip mat 2 are sequentially arranged in a stacked mode in the direction pointing to the center of the manipulator driving module, and the thin film angle sensor 15 and the thin film pressure sensor 14 are connected with a terminal through the signal collector 17. The flexible soft fingers 1 are oppositely arranged on one side close to the center of the manipulator driving module.
As shown in fig. 4, 5 and 6, the manipulator driving module includes a motor fixing platform 4, a stepping motor 7, a threaded flange 8, a lifting platform 9 and a bottom plate 11;
the bottom plate 11, the lifting platform 9 and the motor fixing platform 4 are sequentially arranged at intervals from bottom to top, a bottom plate square groove 11c is formed in the bottom plate 11, a platform flange through hole 9b is formed in the middle of the lifting platform 9, a plurality of bosses are radially and outwardly extended from the edge of the lifting platform 9 and are circumferentially arranged at intervals, the number of the bosses is the same as that of the mechanical soft fingers, strip-shaped through groove strip-shaped through grooves 9c are formed in the lifting platform 9 between the bosses and the platform flange through hole 9b, the strip-shaped through grooves 9c are radially arranged along the manipulator driving module, a plurality of slide bar clamping grooves are formed in the motor fixing platform 4, the number of the slide bar clamping grooves is the same as that of the mechanical soft fingers, a semi-cylinder at the upper end of a fixed slide bar 5 is fixedly installed on the motor fixing platform 4, and the upper end of the fixed slide bar 5 is hinged to one side, close to the center of the manipulator driving module, of the corresponding mechanical soft finger, of the bottom surface through a gasket 12 and a fixed pin 13 after passing through the strip-shaped through groove 9c, the lower end of the fixed slide rod 5 can movably penetrate through the strip-shaped through groove 9c along the radial direction and is fixedly arranged in a bottom plate square groove 11c on the bottom plate 11 through a screw, and one side of the bottom surface of the mechanical soft finger, which is far away from the center of the mechanical hand driving module, is hinged with a boss of the lifting platform 9 through a gasket 12 and a fixed pin rod 13 through a connecting rod 6;
a bottom plate counter bore 11b is formed in the middle of the bottom plate 11, a threaded flange 8 is fixedly mounted in the middle of the lifting platform 9, and the threaded flange 8 is embedded in a platform flange through hole 9 b; the lower surface of the motor fixing platform 4 is fixedly provided with a stepping motor 7, an output shaft screw rod 10 of the stepping motor 7 is coaxially connected with a threaded flange 8 through threads, and the end part of the output shaft screw rod 10 penetrates through the threaded flange 8 and then is movably arranged in a bottom plate counter bore 11 b.
The cross-section of flexible soft finger 1 when non-operating condition is isosceles triangle, be provided with the horizontal muscle 1a of a plurality of flexible couplings between the two waists, interval and slope distribution between the horizontal muscle 1a of a plurality of flexible couplings, make the length direction of the horizontal muscle 1a of flexible coupling and fruit and the pressure direction that flexible soft finger 1 contact produced approximately perpendicular, the resistance that the deformation received is littleer, flexible soft finger 1 during operation, under the effect of connecting rod 6 lifting, two waist bending become the arc of different curvatures, flexible soft finger 1 becomes approximately the falcate, the surface of closely laminating fruit 16, or parallel and interval setting between the horizontal muscle of a plurality of flexible couplings (1a), as shown in fig. 10.
The fixed sliding rod 5 close to the lifting platform 9 is arranged into an outward bending shape from bottom to top, namely has a certain bending degree, so that the lifting platform 9 is limited, and the opening angle range of the flexible soft finger 1 is finally controlled.
