Rice seedling tray seeding rate variable-speed weighing device and variable-speed weighing method

Abstract

The invention relates to the technical field of agricultural detection, in particular to a rice seedling tray seeding rate variable-speed weighing device and a variable-speed weighing method.The rice seedling tray seeding rate variable-speed weighing device comprises a rack, a weighing device, a variable-speed driving device, a positioning device and a control system.The variable-speed driving device drives a seedling tray to do variable-speed motion from back to front, so that the seedling tray is dynamically carried and statically weighed; the weighing device accurately weighs the mass of the seedling tray, the positioning device accurately positions whether the seedling tray enters the weighing position or not, the control system can receive weighing data and carry out algorithm processing, and finally the final measurement result of the seedling tray is obtained. According to the variable-speed weighing device, dynamic carrying and static weighing of the seedling trays are achieved, automatic, continuous and rapid weighing of the seedling trays is further achieved, the weighing precision is high, and the production efficiency is improved. According to the variable-speed weighing method disclosed by the invention, the seedling trays can be kept spaced from the front seedling tray and the rear seedling tray during weighing, so that mechanical interference is avoided, the weighing precision is improved, and the practical value is high.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural detection, in particular to a variable speed weighing device for the sowing amount of a rice seedling tray, and also to a variable speed weighing method for the sowing amount of a rice seedling tray. Background Art

[0002] The accuracy of the seeding amount on the rice seedling tray directly affects the quality of the rice seedlings, and then affects the quality of the seedling planting. Therefore, it is crucial to accurately weigh the mass of the seedling tray before and after sowing.

[0003] The existing seeding tray sowing amount mainly adopts the pre-calibration method to achieve quantitative sowing of seeding trays. When the moisture content and variety of seeds change, the seeding tray sowing amount changes greatly, affecting the quality of seedling cultivation. The existing weighing device mainly has the following problems: (1) Due to the continuous transportation of seedling trays during seedling cultivation, there is no gap between the seedling trays and the front and rear seedling trays when the seedling trays arrive at the weighing position, resulting in a certain interference with the measurement accuracy when the seedling trays are weighed; (2) The weighing position positioning device uses a diffuse reflection photoelectric sensor. Due to its own scattering and other problems, there is a deviation in the predicted position of the weighing seedling tray arrival; (3) The device uses a single-chip microcomputer as the control core, and the single-chip microcomputer has poor anti-interference ability and is greatly affected by environmental factors such as strong and weak electricity, climate and temperature. The working stability under complex field conditions is poor. Summary of the invention

[0004] In view of the technical problems existing in the prior art, the purpose of the present invention is to provide a variable speed weighing device for the sowing amount of rice seedling trays, which can realize dynamic transportation and static weighing of the seedling trays, thereby improving the weighing accuracy and stability.

[0005] Another object of the present invention is to provide a variable speed weighing method for the sowing amount of rice seedling trays, which can ensure that the seedling tray maintains a certain distance from the front and rear seedling trays during weighing, thereby reducing the mechanical interference between the seedling trays and improving the weighing accuracy.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A variable speed weighing device for measuring the amount of rice seedling tray sowing, comprising a frame, a weighing device, a variable speed drive device, a positioning device and a control system, wherein the variable speed weighing device is used to weigh the amount of rice seedling tray sowing, the frame is arranged across the front and rear directions, and the variable speed drive device, the positioning device and the control system are all installed on the frame; the variable speed drive device is used to drive the rice seedling tray to perform variable speed movement from back to front, comprising a front drive assembly, a variable speed drive assembly and a rear drive assembly which are sequentially arranged on the frame from front to back; the weighing device is arranged below the variable speed drive assembly and is separated from the frame, comprising a supporting frame, a bottom plate, a weighing sensor, a load-bearing frame and a mudguard which are sequentially arranged from bottom to top, and the front and rear sides of the load-bearing frame are respectively provided with supporting wheel groups, and the two groups The supporting wheel groups are respectively located at the intervals between the rear drive assembly, the variable speed drive assembly and the front drive assembly; the front drive assembly and the rear drive assembly each include a plurality of groups of rubber drive wheels arranged at intervals, the variable speed drive assembly includes a front drive wheel and a rear drive wheel, the tops of the rubber drive wheel, the front drive wheel and the rear drive wheel are flush and lower than the top of the supporting wheel group; the radii of the front drive wheel and the rear drive wheel are the same, the radius of the rubber drive wheel is smaller than the radius of the front drive wheel and the rear drive wheel, and the axles of the front drive wheel and the rear drive wheel are both lower than the axles of the rubber drive wheel; the rotational speeds of the rubber drive wheel, the front drive wheel and the rear drive wheel are the same, the linear speed of the rubber drive wheel is V0, the linear speed of the front drive wheel and the rear drive wheel is V1, and V1 is greater than V0.

