Lower limiting fixed sensing device for greenhouse cotton quilt and control method of lower limiting fixed sensing device

Abstract

The invention relates to a lower limit fixing sensing device for greenhouse quilts and a control method thereof, the lower limit fixing sensing device comprises a fixing plate, fixing boxes, a sensor and a controller, the fixing plate is of a long-strip-shaped structure and is arranged in the rolling and laying direction of the greenhouse quilts, the number of the fixing boxes is two or more, the fixing boxes are arranged in the length direction of the fixing plate, the controller is electrically connected with the sensor, and the sensor is electrically connected with the controller. The sensors are mercury limiting sensors and are arranged in the fixing box, the two or more sensors are connected in parallel, when the greenhouse cotton quilt is in a non-spread state, any adjacent sensors are spaced by the same preset angle, and the lower limiting sensing fixing device can be flexibly installed on the surface of the greenhouse cotton quilt. The fixing plate can be rolled up and spread out along with the greenhouse cotton quilts and is not affected by the greenhouse or other factors, and therefore the real state of the greenhouse cotton quilts can be accurately obtained.

Description

Technical Field

[0001] The present application relates to the field of agricultural automation technology, and particularly relates to a lower limit fixed sensing device for a greenhouse cotton quilt and a control method therefor. Background Art

[0002] With the continuous development of the greenhouse industry, greenhouse cotton quilts are gradually being adopted by farmers. The popularization and application of solar greenhouse greenhouses are an important symbol of modern agriculture. It gets rid of the restriction of traditional agriculture by natural climate conditions, greatly increases the yield per unit area, and at the same time ensures the year-round balanced supply of vegetables and fruits. However, in winter and at the turn of autumn and winter and winter and spring in most parts of our country, the climate is cold and the temperature difference between day and night is large. In order to meet the requirements of crop growth, in addition to relying on solar radiation during the day, solar greenhouses use greenhouse cotton quilts to be rolled and laid outside the greenhouse at night to keep the vegetables and fruits inside the greenhouse warm. In the prior art, a greenhouse is composed of a shed film and an arc-shaped support. The shed film is provided on the arc-shaped support, and a rolling machine is used to control the rolling up and rolling out of the greenhouse cotton quilt outside the greenhouse. During the day in winter, the greenhouse cotton quilt needs to be rolled up for lighting, and at night for heat preservation, the greenhouse cotton quilt is released and rolled out to keep the inside of the greenhouse warm.

[0003] The lower limit sensor of the greenhouse cotton quilt is usually used to control the lowest position of the cotton quilt to prevent the cotton quilt from being pulled down too much or to an inappropriate position. This kind of sensor is usually a mechanical device with a sensor and a robotic arm. When the cotton quilt moves down to the lowest position, the sensor will trigger the robotic arm, thus preventing the cotton quilt from being pulled down further. The installation and use methods of the lower limit sensor may vary depending on the types of greenhouses and cotton quilts. However, the robotic arm extends outside the shed through the shed film. Since this method requires a square hole to be opened in the shed film, it is easy for wind to enter the shed in winter, which is not conducive to the heat preservation and heat storage of the shed and the installation is relatively cumbersome. Summary of the Invention

[0004] In view of this, the present application provides a lower limit fixed sensing device for a greenhouse cotton quilt and a control method therefor.

[0005] According to one aspect of the present application, there is provided a lower limit fixed sensing device for a greenhouse cotton quilt and a control method therefor, including: a fixing plate, a fixing box, a sensor and a controller;

[0006] The fixing plate is in a long strip shape and is arranged along the rolling and laying direction of the greenhouse cotton quilt;

[0007] There are two or more fixing boxes, which are arranged along the length direction of the fixing plate;

[0008] The controller is electrically connected to the sensor;

[0009] The sensor is a mercury limit sensor, which is arranged inside the fixed box. Two or more of the sensors are connected in parallel, and when the greenhouse cotton quilt is in an unfolded state, any adjacent sensors are spaced at the same preset angle.

[0010] In a possible implementation manner, two or more of the sensors have the same installation direction.

[0011] In a possible implementation manner, the fixing plate is made of a deformable material;

[0012] The fixing plate is in conformity with the surface of the greenhouse cotton quilt.

