GB2587736A

GB2587736A - Flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising and control method thereof

Info

Publication number: GB2587736A
Application number: GB2019526.9A
Authority: GB
Inventors: Chen Jin; Wei Yunyu; Li Yaoming; Yang Ming; Qiao Xiangshan
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2019-12-31
Filing date: 2020-01-09
Publication date: 2021-04-07
Anticipated expiration: 2040-01-09
Also published as: JP2022509899A; GB202019526D0; GB2587736B; JP7055490B2; CH717531B1

Abstract

The present invention provides a flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising and a control method thereof. The flowline operation apparatus sequentially includes a bottom-soil laying device 2, a bottom-soil sweeping device 3, a hole-pressing device 4, a seeding device, a surface-soil covering device 10, a surface-soil sweeping device 11, and a water spraying device 12, the seeding mechanism comprising a seeding manipulator 6 and a vibration table 8, the lower end of the manipulator being connected to a suction tray 7, a vibration tray 9 is fixed on the vibration table and an air intake of the vibration 9 is connected to a vacuum pump 14 and further includes a three-section conveyor belt and a control system. The flowline operation apparatus is controlled by a PLC, wherein each working process is independently controlled; wherein an output vibration frequency of the vibration table is controlled according to a vibration frequency of the vibration tray. In automatic control the frequency of the vibration tray may be controlled according to changes of the conveyor belt speed and the seeding speed, thereby increasing the suction rate and improving the seedling qualification rate.

Description

FLOWLINE OPERATION APPARATUS OF PNEUMATIC VIBRATION TRAY-TYPE PRECISION SEEDING FOR SEEDLING RAISING AND CONTROL METHOD THEREOF

Technical Field

The present invention relates to the technical field of agricultural seeders, and in particular, to a flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising and a control method thereof

Background

Rice is widely planted around the world and can be found in Asia, Europe, America, Africa, and Oceania. About 90% of the world's rice fields and yields are in Asia, and rice is one of the main food crops in Asia. The raising of rice seedlings gradually develops from artificial to mechanized manners, and the operation mode thereof also changes from separated processes to flowline operation. As for mechanized seedling raising, mechanical, fluted-roller, and socket-roller seeding are mostly adopted, but the seeding precision is low and the seed damage rate is high; while pneumatic seeding can largely reduce the seed damage rate to improve the survival rate and has high precision, thus meeting the seeding requirement of 1-2 grains per hole for seedling raising of super rice. However, in view of the operation features of pneumatic tray-type seeding, the seedling tray needs to wait for seeding at a seeding position; therefore, the flowline operation has not been realized, and the existing seeders have not achieved adaptive seeding.

Summary

Therefore, the present invention provides a flowline operation apparatus of pneumatic 25 vibration tray-type precision seeding for seedling raising and a control method thereof, which are applicable to precision seeding and particularly to pneumatic vibration tray-type seeding. The present invention can realize automation of the entire seeding process, achieve flexible seeding with a multi-degree-of-freedom manipulator, and achieve adaptive control of vibration parameters of a vibration tray along with the seeding process and the quantity of seeds.

The present invention adopts the following technical solutions.

A flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising is provided, wherein a three-section conveyor belt structure is adopted, a soil laying and hole-pressing mechanism, a seeding mechanism, and a soil covering and water spraying mechanism arc sequentially and separately disposed on the three sections of the conveyor belt in the working direction, the seeding mechanism includes a seeding manipulator and an electromagnetic vibration table, a lower end of the seeding manipulator is connected to a suction tray, a vibration tray is fixed on the electromagnetic vibration table, and an air intake of the vibration tray is connected to a vacuum pump; the apparatus further includes a PLC controller, a signal acquisition sensor, and a touch screen, for controlling the soil laying and hole-pressing mechanism, the seeding mechanism, and the soil covering and water spraying mechanism to operate according to specific positions of a seedling tray in the flowline operation apparatus; when the seedling tray reaches a seeding position, seed discharge is performed; and in the seedling-raising process, the output vibration frequency of the electromagnetic vibration table is controlled according to the vibration frequency of the vibration tray.

In the above technical solution, the hole-pressing device includes a second support threaded rod, and the second support threaded rod is connected to a hole-pressing roller frame.

In the above technical solution, the bottom-soil sweeping device includes a first support threaded rod, and the first support threaded rod is connected to a brush frame.