[0007] Furthermore, there is a height difference ΔZ1 between the speed change driving device and the top of the supporting wheel set; there is a height difference ΔZ2 between the axis centers of the front driving wheel and the rear driving wheel and the axis center of the rubber driving wheel.

[0008] Furthermore, the supporting wheel group includes a front supporting wheel and a rear supporting wheel located at the front and rear sides of the load-bearing frame; wherein the front supporting wheel is located at the gap between the front drive assembly and the speed-changing drive assembly, and the rear supporting wheel is located at the gap between the speed-changing drive assembly and the rear drive assembly.

[0009] Furthermore, the positioning device includes a through-beam photoelectric sensor light emitter, a through-beam photoelectric sensor receiver and a mounting plate; the through-beam photoelectric sensor light emitter and the through-beam photoelectric sensor receiver are both fixed above the frame through the mounting plate and are located on the left and right sides of the front support wheel; the positioning device is used to identify whether the seedling tray has reached the weighing position.

[0010] Furthermore, the control system is electrically connected to the weighing sensor and the positioning device; the control system includes a pulse signal receiving unit, a data acquisition unit, a data processing unit, a human-computer interaction unit and a power supply unit; wherein the data acquisition unit includes a digital transmitter.

[0011] A variable speed weighing method for rice seedling tray sowing amount adopts the variable speed weighing device for rice seedling tray sowing amount as mentioned above; the method comprises: S1: Turn on the variable speed weighing device and place the seedling trays to be weighed on the rear drive assembly in sequence; S2: The rear drive assembly drives the seedling tray to be weighed to start moving at a speed of V0; S3: When the seedling tray to be weighed moves to the rear support wheel, the front end of the seedling tray to be weighed starts to contact the rear support wheel and climbs upward along the rear support wheel. When the center of mass passes the rear support wheel, the rear end of the seedling tray to be weighed is separated from the rear drive assembly, and the front end contacts the front drive wheel; S4: the front driving wheel drives the seedling tray to be weighed to move at a speed of V1, at which time the seedling tray to be weighed is farther away from another seedling tray to be weighed located behind it; Until the front end of the seedling tray to be weighed contacts the front support wheel and begins to climb upward by inertia, after the front end of the seedling tray to be weighed climbs onto the front support wheel, it briefly stops on the support wheel set under the action of friction, and at this time, the next seedling tray to be weighed continues to move forward, and the distance between it and the seedling tray that is stationary on the support wheel set is shortened; The positioning device detects that the seedling tray to be weighed has reached the preset weighing position and transmits a pulse signal to the control system. After the pulse signal receiving unit receives the pulse signal, the control system controls the weighing sensor to start weighing the seedling tray to be weighed which is stationary on the supporting wheel set. The weighing sensor outputs the obtained weighing data to the control system in the form of an analog signal. S5: When the next seedling tray to be weighed hits the stationary seedling tray on the supporting wheel set, the next seedling tray to be weighed pushes the seedling tray on the supporting wheel set to move forward. At this time, one weighing is completed, and the data acquisition unit obtains an analog signal from the weighing sensor. After the weighing is completed, the seedling tray continues to move forward. When the rear end of the seedling tray falls from the rear supporting wheel to the rear driving wheel, the rear driving wheel drives the seedling tray to move forward at a speed V1; S6: After the weighing is completed, the seedling tray continues to move forward under the drive of the variable speed drive assembly. At this time, the distance between the seedling tray after weighing and the next seedling tray to be weighed is increased until the center of mass of the seedling tray after weighing passes the front supporting wheel. At this time, the rear end of the seedling tray after weighing is separated from the variable speed drive assembly, and the front end begins to contact with the front drive assembly, and the front drive assembly begins to drive the seedling tray after weighing to continue to move forward; S7: Repeat steps S2 to S6 for the next seedling tray to be weighed until the weighing of the penultimate seedling tray to be weighed is completed; S8: The last seedling tray to be weighed is weighed by human intervention.

[0012] Furthermore, in step S4, when the seedling tray reaches the detection position, i.e., the seedling tray weighing position, the light beam emitted by the through-beam photoelectric sensor light emitter is blocked by the seedling tray, and the through-beam photoelectric sensor receiver cannot receive the light beam. At this time, the output signal of the through-beam photoelectric sensor receiver changes from a low level to a high level, and the pulse signal receiving unit of the control system receives a rising edge signal, i.e., a pulse signal, indicating that the seedling tray reaches the weighing position. The data acquisition unit starts to receive and read the analog signal from the weighing sensor, and the digital transmitter amplifies the analog signal output by the weighing sensor and converts it into a digital signal and transmits it to the data processing unit.

