A clamping force detection system and method for a forest fruit vibration harvester

Abstract

The application discloses a kind of clamping force detection system and detection method of forest fruit vibration harvester, belong to clamping force detection technical field.System includes clamping force sensor, be located between movable plate and soft pad, for detecting the clamping load of clamping mechanism to output detection signal;Instrument amplification module is connected clamping force sensor, for the detection signal of clamping force sensor output is amplified, obtains analog voltage signal, analog voltage signal includes no-load zero point voltage and loading voltage;Data acquisition module is connected instrument amplification module, for the analog voltage signal of instrument amplification module output is collected;Data processing module is connected data acquisition module, for obtaining the clamping force of forest fruit vibration harvester according to analog voltage signal and the gain of pre-acquired instrument amplification module, calculation.This application is suitable for clamping force detection of vibration harvesting whole process.

Description

Technical Field

[0001] This invention belongs to the field of clamping force detection technology, specifically relating to a clamping force detection system and method for a vibratory fruit harvester. Background Technology

[0002] In the mechanized harvesting of forest fruits, the clamping mechanism typically applies a clamping load to the trunk or branches of the fruit tree and harvests the fruit through clamping, vibration, and posture maintenance. The magnitude of the clamping force directly affects the effectiveness of the vibration harvesting operation: if the clamping force is too small, slippage of the clamping interface is likely to occur, making it difficult to effectively transfer vibration energy and causing instability in the operating posture; if the clamping force is too large, it may cause damage to the bark, crushing of branches and trunks, overload of the mechanism, and increased energy consumption, thereby reducing the safety and reliability of the harvesting operation.

[0003] Under vibration harvesting conditions, the clamping force is not a constant static load, but changes continuously as the clamping mechanism approaches the trunk, clamps the trunk, vibrates during harvesting, and releases the trunk, accompanied by significant impact loads and high-intensity vibrations. Due to the large clamping force and high vibration intensity during vibration harvesting, ordinary force sensors are prone to damage or even failure under long-term repeated vibration and impact due to insufficient structural strength, poor impact resistance, or unreasonable installation stress, making it difficult to meet the requirements for continuous and stable detection under vibration harvesting conditions in forestry and fruit orchards.

[0004] Strain gauge force sensors are characterized by their compact structure, high sensitivity, good linear response, and strong engineering applicability, making them suitable for mechanical load detection. These sensors typically generate strain through the deformation of a force-measuring unit under load, and then convert the strain change into a millivolt-level differential voltage signal using a strain gauge bridge. However, the original output signal amplitude of the sensor is relatively small, and it is easily affected by factors such as zero-point drift, dynamic impact, vibration interference, and improper range matching during vibration data acquisition. Conventional data acquisition modules struggle to directly, stably, and accurately read the signal. Without stable bridge supply, differential amplification, zero-point setting, range matching, and calibration conversion, problems such as output saturation, insufficient resolution, large fluctuations in acquired data, and difficulty in directly analyzing clamping force data can easily occur. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a clamping force detection system and method for a vibratory harvester of forest fruits, so that the clamping load can be converted into mechanical quantity, bridge differential voltage, conditioning amplification voltage and digital force value in sequence along the force transmission path, thereby forming a clamping force detection system applicable to the entire vibratory harvesting process.

[0006] This invention provides the following technical solution:

[0007] A clamping force detection system for a vibratory harvester of forest fruits is used to detect the clamping force of the clamping mechanism of the vibratory harvester of forest fruits. The clamping mechanism includes a fixed plate, a movable plate slidably connected to the fixed plate, and a soft pad disposed above the movable plate. The movable plate moves upward along the fixed plate until it engages with the top of the fixed plate to clamp the object.

[0008] The clamping force detection system includes:

[0009] A clamping force sensor, located between the movable plate and the soft pad, is used to detect the clamping load of the clamping mechanism and output a detection signal.

[0010] The instrument amplification module is connected to the clamping force sensor and is used to amplify the detection signal output by the clamping force sensor to obtain an analog voltage signal, which includes the no-load zero-point voltage and the applied voltage.

[0011] The data acquisition module connects to the instrumentation amplification module and is used to acquire the analog voltage signal output by the instrumentation amplification module.