The working process of the invention is as follows:
the stepping motor 6 is started to drive the output shaft screw rod 10 to rotate, the output shaft screw rod 10 is in threaded connection with the threaded flange 8, the threaded flange 8 is fixed relative to the lifting platform 9, and along with the rotation of the output shaft screw rod 10, the lifting platform 9 moves in a linear motion parallel to the output shaft screw rod 10, so that the rotating motion of the output shaft of the motor is converted into the lifting and descending motion of the lifting platform 9, the connecting rod 6 and the soft finger base 3 are driven to move, and the opening and closing motion of the soft finger 1 is finally formed; the fixed sliding rod 5 has a certain bending degree, and can limit the lifting platform 9, so that the opening angle range of the flexible soft finger 1 is controlled.
When the flexible soft finger 1 works, under the lifting action of the lifting platform 9, two sides of the isosceles triangle are bent into arcs with different curvatures, and the flexible soft finger 1 is approximately crescent and is tightly attached to the surface of the fruit 16. The film pressure sensor 14 and the film angle sensor 15 of each flexible soft finger 1 generate different electric signals after being subjected to different forces and bending deformation angles, and the generated electric signals are transmitted to the terminal 18 through the signal collector 17 to be subjected to corresponding data processing, so that the fruit hardness can be sensed.
The method comprises the following steps:
the method comprises the following steps: the soft finger manipulator is driven to close by controlling the stepping motor 6 to rotate forwards, and closing force is continuously exerted on the soft finger manipulator, so that the soft finger manipulator grips the fruits 16, and each working surface of the soft finger manipulator is attached to the surface of the fruits 16 to generate bending deformation; the film pressure sensors 14 and the film angle sensors 15 of the working surfaces respectively acquire pressure and bending angles after bending deformation is generated, the pressure and the bending angles are used as sensing signals and sent to the signal collector 17, and the signal collector 17 respectively calculates the pressure and the bending angles to respectively obtain pressure voltages of the film pressure sensors 14 and bending voltages of the film angle sensors 15;
in the first step, the signal collector 17 performs voltage conversion according to the pressure collected by the film pressure sensor 14 and the following formula to obtain the pressure voltage of the film pressure sensor 14:
Fpressure＝3.29Vpressure -2.061
wherein, VpressurePressure in newtons N, V collected for the thin film pressure sensor 14pressureIs the pressure voltage of the membrane pressure sensor 14 in the detection circuit in volts V.
The signal collector 17 performs voltage conversion according to the bending angle collected by the film angle sensor 15 according to the following formula to obtain the bending voltage of the film angle sensor 15:
wherein θ is the bending angle of the film angle sensor 15, and the unit is degree; vbendingThe bending voltage output by the thin-film angle sensor 15 in the detection circuit is in volts V.
Step two: the terminal 18 analyzes the pressure voltage and the bending voltage to obtain the hardness of the fruit 16; in specific implementation, the terminal sends a corresponding command to control the motor 6 to apply force repeatedly, and further repeats the process of the step one, the total is three times, and finally the average value is used as the final approximate hardness of the fruit 16. And the terminal compares and analyzes the hardness of the fruit 16 and the relation table of the hardness and the maturity of the fruit, so as to preliminarily obtain the maturity condition of the fruit.
The second step is specifically as follows:
the hardness of the fruit 16 is obtained by analyzing the pressure and bending voltages at the terminals 18 according to the following formula:
wherein H is the hardness of the fruit 16, and the unit is kilogram force/square centimeter (kgf/cm)2) (ii) a ρ represents the curvature of the fruit 16 obtained in the experiment, and the curvature ρ of the fruit 16 is obtained by the measurement of the experiment and has a unit of millimeter-1mm-1R represents the median of the radius of the fruit of the type, and the unit is millimeter mm, so that the median is used as the reference of fruit shape correction; r' represents the radius of a fitting circle of the deformed working surface of the flexible soft finger 1, and the unit is millimeter mm; l is the total length of the film pressure sensor 14 in mm, the actual length is 50mm, 6.4290 is a proportional amplification factor constant, and a is a voltage initial offset compensation coefficient; generally, 0.2V is taken; 0.0101972 is used for converting pressure unit of kilopascal KPa into kilogram force/square centimeter kgf/cm2The multiplied constant.