[0013] Furthermore, the data processing unit first intercepts relatively stable weighing data in the digital signal to obtain a set of real measurement value data sets, and then performs noise reduction processing on the collected weighing data through a scalar Kalman filtering algorithm to obtain a set of optimized data sets, and finally processes the optimized data sets through a median average filtering algorithm to obtain the final weighing result of the rice seedling tray quality.

[0014] Furthermore, the scalar Kalman filter algorithm is divided into two processes: prediction and update. The prediction process uses the estimate of the previous state to make an estimate of the current state; the update process uses the observed value of the current state to optimize the predicted value obtained in the prediction stage to obtain a more accurate optimal estimate x k|k : Prediction equation:

[0015] Update equation: Among them, x k|k-1 is the current state result predicted by the optimal estimate at time k-1; k-1|k-1 is the optimal estimate at time k-1; u k is the control gain of the current state; p k-1|k-1 is the covariance of the estimated value at time k-1; p k|k-1 is the current covariance result predicted by the covariance at time k-1; a is the state transfer coefficient; b is the input gain coefficient; q is the excitation noise; h is the measurement coefficient; r is the measurement noise; g k is the optimal Kalman gain at time k; z k is a real measurement value at time k, that is, a real measurement value dataset; x k|k is the optimal estimate at time k, that is, the optimized data set; p k|k is the covariance of the estimated value at time k.

[0016] Furthermore, the median average filtering algorithm is used to reduce the noise of the n optimal estimates x k|kTo process, first sort the n data from small to large, then remove the minimum m1 and maximum m2 values, and finally average the n-m1-m2 optimal estimates:

[0017] Among them, M is the final weighing result of the seedling tray mass.

[0018] The present invention has the following advantages: 1. The variable speed weighing device of the present invention arranges the variable speed drive device, the positioning device and the control system on the frame, and the weighing device is separated from the frame, so that the seedling tray can be driven by the variable speed drive device to be dynamically carried above the frame and statically weighed above the weighing device. Moreover, since the weighing device is separated from the frame, the influence of the mechanical vibration of the frame on the weighing accuracy is eliminated, so that the weighing result is more accurate.

[0019] 2. The variable speed weighing method of the present invention uses a variable speed drive device to enable the seedling tray to be carried at a variable speed on the frame. During static weighing, a certain distance is maintained between the seedling trays in front and behind, so that the seedling trays in front and behind have no mechanical interference with the seedling trays that are stationary on the weighing device for weighing, making the weighing results more accurate and reliable. After the weighing is completed, the seedling trays on the frame continue to move forward, realizing automatic continuous and rapid weighing, greatly improving the weighing efficiency, and thus improving the production efficiency.

[0020] 3. In the variable speed weighing device of the present invention, the positioning device for identifying whether the seedling tray has reached the weighing position adopts a through-beam photoelectric sensor, which has a fast response speed and the detection distance is not affected by the color and structure of the detection target, so that the weighing accuracy is higher.

[0021] 4. In the variable speed weighing device of the present invention, the control system adopts Mitsubishi PLC, which has the advantages of strong anti-interference ability, large noise tolerance, not susceptible to strong electromagnetic interference generated by frequency converters, motors, etc., high stability, and can work in complex and changeable field environments such as temperature and humidity.

[0022] 5. In the variable speed weighing method of the present invention, a scalar Kalman filter algorithm is used to perform noise reduction preprocessing on the collected weighing data, and then the quality of the rice seedling tray is obtained by a median average filter algorithm. The data processing has high accuracy, good stability, and high confidence in the processing results.

[0023] 6. The variable speed weighing device of the present invention can be used not only for rice, but also for weighing the quality of other seedling production lines such as flowers, vegetables and fruits. It has reliable performance and practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the variable speed weighing device in the present invention.

[0025] Figure 2 It is a side view of the variable speed weighing device of the present invention.

[0026] Figure 3 It is an exploded view of the weighing device of the variable speed weighing device in the present invention.

[0027] Figure 4 It is a schematic diagram of the variable speed drive device of the variable speed weighing device in the present invention.

[0028] Figure 5 It is a schematic diagram of the positioning device of the variable speed weighing device in the present invention.

[0029] Figure 6 It is a schematic diagram of the variable speed drive assembly of the variable speed weighing device in the present invention.

[0030] Figure 7 It is a top view of the weighing position of the variable speed weighing device in the present invention.

[0031] Figure 8 It is a hardware principle block diagram of the control system of the variable speed weighing device in the present invention.

[0032] Fig. 9 It is a schematic diagram of the state of the seedling tray to be weighed before being driven by the front driving wheel in step S3 of the present invention.

[0033] Fig.10 It is a schematic diagram of the state in which the seedling tray to be weighed climbs upward along the front supporting wheel in step S4 of the present invention.