In the above technical solution, the bottom-soil laying device includes a soil storage tank, and a stirring shaft is fixed on an upper end of the soil storage tank.

In the above technical solution, the first conveyor belt consists of a first conveyor belt part-A and a first conveyor belt part-B that are connected through chain transmission, and the running speed of the first conveyor belt part-B is greater than that of the first conveyor belt part-A.

In the above technical solution, the third conveyor belt consists of a third conveyor belt part-A 5 and a third conveyor belt part-B that are connected through chain transmission, and the running speed of the third conveyor belt part-A is the same as that of the third conveyor belt part-B.

A control method of the flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising is provided, which includes: detecting the specific positions of the seedling tray in the flowlinc operation apparatus and 10 controlling the on-off of the corresponding working members; automatically adapting the hole-pressing device to the speed of the first conveyor belt, and performing aligned pressing against the holes in the seedling tray; discharging seeds after a limit switch is triggered during seeding; controlling the output vibration frequency of the electromagnetic vibration table according to 15 the vibration frequency of the vibration tray; detecting the rotation speeds of the bottom-soil laying device, the surface-soil covering device, the first conveyor belt, the second conveyor belt, and the third conveyor belt, displaying the detection results on the touch screen, and meanwhile, controlling the working members to operate coordinately by the PLC according to the detection results.

Further, the electromagnetic vibration table adopts frequency conversion control, and the specific control process is as follows: when the flowline operation apparatus is started, the vibration tray vibrates at a low frequency; in the suction operation, the electromagnetic vibration table drives the vibration tray to vibrate at a high frequency, and after the suction ends, the electromagnetic vibration table recovers low-frequency vibration; with the ongoing seeding, the quantity of seeds in the vibration tray is gradually reduced, and the vibration frequency of the electromagnetic vibration table is increased; when the quantity of seeds in the vibration tray is reduced to a certain number, seeds are added, the vibration frequency of the electromagnetic vibration table is adjusted, the PLC controller controls the seeding speed to be slowed down, and time is reserved for uniform distribution of the seeds in the vibration tray.

Compared with the prior art, the present invention has the following advantages and positive effects: (1) The hole-pressing device in the flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising of the present invention adopts a vertically adjustable hole-pressing roller to adjust the depth of holes in the seedling tray, thereby effectively improving the seedling-raising effect.

(2) The electromagnetic vibration table in the flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising of the present invention adopts frequency conversion control, and adjusts frequency according to different working states. Specifically, during the suction operation, the electromagnetic vibration table drives the vibration tray to vibrate at a high frequency; when the suction ends, the electromagnetic vibration table recovers low-frequency vibration; and when seeds are added, the vibration frequency of the electromagnetic vibration table is adjusted. The frequency of the vibration tray is automatically adjusted, the "boiling" effect of the seed population in the vibration tray is improved, the seeding qualification rate is raised, and the miss-seeding rate is reduced.

(3) In the present invention, the multi-degree-of-freedom manipulator is further adopted for seed suction and discharge, and the photoelectric sensors are used for detecting the positions of the seedling tray, so that the working members can be flexibly enabled and disabled and the degree of automation in the flowline operation of precision seeding is effectively improved. Besides, system control based on a touch screen is implemented, thereby improving the intelligence level of rice seedling raising.

Brief Description of the Drawings

FIG. 1 is a schematic diagram of an overall structure of a flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising according to the present invention; FIG. 2 is a top view of the structure of the flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising according to the present invention; FIG. 3 is a schematic structural diagram of a bottom-soil laying device and a surface-soil covering device according to the present invention; FIG. 4 is a schematic structural diagram of a bottom-soil sweeping device and a hok-pressing 10 device according to the present invention, wherein FIG. 4(a) is an isometric view of the bottom-soil sweeping device and the hole-pressing device, and FIG. 4(b) is a sectional view of the hole-pressing device; FIG. 5 is a schematic structural diagram of a second conveyor belt support frame according to the present invention; FIG. 6 is a schematic structural diagram of a water spraying device according to the present invention; FIG. 7 is a schematic structural diagram of a horizontal adjustment wheel according to the present invention; FIG. 8 is a flow chart of a seeding process in the flowline operation of the present invention; FIG. 9 is a structural diagram of hardware in a flowline operation control system according to the present invention; FIG. 10 is a circuit diagram of a frequency control system of a vibration tray according to the present invention; FIG. 11 is a diagram showing the principle of a frequency control system of an 25 electromagnetic vibration table according to the present invention, wherein FIG. 11(a) is a diagram showing the principle of controlling the frequency of the electromagnetic vibration table according to the change of the quantity of seeds in the vibration tray, and FIG. 11(b) is a diagram showing the principle of controlling the frequency of the electromagnetic vibration table according to the change of the quantity of trays for seeding; FIG. 12 is a flow chart of an adaptive control algorithm in the seeding process according to 5 the present invention; FIG. 13 is a schematic diagram of a control interface on a touch screen according to the present invention; and FIG. 14 is a flow chart of process control in the flowline operation according to the present invention.