Step three: and controlling the stepping motor 6 to rotate reversely, driving the soft finger manipulator to open, loosening the fruit 16 by the soft finger manipulator, and detecting the next fruit after taking down the fruit.
As shown in fig. 9, the data of the soft finger manipulator of the present invention in the experiment for sensing the hardness of the fruit is shown.
As shown in fig. 10, another embodiment of the present invention is a three-finger flexible manipulator, which can also achieve fruit grabbing and hardness information sensing and obtaining.
According to the fruit gripping device, the flexible soft fingers are mounted above the motor fixing platform, and the anti-slip pads are arranged on the sides, gripping fruits, of the flexible soft fingers, so that the fruits can be effectively gripped while the fruits can be prevented from being extruded and damaged. Through going out an axle lead screw, step motor drives the dull and stereotyped reciprocating in below, drives connecting rod and flexible soft motion to realize opening and shutting of flexible soft finger, realize snatching of fruit. The mechanical device is simple in principle and efficient to control, and can guarantee nondestructive testing of fruit hardness. The manipulator device is small and exquisite, can be installed at the tail end of different arms as the end effector, has better commonality. The detection method relies on two types of film pressure sensors, a signal collector simultaneously collects electric signals of the pressure sensors and the angle sensors, corresponding pressure values and bending angle values of the flexible soft claws can be obtained on a terminal through analysis and calculation, fruit hardness values can be obtained according to a theoretical formula, and further the maturity of fruits is evaluated.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and any minor modifications, equivalent replacements and improvements made to the above embodiment according to the technical spirit of the present invention should be included in the protection scope of the technical solution of the present invention.
Claims (9)
1. The utility model provides a perception fruit hardness's soft finger manipulator which characterized in that: the soft finger manipulator is integrally and symmetrically arranged and comprises a plurality of mechanical soft fingers, fixed sliding rods (5), connecting rods (6) and a manipulator driving module, wherein the plurality of mechanical soft fingers are arranged on the manipulator driving module at equal intervals along the circumference, each mechanical soft finger is hinged with the manipulator driving module through the fixed sliding rods (5) and the connecting rods (6), and the plurality of mechanical soft fingers are electrically connected with a terminal (18) through a signal collector (17); place fruit (16) between a plurality of soft fingers of machinery, manipulator drive module's start, manipulator drive module drives a plurality of soft directional insides of machinery simultaneously and carries out the gripping of fruit (16) after drawing close, a plurality of soft fingers of machinery gather perception signal and send perception signal for signal collector (17) after gripping fruit (16), signal collector (17) obtain voltage signal after handling perception signal, voltage signal sends for terminal (18), obtain fruit hardness after terminal (18) calculate, realize perception fruit hardness.
2. The soft finger manipulator for sensing the hardness of the fruit according to claim 1, wherein: the plurality of mechanical soft fingers have the same structure, and each mechanical soft finger structure specifically comprises:
comprises a flexible soft finger (1), a soft finger base (3), a film pressure sensor (14), a film angle sensor (15) and an anti-skid pad (2);
the flexible soft finger (1) is fixedly arranged on the soft finger base (3), and the soft finger base (3) is hinged with the manipulator driving module through a fixed sliding rod (5) and a connecting rod (6); one side face, close to the center of the manipulator driving module, of the flexible soft finger (1) serves as a working face, the working face is formed by compounding multiple layers, a film angle sensor (15), a film pressure sensor (14) and an anti-slip pad (2) are sequentially arranged in a stacking mode in the direction pointing to the center of the manipulator driving module, and the film angle sensor (15) and the film pressure sensor (14) are connected with a terminal through a signal collector (17).