[0034] Fig.11 It is a schematic diagram of the state in which the front end of the seedling tray to be weighed climbs onto the front supporting wheel in step S4 of the present invention.

[0035] Fig.12 It is a schematic diagram of the state in which the last seedling tray to be weighed collides with the seedling tray stationary on the supporting wheel set in step S5 of the present invention.

[0036] Fig.13 It is a schematic diagram of a state in which the front end of the seedling tray falls onto the front drive assembly after weighing is completed in step S6 of the present invention.

[0037] in, 1 is a rack.

[0038] 2 is a weighing device, 21 is a supporting frame, 22 is a bottom plate, 23 is a weighing sensor, 24 is a load-bearing frame, 25 is a fender, 26 is a supporting wheel group, 261 is a front supporting wheel, and 262 is a rear supporting wheel.

[0039] 3 is a variable speed drive device, 31 is a front drive assembly, 311 is a rubber drive wheel, 32 is a variable speed drive assembly, 321 is a front drive wheel, 322 is a rear drive wheel, and 33 is a rear drive assembly.

[0040] 4 is a positioning device, 41 is a light emitter of the through-beam photoelectric sensor, 42 is a receiver of the through-beam photoelectric sensor, and 43 is a mounting plate.

[0041] 5 is the control system.

[0042] 6 is a seedling tray, 61 is a seedling tray to be weighed, 62 is a subsequent seedling tray to be weighed, and 63 is a seedling tray after weighing is completed. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0044] like Figures 1 to 8 As shown, a variable speed weighing device for rice seeding tray sowing amount comprises a frame, a weighing device, a variable speed driving device, a positioning device and a control system, wherein the variable speed weighing device is used to weigh the seeding amount of the rice seeding tray, the frame is arranged across the front and rear directions, and the variable speed driving device, the positioning device and the control system are all installed on the frame; The variable speed drive device is used to drive the seedling tray to perform variable speed movement from the back to the front, and includes a front drive assembly, a variable speed drive assembly and a rear drive assembly which are sequentially arranged on the frame from the front to the back at intervals; The weighing device is arranged below the variable speed drive assembly and is separated from the frame, and includes a support frame, a base plate, a weighing sensor, a load-bearing frame and a mudguard which are arranged in sequence from bottom to top. Support wheel groups are respectively arranged on the front and rear sides of the load-bearing frame, and the two groups of support wheel groups are respectively located at the intervals between the rear drive assembly, the variable speed drive assembly and the front drive assembly.

[0045] Specifically, the weighing device is separated from the frame, eliminating the influence of mechanical vibration on the weighing accuracy. The variable speed drive device is used to drive the seedling tray, so that the seedling tray can be continuously and dynamically transported on the frame, and static weighing is performed, which avoids the contact between the seedling tray and the front and rear seedling trays during weighing, improves the weighing accuracy, and makes the confidence of the weighing data value higher.

[0046] In this embodiment, the weighing sensor adopts an electromagnetic force weighing sensor, which has high weighing accuracy, fast response speed and good stability.

[0047] like Figure 4As shown, the front drive assembly and the rear drive assembly both include a plurality of groups of rubber drive wheels arranged at intervals, the variable speed drive assembly includes a front drive wheel and a rear drive wheel, the tops of the rubber drive wheel, the front drive wheel and the rear drive wheel are flush and lower than the top of the supporting wheel assembly; the radii of the front drive wheel and the rear drive wheel are the same, the radius of the rubber drive wheel is smaller than the radius of the front drive wheel and the rear drive wheel, and the axles of the front drive wheel and the rear drive wheel are lower than the axles of the rubber drive wheel; the rotation speeds of the rubber drive wheel, the front drive wheel and the rear drive wheel are the same, the linear speed of the rubber drive wheel is V0, the linear speed of the front drive wheel and the rear drive wheel is V1, and V1 is greater than V0.

[0048] like Figure 6 As shown, in this embodiment, there is a height difference ΔZ1=2mm between the speed change drive device and the top of the supporting wheel set; there is a height difference ΔZ2=2mm between the axis of the front driving wheel, the rear driving wheel and the axis of the rubber driving wheel.

[0049] Specifically, the tops of the rubber driving wheel, the front driving wheel and the rear driving wheel are flush, the radius of the front driving wheel and the rear driving wheel is R2=27mm, the radius of the rubber driving wheel is R1=25mm, the radii of the front driving wheel and the rear driving wheel are the same, the radius of the rubber driving wheel is smaller than the radii of the front driving wheel and the rear driving wheel, so the axles of the front driving wheel and the rear driving wheel are both lower than the axle of the rubber driving wheel by ΔZ2=2mm.

