Fruit diameter detection device and method based on flexible sensing manipulator

Abstract

The invention discloses a fruit diameter detection device and method based on a flexible sensing manipulator. The device comprises two flexible sensing grabbing mechanisms, a driving mechanism, a fixed sliding rod and a connecting rod. The two flexible sensing grabbing mechanisms are symmetrically arranged, each flexible sensing grabbing mechanism is hinged to the driving mechanism through a fixed sliding rod and a connecting rod, and each flexible sensing grabbing mechanism is in communication connection with the upper computer through the signal acquisition module and the control module in sequence. The method comprises the steps that firstly, a fruit is grabbed, then the signal acquisition module obtains a pressure signal value and a bending angle signal value through the two sensors, then the pressure signal value and the bending angle signal value are transmitted to the control module for fusion processing, the result is transmitted to the upper computer after fusion processing, and the upper computer records the effective grabbing duration and processes the result according to the fusion processing result to obtain the fruit diameter of the fruit. The device is simple in structure and accurate in detection, efficient integration of fruit grabbing and fruit diameter measurement is achieved, and the device can be widely applied to the field of agricultural automation and fruit robot sorting.

Description

Technical Field

[0001] The present invention relates to a method for detecting the fruit diameter of fruits, and particularly to a device and method for detecting the fruit diameter of fruits based on a flexible sensing manipulator. Background Art

[0002] The fruit diameter size is one of the important indicators for measuring its quality and grading. During the fruit grading process, the fruit diameter is usually used to judge the size grade of fruits, thereby affecting their market value and sales strategies.

[0003] Existing fruit grading technologies mainly rely on methods such as mechanical calipers and visual detection to measure fruit sizes. A mechanical caliper is a traditional measuring tool that measures the diameter of fruits by directly contacting them. However, this method has low efficiency and is prone to damaging the fruits. Visual detection technology utilizes computer vision and image processing technologies to collect fruit images through a camera and analyze their features such as size and shape. However, these methods all have certain limitations. The measurement accuracy of mechanical calipers is greatly affected by human operation, while visual detection technology is limited by equipment complexity, environmental lighting conditions, and insufficient accuracy of non-contact detection. In addition, when the visual detection system processes complex backgrounds or reflected light on the fruit surface, misjudgment or a decrease in accuracy may occur.

[0004] The limitations of these technologies make it difficult for them to meet the needs of diversified fruit grading. Especially when faced with fruits of different types, shapes, and sizes, existing grading technologies often cannot achieve efficient and accurate grading. Therefore, developing more intelligent, high-precision, and adaptable fruit grading technologies has become an important research direction. Summary of the Invention

[0005] In order to solve the problems in the background art, the present invention provides a device and method for detecting the fruit diameter of fruits based on a flexible sensing manipulator. By recording the effective duration of the grasping comprehensive signal and combining the linear fitting relationship, the fruit diameter is accurately predicted, providing a reliable basis for fruit grading and quality control.

[0006] The technical solution adopted by the present invention is as follows:

[0007] I. A device for detecting the fruit diameter of fruits based on a flexible sensing manipulator

[0008] The fruit diameter detection device is arranged symmetrically as a whole, and includes two flexible sensing grasping mechanisms, a driving mechanism, a fixed slide bar, and a connecting rod; the two flexible sensing grasping mechanisms are arranged symmetrically, and each flexible sensing grasping mechanism is hinged to the driving mechanism through the fixed slide bar and the connecting rod. Each flexible sensing grasping mechanism is sequentially connected to the upper computer through a signal acquisition module and a control module for communication.

[0009] Place the fruit between two flexible sensing grasping mechanisms. After the driving mechanism is started, it drives the two flexible sensing grasping mechanisms to move closer inward to grasp the fruit. The signal acquisition module obtains two sensing signals after the two flexible sensing grasping mechanisms grasp the fruit. The signal acquisition module outputs the two sensing signals to the control module. The control module performs fusion processing on the two sensing signals to obtain a grasping comprehensive signal value. The grasping comprehensive signal value is sent to the host computer, and the host computer performs data analysis and processing to obtain the fruit diameter of the fruit, realizing the detection of the fruit diameter.