3. The soft finger manipulator for sensing the hardness of the fruit according to claim 1, wherein: the manipulator driving module comprises a motor fixing platform (4), a stepping motor (7), a threaded flange (8), a lifting platform (9) and a bottom plate (11);
bottom plate (11), lift platform (9) and motor fixed platform (4) from the bottom up interval arrangement in proper order, open at the middle part of lift platform (9) has platform flange through-hole (9b), the edge of lift platform (9) is provided with a plurality of bosss radially outwards extending, a plurality of bosss are along circumference interval arrangement, it leads to groove bar through groove bar (9c) all to open the bar on lift platform (9) between a plurality of bosss and platform flange through-hole (9b), the bar leads to groove bar (9c) and follows the radial arrangement of manipulator drive module, a plurality of slide bar draw-in grooves have been seted up on motor fixed platform (4), the upper end fixed mounting of fixed slide bar (5) is at motor fixed platform (4), the upper end of fixed slide bar (5) is passed behind groove (9c) and is articulated with the bottom surface one side that the soft finger of the machinery that corresponds is close to manipulator drive module center in bar, the lower extreme of fixed slide bar (5) passes through groove bar (9c) fixed mounting on bottom plate (11) along radial movably One side of the bottom surface of the mechanical soft finger, which is far away from the center of the mechanical arm driving module, is hinged with a boss of a lifting platform (9) through a connecting rod (6);
the middle part of bottom plate (11) is opened there is bottom plate counter bore (11b), the middle part fixed mounting of lift platform (9) has screw flange (8), the lower fixed surface of motor fixed platform (4) installs step motor (7), the play axle lead screw (10) of step motor (7) passes through screw thread coaxial coupling with screw flange (8), the tip that goes out axle lead screw (10) passes screw flange (8) back activity and installs in bottom plate counter bore (11 b).
4. The soft finger manipulator for sensing the hardness of the fruit according to claim 2, wherein: the non-slip mat (2) is a flexible non-slip mat, and protruding particles are arranged on the surface of the flexible non-slip mat.
5. The soft finger manipulator for sensing the hardness of the fruit according to claim 2, wherein: the cross section of the flexible soft finger (1) in the non-working state is an isosceles triangle, a plurality of flexible connection transverse ribs (1a) are arranged between two waists, and the plurality of flexible connection transverse ribs (1a) are distributed in an inclined mode at intervals or the plurality of flexible connection transverse ribs (1a) are arranged in a parallel mode at intervals.
6. The soft finger manipulator for sensing the hardness of the fruit according to claim 3, wherein: the fixed sliding rod (5) close to the lifting platform (9) is arranged into an outward bending shape from bottom to top, so that the lifting platform (9) is limited, and the opening angle range of the flexible soft finger (1) is finally controlled.
7. A method for sensing hardness of a fruit for implementing the soft finger robot of any one of claims 1-6, comprising the steps of:
the method comprises the following steps: the soft finger manipulator is driven to close by controlling the stepping motor (6) to rotate forwards, and closing force is continuously applied to the soft finger manipulator, so that each working surface of the soft finger manipulator is attached to the surface of a fruit (16) to generate bending deformation; the film pressure sensors (14) and the film angle sensors (15) of all working surfaces respectively acquire pressure and bending angles after bending deformation is generated, the pressure and the bending angles are used as sensing signals and sent to the signal collector (17), and the signal collector (17) respectively calculates the pressure and the bending angles to respectively obtain pressure voltage of the film pressure sensors (14) and bending voltage of the film angle sensors (15);
step two: the terminal (18) analyzes the pressure voltage and the bending voltage to obtain the hardness of the fruit (16);
step three: and controlling the stepping motor (6) to rotate reversely, driving the soft finger manipulator to open, loosening the fruit (16) by the soft finger manipulator, and detecting the next fruit after taking down the fruit.
8. The detection method for sensing the hardness of the fruit according to claim 1, wherein in the first step, the signal collector (17) performs voltage conversion according to the pressure collected by the film pressure sensor (14) according to the following formula to obtain the pressure voltage of the film pressure sensor (14):
Fpressure＝3.29Vpressure -2.061
wherein, FpressurePressure, V, acquired for a membrane pressure sensor (14)pressureIs the pressure voltage of the membrane pressure sensor (14),
the signal collector (17) carries out voltage conversion according to the bending angle collected by the film angle sensor (15) according to the following formula to obtain the bending voltage of the film angle sensor (15):
wherein theta is a bending angle of the film angle sensor (15); vbendingIs the bending voltage output by the film angle sensor (15).