[0050] In this embodiment, there is a height difference ΔZ1=2mm between the supporting wheel group and the speed-changing drive device, so that the seedling tray can be separated from the rear drive assembly in time when entering the speed-changing drive assembly, thereby avoiding mechanical interference. Similarly, when the seedling tray enters the front drive assembly, it can also be separated from the speed-changing drive assembly in time to avoid mechanical interference. Such an arrangement further avoids the influence of other mechanical components on the weighing process of the weighing device when the seedling tray enters and exits the weighing position, further improves the weighing accuracy, and makes the generated data more confident.

[0051] like Figure 5 and 7 As shown, the positioning device includes a through-beam photoelectric sensor light emitter, a through-beam photoelectric sensor receiver and a mounting plate; the through-beam photoelectric sensor light emitter and the through-beam photoelectric sensor receiver are both fixed on the top of the frame through the mounting plate and are located on the left and right sides of the front support wheel; the positioning device is used to identify whether the seedling tray has reached the weighing position.

[0052] In this embodiment, the positioning device uses a through-beam photoelectric sensor, which has a fast response speed and the detection distance is not affected by the color and structure of the detection target, so that the weighing accuracy is higher.

[0053] like Figure 8As shown, the control system is electrically connected to the weighing sensor and the positioning device; the control system includes a pulse signal receiving unit, a data acquisition unit, a data processing unit, a human-computer interaction unit and a power supply unit; wherein the data acquisition unit includes a digital transmitter.

[0054] In this embodiment, the control system uses Mitsubishi's PLC, which has the advantages of strong anti-interference ability, large noise tolerance, not being susceptible to strong electromagnetic interference generated by inverters, motors, etc., high stability, and being able to work in complex and changeable field environments such as temperature and humidity.

[0055] Specifically, when the seedling tray reaches the detection position, i.e., the seedling tray weighing position, the light beam emitted by the through-beam photoelectric sensor light emitter is blocked by the seedling tray, and the through-beam photoelectric sensor receiver cannot receive the light beam. At this time, the output signal of the through-beam photoelectric sensor receiver changes from a low level to a high level, and the pulse signal receiving unit of the control system receives a rising edge signal, i.e., a pulse signal, indicating that the seedling tray has reached the weighing position. The data acquisition unit begins to receive and read the analog signal from the weighing sensor, and the digital transmitter amplifies the analog signal output by the weighing sensor and converts it into a digital signal and transmits it to the data processing unit.

[0056] Among them, the human-computer interaction unit is used for staff to perform related operations; the power supply unit is used to supply power to the control system, photoelectric sensor, weighing sensor, etc.

[0057] like Figures 8 to 12 As shown, a variable speed weighing method for rice seedling tray sowing amount adopts a variable speed weighing device for rice seedling tray sowing amount as mentioned above; the method comprises: S1: Turn on the variable speed weighing device and place the seedling trays to be weighed on the rear drive assembly in sequence; S2: The rear drive assembly drives the seedling tray to be weighed to start moving at a speed of V0; S3: When the seedling tray to be weighed moves to the rear support wheel, the front end of the seedling tray to be weighed starts to contact the rear support wheel and climbs upward along the rear support wheel. When the center of mass passes the rear support wheel, the rear end of the seedling tray to be weighed is separated from the rear drive assembly, and the front end contacts the front drive wheel; S4: the front driving wheel drives the seedling tray to be weighed to move at a speed of V1, at which time the seedling tray to be weighed is farther away from another seedling tray to be weighed located behind it; Until the front end of the seedling tray to be weighed contacts the front support wheel and begins to climb upward by inertia, after the front end of the seedling tray to be weighed climbs onto the front support wheel, it briefly stops on the support wheel set under the action of friction, and at this time, the next seedling tray to be weighed continues to move forward, and the distance between it and the seedling tray that is stationary on the support wheel set is shortened; The positioning device detects that the seedling tray to be weighed has reached the preset weighing position and transmits a pulse signal to the control system. After the pulse signal receiving unit receives the pulse signal, the control system controls the weighing sensor to start weighing the seedling tray to be weighed which is stationary on the supporting wheel set. The weighing sensor outputs the obtained weighing data to the control system in the form of an analog signal. S5: When the next seedling tray to be weighed hits the stationary seedling tray on the supporting wheel set, the next seedling tray to be weighed pushes the seedling tray on the supporting wheel set to move forward. At this time, one weighing is completed, and the data acquisition unit obtains an analog signal from the weighing sensor. After the weighing is completed, the seedling tray continues to move forward. When the rear end of the seedling tray falls from the rear supporting wheel to the rear driving wheel, the rear driving wheel drives the seedling tray to move forward at a speed V1; S6: After the weighing is completed, the seedling tray continues to move forward under the drive of the variable speed drive assembly. At this time, the distance between the seedling tray after weighing and the next seedling tray to be weighed is increased until the center of mass of the seedling tray after weighing passes the front supporting wheel. At this time, the rear end of the seedling tray after weighing is separated from the variable speed drive assembly, and the front end begins to contact with the front drive assembly, and the front drive assembly begins to drive the seedling tray after weighing to continue to move forward; S7: Repeat steps S2 to S6 for the next seedling tray to be weighed until the weighing of the penultimate seedling tray to be weighed is completed; S8: The last seedling tray to be weighed is weighed by human intervention.

[0058] Specifically, in step S3, if Fig. 9 As shown, when the center of mass passes over the rear support wheel, the rear end of the seedling tray to be weighed begins to separate from the rear drive assembly, and the front end begins to contact the front drive wheel. At this time, the speed of the seedling tray is V0.

[0059] In step S4, if Fig.10 As shown, the seedling tray to be weighed is driven by the front driving wheel and moves forward at a speed of V1. The front end of the seedling tray contacts the front supporting wheel and begins to climb upward by inertia.

[0060] In step S4, if Fig.11 As shown, after the front end of the seedling tray to be weighed climbs onto the front supporting wheel, it briefly stops on the supporting wheel group under the action of friction. At this time, the next seedling tray to be weighed continues to move forward, and the distance between it and the seedling tray that is stationary on the supporting wheel group is shortened.

[0061] In step S5, Fig.12 As shown, when the next seedling tray to be weighed hits the seedling tray stationary on the supporting wheel set, the next seedling tray to be weighed pushes the seedling tray on the supporting wheel set to move forward.

[0062] In step S6, if Fig.13As shown, after weighing is completed, the rear end of the seedling tray is separated from the variable speed drive assembly, and the front end begins to contact the front drive assembly. The front drive assembly begins to drive the seedling tray to continue moving forward after weighing is completed. At this time, the seedling tray continues to move forward at a speed V0 after weighing is completed.

[0063] In the present invention, the positioning device, the weighing device and the control system cooperate with each other to weigh the quality of the seedling tray. The working process is as follows: When the seedling tray reaches the weighing position, the light beam emitted by the light emitter of the through-beam photoelectric sensor is blocked by the seedling tray, and the receiver of the through-beam photoelectric sensor cannot receive the light beam. At this time, the output signal of the through-beam photoelectric sensor receiver changes from low level to high level, and the pulse signal receiving unit of the control system receives a rising edge signal, indicating that the seedling tray reaches the weighing position. The data acquisition unit of the control system begins to receive and read the analog signal from the weighing sensor, and the digital transmitter amplifies the analog signal output by the weighing sensor, converts it into a digital signal, and transmits it to the data processing unit.

[0064] In the present invention, the data information processing method for the seedling tray is: The data processing unit first intercepts the relatively stable weighing data in the digital signal to obtain a set of real measurement value data sets, and then uses the scalar Kalman filtering algorithm to reduce the noise of the collected weighing data to obtain a set of optimized data sets. Finally, the optimized data sets are processed by the median average filtering algorithm to obtain the final weighing result of the rice seedling tray quality.

[0065] The scalar Kalman filter algorithm is divided into two processes: prediction and update. The prediction process uses the estimate of the previous state to make an estimate of the current state; the update process uses the observed value of the current state to optimize the predicted value obtained in the prediction stage to obtain a more accurate optimal estimate x. k|k : Prediction equation:

[0066] Update equation:

[0067] Among them, x k|k-1 is the current state result predicted by the optimal estimate at time k-1; k-1|k-1 is the optimal estimate at time k-1; u k is the control gain of the current state; p k-1|k-1 is the covariance of the estimated value at time k-1; p k|k-1 is the current covariance result predicted by the covariance at time k-1; a is the state transfer coefficient; b is the input gain coefficient; q is the excitation noise; h is the measurement coefficient; r is the measurement noise; g k is the optimal Kalman gain at time k; zk is a real measurement value at time k, that is, a real measurement value dataset; x k|k is the optimal estimate at time k, that is, the optimized data set; p k|k is the covariance of the estimated value at time k.

[0068] The median average filtering algorithm is used to calculate the n optimal estimates x after noise reduction. k|k To process, first sort the n data from small to large, then remove the minimum m1 and maximum m2 values, and finally average the n-m1-m2 optimal estimates:

[0069] Among them, M is the final weighing result of the seedling tray mass.

[0070] In general, in the variable speed weighing device of the present invention, the variable speed drive device, the positioning device and the control system are arranged on the frame, and the weighing device is separated from the frame, so that the seedling tray can be driven by the variable speed drive device to be dynamically carried above the frame, and statically weighed above the weighing device, and because the weighing device is separated from the frame, the influence of the mechanical vibration of the frame on the weighing accuracy is eliminated, so that the weighing result is more accurate. In addition, in the variable speed weighing device of the present invention, a photoelectric sensor is used as a positioning device, a PLC is used as a control system, and an electromagnetic force type weighing sensor is used as a weighing sensor, which further improves the accuracy and stability of the weighing, so that the confidence of the weighing data is higher.

[0071] The variable speed weighing method of the present invention uses a variable speed drive device to enable the seedling tray to be carried at a variable speed on the frame. During static weighing, a certain distance is maintained between the seedling trays in front and behind, so that the seedling trays in front and behind have no mechanical interference with the seedling trays that are stationary on the weighing device for weighing, making the weighing results more accurate and reliable. After the weighing is completed, the seedling trays on the frame continue to move forward, realizing automatic and rapid weighing, greatly improving the weighing efficiency, and thus improving the production efficiency.

[0072] 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 variable speed weighing device for rice seeding tray sowing amount, comprising a frame, a weighing device, a variable speed driving device, a positioning device and a control system, wherein the variable speed weighing device is used to weigh the seeding amount of the rice seeding tray, and is characterized in that: The frame is arranged across the front and rear directions, and the variable speed drive device, positioning device and control system are all installed on the frame; The variable speed drive device is used to drive the seedling tray to perform variable speed movement from the back to the front, and includes a front drive assembly, a variable speed drive assembly and a rear drive assembly which are sequentially arranged on the frame from the front to the back at intervals; The weighing device is arranged below the variable speed drive assembly and is separated from the frame, and includes a support frame, a bottom plate, a weighing sensor, a load-bearing frame and a fender which are arranged in sequence from bottom to top, and a support wheel set is arranged on the front and rear sides of the load-bearing frame respectively, and the two sets of support wheel sets are respectively located at the intervals between the rear drive assembly, the variable speed drive assembly and the front drive assembly; The front drive assembly and the rear drive assembly both include a plurality of groups of rubber drive wheels arranged at intervals, the variable speed drive assembly includes a front drive wheel and a rear drive wheel, the tops of the rubber drive wheel, the front drive wheel and the rear drive wheel are flush and lower than the top of the supporting wheel assembly; the radii of the front drive wheel and the rear drive wheel are the same, the radius of the rubber drive wheel is smaller than the radius of the front drive wheel and the rear drive wheel, and the axles of the front drive wheel and the rear drive wheel are both lower than the axles of the rubber drive wheel; the rotational speeds of the rubber drive wheel, the front drive wheel and the rear drive wheel are the same, the linear speed of the rubber drive wheel is V0, the linear speed of the front drive wheel and the rear drive wheel is V1, and V1 is greater than V0.

2. A variable speed weighing device for rice seeding tray sowing amount according to claim 1, characterized in that: There is a height difference ΔZ1 between the speed change driving device and the top of the supporting wheel set; there is a height difference ΔZ2 between the axis centers of the front driving wheel, the rear driving wheel and the axis center of the rubber driving wheel.

3. The variable speed weighing device for rice seedling tray sowing amount according to claim 1, characterized in that: The supporting wheel group includes a front supporting wheel and a rear supporting wheel located at the front and rear sides of the load-bearing frame; wherein the front supporting wheel is located at the interval between the front drive assembly and the speed-changing drive assembly, and the rear supporting wheel is located at the interval between the speed-changing drive assembly and the rear drive assembly.

4. A variable speed weighing device for rice seedling tray sowing amount according to claim 1, characterized in that: The positioning device includes a through-beam photoelectric sensor light emitter, a through-beam photoelectric sensor receiver and a mounting plate; the through-beam photoelectric sensor light emitter and the through-beam photoelectric sensor receiver are both fixed on the top of the frame through the mounting plate and are located on the left and right sides of the front supporting wheel; the positioning device is used to identify whether the seedling tray has reached the weighing position.

5. The variable speed weighing device for rice seedling tray sowing amount according to claim 1, characterized in that: The control system is electrically connected with the weighing sensor and the positioning device; the control system comprises a pulse signal receiving unit, a data acquisition unit, a data processing unit, a human-computer interaction unit and a power supply unit; wherein the data acquisition unit comprises a digital transmitter.

6. A variable speed weighing method for rice seedling tray sowing amount, characterized in that: A variable speed weighing device for sowing amount of rice seedling trays as described in any one of claims 1 to 5 is used; Methods include: S1: Turn on the variable speed weighing device and place the seedling trays to be weighed on the rear drive assembly in sequence; S2: The rear drive assembly drives the seedling tray to be weighed to start moving at a speed of V0; S3: When the seedling tray to be weighed moves to the rear support wheel, the front end of the seedling tray to be weighed starts to contact the rear support wheel and climbs upward along the rear support wheel. When the center of mass passes the rear support wheel, the rear end of the seedling tray to be weighed is separated from the rear drive assembly, and the front end contacts the front drive wheel; S4: the front driving wheel drives the seedling tray to be weighed to move at a speed of V1, at which time the seedling tray to be weighed is farther away from another seedling tray to be weighed located behind it; Until the front end of the seedling tray to be weighed contacts the front support wheel and begins to climb upward by inertia, after the front end of the seedling tray to be weighed climbs onto the front support wheel, it briefly stops on the support wheel set under the action of friction, and at this time, the next seedling tray to be weighed continues to move forward, and the distance between it and the seedling tray that is stationary on the support wheel set is shortened; The positioning device detects that the seedling tray to be weighed has reached the preset weighing position and transmits a pulse signal to the control system. After the pulse signal receiving unit receives the pulse signal, the control system controls the weighing sensor to start weighing the seedling tray to be weighed which is stationary on the supporting wheel set. The weighing sensor outputs the obtained weighing data to the control system in the form of an analog signal. S5: When the next seedling tray to be weighed hits the stationary seedling tray on the supporting wheel set, the next seedling tray to be weighed pushes the seedling tray on the supporting wheel set to move forward. At this time, one weighing is completed, and the data acquisition unit obtains an analog signal from the weighing sensor. After the weighing is completed, the seedling tray continues to move forward. When the rear end of the seedling tray falls from the rear supporting wheel to the rear driving wheel, the rear driving wheel drives the seedling tray to move forward at a speed V1; S6: After the weighing is completed, the seedling tray continues to move forward under the drive of the variable speed drive assembly. At this time, the distance between the seedling tray after weighing and the next seedling tray to be weighed is increased until the center of mass of the seedling tray after weighing passes the front supporting wheel. At this time, the rear end of the seedling tray after weighing is separated from the variable speed drive assembly, and the front end begins to contact with the front drive assembly, and the front drive assembly begins to drive the seedling tray after weighing to continue to move forward; S7: Repeat steps S2 to S6 for the next seedling tray to be weighed until the weighing of the penultimate seedling tray to be weighed is completed; S8: The last seedling tray to be weighed is weighed by human intervention.

7. A variable speed weighing method for rice seeding tray sowing amount according to claim 6, characterized in that: In step S4, when the seedling tray reaches the detection position, i.e., the seedling tray weighing position, the light beam emitted by the through-beam photoelectric sensor light emitter is blocked by the seedling tray, and the through-beam photoelectric sensor receiver cannot receive the light beam. At this time, the output signal of the through-beam photoelectric sensor receiver changes from a low level to a high level, and the pulse signal receiving unit of the control system receives a rising edge signal, i.e., a pulse signal, indicating that the seedling tray reaches the weighing position. The data acquisition unit starts to receive and read the analog signal from the weighing sensor, and the digital transmitter amplifies the analog signal output by the weighing sensor and converts it into a digital signal and transmits it to the data processing unit.

8. A variable speed weighing method for rice seeding tray sowing amount according to claim 7, characterized in that: The data processing unit first intercepts the relatively stable weighing data in the digital signal to obtain a set of real measurement value data sets, and then uses the scalar Kalman filtering algorithm to reduce the noise of the collected weighing data to obtain a set of optimized data sets. Finally, the optimized data sets are processed by the median average filtering algorithm to obtain the final weighing result of the rice seedling tray quality.

9. A variable speed weighing method for rice seeding tray sowing amount according to claim 8, characterized in that: The scalar Kalman filter algorithm is divided into two processes: prediction and update. The prediction process uses the estimate of the previous state to make an estimate of the current state; the update process uses the observed value of the current state to optimize the predicted value obtained in the prediction stage to obtain a more accurate optimal estimate x. k|k : Prediction equation: Update equation: Among them, x k|k-1 is the current state result predicted by the optimal estimate at time k-1; k-1|k-1 is the optimal estimate at time k-1; u k is the control gain of the current state; p k-1|k-1 is the covariance of the estimated value at time k-1; p k|k-1 is the current covariance result predicted by the covariance at time k-1; a is the state transfer coefficient; b is the input gain coefficient; q is the excitation noise; h is the measurement coefficient; r is the measurement noise; g k is the optimal Kalman gain at time k; z k is a real measurement value at time k, that is, a real measurement value dataset; x k|k is the optimal estimate at time k, that is, the optimized data set; p k|k is the covariance of the estimated value at time k.

10. A variable speed weighing method for rice seeding tray sowing amount according to claim 9, characterized in that: The median average filtering algorithm is used to calculate the n optimal estimates x after noise reduction. k|k To process, first sort the n data from small to large, then remove the minimum m1 and maximum m2 values, and finally average the n-m1-m2 optimal estimates: Among them, M is the final weighing result of the seedling tray mass.

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