In the figures: 1-first conveyor belt support frame, 2-bottom-soil laying device, 2a-soil feed hopper, 2b-soil storage tank, 2c-stirring shaft, 2d-soil laying amount adjustment plate, 2e-soil laying track, 2f-first track shaft, 2g-second track shaft, 3-bottom-soil sweeping device, 3a-brush frame, 3b-first motor frame, 3c-first stepper motor, 3d-brush, 3e-first support threaded rod, 3f-first coupling, 4-hole-pressing device, 4a-hole-pressing roller frame, 4b-second motor frame, 4c-second stepper motor, 4d-hole-pressing roller, 4e-second support threaded rod, 4f-second coupling, 4g-cleaning brush, 5-second conveyor belt support frame, 5a-second conveyor belt support frame beam, 5b-first support plate, 5c-second support plate, 6-seeding manipulator, 7-suction fray, 8-electromagnetic vibration table, 9-vibration tray, 10-surface-soil covering device, 11-surface-soil sweeping device, 12-water spraying device, 12a-water spraying frame, 12b-water pipe, 12c-atomizing nozzle, 12d-adjustable electromagnetic valve, 13-third conveyor belt support frame, 14-vacuum pump, 15-first drive motor, 16-second drive motor, 17-third drive motor, 18-fourth drive motor, 19-fifth drive motor, 20-adjustable universal wheel, 21-horizontal adjustment wheel, 21a-adjustment threaded rod, 21b-auxiliary threaded rod, 21c-support top plate, 21d-support bottom plate, 21e-wheel, 22-first bridging plate, 23-second bridging plate, 24-first conveyor belt, 24a-first conveyor belt part-A, 24b-first conveyor belt part-B, 25-second conveyor belt, 26-third conveyor belt, 26a-third conveyor belt part-A, 26b-third conveyor belt part-B, 27-first photoelectric sensor, 28-second photoelectric sensor, 29-third photoelectric sensor, 30-fourth photoelectric sensor, 31-fifth photoelectric sensor, 32-sixth photoelectric sensor, 33-seventh photoelectric sensor, 34-eighth photoelectric sensor, 35-ninth photoelectric sensor, 36-tenth photoelectric sensor, 37-eleventh photoelectric sensor, 38-twelfth photoelectric sensor, 39-thirteenth photoelectric sensor, 40-limit switch, 41-first speed sensor, 42-second speed sensor, 43-third speed sensor, 44-fourth speed sensor, 45-fifth speed sensor, 46-frequency sensor, 47-positioning stopper.

Detailed Description of the Embodiments

The technical solutions of the present invention are further described below with reference to 10 the accompanying drawings, but the protection scope of the present invention is not limited thereto. As shown in FIG. 1 and FIG. 2, the present invention provides a flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising, including a first conveyor belt support frame 1, a bottom-soil laying device 2, a bottom-soil sweeping device 3, a hole-pressing device 4, a second conveyor belt support frame 5, a seeding manipulator 6, a suction 15 tray 7, an electromagnetic vibration table 8, a vibration tray 9, a surface-soil covering device 10, a surface-soil sweeping device 11, a water spraying device 12, a third conveyor belt support frame 13, and a vacuum pump 14 The first conveyor belt support frame 1, the second conveyor belt support frame 5, and the third conveyor belt support frame 13 each have one end provided with a conveyor-belt tension adjustment groove.