[0010] The two flexible sensing grasping mechanisms have the same structure; each flexible sensing grasping mechanism includes a flexible soft finger, a soft finger base, a bending angle sensor, and a flexible pressure sensor; the flexible soft finger is fixedly installed on the soft finger base, and the soft finger base is hinged to the driving mechanism through a fixed slide bar and a connecting rod; the side of the flexible soft finger close to the center of the driving mechanism is the grasping inner side, and the other side is the grasping outer side; the flexible pressure sensor is installed on the grasping inner side of the flexible soft finger, and the bending angle sensor is installed on the grasping outer side of the flexible soft finger. Both the bending angle sensor and the flexible pressure sensor are connected to the control module through the signal acquisition module.

[0011] The cross-section of the flexible soft finger in the non-working state is an isosceles triangle, and a plurality of flexible connecting cross ribs are arranged between the two waists. The plurality of flexible connecting cross ribs are parallel and spaced apart.

[0012] The driving module includes a motor fixing platform, a stepping motor, a threaded flange, a flange lifting platform, and a bottom plate; the bottom plate, the flange lifting platform, and the motor fixing platform are arranged at intervals from bottom to top. A platform flange through hole is opened in the middle of the flange lifting platform. Convex platforms are respectively arranged on the two edges of the flange lifting platform extending radially outward. Strip-shaped through grooves are opened on the flange lifting platform between the two convex platforms and the platform flange through hole. The strip-shaped through grooves are arranged along the radial direction of the driving module. Two slide bar card slots are opened on the motor fixing platform. The upper end of the fixed slide bar is fixedly installed in the slide bar card slot of the motor fixing platform. The upper end of the fixed slide bar passes through the strip-shaped through groove and is hinged to one side of the corresponding soft finger base close to the center of the driving module. The lower end of the fixed slide bar passes through the strip-shaped through groove radially movably and is fixedly installed on the bottom plate. The other side of the soft finger base away from the center of the driving module is hinged to the convex platform of the flange lifting platform through a connecting rod.

[0013] A bottom plate counterbore is opened in the middle of the bottom plate. A threaded flange is fixedly installed in the middle of the flange lifting platform. A stepping motor is fixedly installed on the lower surface of the motor fixing platform. The output shaft screw of the stepping motor is coaxially connected to the threaded flange through a thread. The end of the output shaft screw passes through the threaded flange and is movably installed in the bottom plate counterbore. The stepping motor is electrically connected to the control module through a motor drive circuit.

[0014] The fixed sliding rod near the flange lifting platform is set to be bent outward from bottom to top, so as to limit the flange lifting platform and finally control the opening angle range of the flexible sensing grasping mechanism.

[0015] II. Fruit diameter detection method of a fruit diameter detection device based on a flexible sensing manipulator

[0016] S1. Place the fruit between two flexible sensing grasping mechanisms. The control module controls the stepping motor to rotate forward through the motor drive circuit to drive the flexible sensing grasping mechanism to close, and continuously applies a closing force on the flexible sensing grasping mechanism, so that the inner side of the flexible sensing grasping mechanism fits the fruit surface and generates a bending deformation.

[0017] The signal acquisition module obtains the sensed signal pressure signal value after bending deformation through the flexible pressure sensor on the inner side, and the signal acquisition module obtains the sensed signal bending angle signal value after bending deformation through the bending angle sensor on the outer side.

[0018] S2. The pressure signal value and the bending angle signal value are transmitted to the control module in real time. The control module performs fusion processing on the pressure signal value and the bending angle signal value to obtain a grasping comprehensive signal value.

[0019] S3. The grasping comprehensive signal value is sent to the host computer in real time. The host computer judges and processes according to the grasping comprehensive signal value to obtain the effective grasping signal duration.

[0020] S4. The fruit diameter is obtained by processing according to the effective grasping duration using an approximate fitting formula.

[0021] S5. The control module controls the stepping motor to reverse through the motor drive circuit, drives the flexible sensing grasping mechanism to open, the flexible sensing grasping mechanism releases the fruit, and after removing the fruit, the next fruit diameter is detected.

[0022] In the step S2, after the control module performs fusion processing on the pressure signal value and the bending angle signal value, the grasping comprehensive signal value is obtained according to the following formula:

[0023]

[0024] Among them, H is the grasping comprehensive signal value after fusion processing, F is the pressure signal value measured by the flexible pressure sensor, θ is the bending angle signal value measured by the bending angle sensor, and k is the fusion coefficient.

[0025] The judgment processing in the step S3 specifically includes the following steps:

[0026] D1. When the grasping comprehensive signal value is first equal to the preset effective grasping signal threshold, the host computer records the moment as the effective grasping start moment and continues to perform grasping.