[0012] The data processing module, connected to the data acquisition module, is used to calculate the clamping force of the vibratory fruit harvester based on the analog voltage signal and the pre-acquired gain of the instrument amplification module.

[0013] As an optional technical solution of the present invention, the clamping force sensor includes a fixed platform, a floating platform, a force measuring unit, and a connecting component;

[0014] The force measuring unit is mounted between the fixed platform and the floating platform via a connector;

[0015] The floating platform receives the clamping load from the clamping mechanism and transmits the clamping load to the force measuring unit through the connector.

[0016] As an optional technical solution of the present invention, the strain-sensitive area of ​​the force measuring unit is provided with multiple strain gauges;

[0017] When the clamping load is transmitted to the force measuring unit, the strain gauge deforms to generate a detection signal.

[0018] As an optional technical solution of the present invention, the instrument amplification module includes a differential input unit, a gain adjustment unit, a reference voltage adjustment unit and an analog output unit connected in sequence.

[0019] As an optional technical solution of the present invention, it also includes a voltage stabilizing power supply module connected to the clamping force sensor, used to provide a bridge voltage to the clamping force sensor.

[0020] In a second aspect, a detection method is provided based on the clamping force detection system of the vibrating harvester for forest fruits described in the first aspect, comprising: when the clamping mechanism is not in contact with the clamping object and is in an unloaded state, the data processing module acquires the unloaded zero-point voltage;

[0021] When the clamping mechanism clamps the object, the data processing module acquires the applied voltage;

[0022] The data processing module calculates the clamping force of the vibratory fruit harvester based on the applied voltage, the no-load zero-point voltage, and the preset gain of the instrument amplification module.

[0023] As an optional technical solution of the present invention, the data processing module calculates the clamping force of the vibratory harvester of forest fruits based on the applied voltage, the no-load zero-point voltage, and the gain of the pre-acquired instrument amplification module, including:

[0024] The voltage change output by the instrumentation amplification module is calculated based on the applied voltage and the no-load zero-point voltage, and is expressed as follows:

[0025] ;

[0026] in, It represents the amount of voltage change. Indicates the applied voltage. Indicates the no-load zero-point voltage;

[0027] The voltage increment is calculated and expressed as:

[0028] ;

[0029] in, Indicates voltage increment. Indicates the gain of the instrument's amplification module;

[0030] The clamping force of the vibratory fruit harvester is calculated and expressed as:

[0031] ;

[0032] in, This indicates the clamping force of the vibratory fruit harvester. This represents the sensor calibration coefficient.

[0033] As an optional technical solution of the present invention, the gain of the instrument amplification module is expressed as follows:

[0034] ;

[0035] in, Indicates the gain resistor. It represents 1,000 euros.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] The clamping force detection system for a vibratory fruit harvester provided by this invention places a clamping force sensor between a movable plate and a soft pad. When clamping occurs, it detects the clamping load of the clamping mechanism. The detection signal is amplified by an instrument amplification module to improve the stability of the detection signal. The data processing module calculates the clamping force of the vibratory fruit harvester based on the analog voltage signal. It is suitable for clamping force detection throughout the entire vibratory harvesting process and meets the requirements for continuous and stable detection under the clamping conditions of vibratory fruit harvesting. Attached Figure Description

[0038] Figure 1 This is an assembly diagram of the clamping force detection system in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of the clamping force detection system in an embodiment of the present invention;

[0040] Figure 3 This is a cross-sectional view of the clamping force sensor in an embodiment of the present invention;

[0041] Figure 4 This is a circuit diagram of the force measuring unit in an embodiment of the present invention.

[0042] The components in the diagram are labeled as follows: fixed plate 1, movable plate 2, guide rail 3, soft pad 4, first rubber block 5, second rubber block 6, voltage stabilizing power supply module 7-1, clamping force sensor 7-2, instrument amplification module 7-3, data acquisition module 7-4, data processing module 7-5, fixed platform 701, force measuring unit 702, first nut 703, connector 704, second nut 705, and floating platform 706. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0044] Example 1

[0045] This embodiment provides a clamping force detection system for a vibratory fruit harvester, used to detect the clamping force of the vibratory fruit harvester's clamping mechanism. For example... Figure 1 As shown, the clamping mechanism includes a fixed plate 1, a movable plate 2 slidably connected to the fixed plate 1, and a soft pad 4 disposed above the movable plate 2. The movable plate 2 moves forward along the fixed plate 1 until it engages with the top of the fixed plate 1 to clamp the object. In this embodiment, the soft pad 4 is a rubber pad.