As shown in FIG. 3, the bottom-soil laying device 2 includes a soil storage tank 2b and a soil feed hopper 2a that are integrally fixed. The soil feed hopper 2a is located on an upper end of the soil storage tank 2b. The soil storage tank 2b has a hollow structure with an open upper end and a semi-closed front end. A soil laying amount adjustment plate 2d is fixed on the front end of the soil storage tank 2b through two studs and wing nuts. The height of the soil laying amount adjustment plate 2d can be adjusted by loosening the wing nuts, thereby controlling the laying thickness of the bottom soil. A first track shaft 2f and a second track shaft 2g are fixed on the same level in the soil storage tank 2b. A soil laying track 2e is fixed by the first track shaft 2f and the second track shaft 2g. The soil laying track 2e is located below the soil laying amount adjustment plate 2d. A stirring shaft 2c is fixed at a central position on the upper end of the soil storage tank 2b, to prevent the soil matrix in the soil storage tank 2b from getting lumpy. A first speed sensor 41 is further disposed on the soil storage tank 2b, and is used for measuring the rotation speed of the first track shaft 2f. The structure of the surface-soil covering device 10 is the same as that of the bottom-soil laying device 2. A fourth speed sensor 44 is disposed on the surface-soil covering device 10, and is used for measuring the rotation speed of the track shaft of the surface-soil covering device.

As shown in FIG. 4(a), the bottom-soil sweeping device 3 includes a first support threaded rod 3e which is fixed on the first conveyor belt support frame 1 through a bolt and is connected to a brush frame 3a through a nut. A brush 3d is fixed on the brush frame 3a. A first motor frame 3b is connected to one end of the brush frame 3a through a bolt. A first stepper motor 3c is fixed on the first motor frame 3b. A shaft of the first stepper motor is connected to a shaft of the brush through a first coupling 3f. The structure of the surface-soil sweeping device 11 is the same as that of the bottom-soil sweeping device 3. The rotation direction of the brush 3d is opposite to the running direction of the first conveyor belt 24. The height of the brush frame 3a can be adjusted by rotating the first support threaded rod 3e, to achieve a flat surface of a seedling tray laid with bottom soil.

As shown in FIG. 4(a), the hole-pressing device 4 includes a second support threaded rod 4e which is fixed on the first conveyor belt support frame 1 through a bolt and is connected to a hole-pressing roller frame 4a through a nut. The hole-pressing roller frame 4a is connected to a hole-pressing roller 4d through a nut. A second motor frame 4b is connected to one end of the hole-pressing roller frame 4a through a bolt. A second stepper motor 4c is fixed on the second motor frame 4b. A shaft of the second stepper motor is connected to a shaft of the hole-pressing roller through a second coupling 4f. The rotation direction of the hole-pressing roller 4d is the same as the running direction of the first conveyor belt 24. The height of the hole-pressing roller frame 4a can be adjusted by rotating the second support threaded rod 4e, so that holes can be sequentially made on the surface of the seedling tray laid with bottom soil. As shown in FIG. 4(b), a cleaning brush 4g is fixed on an inner wall of the hole-pressing roller frame 4a, and is used for brushing away soil attached to the surface of the hole-pressing roller 4d in time.

The first conveyor belt support frame 1 and the second conveyor belt support frame 5 are bridged through a first bridging plate 22, and the second conveyor belt support frame 5 and the third conveyor belt support frame 13 are bridged through a second bridging plate 23. Adjustable universal wheels 20 are separately connected to bottom ends of the first conveyor belt support frame 1 and the third conveyor belt support frame 13 through bolts. The first conveyor belt 24 is mounted on the first conveyor belt support frame 1. The first conveyor belt 24 consists of a first conveyor belt part-A 24a and a first conveyor belt part-B 24b that are connected by two chain wheels through chain transmission. The running speed of the first conveyor belt part-B 24b is greater than that of the first conveyor belt part-A 24a, so that proper intervals are formed during continuous placement of the seedling trays and the bottom soil swept away by the bottom-soil sweeping device 2 from a previous tray is prevented from falling on a next tray. The bottom-soil laying device 2, the bottom-soil sweeping device 3, and the hole-pressing device 4 are sequentially connected through bolts above the first conveyor belt support frame 1 in the working direction. The bottom-soil laying device 2 is located on the first conveyor belt part-A 24a, and the bottom-soil sweeping device 3 and the hole-pressing device 4 are located on the first conveyor belt part-B 24b. A first drive motor 15 and a second drive motor 16 are further fixed on the first conveyor belt support frame 1. The first drive motor 15 is used for powering the bottom-soil laying device 2. The second drive motor 16 is used for powering the first conveyor belt 24. A second speed sensor 42 is further disposed on the first conveyor belt support frame 1, and is used for measuring the rotation speed of the first conveyor belt 24. A third conveyor belt 26 and a fifth speed sensor 45 are mounted on the third conveyor belt support frame 13. The fifth speed sensor 45 is used for measuring the rotation speed of the third conveyor belt 26. The third conveyor belt 26 consists of a third conveyor belt part-A 26a and a third conveyor belt part-B 26b that are connected by two chain wheels through chain transmission. The third conveyor belt part-A 26a and the third conveyor belt part-B 26b run at the same speed, so that the water spraying process is separated from the surface-soil covering process and the surface-soil sweeping process, and the soil matrix scattered on the third conveyor belt part-A 26a is prevented from getting wet and being attached to the third 5 conveyor belt part-B 26b to cause the entire conveyor belt to become muddy. The surface-soil covering device 10, the surface-soil sweeping device 11, and the water spraying device 12 are sequentially connected through bolts above the third conveyor belt support frame 13 in the working direction. A fourth drive motor 18 and a fifth drive motor 19 are further fixed on the third conveyor belt support frame 13. Thc fourth drive motor 18 is used for powcring thc surface-soil covering 10 device 10. The fifth drive motor 19 is used for powering the third conveyor belt 26.

As shown in FIG. 5, the second conveyor belt support frame 5 includes second conveyor belt support frame beams 5a as well as first support plates 5b and second support plates Sc that are disposed on one side of the support frame. Horizontal adjustment wheels 21 are mounted on a lower end of the second conveyor belt support frame 5. The seeding manipulator 6 and a third drive motor 17 are fixedly connected on the first support plates 5b. The seeding manipulator 6 is a five-axis manipulator. A lower end of the seeding manipulator 6 is connected to the suction fray 7. The electromagnetic vibration table 8 and the vacuum pump 14 are fixed on the second support plates Sc. The vibration tray 9 is fixed on the electromagnetic vibration table 8 through a bolt. An air intake of the vibration fray 9 is connected to the vacuum pump 14 through a hose. A frequency sensor 46 is disposed on the bottom of the vibration tray 9, and is used for measuring the frequency of the vibration fray 9. A second conveyor belt 25 and a third speed sensor 43 used for measuring the rotation speed of the second conveyor belt 25 are mounted on the second conveyor belt support frame beams 5a. A limit switch 40 and a positioning stopper 47 are further disposed on tail ends of the second conveyor belt support frame beams 5a. At a seeding position, the limit switch 40 is located at the comer of the suction tray 7 and is used for controlling the seeding distance between the suction fray 7 and the seedling tray, and the positioning stopper 47 is located in front of the seedling tray.

In the delivery direction of the conveyor belt, a second photoelectric sensor 28 and a first photoelectric sensor 27 are respectively disposed on a front end and a rear end of the bottom-soil laying device 2, a third photoelectric sensor 29 and a fourth photoelectric sensor 30 are respectively 5 disposed on a front end and a rear end of the bottom-soil sweeping device 3, a fifth photoelectric sensor 31 and a sixth photoelectric sensor 32 are respectively disposed on a front end and a rear end of the hole-pressing device 4, a seventh photoelectric sensor 33 is disposed on a tail end of the first conveyor belt 24, an eighth photoelectric sensor 34 and a ninth photoelectric sensor 35 are respectively disposed on a front end and a rear end of thc surface-soil covering device 10, a tenth 10 photoelectric sensor 36 and an eleventh photoelectric sensor 37 are respectively disposed on a front end and a rear end of the surface-soil sweeping device 11, and a twelfth photoelectric sensor 38 and a thirteenth photoelectric sensor 39 are respectively disposed on a front end and a rear end of the water spraying device 12.

As shown in FIG. 6, the water spraying device 12 includes two rectangular water spraying frames 12a, and bottom ends of the two rectangular water spraying frames 12a are fixed on the third conveyor belt support frame 13. Several water pipes 12b are fixed on the two water spraying frames 12a. Atomizing nozzles 12c are uniformly arranged on each water pipe 12b. An adjustable electromagnetic valve 12d is disposed on a pipeline connecting the water pipes 12b to a water source. The water spraying amount can be controlled by adjusting the opening of the adjustable electromagnetic valve 12d.

As shown in FIG. 7, the horizontal adjustment wheel 21 includes an adjustment threaded rod 21a, an auxiliary threaded rod 21b, a support top plate 21c, a support bottom plate 21d, and a wheel 21e. The support top plate 21c and the support bottom plate 21d are connected through the adjustment threaded rod 21a and the auxiliary threaded rod 21b, and the wheel 21e is fixed below the support bottom plate 21d.