[0027] When the grasping comprehensive signal value is equal to the preset effective grasping signal threshold for the second time, the host computer records the moment as the end moment of effective grasping, and then stops the grasping operation.

[0028] D2. Obtain the duration of the effective grasping signal based on the end moment and the start moment of effective grasping.

[0029] The fruit diameter in step S4 is obtained through the following approximate fitting formula:

[0030]

[0031] where D is the fruit diameter, T is the duration of the effective grasping signal, V is the rotational speed of the stepper motor, λ is the rotational speed adjustment factor of the stepper motor, and m is the correction coefficient.

[0032] The beneficial effects of the present invention are as follows:

[0033] 1. High efficiency: Grasping and signal acquisition are completed synchronously, with a fast detection speed, suitable for large-scale assembly line operations;

[0034] 2. High precision: Based on multi-modal signal fusion processing, the fruit diameter prediction accuracy is high, with small errors;

[0035] 3. Strong applicability: Suitable for fruits of various shapes, sizes, and surface characteristics;

[0036] 4. Low cost: The equipment cost is relatively low, making it easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is the overall schematic diagram of the device of the present invention;

[0038] Figure 2 is the fixed schematic diagram of the stepper motor of the present invention;

[0039] Figure 3 is the schematic diagram of the stepper motor driving the flange lifting platform of the present invention;

[0040] Figure 4 is the schematic diagram of the principle of the method of the present invention.

[0041] In the figure: 1. Flexible sensing and grasping mechanism, 1a. Bending angle sensor, 1b. Flexible pressure sensor, 1c. Flexible soft finger, 1d. Soft finger base, 2. Driving module, 2a. Stepper motor, 2b. Output shaft lead screw, 2c. Flange lifting platform, 2d. Motor driving circuit, 2e. Motor fixing platform, 2f. Threaded flange, 2g. Base plate, 2h. Platform flange through hole, 2i. Strip-shaped through slot, 2j. Base plate counterbore, 3. Signal acquisition module, 4. Control module, 5. Host computer, 6. Fruit, 7. Fixed slide bar, 8. Connecting rod. Detailed implementation mode

[0042] The present invention will be described in more detail below with reference to the accompanying drawings and embodiments. However, the present invention is not limited thereto. For those of ordinary skill in the art in the technical field, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as within the protection scope of the present invention. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0043] As Figure 1 shown, the fruit diameter detection device in the specific embodiment of the present invention includes two flexible sensing and grasping mechanisms 1, a driving mechanism 2, a fixed slide bar 7 and a connecting rod 8; the two flexible sensing and grasping mechanisms 1 are symmetrically arranged, and each flexible sensing and grasping mechanism 1 is hinged to the driving mechanism through the fixed slide bar 7 and the connecting rod 8, and each flexible sensing and grasping mechanism 1 is sequentially connected to the host computer 5 through the signal acquisition module 3 and the control module 4 for communication.

[0044] A fruit 6 is placed between the two flexible sensing and grasping mechanisms 1. After the driving mechanism 2 is started, it drives the two flexible sensing and grasping mechanisms 1 to move closer inward to grasp the fruit 6. The signal acquisition module 3 obtains two sensing signals after grasping the fruit through the two flexible sensing and grasping mechanisms 1. The signal acquisition module 3 outputs the two sensing signals to the control module 4. The control module 4 performs fusion processing on the two sensing signals to obtain a grasping comprehensive signal value, and the grasping comprehensive signal value is sent to the host computer 5. The host computer 5 performs data analysis and processing to obtain the fruit diameter of the fruit 6, realizing the detection of the fruit diameter of the fruit 6. The transmission protocol between the control module 4 and the host computer 5 is UART communication.

[0045] The two flexible sensing grasping mechanisms 1 have the same structure; each flexible sensing grasping mechanism 1 includes a flexible soft finger 1c, a soft finger base 1d, a bending angle sensor 1a, and a flexible pressure sensor 1b; the flexible soft finger 1c is fixedly installed on the soft finger base 1d, and the soft finger base 1d is hinged to the driving mechanism 2 through a fixed slide bar 7 and a connecting rod 8; the side of the flexible soft finger 1c close to the center of the driving mechanism 2 is the inner grasping surface, and the other side is the outer grasping surface; the flexible pressure sensor 1b is installed on the inner grasping surface of the flexible soft finger 1c, and the bending angle sensor 1a is installed on the outer grasping surface of the flexible soft finger 1c. Both the bending angle sensor 1a and the flexible pressure sensor 1b are connected to the control module 4 through a signal acquisition module 3.

[0046] As Figure 1 shown, the cross-section of the flexible soft finger 1c in the non-working state is an isosceles triangle, and multiple flexible connecting cross ribs are arranged between the two waists. The multiple flexible connecting cross ribs are parallel and spaced, so that the length direction of the flexible connecting cross ribs is approximately perpendicular to the direction of the pressure generated by the contact between the fruit 6 and the flexible sensing grasping mechanism 1, and the resistance to deformation is smaller. When the flexible sensing grasping mechanism 1 works, under the lifting action of the connecting rod 8, the two waists are bent into arcs with different curvatures, and the flexible sensing grasping mechanism 1 forms an approximate crescent moon, closely fitting the surface of the fruit 6.

[0047] As Figure 2 and Figure 3 shown, the driving module 2 includes a motor fixing platform 2e, a stepping motor 2a, a threaded flange 2f, a flange lifting platform 2c, and a bottom plate 2g; the bottom plate 2g, the flange lifting platform 2c, and the motor fixing platform 2e are arranged at intervals from bottom to top. A platform flange through hole 2h is opened in the middle of the flange lifting platform 2c. On the flange lifting platform 2c at both edges, bosses are respectively arranged extending radially outward. Strip-shaped through grooves 2i are opened on the flange lifting platform 2c between the two bosses and the platform flange through hole 2h. The strip-shaped through grooves 2i are arranged along the radial direction of the driving module 2. Two slide bar card slots are opened on the motor fixing platform 2e. The upper end of the fixed slide bar 7 is fixedly installed in the slide bar card slot of the motor fixing platform 2e. The upper end of the fixed slide bar 7 passes through the strip-shaped through groove 2i and is hinged to one side of the corresponding soft finger base 1d close to the center of the driving module 2 through a gasket and a fixed pin rod. The lower end of the fixed slide bar 7 passes through the strip-shaped through groove 2i movably along the radial direction and is fixedly installed on the bottom plate 2g. The other side of the soft finger base 1d far from the center of the driving module 2 is hinged to the boss of the flange lifting platform 2c through a connecting rod 8 through a gasket and a fixed pin rod.

[0048] A bottom plate sunken hole 2j is formed in the middle of the bottom plate 2g. A threaded flange 2f is fixedly installed in the middle of the flange lifting platform 2c. A stepping motor 2a is fixedly installed on the lower surface of the motor fixed platform 2e. The output shaft lead screw 2b of the stepping motor 2a is coaxially connected to the threaded flange 2f through a thread. The end of the output shaft lead screw 2b passes through the threaded flange 2f and is movably installed in the bottom plate sunken hole 2j. The stepping motor 2a is electrically connected to the control module 4 through the motor drive circuit 2d.

[0049] The fixed slide bar 7 close to the flange lifting platform 2c is arranged in a shape that bends outward from bottom to top, so as to limit the flange lifting platform 2c, and finally control the opening angle range of the flexible sensing grasping mechanism 1.

[0050] The working process of the present invention is as follows:

[0051] When the stepping motor 2a starts, it drives the output shaft lead screw 2b to start rotating. Since the output shaft lead screw 2b and the threaded flange 2f are internally connected by a thread, and the relative position of the threaded flange 2f and the flange lifting platform 2c is fixed, with the rotation of the output shaft lead screw 2b, the movement of the flange lifting platform 2c is a linear movement parallel to the output shaft lead screw 2b, so as to realize the conversion of the rotational movement of the output shaft lead screw 2b into the lifting and lowering movement of the flange lifting platform 2c, drive the connecting rod 8 and the soft finger base 1d to move, and finally form the opening and closing movement of the flexible sensing grasping mechanism 1; the fixed slide bar 7 has a certain degree of curvature, which can limit the flange lifting platform 2c, so as to control the opening angle range of the flexible sensing grasping mechanism 1.

[0052] When the flexible sensing grasping mechanism 1 works, under the action of the lifting of the flange lifting platform 2c, the two waists of the isosceles triangle are bent into arcs with different curvatures, and the flexible sensing grasping mechanism 1 becomes approximately a crescent moon, closely fitting the surface of the fruit 6. The flexible pressure sensor 1b and the bending angle sensor 1a of each flexible sensing grasping mechanism 1 will generate different sensing signals after being subjected to different magnitudes of forces and bending deformation angles. The signal acquisition module 3 obtains the sensing signals through the two flexible sensing grasping mechanisms 1. The signal acquisition module 3 outputs the sensing signals to the control module 4. The control module 4 performs fusion processing on the sensing signals to obtain a grasping comprehensive signal value. The grasping comprehensive signal value is sent to the host computer 5, and the host computer 5 performs data analysis and processing to obtain the fruit diameter of the fruit 6, realizing the detection of the fruit diameter of the fruit 6.

[0053] The specific embodiments of the present invention are implemented according to the following steps:

[0054] S1. Place the fruit 6 between two flexible sensing and grasping mechanisms 1. The control module 4 controls the stepper motor 2a to rotate forward through the motor drive circuit 2d to drive the flexible sensing and grasping mechanism 1 to close, and continuously applies a closing force on the flexible sensing and grasping mechanism 1, so that the inner side surface of the flexible sensing and grasping mechanism 1 fits the surface of the fruit 6 and generates a bending deformation.

[0055] The signal acquisition module obtains the sensed signal pressure signal value after the bending deformation through the flexible pressure sensor 1b on the inner side surface, and the signal acquisition module obtains the sensed signal bending angle signal value after the bending deformation through the bending angle sensor 1a on the outer side surface.

[0056] As Figure 1 and Figure 4 shown, after the control module 4 performs fusion processing on the pressure signal value and the bending angle signal value, the grasping comprehensive signal value is obtained according to the following formula:

[0057]

[0058] where H is the grasping comprehensive signal value after fusion processing, with the unit N / deg, F is the pressure signal value measured by the flexible pressure sensor 1b, with the unit N, θ is the bending angle signal value measured by the bending angle sensor 1a, with the unit of degree or deg, and k is the fusion coefficient.

[0059] S2. The pressure signal value and the bending angle signal value are transmitted to the control module 4 in real time. The control module 4 performs fusion processing on the pressure signal value and the bending angle signal value to obtain the grasping comprehensive signal value.

[0060] S3. The grasping comprehensive signal value is sent to the host computer 5 in real time. The host computer 5 judges and processes according to the grasped comprehensive signal value obtained in real time to obtain the effective grasping signal duration.

[0061] The judgment and processing specifically include the following steps:

[0062] D1. When the grasping comprehensive signal value is first equal to the preset effective grasping signal threshold, the host computer records the moment as the start moment of effective grasping and continues to perform grasping.

[0063] When the grasping comprehensive signal value is second equal to the preset effective grasping signal threshold, the host computer records the moment as the end moment of effective grasping, and then stops performing grasping.

[0064] D2. Obtain the effective grasping signal duration according to the end moment of effective grasping and the start moment of effective grasping.

[0065] In specific implementation, the preset effective grasping signal threshold is 10 N / deg.

[0066] In a specific implementation, the effective grabbing signal duration is obtained by subtracting the effective grabbing end time from the effective grabbing start time.

[0067] In the specific implementation, the grasping comprehensive signal value changes from small to large, and then becomes small again. In the process of changing from small to large, there will be a moment when it is equal to the preset effective grasping signal threshold for the first time, and this moment is recorded as the effective grasping start time. In the process of becoming smaller again, the grasping comprehensive signal value will be equal to the preset effective grasping signal threshold for the second time, and this moment is recorded as the effective grasping end time. The effective grasping end time is subtracted from the effective grasping start time to obtain the effective grasping signal duration.

[0068] S4, the upper computer 5 uses an approximate fitting formula to process according to the effective grasping time to obtain the fruit diameter of the fruit 6.

[0069] like Figure 4 As shown, the fruit diameter of fruit 6 is obtained by the following approximate fitting formula:

[0070]

[0071] Wherein, D is the diameter of the fruit 6, in mm, T is the effective grabbing signal duration, in ms, V is the speed of the stepper motor 2a, in revolutions per second, λ is the speed adjustment factor of the stepper motor 2a, and m is the correction coefficient.

[0072] The results obtained can be directly used for fruit grading, quality assessment and subsequent processing.

[0073] S5, the control module 4 controls the stepping motor 2a to reverse through the motor driving circuit 2d, drives the flexible sensing grasping mechanism 1 to open, and the flexible sensing grasping mechanism 1 releases the fruit 16, and detects the diameter of the next fruit 6 after taking the fruit.

[0074] In specific implementation, the effective grasping signal duration has nothing to do with the total duration of continuous grasping of the flexible sensing grasping mechanism 1, but only with the speed of the stepper motor 2a. After the speed of the stepper motor 2a is fixed at the beginning, the effective grasping signal duration is also fixed.

[0075] The invention proposes a fruit diameter detection device and method based on a flexible sensing manipulator, which uses the relationship between the grasping comprehensive signal value and the fruit diameter to achieve fast and accurate fruit size measurement. A flexible sensing manipulator with high efficiency and low cost and capable of both grasping and measuring functions is developed to meet the needs of fruit diameter detection.

[0076] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any slight modifications, equivalent substitutions and improvements made to the above embodiments based on the technical essence of the present invention should be included in the protection scope of the technical solution of the present invention.

Claims

1. A fruit diameter detection device based on a flexible sensing manipulator, characterized in that: The fruit diameter detection device is arranged symmetrically as a whole, and comprises two flexible sensing grasping mechanisms (1), a driving mechanism (2), a fixed sliding rod (7) and a connecting rod (8); the two flexible sensing grasping mechanisms (1) are arranged symmetrically, each flexible sensing grasping mechanism (1) is hinged to the driving mechanism via the fixed sliding rod (7) and the connecting rod (8), and each flexible sensing grasping mechanism (1) is communicatively connected to the host computer (5) via the signal acquisition module (3) and the control module (4) in turn; A fruit (6) is placed between two flexible sensing grasping mechanisms (1), and after the driving mechanism (2) is started, the two flexible sensing grasping mechanisms (1) are driven to move inwards and grasp the fruit (6), and the signal acquisition module (3) obtains a sensing signal after grasping the fruit through the two flexible sensing grasping mechanisms (1), and the signal acquisition module (3) outputs the sensing signal to the control module (4), and the control module (4) performs fusion processing on the sensing signal to obtain a grasping comprehensive signal value, and the grasping comprehensive signal value is sent to a host computer (5), and the host computer (5) performs data analysis processing to obtain the fruit diameter of the fruit (6), thereby realizing the detection of the fruit diameter of the fruit (6).

2. The fruit diameter detection device based on a flexible sensing manipulator according to claim 1 is characterized in that: The two flexible sensing grasping mechanisms (1) have the same structure; each flexible sensing grasping mechanism (1) comprises a flexible soft finger (1c), a soft finger base (1d), a bending angle sensor (1a) and a flexible pressure sensor (1b); the flexible soft finger (1c) is fixedly mounted on the soft finger base (1d), and the soft finger base (1d) is hinged to the driving mechanism (2) via a fixed sliding rod (7) and a connecting rod (8); a side surface of the flexible soft finger (1c) close to the center of the driving mechanism (2) is a grasping inner side surface, and the other side surface is a grasping outer side surface; the flexible pressure sensor (1b) is mounted on the grasping inner side surface of the flexible soft finger (1c), and the bending angle sensor (1a) is mounted on the grasping outer side surface of the flexible soft finger (1c); the bending angle sensor (1a) and the flexible pressure sensor (1b) are both connected to the control module (4) via a signal acquisition module (3).

3. The fruit diameter detection device based on a flexible sensing manipulator according to claim 2 is characterized in that: The cross section of the flexible soft finger (1c) in a non-working state is an isosceles triangle, and a plurality of flexible connecting transverse ribs are arranged between the two sides, and the plurality of flexible connecting transverse ribs are arranged in parallel and at intervals.

4. The fruit diameter detection device based on a flexible sensing manipulator according to claim 2 is characterized in that: The driving module (2) comprises a motor fixing platform (2e), a stepping motor (2a), a threaded flange (2f), a flange lifting platform (2c) and a bottom plate (2g); the bottom plate (2g), the flange lifting platform (2c) and the motor fixing platform (2e) are arranged in sequence from bottom to top, a platform flange through hole (2h) is provided in the middle of the flange lifting platform (2c), two edges of the flange lifting platform (2c) are respectively provided with bosses extending radially outward, and the flange lifting platform (2c) between the two bosses and the platform flange through hole (2h) is provided with a strip through groove (2i), and the strip through groove (2 i) arranged along the radial direction of the driving module (2), two slide bar slots are provided on the motor fixing platform (2e), the upper end of the fixed slide bar (7) is fixedly mounted on the slide bar slot of the motor fixing platform (2e), the upper end of the fixed slide bar (7) passes through the strip through slot (2i) and is hinged to one side of the corresponding soft finger base (1d) close to the center of the driving module (2), the lower end of the fixed slide bar (7) can moveably pass through the strip through slot (2i) along the radial direction and is fixedly mounted on the bottom plate (2g), and the other side of the soft finger base (1d) away from the center of the driving module (2) is hinged to the boss of the flange lifting platform (2c) through a connecting rod (8); A bottom plate countersunk hole (2j) is opened in the middle of the bottom plate (2g); a threaded flange (2f) is fixedly installed in the middle of the flange lifting platform (2c); a stepping motor (2a) is fixedly installed on the lower surface of the motor fixing platform (2e); an outgoing shaft screw rod (2b) of the stepping motor (2a) is coaxially connected to the threaded flange (2f) via a thread; an end of the outgoing shaft screw rod (2b) passes through the threaded flange (2f) and is movably installed in the bottom plate countersunk hole (2j); and the stepping motor (2a) is electrically connected to the control module (4) via a motor driving circuit (2d).

5. The fruit diameter detection device based on the flexible sensing manipulator according to claim 4 is characterized in that: The fixed slide bar (7) close to the flange lifting platform (2c) is arranged to be bent outward from bottom to top, thereby limiting the flange lifting platform (2c) and ultimately controlling the opening angle range of the flexible sensing grasping mechanism (1).

6. A fruit diameter detection method for implementing the fruit diameter detection device based on a flexible sensing manipulator according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: S1, placing the fruit (6) between the two flexible sensing grasping mechanisms (1), the control module (4) controlling the stepping motor (2a) to rotate forward to drive the flexible sensing grasping mechanism (1) to close, and continuously applying a closing force on the flexible sensing grasping mechanism (1), so that the inner side surface of the flexible sensing grasping mechanism (1) fits the surface of the fruit (6) to generate a bending deformation; The signal acquisition module acquires the pressure signal value after bending deformation through the flexible pressure sensor (1b) on the inner side, and the signal acquisition module acquires the bending angle signal value after bending deformation through the bending angle sensor (1a) on the outer side; S2, the pressure signal value and the bending angle signal value are transmitted to the control module (4) in real time, and the control module (4) performs fusion processing on the pressure signal value and the bending angle signal value to obtain a comprehensive grasping signal value; S3, the grasping comprehensive signal value is sent to the upper computer (5) in real time, and the upper computer (5) performs judgment and processing based on the grasping comprehensive signal value to obtain the effective grasping signal duration; S4, using an approximate fitting formula to process according to the effective grasping time to obtain the fruit diameter of the fruit (6); S5, the control module (4) controls the stepper motor (2a) to reverse, drives the flexible sensing grasping mechanism (1) to open, and the flexible sensing grasping mechanism (1) releases the fruit (6), and detects the diameter of the next fruit (6) after the fruit is taken out.

7. The method for detecting the diameter of a fruit according to claim 6, characterized in that: In step S2, the control module (4) performs fusion processing on the pressure signal value and the bending angle signal value, and obtains the grasping comprehensive signal value according to the following formula: Wherein, H is the grasping integrated signal value after fusion processing, F is the pressure signal value measured by the flexible pressure sensor (1b), θ is the bending angle signal value measured by the bending angle sensor (1a), and k is the fusion coefficient.

8. The method for detecting the diameter of a fruit according to claim 6, characterized in that: The determination process in step S3 specifically includes the following steps: D1. When the grasping comprehensive signal value is equal to the preset effective grasping signal threshold for the first time, the host computer records the moment as the effective grasping start moment and continues grasping; When the grasping comprehensive signal value is equal to the preset effective grasping signal threshold for the second time, the upper computer records the time as the effective grasping end time, and then stops grasping; D2. Obtain the effective grabbing signal duration according to the effective grabbing end time and the effective grabbing start time.

9. The method for detecting the diameter of a fruit according to claim 6, characterized in that: The fruit diameter of the fruit (6) in step S4 is obtained by the following approximate fitting formula: Wherein, D is the diameter of the fruit (6), T is the effective grasping signal duration, V is the rotation speed of the stepper motor (2a), λ is the rotation speed adjustment factor of the stepper motor (2a), and m is the correction coefficient.

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