[0046] Furthermore, the top of the fixed plate 1 is provided with a first rubber block 5 and a second rubber block 6. The movable plate 2 moves forward along the guide rail 3 on the fixed plate 1 until it cooperates with the first rubber block 5 and the second rubber block 6 to clamp the object.

[0047] like Figure 2 As shown, the clamping force detection system includes:

[0048] The voltage regulator module 7-1 is connected to the clamping force sensor 7-2 and is used to provide a bridge voltage to the clamping force sensor 7-2. To ensure that the measurement conditions are consistent with the sensor calibration conditions, the bridge voltage is preferably 10 V in this embodiment. In other embodiments, other bridge voltages consistent with the sensor calibration report can also be used. The voltage regulator module 7-1 can also provide operating power to the instrumentation amplification module 7-3, or cooperate with the instrumentation amplification module 7-3 to form a unified potential reference.

[0049] The clamping force sensor 7-2 is located between the movable plate 2 and the soft pad 4 and is used to detect the clamping load of the clamping mechanism and output a detection signal.

[0050] The instrument amplification module 7-3 is connected to the clamping force sensor 7-2 and is used to amplify the detection signal output by the clamping force sensor 7-2 to obtain an analog voltage signal, which includes the no-load zero-point voltage and the applied voltage.

[0051] The data acquisition module 7-4 is connected to the instrumentation amplification module 7-3 and is used to acquire the analog voltage signal output by the instrumentation amplification module 7-3.

[0052] The data processing module 7-5 is connected to the data acquisition module 7-4 and is used to calculate the clamping force of the fruit vibration harvester based on the analog voltage signal and the gain of the pre-acquired instrument amplification module 7-3.

[0053] like Figure 3As shown, the clamping force sensor 7-2 includes a fixed platform 701, a floating platform 706, a force measuring unit 702, and a connector 704. The force measuring unit 702 is disposed between the fixed platform 701 and the floating platform 706 via the connector 704, a first nut 703, and a second nut 705. The floating platform 706 receives the clamping load from the clamping mechanism and transmits the clamping load to the force measuring unit 702 via the connector 704. Multiple strain gauges are provided on the strain-sensitive area of ​​the force measuring unit 702; when the clamping load is transmitted to the force measuring unit 702, the strain gauges deform to generate a detection signal. When the clamping mechanism clamps the tree trunk, the first rubber block 5 and the second rubber block 6 above the clamping mechanism fixed plate 1 correspond to the clamping position of the tree trunk. The clamping mechanism movable plate 2 moves forward along the guide rail 3 and clamps the tree trunk. The clamping load acts on the floating platform 706 along the force transmission path and is transmitted to the force measuring unit 702 through the connector 704, causing the force measuring unit 702 to undergo elastic deformation.

[0054] Furthermore, multiple strain gauges are connected to a Wheatstone bridge measurement circuit. When the force measuring unit 702 undergoes elastic deformation under the clamping load, the resistance of the strain gauges changes accordingly, and the Wheatstone bridge outputs a millivolt-level differential voltage signal corresponding to the clamping load. For example... Figure 4 As shown, the clamping force sensor 7-2 has four leads: a positive power supply terminal U+, a negative power supply terminal U-, a positive signal terminal S+, and a negative signal terminal S-. When connected according to the specified polarity and a positive clamping load is applied to the floating platform 706, the sensor output voltage increment is positive.

[0055] Furthermore, the positive terminal S+ of the sensor signal is connected to the positive input terminal of the instrumentation amplification module 7-3, and the negative terminal S- of the sensor signal is connected to the negative input terminal of the instrumentation amplification module 7-3; the output terminal of the instrumentation amplification module 7-3 is connected to the analog input terminal of the data acquisition module 7-4 through a protection resistor, and the negative terminal of the voltage regulator module 7-1, the ground terminal of the instrumentation amplification module 7-3, and the ground terminal of the data acquisition module 7-4 are connected to a common ground to form a unified potential reference.

[0056] The instrumentation amplification module 7-3 amplifies and conditions the detection signal into an analog voltage signal that can be stably read by the data acquisition module 7-4. It includes a differential input unit, a gain adjustment unit, a reference voltage adjustment unit, and an analog output unit connected in sequence. In this embodiment, the instrumentation amplification module 7-3 uses an AD620 instrumentation amplifier. The positive terminal S+ of the sensor signal is connected to the positive input terminal of the AD620, and the negative terminal S- of the sensor signal is connected to the negative input terminal of the AD620.

[0057] In this embodiment, the data acquisition module 7-4 uses an Arduino UNO data acquisition card, and the output terminal of the instrumentation amplification module 7-3 is connected to the A0 analog input terminal of the Arduino UNO through a protection resistor. The protection resistor limits the current flowing into the analog input terminal under abnormal wiring or transient overvoltage conditions. The negative terminal of the voltage regulator module 7-1, the ground terminal of the instrumentation amplification module 7-3, and the ground terminal of the data acquisition module 7-4 share the same reference ground to ensure that the bridge, amplification, and acquisition processes are under a unified potential reference.

[0058] Example 2

[0059] This embodiment provides a detection method for the clamping force detection system of the vibratory fruit harvester described in Embodiment 1, comprising:

[0060] Step 1: When the clamping mechanism is not in contact with the clamped object and is in an unloaded state, the data processing module 7-5 acquires the unloaded zero-point voltage.

[0061] When the clamping mechanism is not in contact with the object being clamped and is in an unloaded state, the clamping mechanism has not yet applied an effective clamping load to the object being clamped. The data processing module 7-5 collects a segment of the unloaded output voltage and takes its average value as the unloaded zero-point voltage. This establishes a zero-point reference for this measurement, thereby reducing the influence of sensor zero-point drift and installation preload on the measurement results.

[0062] Step 2: When the clamping mechanism clamps the object, the data processing module 7-5 acquires the applied voltage.

[0063] During the processes of clamping the tree trunk, vibrating harvesting, and releasing unloading, the data acquisition module 7-4 continuously acquires the loading voltage of the instrument amplification module 7-3. The collected data is then transmitted to the data processing module 7-5. The data processing module 7-5 saves the voltage data in the order of sampling time, forming a data sequence of clamping force changing over time.

[0064] Step 3: The data processing module 7-5 calculates the clamping force of the vibratory fruit harvester based on the applied voltage, the no-load zero-point voltage, and the preset gain of the instrument amplification module 7-3. Specifically:

[0065] The voltage change output by instrument amplification module 7-3 is calculated based on the applied voltage and the no-load zero-point voltage, and is expressed as follows:

[0066] ;

[0067] in, It represents the amount of voltage change. Indicates the applied voltage. This indicates the no-load zero-point voltage.

[0068] The voltage increment is calculated and expressed as:

[0069] ;

[0070] in, Indicates voltage increment. This indicates the gain of the instrumentation amplifier module 7-3.

[0071] The clamping force of the vibratory fruit harvester is calculated and expressed as:

[0072] ;

[0073] in, This indicates the clamping force of the vibratory fruit harvester. This represents the sensor calibration coefficient. Wherein, , and The unit is V. The unit is mV.

[0074] Furthermore, the gain of the instrument amplification module 7-3 is set according to the sensor's rated range, sensor calibration coefficient, and the analog input range of the data acquisition module 7-4. Taking a rated range of 300 kg, a sensor calibration coefficient K = 14.617 kg / mV, and a data acquisition module input range of 0-5 V as an example, the original output voltage increment of the sensor corresponding to full scale is approximately... =20.52 mV. The gain of the instrument amplification module 7-3 should satisfy that G×20.52 mV is less than the upper limit of the input of the data acquisition module 7-4, and allowance should be reserved for impact load and dynamic fluctuation. The gain of the instrument amplification module 7-3 is expressed as:

[0075] ;

[0076] in, Indicates the gain resistor. It represents 1,000 euros.

[0077] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0078] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0079] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A clamping force detection system for a vibratory fruit harvester, characterized in that, The clamping force of the clamping mechanism of the vibrating harvester for forest fruit is used to detect the clamping force. The clamping mechanism includes a fixed plate (1), a movable plate (2) slidably connected to the fixed plate (1), and a soft pad (4) provided above the movable plate (2). The movable plate (2) moves forward along the fixed plate (1) until it engages with the top of the fixed plate (1) to clamp the object. The clamping force detection system includes: A clamping force sensor (7-2) is located between the movable plate (2) and the soft pad (4) to detect the clamping load of the clamping mechanism and output a detection signal; The instrument amplification module (7-3) is connected to the clamping force sensor (7-2) and is used to amplify the detection signal output by the clamping force sensor (7-2) to obtain an analog voltage signal, which includes the no-load zero-point voltage and the applied voltage. The data acquisition module (7-4) is connected to the instrumentation amplification module (7-3) and is used to acquire the analog voltage signal output by the instrumentation amplification module (7-3). The data processing module (7-5) is connected to the data acquisition module (7-4) and is used to calculate the clamping force of the fruit vibration harvester based on the analog voltage signal and the gain of the pre-acquired instrument amplification module (7-3).

2. The clamping force detection system for the vibratory fruit harvester according to claim 1, characterized in that: The clamping force sensor (7-2) includes a fixed platform (701), a floating platform (706), a force measuring unit (702), and a connector (704). The force measuring unit (702) is disposed between the fixed platform (701) and the floating platform (706) via a connector (704); The floating platform (706) receives the clamping load from the clamping mechanism and transmits the clamping load to the force measuring unit (702) through the connector (704).

3. The clamping force detection system for the vibratory fruit harvester according to claim 2, characterized in that: The force measuring unit (702) has multiple strain gauges on its strain-sensitive area; When the clamping load is transmitted to the force measuring unit (702), the strain gauge deforms to generate a detection signal.

4. The clamping force detection system for the vibratory fruit harvester according to claim 1, characterized in that: The instrumentation amplification module (7-3) includes a differential input unit, a gain adjustment unit, a reference voltage adjustment unit, and an analog output unit connected in sequence.

5. The clamping force detection system for the vibratory fruit harvester according to claim 1, characterized in that: It also includes a voltage regulator module (7-1), which is connected to the clamping force sensor (7-2) and is used to provide a bridge voltage to the clamping force sensor (7-2).

6. A detection method for a clamping force detection system based on the vibratory harvester for forest fruits according to any one of claims 1 to 5, characterized in that, include: When the clamping mechanism is not in contact with the clamped object and is in an unloaded state, the data processing module (7-5) acquires the unloaded zero-point voltage; When the clamping mechanism clamps the object, the data processing module (7-5) acquires the applied voltage; The data processing module (7-5) calculates the clamping force of the vibratory fruit harvester based on the applied voltage, the no-load zero-point voltage, and the gain of the preset instrument amplification module (7-3).

7. The control method for the clamping force detection system of the vibratory fruit harvester according to claim 6, characterized in that: The data processing module (7-5) calculates the clamping force of the vibratory fruit harvester based on the applied voltage, the no-load zero-point voltage, and the pre-acquired gain of the instrument amplification module (7-3), including: The voltage change output by the instrument amplification module (7-3) is calculated based on the applied voltage and the no-load zero-point voltage, and expressed as follows: ； in, It represents the amount of voltage change. Indicates the applied voltage. Indicates the no-load zero-point voltage; The voltage increment is calculated and expressed as: ； in, Indicates voltage increment. This indicates the gain of the instrument amplification module (7-3); The clamping force of the vibratory fruit harvester is calculated and expressed as: ； in, This indicates the clamping force of the vibratory fruit harvester. This represents the sensor calibration coefficient.

8. The control method for the clamping force detection system of the vibratory fruit harvester according to claim 7, characterized in that: The gain of the instrument amplification module (7-3) is expressed as follows: ； in, Indicates the gain resistor. It represents 1,000 euros.

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