9. The method for detecting the hardness of the sensed fruit according to claim 1, wherein the second step is specifically as follows:
after the terminal (18) analyzes the pressure voltage and the bending voltage, the hardness of the fruit (16) is obtained according to the following formula:
wherein H is the hardness of the fruit (16); ρ represents the curvature obtained in the experiment of the fruit (16), R represents the median of the radius of this type of fruit; r' represents the radius of a fitting circle after the working surface of the flexible soft finger (1) is deformed; l is the total length A of the film pressure sensor (14) and is the voltage initial offset compensation coefficient.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111026386.XA CN113733149B (en) | 2021-09-02 | 2021-09-02 | Soft finger manipulator for sensing fruit hardness and detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111026386.XA CN113733149B (en) | 2021-09-02 | 2021-09-02 | Soft finger manipulator for sensing fruit hardness and detection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113733149A true CN113733149A (en) | 2021-12-03 |
| CN113733149B CN113733149B (en) | 2024-03-19 |
Family
ID=78735018
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111026386.XA Active CN113733149B (en) | 2021-09-02 | 2021-09-02 | Soft finger manipulator for sensing fruit hardness and detection method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113733149B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114408270A (en) * | 2022-01-24 | 2022-04-29 | 中国农业大学 | Manipulator, packaging machine and method for fruit maturity graded packaging |
| CN114851230A (en) * | 2022-04-19 | 2022-08-05 | 浙江大学 | Flexible manipulator with fin-shaped structure |
| CN115107072A (en) * | 2022-08-26 | 2022-09-27 | 江苏省农业科学院 | Spherical fruit picking method and system |
| CN115157294A (en) * | 2022-08-03 | 2022-10-11 | 北京航空航天大学 | Perception finger and bionic equipment |
| CN115191223A (en) * | 2022-07-15 | 2022-10-18 | 江苏大学 | Cluster-shaped tomato powder fruit picking mechanical arm and picking method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60221288A (en) * | 1984-04-13 | 1985-11-05 | 株式会社 富士電機総合研究所 | Pressure sensing recognizing controller |
| US20160073584A1 (en) * | 2014-09-12 | 2016-03-17 | Washington State University | Robotic systems, methods, and end-effectors for harvesting produce |
| CN109105001A (en) * | 2018-10-18 | 2019-01-01 | 石河子大学 | A kind of bergamot pear terminal executor of picking robot and picking method |
| CN110039533A (en) * | 2019-04-17 | 2019-07-23 | 苏州柔性智能科技有限公司 | For detecting the multi-functional software manipulator of fruit maturity |
| CN112265009A (en) * | 2020-09-11 | 2021-01-26 | 燕山大学 | Variable-rigidity multidirectional grabbing robot based on folding plate mechanism |
| CN112485140A (en) * | 2020-11-06 | 2021-03-12 | 浙江大学 | Fruit hardness sensor integrated on flexible finger |
| CN112976025A (en) * | 2021-02-22 | 2021-06-18 | 浙江工业大学 | Object soft and hard recognition and self-adaptive grabbing method based on humanoid manipulator device |
-
2021
- 2021-09-02 CN CN202111026386.XA patent/CN113733149B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60221288A (en) * | 1984-04-13 | 1985-11-05 | 株式会社 富士電機総合研究所 | Pressure sensing recognizing controller |
| US20160073584A1 (en) * | 2014-09-12 | 2016-03-17 | Washington State University | Robotic systems, methods, and end-effectors for harvesting produce |
| CN109105001A (en) * | 2018-10-18 | 2019-01-01 | 石河子大学 | A kind of bergamot pear terminal executor of picking robot and picking method |
| CN110039533A (en) * | 2019-04-17 | 2019-07-23 | 苏州柔性智能科技有限公司 | For detecting the multi-functional software manipulator of fruit maturity |
