Fresh corn freshness detection device and method based on mechanical arm

Abstract

The invention provides a fresh corn freshness detection method and system based on a mechanical arm, and belongs to the technical field of intelligent agricultural equipment. The detection device comprises a mechanical arm, the mechanical arm is provided with a mechanical clamping jaw, and the detection device further comprises a driving motor used for driving the mechanical clamping jaw to be opened and closed; the flexible film pressure sensor is mounted on the surfaces of the two clamping arms of the mechanical clamping jaw in a covering manner, and a sensor hole is formed in the flexible film pressure sensor; the pressure sensor device comprises a probe type pressure sensor and a driving device, the probe type pressure sensor is installed in the sensor hole, and the driving device is used for driving the probe type pressure sensor. The detection method is realized based on the detection device. The method can be used for efficient treatment of fresh corn and lossless evaluation of freshness.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent agricultural equipment, and in particular to a device and method for detecting the freshness of fresh corn based on a robotic arm. Background Art

[0002] Fresh corn is popular in the market for its tender taste and rich nutrition. Its freshness directly affects the consumer experience and economic value. However, the current freshness detection mostly relies on traditional manual touch or external instrument detection, such as spectrometers, humidity meters, etc. Although these methods are effective, they have problems such as expensive equipment, low detection efficiency, and cumbersome processes. In addition, the common robotic arms in the market are mainly used for handling or sorting, lacking the function of freshness detection, and it is difficult to meet the needs of modern agriculture for high efficiency and high precision. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention proposes a high-efficiency and high-precision machine vision-based stainless steel spot welding surface quality detection method and system, which can achieve non-destructive freshness evaluation while completing the corn grabbing action.

[0004] The specific technical solutions are:

[0005] A fresh corn freshness detection device based on a mechanical arm comprises a mechanical arm, the mechanical arm is provided with a mechanical clamp, and the detection device further comprises:

[0006] A driving motor, used to drive the mechanical gripper to open and close;

[0007] A flexible film pressure sensor covers the surfaces of two clamping arms installed on the mechanical clamp, and a sensor hole is provided on the flexible film pressure sensor;

[0008] The pressure sensor device comprises a probe type pressure sensor and a driving device, wherein the probe type pressure sensor is installed in a sensor hole, and the driving device is used for driving the probe type pressure sensor.

[0009] Furthermore, the number of the pressure sensor devices is more than two, and the driving device includes a linear vibration motor and a flexible coupling, and the two ends of the flexible coupling are respectively connected to the linear vibration motor and the probe-type pressure sensor.

[0010] Furthermore, the detection device also includes a silicone layer, which is arranged on the surface of the flexible film pressure sensor, and the silicone layer is provided with silicone layer holes corresponding to the sensor holes.

[0011] Furthermore, the detection device also includes a microprocessor for receiving signals from the flexible film pressure sensor and the probe pressure sensor, determining whether fresh corn is clamped and determining the freshness of the fresh corn, and controlling the drive motor.

[0012] Furthermore, the mechanical gripper is made of aluminum alloy, and the drive motor is installed inside the mechanical gripper.

[0013] Furthermore, the flexible film pressure sensor uses polydimethylsiloxane as a substrate.

[0014] Furthermore, the probe of the probe type pressure sensor is made of stainless steel, and the top end is polished.

[0015] The present invention also provides a method for detecting the freshness of fresh corn based on a robotic arm implemented by the above detection device, the method comprising:

[0016] Step 1: Start the detection device;

[0017] Step 2: The mechanical gripper of the detection device approaches the fresh corn, and the flexible film pressure sensor on the mechanical gripper starts to monitor the pressure in real time while gripping the fresh corn;

[0018] Step 3: judging whether the pressure of the mechanical gripper reaches a threshold value according to the pressure value monitored by the flexible film sensor;

[0019] If the pressure of the mechanical gripper to grip the fresh corn does not reach the set threshold, the gripper repeats step 2;

[0020] If the pressure of the clamping jaws to hold the corn reaches the set threshold, proceed to the next step;

[0021] Step 4: Start the linear vibration motor, and the probe pressure sensor starts to work, squeezing the surface of the fresh corn and obtaining squeezing force data;

[0022] Step 5: The probe pressure sensor converts the extrusion force signal into an electrical signal and transmits it to the microprocessor, and the microprocessor collects the peak value data of the probe pressure sensor;

[0023] Step 6: The microprocessor compares the peak value data of the probe pressure sensor with the fresh corn freshness grade model to complete the determination of the corn freshness grade.

[0024] Furthermore, the method further comprises:

[0025] Step 7: The microprocessor outputs the detection result of the fresh corn, and then the mechanical gripper releases the fresh corn or transfers the fresh corn to the next process according to the instruction of the microprocessor.

[0026] The beneficial effects of the above technical solution of the present invention are as follows:

[0027] Compared with the existing detection devices and methods, the freshness detection device and method of fresh corn based on a robotic arm provided by the present invention have the following advantages:

[0028] First, the present invention realizes precise control of the clamping force and the probe-type pressure sensor based on the real-time monitoring of the flexible film pressure sensor and the precise control of the micro-drive motor and the micro-linear vibration motor by the microprocessor, thereby realizing non-destructive detection of the freshness of fresh corn and avoiding damage to the corn caused by traditional detection.

[0029] Secondly, the present invention realizes intelligent operation and builds an intelligent operating system by cleverly integrating core components such as flexible film pressure sensors, probe pressure sensors, micro linear vibration motors and microprocessors. The system not only integrates a series of functions such as fresh corn clamping, detection and sorting, but also can dynamically and accurately adjust the clamping force of the clamping claws based on sensor feedback by means of the mechanical arm, ensuring that the detection data is highly accurate and reliable, and comprehensively improving the work efficiency of the entire fresh corn detection and sorting process, bringing efficient, non-destructive and intelligent innovative solutions to the field of agricultural product detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a cross-sectional structural diagram of the detection device of the present invention;

[0031] Figure 2 The present invention is a flow chart of freshness detection of fresh corn.

[0032] The reference numerals are as follows:

[0033] 1. Driving motor; 2. Flexible film pressure sensor; 3. Silicone layer; 4. Holes; 5. Linear vibration motor; 6. Flexible coupling; 7. Probe pressure sensor. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] See also Figure 1 A fresh corn freshness detection device comprises a mechanical arm, the mechanical arm comprises a mechanical gripper, the gripper adopts a human hand-like structure, and can firmly grasp corn with irregular shapes;

[0037] A micro drive motor 1 is installed inside the mechanical gripper to achieve precise opening and closing grasping action;

[0038] A flexible film pressure sensor 2, which covers the surfaces of the two clamping arms of the mechanical gripper and is used to detect whether the mechanical gripper has clamped the fresh corn. The flexible film pressure sensor has a plurality of holes 4;

[0039] The food-grade silicone layer 3 is located on the surface of the flexible film pressure sensor 2, has good elasticity and cushioning properties to protect the fresh corn from being pinched, has appropriate surface friction to prevent the corn from sliding, is non-toxic and tasteless, has stable chemical properties, and meets food safety standards to ensure the quality and safety of the fresh corn. There are also holes 4 on it that are equivalent to those on the flexible film pressure sensor 2.

[0040] The micro linear vibration motor 5 has a rectangular shape and is relatively flat. Each micro linear vibration motor 5 is set with a fixed vibration frequency (18 Hz) and amplitude (2 mm).

[0041] The probe pressure sensor 7 is located in each hole 4. It will press 2mm into the corn along with the micro linear vibration motor 5 to determine the freshness of the corn by the size of the detection force.

[0042] The flexible coupling 6 connects the probe-type pressure sensor 7 and the micro linear vibration motor 5 .

[0043] The microprocessor (not shown in the figure) receives and converts the signals from the flexible film pressure sensor 2 and the probe pressure sensor 7, and can also control the start of the linear vibration motor. At the same time, it analyzes the data collected by the probe pressure sensor 7, determines the internal characteristics of the corn, and stops the vibration of the micro drive motor in time when an abnormality is detected, thereby realizing intelligent control and signal processing of the entire fresh corn detection process.

[0044] In this embodiment, the mechanical gripper is made of lightweight high-strength aluminum alloy, which has sufficient mechanical strength and toughness to ensure long-term stable operation. A micro drive motor is installed inside the mechanical gripper to accurately control the opening and closing action. The opening and closing range is 0-10 cm, which can meet the needs of clamping fresh corn of different sizes.

[0045] In this embodiment, a flexible film pressure sensor 2 with polydimethylsiloxane (PDMS) as the substrate is selected, with a thickness of 0.2-0.3 mm and excellent flexibility and pressure sensitivity. Tiny holes 4 are evenly distributed on the surface of the film, and the holes 8 are arranged in a matrix with a spacing of 3-5 mm and an aperture of 1-2 mm, which is convenient for the subsequent installation of the probe-type pressure sensor 7 and can ensure the continuity of its own pressure perception. It is tightly attached to the gripping surface of the clamp through a special silicone adhesive, and a stable connection is formed after the adhesive is cured, ensuring that the flexible film pressure sensor 2 deforms synchronously with the action of the clamp, accurately sensing the clamping pressure, and the pressure measurement accuracy can reach ±0.05 Newton.

[0046] In this embodiment, a micro-probe pressure sensor 7 is installed in each hole 4. The sensor probe is made of food-grade stainless steel, with a rounded top, a diameter of 0.8-1 mm, and a length of 5-8 mm to ensure that the corn skin is not damaged when it contacts the corn. The sensor works based on the piezoresistive effect, with a range of 0-5 Newtons and a resolution of 0.01 Newtons, and can accurately capture the microscopic mechanical changes inside the corn.

[0047] In this embodiment, the bottom of the probe pressure sensor 7 is connected to the output shaft of the micro linear vibration motor 5 through a flexible coupling 6. The linear vibration motor 5 is a brushless DC type with a compact size of 20-30 mm, 15-20 mm, and 10-15 mm in length, width, and height, respectively. The motor has a built-in high-precision controller, which can accurately output 18Hz frequency and 2mm amplitude vibration after receiving an external control signal, driving the probe to squeeze 2mm into the corn, and the control accuracy of the extrusion process force is ±0.1 Newton.

[0048] In this embodiment, the signal acquisition circuit connected to the flexible film pressure sensor 2 and the probe pressure sensor 7 converts the analog signal into a digital signal and transmits it to the microprocessor. The microprocessor uses a high-performance embedded chip and runs an advanced algorithm to determine whether the clamp successfully clamps the corn based on the signal of the flexible film pressure sensor. The clamping force threshold is set at 0.5-1.5 Newtons, and it is determined to be a successful clamp if the threshold is exceeded.

[0049] In this embodiment, the successful clamping signal triggers the linear vibration motor start command, and the motor vibrates according to preset parameters. During this period, the probe pressure sensor continues to collect data, and the microprocessor distinguishes the freshness level of corn by analyzing the peak pressure output by the sensor. If a sudden pressure change exceeding the set range is detected, the motor vibration is stopped immediately to prevent damage to the corn. The data processing and response time is 10-20 milliseconds.

[0050] The collected signals are processed by the microprocessor located inside the mechanical arm. The microprocessor uses a high-performance embedded chip and runs an advanced algorithm to determine whether the clamp successfully clamps the corn based on the signal of the flexible film pressure sensor 2. The clamping force threshold is set at 0.5-1.5 Newtons. If the threshold is exceeded, it is determined to be a successful clamping. The successful clamping signal triggers the linear vibration motor start command, and the motor vibrates according to the preset parameters. During this period, the probe pressure sensor continues to collect data. The microprocessor distinguishes the freshness level of corn by analyzing the pressure peak value output by the probe pressure sensor 7. The basis is to first perform a probe pressure test on corns of different freshness, and determine their freshness level in combination with standard testing, thereby establishing a corresponding model between pressure data and the freshness level of fresh corn, and setting the pressure threshold range of each level in the microprocessor. The levels are divided into: too tender corn (pressure peak value is 1-3N); fresh corn (pressure peak value is 3-5N); too old corn (pressure peak value is 5-8N). If a sudden change in pressure is detected that exceeds the set range, the motor vibration is stopped immediately to prevent damage to the corn. The data processing and response time is 10-20 milliseconds.

[0051] Example 2

[0052] See also Figure 2 , which shows the workflow diagram of the present invention for fresh corn freshness detection. The present invention implements the function of clamping and completing the corn freshness detection, including the following steps:

[0053] Step 1: The equipment starts, the detection device starts running, and then proceeds to the next step;

[0054] Step 2: The mechanical gripper of the device approaches the fresh corn, and while gripping the fresh corn, the flexible film pressure sensor on the mechanical gripper starts to monitor the pressure in real time, and then proceeds to the next step;

[0055] Step 3: Determine whether the pressure of the mechanical gripper to grip the corn reaches a threshold;

[0056] If the pressure of the mechanical gripper gripping the corn does not reach the set threshold, the mechanical gripper repeats step 2 and continues to move closer to the corn until the pressure reaches the set threshold;

[0057] If the pressure of the clamping jaws to hold the corn reaches the set threshold, proceed to the next step;

[0058] Step 4: Start the linear vibration motor, and the probe pressure sensor starts to work, squeezing the surface of the fresh corn and obtaining squeezing force data;

[0059] Step 5: The probe pressure sensor converts the extrusion force signal into an electrical signal and transmits it to the microprocessor, and the microprocessor collects the peak value data of the probe pressure sensor;

[0060] Step 6: The microprocessor compares the peak value data of the probe pressure sensor with the fresh corn freshness grade model to complete the determination of the fresh corn freshness grade.

[0061] Step 7: Output the inspection result of the corn, and then the mechanical gripper releases the fresh corn or transfers the fresh corn to the next process according to the instruction.

[0062] This embodiment ensures that the freshness of the fresh corn can be accurately detected without damaging the fresh corn.

[0063] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A fresh corn freshness detection device based on a mechanical arm, comprising a mechanical arm, the mechanical arm is provided with a mechanical gripper, characterized in that: The detection device also includes: A driving motor, used to drive the mechanical gripper to open and close; A flexible film pressure sensor covers the surfaces of two clamping arms installed on the mechanical clamp, and a sensor hole is provided on the flexible film pressure sensor; The pressure sensor device comprises a probe type pressure sensor and a driving device, wherein the probe type pressure sensor is installed in a sensor hole, and the driving device is used for driving the probe type pressure sensor.

2. The freshness detection device for fresh corn based on a robotic arm as claimed in claim 1, characterized in that: The number of the pressure sensor devices is more than two, and the driving device includes a linear vibration motor and a flexible coupling, and the two ends of the flexible coupling are respectively connected to the linear vibration motor and the probe-type pressure sensor.

3. The freshness detection device for fresh corn based on a robotic arm as claimed in claim 2, characterized in that: The detection device further comprises a silicone layer, which is arranged on the surface of the flexible film pressure sensor and has silicone layer holes corresponding to the sensor holes.

4. The freshness detection device for fresh corn based on a robotic arm as claimed in claim 3, characterized in that: The detection device also includes a microprocessor for receiving signals from the flexible film pressure sensor and the probe pressure sensor, determining whether fresh corn is clamped and determining the freshness of the fresh corn, and controlling the drive motor.

5. The freshness detection device for fresh corn based on a robotic arm as claimed in claim 4, characterized in that: The mechanical gripper is made of aluminum alloy, and the drive motor is installed inside the mechanical gripper.

6. The freshness detection device for fresh corn based on a robotic arm as claimed in claim 4, characterized in that: The flexible film pressure sensor is based on polydimethylsiloxane.

7. The freshness detection device for fresh corn based on a mechanical arm as claimed in claim 4, characterized in that: The probe of the probe type pressure sensor is made of stainless steel, and the top end is polished.

8. A method for detecting freshness of fresh corn based on a robotic arm and the detection device according to any one of claims 4 to 7, characterized in that: The method comprises: Step 1: Start the detection device; Step 2: The mechanical gripper of the detection device approaches the fresh corn, and the flexible film pressure sensor on the mechanical gripper starts to monitor the pressure in real time while gripping the fresh corn; Step 3: judging whether the pressure of the mechanical gripper reaches a threshold value according to the pressure value monitored by the flexible film sensor; If the pressure of the mechanical gripper to grip the fresh corn does not reach the set threshold, the gripper repeats step 2; If the pressure of the clamping jaws to hold the corn reaches the set threshold, proceed to the next step; Step 4: Start the linear vibration motor, and the probe pressure sensor starts to work, squeezing the surface of the fresh corn and obtaining squeezing force data; Step 5: The probe pressure sensor converts the extrusion force signal into an electrical signal and transmits it to the microprocessor, and the microprocessor collects the peak value data of the probe pressure sensor; Step 6: The microprocessor compares the peak value data of the probe pressure sensor with the fresh corn freshness grade model to complete the determination of the corn freshness grade.

9. The method for detecting freshness of fresh corn based on a robotic arm as claimed in claim 8, characterized in that: The method further comprises: Step 7: The microprocessor outputs the detection result of the fresh corn, and then the mechanical gripper releases the fresh corn or transfers the fresh corn to the next process according to the instruction of the microprocessor.

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