FIG. 8 is a flow chart of a seeding process of the flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising according to the present invention. A seedling tray is manually placed at a starting end of the first conveyor belt 24 and sequentially passes through the bottom-soil laying device 2, the bottom-soil sweeping device 3, the hole-pressing device 4, the second conveyor belt support frame 5, the surface-soil covering device 10, the surface-soil sweeping device 11, and the water spraying device 12 for bottom-soil laying, bottom-soil sweeping, hole-pressing, seeding, surface-soil covering, surface-soil sweeping, and water spraying, and finally the seedling tray is manually taken away.

FIG. 9 is a schematic structural diagram of hardware in a control system of the flowline operation apparatus of pneumatic vibration tray-typc prccision seeding for seedling raising according to the present invention. The photoelectric sensors, the speed sensors, the limit switch 40, and the frequency sensor 46 are all connected to signal input ends of the PLC controller. Output ends of the PLC controller are connected to drivers of the stepper motors, frequency converters of the drive motors, a frequency converter of the vacuum pump 14, a frequency converter of the electromagnetic vibration table 8, and the adjustable electromagnetic valve 12d. The PLC controller communicates with an industrial touch screen. The PLC controller, functioning as a main control unit, is responsible for coordinating the running of the flowline operation apparatus, and performs logical operation and gives instructions after receiving signals, thereby controlling the running of the members in the flowline operation apparatus. The frequency converters are drive units for the drive motors, the electromagnetic vibration table, and the vacuum pump separately, and are responsible for speed adjustment of the motors, vibration frequency adjustment of the electromagnetic vibration table, and negative pressure adjustment of the vacuum pump. The speed sensors monitor the speed of each running equipment. The photoelectric sensors acquire specific positions of the seedling tray on the flowline operation apparatus and send to the PLC controller. The PLC controller performs logical processing, and sends instructions to the corresponding equipment, realizing on-off of the equipment. The adjustable electromagnetic valve is responsible for controlling the water spraying amount of the nozzles.

FIG. 10 is a circuit diagram of a frequency control system of the vibration tray. The vibration frequency of the electromagnetic vibration table 8 is adjusted based on a feedback signal carrying reduction of the quantity of seeds in the vibration tray 9.

FIG. 11 is a diagram showing the principle of a frequency control system of the electromagnetic vibration table. As shown in FIG. 11(a), the quantity of seeds in the vibration tray is detected, and the vibration tray 9 is adjusted accordingly. As shown in FIG. 11(b), the change of the quantity of seeds in the vibration tray is transformed into the quantity of trays for seeding and serves as an input signal for vibration frequency control of the vibration tray 9.

As shown in FIG. 12, the ekctromagnetic vibration tabk 8 adopts a frequency conversion control manner. Firstly, the vibration tray 9 vibrates at a set low frequency after power-on. When the seeding manipulator 6 drives the suction tray 7 to perform suction operation, the electromagnetic vibration table 8 drives the vibration tray 9 to perform high-frequency vibration. When the suction operation ends, the electromagnetic vibration table 8 recovers low-frequency vibration. Meanwhile, as seeding proceeds, the quantity of seeds in the vibration tray 9 gradually reduces, and the vibration frequency of the electromagnetic vibration table 8 during the suction operation increases with the change of the quantity of seeds in the vibration tray 9. Therefore, the optimal "boiling" effect of the seed population is achieved, the suction rate of the suction tray 7 is ensured, and a maximum seeding qualification rate is obtained. Finally, when the quantity of seeds in the vibration tray 9 is reduced to a certain number (20-30 trays), seeds need to be added. After seeds are added, the electromagnetic vibration table 8 properly adjusts the vibration frequency according to the seed addition quantity immediately, so that the seed population is rapidly and uniformly distributed in the vibration tray 7. Meanwhile, adjustment is made by slowing down the operating speed of the seeding manipulator 6 during the process from the end of the previous seeding to the ongoing suction, enabling uniform distribution of the seed population in the vibration tray 9 to be carried out in a proper period of time. Correspondingly, adjustments are also made in the other processes of the flowline operation apparatus, to realize adaptive control of the entire flowline operation of seeding and ensure the maximum seeding qualification rate and maximum seeding efficiency.

FIG. 13 and FIG. 14 illustrate a flow chart of process control in the flowline operation according to the present invention. After the flowline operation apparatus is powered on, the touch screen lights up and presents a mode selection interface. In a manual control mode, tap "Manual Mode" on the "Mode Selection" interface to enter a "Manual Mode" control interface, on which each member in the "Working Members" column can be selected. Every time one button is tapped, working parameters of the corresponding member can be set in the "Settings" column Tap "OK" aflia each parameter is set, and the corresponding member is enabled to run according to the set parameter. Tap the member button in the "Working Members" column again to disable the corresponding working member. Parameter setting options in the "Settings" column can be adjusted according to the selected working members in the "Working Members" column, options that can be set are highlighted, while the other options are in gray and cannot be set. For example, when the bottom-soil laying device 2 is to be set for running, firstly tap the "Manual Mode" button on the "Mode Selection" interface, then tap the "bottom-soil laying device" button in the "Working Members" column, and enter a rotation speed value in the "rotation speed" box in the "Settings" column, fine adjustment can be carried out through an up or down arrow behind the box, and tap the "OK" button after the numerical values are confirmed. Therefore, the bottom-soil laying device 2 starts running according to the set rotation speed.

In an automatic control mode, tap "Automatic Mode" on the "Mode Selection" interface to enter an "Automatic Mode" control interface, on which each member in the "Working Members" column can be selected. Every time one button is tapped, working parameters of the corresponding member can be set in the "Settings" column. Tap "OK" after each parameter is set. After the parameters of all the working members are sequentially set, tap the "Start" button at the top of the interface, and all the working members automatically run according to the set working parameters. Taking seeding in one seedling tray as an example, after all the working parameters are set, tap the "Start" button to start the electromagnetic vibration table 8 and the vacuum pump 14. When the seedling tray is placed in the flowline operation apparatus and its front end firstly triggers the first photoelectric sensor 27, the PLC controller receives a signal and sends an instruction to the first conveyor belt 24, and the first conveyor belt 24 starts to deliver the seedling tray. When the front end of the seedling tray triggers the second photoelectric sensor 28 mounted on the front end of the bottom-soil laying device 2, the bottom-soil laying device 2 starts numing. The seedling tray continuously moves on, and when the front end of the seedling tray triggers the third photoelectric sensor 29, the bottom-soil sweeping device 3 starts running. Then, the front end of the seedling tray triggers the fifth photoelectric sensor 31, and the hole-pressing device 4 starts running. When the tail end of the seedling tray triggers the second photoelectric sensor 28, the bottom-soil laying device 2 stops running. When the tail end of the seedling tray triggers the fourth photoelectric sensor 30, the bottom-soil sweeping device 3 stops running When the tail end of the seedling tray triggers the sixth photoelectric sensor 32, the hole-pressing device 4 stops running. When the front end of the seedling tray triggers the seventh photoelectric sensor 33, a signal is sent to the PLC controller. The PLC controller determines whether the eighth photoelectric sensor 34 is triggered, and if yes, the first conveyor belt 24 stops running; otherwise, the first conveyor belt 24 continues running. Meanwhile, the second conveyor belt 25 starts running, the suction tray 7 starts suction, and the positioning stopper 47 is pushed out. The front end of the seedling tray is hindered by the positioning stopper 47 and triggers the eighth photoelectric sensor 34, and the suction tray 7 discharges seeds. Meanwhile, the suction tray 7 triggers the limit switch 40, the positioning stopper 47 is pulled back, and the third conveyor belt 26 starts running. When the tail end of the seedling tray triggers the eighth photoelectric sensor 34, the second conveyor belt 25 stops running. When the front end of the seedling tray triggers the ninth photoelectric sensor 35, the surface-soil covering device 10 starts running. When the front end of the seedling tray triggers the tenth photoelectric sensor 36, the surface-soil sweeping device 11 starts running. When the front end of the seedling tray triggers the twelfth photoelectric sensor 38, the water spraying device 12 starts running. When the tail end of the seedling tray triggers the ninth photoelectric sensor 35, the surface-soil covering device 10 stops running. When the front end of the seedling tray triggers the eleventh photoelectric sensor 37, the surface-soil sweeping device 11 stops running. When the tail end of the seedling tray triggers the thirteenth photoelectric sensor 39, the water spraying device 12 stops spraying, and the third conveyor belt 26 stops running. So far, the entire flowline operation of seeding is finished. In the automatic seeding mode, the working conditions of the seeding members can be displayed in real time on the industrial touch screen.

The specific implementations are described in detail above according to the technical solutions of the present invention. Persons of ordinary skill in the art can propose a variety of alternative structural modes and implementation manners according to the technical solutions of the present invention without changing the essential spirit of the present invention. Therefore, the specific implementations described above and the accompanying drawings are only exemplary descriptions of the technical solutions of the present invention, and shall not be regarded as the whole present invention or as a limitation or restriction to the technical solutions of the present invention.

Claims

Claims What is claimed is: 1. A flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising, characterized in that. a three-section conveyor belt structure is adopted, a soil laying and hole-pressing mechanism, a seeding mechanism, and a soil covering and water spraying mechanism are sequentially and separately disposed on the three sections of the conveyor belt in a working direction, the seeding mechanism comprises a seeding manipulator (6) and an electromagnetic vibration table (8), a lower end of the seeding manipulator (6) is connected to a suction tray (7), a vibration tray (9) is fixed on the electromagnetic vibration table (8), and an air intake of the vibration tray (9) is connected to a vacuum pump (14); the apparatus further comprises a PLC controller, a signal acquisition sensor, and a touch screen, for controlling the soil laying and hole-pressing mechanism, the seeding mechanism, and the soil covering and water spraying mechanism to operate according to specific positions of a seedling tray in the flowline operation apparatus; when the seedling tray reaches a seeding position, seed discharge is performed; and in a seedling-raising process, an output vibration frequency of the electromagnetic vibration table (8) is controlled according to a vibration frequency of the vibration tray (9).
2. The flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising according to claim 1, characterized in that: the hole-pressing device (4) comprises 20 a second support threaded rod (4e), and the second support threaded rod (4e) is connected to a hole-pressing roller frame (4a).
3. The flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising according to claim 1, characterized in that: the bottom-soil sweeping device (3) comprises a first support threaded rod (3e), and the first support threaded rod (3e) is connected to a 25 brush frame (3a).
4. The flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising according to claim 1, characterized in that: the bottom-soil laying device (2) comprises a soil storage tank (2b), and a stirring shaft (2c) is fixed on an upper end of the soil storage tank (2b).
5. The flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising according to claim 1, characterized in that: the first conveyor belt (24) consists of a first conveyor belt part-A (24a) and a first conveyor belt part-B (24b) that are connected through chain transmission, and a running speed of the first conveyor belt part-B (24b) is greater than that of the first conveyor belt part-A (24a).
6. The flowlinc operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising according to claim 1, characterized in that: the third conveyor belt (26) consists of a third conveyor belt part-A (26a) and a third conveyor belt part-B (26b) that are connected through chain transmission, and a running speed of the third conveyor belt part-A (26a) is the same as that of the third conveyor belt part-B (26b).
7. A control method of the flowline operation apparatus of pneumatic vibration tray-type 15 precision seeding for seedling raising according to any one of claims 1 to 6, characterized by comprising: detecting the specific positions of the seedling tray in the flowline operation apparatus and controlling the on-off of the corresponding working members; automatically adapting the hole-pressing device to the speed of the first conveyor belt, and 20 performing aligned pressing against the holes in the seedling tray; discharging seeds after a limit switch (40) is triggered during seeding; controlling the output vibration frequency of the electromagnetic vibration table (8) according to the vibration frequency of the vibration tray (9); detecting the rotation speeds of the bottom-soil laying device (2), the surface-soil covering device (10), the first conveyor belt (24), the second conveyor belt (25), and the third conveyor belt (26), displaying the detection results on the touch screen, and meanwhile, controlling the working members to operate coordinately by the PLC according to the detection results.
8. The control method of the flowline operation apparatus of pneumatic vibration tray-type precision seeding for seedling raising according to claim 7, characterized in that: the electromagnetic vibration table (8) adopts frequency conversion control, and the specific control 5 process is as follows: when the flowline operation apparatus is started, the vibration tray (9) vibrates at a low frequency; in the suction operation, the electromagnetic vibration table (8) drives the vibration tray (9) to vibrate at a high frequency, and after the suction ends, the electromagnetic vibration table (8) recovers low-frequency vibration; with the ongoing seeding, the quantity of seeds in the vibration tray (9) is gradually reduced, and the vibration frequency of the 10 electromagnetic vibration table (8) is increased; when the quantity of seeds in the vibration tray (9) is reduced to a certain number, seeds are added, the vibration frequency of the electromagnetic vibration table (8) is adjusted, the PLC controller controls the seeding speed to be slowed down, and time is reserved for uniform distribution of the seeds in the vibration tray (9).