| CN112265009A (en) * | 2020-09-11 | 2021-01-26 | 燕山大学 | Variable-rigidity multidirectional grabbing robot based on folding plate mechanism |
| CN112485140A (en) * | 2020-11-06 | 2021-03-12 | 浙江大学 | Fruit hardness sensor integrated on flexible finger |
| CN112976025A (en) * | 2021-02-22 | 2021-06-18 | 浙江工业大学 | Object soft and hard recognition and self-adaptive grabbing method based on humanoid manipulator device |
Non-Patent Citations (2)
| Title |
|---|
| 张方明, 应义斌: "水果分级机器人关键技术的研究和发展", "机器人技术与应用", no. 1 * |
| 张颖, 赵长盛, 苑文博等: "仿人机械手设计与硬度感知研究", "东北大学学报(自然科学版)", vol. 41, no. 1 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114408270A (en) * | 2022-01-24 | 2022-04-29 | 中国农业大学 | Manipulator, packaging machine and method for fruit maturity graded packaging |
| CN114851230A (en) * | 2022-04-19 | 2022-08-05 | 浙江大学 | Flexible manipulator with fin-shaped structure |
| CN114851230B (en) * | 2022-04-19 | 2024-03-29 | 浙江大学 | Flexible manipulator of fin structure |
| CN115191223A (en) * | 2022-07-15 | 2022-10-18 | 江苏大学 | Cluster-shaped tomato powder fruit picking mechanical arm and picking method thereof |
| CN115191223B (en) * | 2022-07-15 | 2024-04-09 | 江苏大学 | Cluster-shaped tomato powder fruit picking manipulator and picking method thereof |
| CN115157294A (en) * | 2022-08-03 | 2022-10-11 | 北京航空航天大学 | Perception finger and bionic equipment |
| CN115107072A (en) * | 2022-08-26 | 2022-09-27 | 江苏省农业科学院 | Spherical fruit picking method and system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113733149B (en) | 2024-03-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113733149A (en) | Soft finger manipulator for sensing hardness of fruits and detection method | |
| CN103688660B (en) | A kind of drive lacking picking end actuating unit and method | |
| Schurmann et al. | A modular high-speed tactile sensor for human manipulation research | |
| CN210059040U (en) | Based on RGB fruit sorter | |
| CN209280891U (en) | A kind of automatic voltage inner walkway machine | |
| CN207547071U (en) | A kind of fruit automatic sorting device | |
| CN109272908B (en) | Full-automatic display screen sensor performance detection device | |
| Zhang et al. | Flexible sensing enabled intelligent manipulator system (FSIMS) for avocados (Persea Americana Mill) ripeness grading | |
| CN207320242U (en) | Battery modules are implanted into all-in-one machine with the detection of firm welding degree and parallel-connection network | |
| Schürmann et al. | A high-speed tactile sensor for slip detection | |
| Li et al. | Learning to detect slip for stable grasping | |
| CN116678307A (en) | Curvature measurement system and method for flexible mechanical claw | |
| CN102282972A (en) | Under-actuated end effector with sensing function | |
| CN112657869A (en) | Nut sorting equipment based on vision and sorting method thereof | |
| CN217494310U (en) | Flexible soft blank mechanical claw | |
| CN216775528U (en) | Mechanical gripper for picking | |
| CN208326550U (en) | Belt of weighing batcher | |
| CN114798481A (en) | Building cement piece pressure measurement | |
| CN111731792B (en) | Transmission line hub positioning device and positioning method thereof | |
| CN210210436U (en) | Flexible mechanical gripper for driving displacement control to clamp and take off force | |
| CN113575131B (en) | Oranges and tangerines are picked letter sorting integrated device based on symmetry indicates holder more | |
| CN221351329U (en) | Abnormal sound detection device for metal matrix | |
| CN217342397U (en) | Pick up mechanism, support plate mechanism and soyfood sorting device | |
| CN210753854U (en) | Bearing classification device | |
| CN212312066U (en) | Manipulator capable of rotating rapidly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |