A device and method for continuously sensing paddy field plow bottom information

Abstract

The present invention relates to a device for continuously sensing information of a paddy field plow bottom layer, comprising a posture sensor, two sets of feeler rod sensing devices, and a data acquisition device. The posture sensor is installed on the tractor body, and the two sets of feeler rod sensing devices are respectively installed on the left and right front wheel kingpins of the tractor; the feeler rod sensing device comprises a support frame, a parallelogram mechanism, a force sensor, an angular displacement sensor, a feeler rod, and a constant pressure mechanism. The support frame is relatively fixed to the kingpin, and the feeler rod, the constant pressure mechanism, and the force sensor are all raised and lowered relative to the support frame through the parallelogram mechanism, and the angular displacement sensor is installed on the parallelogram mechanism. It also relates to a method for continuously sensing information of a paddy field plow bottom layer. The present invention can simultaneously and continuously sense the plow bottom layer depth information and the plow bottom depth soil resistance on the paddy field tractor driving path, enriching the measurement methods of paddy field topography and soil bearing capacity, and belongs to the field of soil information sensing technology.

Description

Technical Field

[0001] The present invention relates to the technical field of soil information perception, and in particular to a device and method for continuous perception of paddy field plow bottom layer information. Background Art

[0002] The perception and detection of paddy field soil information has guiding significance for paddy field crop cultivation and agricultural machinery and equipment design. Traditional methods mainly use soil hardness testers to measure the hardness of soil layers at different depths or use telemetry equipment to perform three-dimensional reconstruction of the field surface. There are also lightweight portable devices that can sample and analyze soil water content and nutrients on site. As agricultural machinery and equipment develop towards automation and intelligence, the automatic navigation operation of tractors puts forward higher requirements for the perception of farmland environmental information.

[0003] At present, there are several research results on obtaining farmland soil information, such as: CN102788566B discloses a soil surface roughness measurement plate and a measurement method, which uses machine vision and image processing technology to obtain the soil surface roughness by calculating the length of probes arranged on the soil surface; CN102607499A discloses a vehicle-mounted farmland three-dimensional terrain measurement device, which can be used to measure the surface terrain of dry land and paddy fields; CN203100958U discloses a disc-type soil resistance continuous and rapid measurement device, which can continuously measure the soil resistance at a certain depth; CN103918365B discloses a deep tillage shovel that can continuously measure the mechanical resistance of the soil, and can monitor the arable land resistance of the deep tillage shovel online. If the blade encounters foreign matter and the resistance exceeds the set threshold, the hydraulic cylinder contracts to make the blade avoid it.

[0004] However, the existing soil testing equipment and methods still have the following technical problems:

[0005] (1) The structure of paddy fields is complex. The hard bottom layer is covered with a cultivated layer and a water layer. The water surface is reflective, transparent, and light-absorbing, which makes it impossible to directly apply traditional ground or space telemetry equipment to paddy field soil analysis.

[0006] (2) Traditional contact topographic measurement devices mainly use discrete point measurement, which cannot meet the needs of rapid and continuous measurement of field soil data;

[0007] (3) Traditional farmland topographic mapping equipment only focuses on soil surface information and cannot obtain the conditions of the driving layer of paddy field tractors or the plow bottom layer;

[0008] (4) Traditional soil information measurement devices either measure soil resistance or map the surface topography, and the information obtained from the measured object is single. Summary of the invention

[0009] In view of the technical problems existing in the prior art, the purpose of the present invention is to provide a device and method for continuously sensing the bottom layer information of a paddy field plow, which can continuously sense the bottom layer information of the plow as the tractor moves.

[0010] In order to achieve the above object, the present invention adopts the following technical solution:

[0011] A continuous sensing device for paddy field plow bottom layer information includes a posture sensor, two sets of feeler rod sensing devices, and a data acquisition device. The posture sensor is installed on the tractor body, and the two sets of feeler rod sensing devices are respectively installed on the left and right front wheel kingpins of the tractor; the feeler rod sensing device includes a support frame, a parallelogram mechanism, a force sensor, an angular displacement sensor, a feeler rod, and a constant pressure mechanism. The support frame is relatively fixed to the kingpin. The feeler rod, the constant pressure mechanism that provides a constant mud entry pressure to the feeler rod, and the force sensor that measures the forward resistance through the feeler rod are all lifted relative to the support frame through the parallelogram mechanism. The angular displacement sensor that obtains the lifting height of the feeler rod through the rotation angle of the parallelogram mechanism is installed on the parallelogram mechanism; the posture sensor, the force sensor, and the angular displacement sensor are all connected to the data acquisition device. The paddy field plow bottom layer information includes the plow bottom layer depth and the soil resistance at the plow bottom depth.

[0012] As a preferred embodiment, the parallelogram mechanism includes a front ear plate, a rear ear plate, two connecting rods, and four rotating shafts; two parallel connecting rods are arranged one high and one low, and each end of each connecting rod is fixedly connected to a rotating shaft, the two rotating shafts located in the front are rotatably connected to the front ear plate, and the two rotating shafts in the front are located in the same vertical plane, and the two rotating shafts located in the rear are rotatably connected to the rear ear plate, and the two rotating shafts in the rear are located in the same vertical plane; the front ear plate is equipped with a feeler rod, a constant pressure mechanism, and a force sensor; the rear ear plate is connected to the support frame. After adopting this structure, it is ensured that the support frame and the tractor front wheels are turned synchronously, and the feeler rod measurement path is always consistent with the tractor wheel walking trajectory.

[0013] As a preferred embodiment, a square hole is provided at the end of the connecting rod, and the rotating shaft is a square shaft, which is inserted into the square hole.

[0014] As a preferred embodiment, the touch rod sensor device further includes a touch rod connector; the touch rod connector is provided with a vertical through hole, which cooperates with the touch rod in the form of a cylindrical pair; the touch rod connector is installed on the force measuring surface of the force sensor, and the force measuring surface faces forward. Preferably, the touch rod connector is a tapered roller bearing with a seat, and the inner ring of the bearing cooperates with the touch rod to be installed on the force measuring surface of the force sensor. The axial positioning end of the touch rod is machined with a limit shoulder, and the other end is machined with a groove and uses an elastic retaining ring.

[0015] As a preference, the angular displacement sensor is connected to any rotating shaft.

[0016] As a preferred embodiment, the constant pressure mechanism includes a plurality of counterweights; the counterweights are symmetrical and detachably mounted on the front ear plate. To simplify the mechanism design, the constant pressure mechanism is a set of counterweights with optional mass and number, which provide constant pressure for the feeler rod to enter the soil and are mounted in pairs on both sides of the front ear plate force sensor of the support frame.

[0017] As a preferred embodiment, the contact rod is an L-shaped rigid rod, including a horizontal section and a vertical section, with rounded corners between the horizontal section and the vertical section, the horizontal section contacts the bottom layer of the plow, and the vertical section extends into the mud surface of the paddy field. It is preferably made of stainless steel; preferably, a reinforcing rod is welded between the horizontal section and the vertical section. The rounded corner transition is used to facilitate the passage of gravel and debris.

[0018] As a preferred embodiment, the force sensor is a high-precision pressure sensor, the angular displacement sensor is a high-precision single-turn potentiometer, and the attitude sensor is a nine-axis attitude heading reference system; the data acquisition device is a multi-serial port acquisition card, which synchronously acquires multiple information. The high-precision pressure sensor can measure the pressure of the touch rod on the sensor. It is installed in the center in front of the front ear plate of the support frame and makes the sensor X-axis parallel to the forward direction of the tractor. The angular displacement sensor is connected to the rotating shaft through a coupling to continuously measure the swing angle of the connecting rod in real time. The coupling is an "8-shaped" coupling. The multi-serial port acquisition card is connected to the force sensor and the angular displacement sensor respectively through the RS-232 serial port line.

[0019] A method for continuously sensing information of a paddy field plow bottom layer adopts a device for continuously sensing information of a paddy field plow bottom layer, and is characterized in that an angular displacement sensor measures the fluctuation of a feeler rod along with the paddy field topography, and the fluctuation is corrected by a posture sensor to obtain the depth information of the plow bottom layer; the paddy field soil resistance increases with the depth of the plow bottom layer, and is a set of distributed force systems, and the equivalent force at the upper end of the feeler rod is measured by a force sensor to characterize the depth resistance of the paddy field plow bottom.

[0020] As a preferred embodiment, the paddy field plow bottom layer depth information H is calculated based on H=[L·sin(α1-α0)]·cosγ, wherein γ is the roll angle of the tractor body, measured by a posture sensor; α0 is the initial angle of the connecting rod, measured by an angular displacement sensor; α1 is the real-time angle of the connecting rod, measured by an angular displacement sensor; L is the length of the connecting rod; the paddy field plow bottom layer depth information H and the equivalent force F measured by the force sensor at the upper end of the feeler rod are stored and dynamically displayed by a laptop computer.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) The paddy field plow bottom layer information continuous sensing device of the present invention comprises a support frame, a force sensor, an angular displacement sensor, a feeler rod connector, a feeler rod, a set of weight blocks with optional mass, and a multi-serial port card. All sensing devices are integrated and installed on the support frame, the multi-serial port acquisition card is placed in the tractor cockpit, and the sensor is connected to the multi-serial port card. It has the characteristics of simple structure, easy operation, strong universality, and a wide variety of measurable parameters.

[0023] 2) The paddy field plow bottom layer information continuous sensing device of the present invention is designed with a touch rod sensor device, which can realize the direct measurement of the paddy field plow bottom layer depth information, breaking through the limitation of the interference of water surface and mud feet when the traditional ground space remote sensing equipment collects paddy field soil information; at the same time, it can realize the continuous measurement of the soil resistance at the paddy field plow bottom depth, and the measurement efficiency is high.

[0024] 3) The paddy field plow bottom layer information continuous sensing device of the present invention is designed with a constant pressure device with adjustable pressure, which ensures that in paddy field environments with different mud hardness, it can provide appropriate constant pressure to make the horizontal section of the feeler rod contact the paddy field plow bottom layer, and has strong versatility. In addition, the constant pressure mechanism can provide constant pressure to the feeler rod regardless of the change in the feeler rod stroke displacement, so as to ensure the consistency of conditions in the measurement process.

[0025] 4) The paddy field plow bottom layer information continuous sensing device of the present invention is designed with an angular displacement sensor and a force sensor, which can meet the needs of continuous measurement of field soil information, has high data collection efficiency and rich measurement information.

[0026] 5) It can simultaneously and continuously sense the plow bottom depth information and the soil resistance at the plow bottom depth on the paddy field tractor's driving path, enriching the measurement methods of paddy field topography and soil bearing capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a stereoscopic diagram of the installation of the touch rod sensor device.

[0028] Figure 2 This is the front view of the touch rod sensor installation.

[0029] Figure 3 It is a top view of the installation of the touch rod sensor device.

[0030] Figure 4 It is the measurement principle diagram of the present invention.

[0031] Figure 5 This is a diagram showing the status of the touch rod sensor device in use.

[0032] Among them, 1 is a coupling, 2 is a constant pressure mechanism, 3 is a force sensor, 4 is a feeler rod connector, 5 is a feeler rod, 6 is a connecting rod, 7 is a rotating shaft, 8 is an angular displacement sensor, 9 is a support frame, 10 is a front wheel, 11 is a bearing, and 12 is a kingpin. V is the forward speed of the tractor. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below in conjunction with specific implementation methods.

[0034] like Figure 1 As shown in FIG. 3 , this embodiment senses the plow bottom depth information and the soil resistance at the plow bottom depth on the walking path of the paddy field transplanter, and the tractor used is the Iseki PZ60 paddy field transplanter.

[0035] A continuous sensing device for bottom layer information of a paddy field plow comprises a pair of touch rod sensing devices and an attitude sensor (a nine-axis attitude and heading reference system), and adopts a notebook computer installed with Matlab as a real-time computing and display terminal for sensing data.

[0036] There are two sets of touch rod sensor devices, which are installed at the bearing end covers of the left and right front wheel shafts of the rice transplanter. Each set of touch rod sensor devices includes: "8"-shaped coupling, counterweight, force sensor, touch rod connector, touch rod, connecting rod with square hole at the end, square shaft, front ear plate, rear ear plate, high-precision single-turn potentiometer, and support frame.

[0037] The parallelogram mechanism includes a front ear plate, a rear ear plate, two connecting rods, and four rotating shafts. The parallelogram mechanism is made of stainless steel, and the changes in the elevation of the touch rod with the plow bottom layer can be converted into an easily measurable angle signal, so that it can be measured using a high-precision single-turn potentiometer. The force sensor is a high-precision pressure sensor that can measure the pressure of the touch rod on the sensor. This embodiment is used to measure the soil resistance F of the paddy field plow bottom depth that the touch rod is subjected to when it moves forward with the transplanter. The touch rod is a rigid rod made of stainless steel, bent into an "L" shape, inserted below the paddy field mud surface, to ensure that the horizontal section of the touch rod is in contact with the plow bottom layer, and the upper part of the vertical section is exposed to the water surface; the touch rod has a rounded transition at the bend, which is conducive to passing through obstacles such as gravel and mud; the upper part of the vertical section of the touch rod is processed with a limited position shoulder and a groove that cooperates with an elastic retaining ring. The touch rod connector is a tapered roller bearing with a seat, which is installed on the force sensor force measuring surface. The inner ring of the bearing cooperates with the touch rod to ensure that the touch rod direction is consistent with the front wheel following when the front wheel turns. The angular displacement sensor is a high-precision single-turn potentiometer with a threaded hole at the bottom. The potentiometer coupling is an "8"-shaped coupling with set screws arranged circumferentially at the shaft hole. The constant pressure mechanism is a set of cubic metal weights with optional number and quality, with threaded holes at the bottom, which are arranged on both sides of the six-dimensional force sensor and installed on the front ear plate in front of the support frame. The data acquisition device is a multi-functional digital-analog signal acquisition card that can simultaneously collect data information from the potentiometer and the six-dimensional force sensor.

[0038] The through hole of the support frame corresponds to the mounting hole of the bearing end cover of the front wheel axle of the rice transplanter, and is fixed by screws, spring washers and washers. The through hole of the front ear plate corresponds to the threaded hole of the force sensor, and is fixed by screws, spring washers and washers. A pair of square hole connecting rods are arranged in parallel, and the two ends of the connecting rods are respectively hinged to the front and rear ear plates through square shafts. The square shaft can rotate relative to the through hole of the ear plate, and the connecting rod and the square shaft cannot rotate. The bottom surface of the force sensor is provided with a threaded hole, which is installed on the front ear plate of the support frame by screws, spring washers and washers. The bottom of the tapered roller bearing with a seat is provided with four through holes, which are installed and fastened to the force measuring surface of the force sensor by screws, spring washers and washers. The feeler rod is interference fit with the inner ring of the tapered roller bearing with a seat, and the axial positioning of the feeler rod is completed by the shoulder of the feeler rod and the elastic retaining ring matched with the groove of the feeler rod. Four cubic metal counterweights are respectively installed on both sides of the six-dimensional force sensor by screws, spring washers and washers. The high-precision single-turn potentiometer is installed on the rear ear plate by screws, spring washers and washers. The shaft holes at both ends of the "8"-shaped coupling are matched with the high-precision single-turn potentiometer shaft and the square shaft respectively.

[0039] Use external power supply to provide stable voltage for multi-serial port cards, high-precision single-turn potentiometers, force sensors, and laptop computers.

[0040] A method for continuously sensing paddy field plow bottom layer information, comprising the following steps:

[0041] 1) Install a pair of touch rod sensor devices on the left and right front wheel axle bearing end covers 11 of the rice transplanter respectively, and use screws, washers, and spring washers to install and fasten them; install the attitude sensor on the rice transplanter body and use screws, washers, and spring washers to install and fix them.

[0042] 2) Drive the rice transplanter to stop on the road surface, ensure that the horizontal section of the touch rod and the four wheels of the rice transplanter are in the same horizontal plane, and use a high-precision single-turn potentiometer to record the initial angle α0 of the connecting rod at this time.

[0043] 3) Drive the rice transplanter into the paddy field to ensure that the horizontal section of the feeler rod extends below the mud surface. Install a pair of counterweights of the same mass on both sides of the front ear plate six-dimensional force sensor in the order of the mass of the counterweights from small to large, until the feeler rod no longer sinks and the length of the part exposed to the mud surface no longer changes. It is considered that the horizontal section of the feeler rod 5 is in critical contact with the bottom layer of the paddy field plow.

[0044] 4) Start the rice transplanter and drive it forward at a constant speed. The touch rod sensor device moves forward under the push of the rice transplanter. The touch rod rises and falls with the terrain of the bottom layer of the plow. The high-precision single-turn potentiometer continuously collects the connecting rod swing angle α1 generated by the ups and downs of the touch rod, converts the angle information into a digital signal and sends it to the multi-serial port card; the force sensor continuously collects the forward resistance representation F of the touch rod, converts the force value information into a digital signal and sends it to the multi-serial port card; the posture sensor measures the body posture and sends the posture value to the multi-serial port card.

[0045] 5) The multi-serial port card sends the received left and right touch rod connecting rod swing angle data to the laptop computer through the data line, and Matlab uses the formula H=[L·sin(α1-α0)]·cosγ to synchronously calculate the paddy field plow bottom elevation in front of the left and right wheels of the tractor, and displays and stores it in real time; at the same time, the multi-serial port card sends the received left and right touch rod forward resistance to the laptop computer through the data line, and Matlab displays and stores the acquired touch rod forward resistance representation F in real time.

[0046] 6) The forward resistance characterization F of the touch rod and the elevation information H of the paddy field plow bottom layer measured by the continuous sensing device for the paddy field plow bottom layer information have enriched the measurement methods of paddy field topography and soil bearing capacity.

[0047] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for continuous sensing of paddy field plow bottom information, characterized in that: A paddy field plow bottom information continuous sensing device is used, which includes a posture sensor, two sets of feeler rod sensing devices, and a data acquisition device. The posture sensor is installed on the tractor body, and the two sets of feeler rod sensing devices are respectively installed on the left and right front wheel kingpins of the tractor; the feeler rod sensing device includes a support frame, a parallelogram mechanism, a force sensor, an angular displacement sensor, a feeler rod, and a constant pressure mechanism. The support frame is relatively fixed to the kingpin, and the feeler rod, the constant pressure mechanism that provides a constant mud entry pressure to the feeler rod, and the force sensor that measures the forward resistance through the feeler rod are all lifted relative to the support frame through the parallelogram mechanism, and the angular displacement sensor that obtains the lifting height of the feeler rod through the rotation angle of the parallelogram mechanism is installed on the parallelogram mechanism; The attitude sensor, force sensor, and angular displacement sensor are all connected to the data acquisition device; The method comprises: using an angular displacement sensor to measure the fluctuation of a feeler rod along with the paddy field topography, and using a posture sensor to correct the fluctuation to obtain the depth information of the plow bottom layer; The soil resistance of paddy fields increases with the depth of the plow bottom layer, which is a set of distributed force systems. The equivalent force at the upper end of the feeler rod is measured by a force sensor to characterize the depth resistance of the plow bottom of the paddy field.

2. A method for continuous sensing of paddy field plow bottom layer information according to claim 1, characterized in that: The parallelogram mechanism includes a front ear plate, a rear ear plate, two connecting rods, and four rotating shafts; two parallel connecting rods are arranged one high and one low, and each end of each connecting rod is fixedly connected to a rotating shaft, the two rotating shafts located in the front are rotatably connected to the front ear plate, and the two rotating shafts in the front are located in the same vertical plane, and the two rotating shafts located in the rear are rotatably connected to the rear ear plate, and the two rotating shafts in the rear are located in the same vertical plane; the front ear plate is equipped with a touch rod, a constant pressure mechanism, and a force sensor; the rear ear plate is connected to the support frame.

3. A method for continuous sensing of paddy field plow bottom information according to claim 2, characterized in that: A square hole is arranged at the end of the connecting rod, and the rotating shaft is a square shaft, which is inserted into the square hole.

4. A method for continuous sensing of paddy field plow bottom information according to claim 2, characterized in that: The touch rod sensing device also includes a touch rod connecting piece; the touch rod connecting piece is provided with a vertical through hole and cooperates with the touch rod in the form of a cylindrical pair; the touch rod connecting piece is installed on the force measuring surface of the force sensor, and the force measuring surface faces forward.

5. A method for continuous sensing of paddy field plow bottom layer information according to claim 2, characterized in that: The angular displacement sensor is connected to any rotating shaft.

6. A method for continuous sensing of paddy field plow bottom information according to claim 2, characterized in that: The constant pressure mechanism comprises a plurality of counterweight blocks; the counterweight blocks are symmetrically and detachably mounted on the front ear plate.

7. A method for continuous sensing of paddy field plow bottom layer information according to claim 4, characterized in that: The contact rod is an L-shaped rigid rod, including a horizontal section and a vertical section, with rounded corners between the horizontal section and the vertical section. The horizontal section contacts the bottom layer of the plow, and the vertical section extends into the mud surface of the paddy field.

8. A method for continuous sensing of paddy field plow bottom information according to any one of claims 1 to 7, characterized in that: The force sensor is a high-precision pressure sensor, the angular displacement sensor is a high-precision single-turn potentiometer, and the attitude sensor is a nine-axis attitude and heading reference system; the data acquisition device is a multi-serial port acquisition card that synchronously collects multiple channels of information.

9. A method for continuous sensing of paddy field plow bottom information according to claim 1, characterized in that: Paddy field plow bottom depth information H basis calculate, Among them, γ is the roll angle of the tractor body, which is measured by the attitude sensor; α0 is the initial angle of the connecting rod, measured by the angular displacement sensor; α1 is the real-time angle of the connecting rod, measured by the angular displacement sensor; L is the length of the connecting rod; The paddy field plow bottom depth information H and the equivalent force F measured by the force sensor on the upper end of the feeler rod are stored and dynamically displayed by a laptop computer.

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