[0013] In a possible implementation manner, a plurality of mounting holes are formed in the plate surface of the fixing plate along the length direction;

[0014] The fixing plate is connected to the greenhouse cotton quilt by wire winding;

[0015] The fixing box is connected to the fixing plate by wire winding.

[0016] In a possible implementation manner, the lower limit fixing sensing device is arranged at the rolling and unrolling end of the greenhouse cotton quilt;

[0017] The lower limit fixing sensing device is spaced from the rolling and unrolling end of the greenhouse cotton quilt by a preset distance.

[0018] In a possible implementation manner, it further includes: a splitter;

[0019] The controller, the splitter and the sensor are electrically connected in sequence.

[0020] In a possible implementation manner, it further includes: a main signal line and branch signal lines;

[0021] Both ends of the main signal line are electrically connected to the controller and the splitter respectively;

[0022] The number of the branch signal lines corresponds to the number of the sensors one by one, and both ends of the branch signal lines are electrically connected to the splitter and the sensor respectively.

[0023] A lower limit fixing sensing control method for a greenhouse cotton quilt, including the lower limit fixing sensing device described above for controlling the rolling and unrolling of the greenhouse cotton quilt, is characterized by including the following steps:

[0024] When it is necessary to roll and unroll the greenhouse cotton quilt, the rolling machine starts to roll and unroll the greenhouse cotton quilt;

[0025] After the greenhouse cotton quilt is rolled and laid to the position of the lower limit fixed sensing device, it drives the fixed plate to spread towards the bottom of the greenhouse. A plurality of the sensors are spread together with the fixed plate and disconnect from the controller;

[0026] After the rolling machine receives the disconnection signal from the controller, the rolling machine stops rolling and laying the greenhouse cotton quilt.

[0027] In a possible implementation manner, when the greenhouse cotton quilt is in an unfolded state, at least one of the sensors is in a connected state;

[0028] When the greenhouse cotton quilt is in a spread state, more than two of the sensors are all in a disconnected state.

[0029] In a possible implementation manner, it further includes:

[0030] When the rolling machine receives the disconnection signal from the controller, it delays the closing of the rolling machine.

[0031] The beneficial effects of the lower limit fixed sensing device for the greenhouse cotton quilt and its control method in the embodiments of the present application: Two encountered sensors are arranged on the fixed plate, and then the fixed plate is attached to the greenhouse cotton quilt. As the greenhouse cotton quilt is spread and rolled up, it gradually becomes completely or gradually straight. The sensors also show different states as the fixed plate bends or straightens, so as to display the state of the greenhouse cotton quilt. Among them, compared with the traditional lower limit sensing device for the greenhouse cotton quilt, the lower limit sensing and fixing device of the present application can be flexibly installed on the surface of the greenhouse cotton quilt. The fixed plate can be rolled up and spread together with the greenhouse cotton quilt, without being affected by the greenhouse itself or other factors, so as to more accurately obtain the true state of the greenhouse cotton quilt.

[0032] According to the following detailed description of the exemplary embodiments with reference to the accompanying drawings, other features and aspects of the present application will become clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings included in the specification and constituting a part of the specification show the exemplary embodiments, features and aspects of the present application together with the specification, and are used to explain the principles of the present application.

[0034] Figure 1 The spreading schematic diagram of the lower limit fixed sensing device for the greenhouse cotton quilt showing the embodiments of the present application;

[0035] Figure 2 The rolling-up schematic diagram of the lower limit fixed sensing device for the greenhouse cotton quilt showing the embodiments of the present application;

[0036] Figure 3 The main body schematic diagram of the lower limit fixed sensing device for the greenhouse cotton quilt showing the embodiments of the present application;

[0037] Figure 4 Schematic connection diagram of the lower limit fixing sensing device for greenhouse quilts according to an embodiment of the present application;

[0038] Figure 5 Schematic flow diagram of the lower limit fixing sensing method for greenhouse quilts according to an embodiment of the present application. Detailed implementation manners

[0039] Various exemplary embodiments, features, and aspects of the present application will be described in detail below with reference to the accompanying drawings. Identical reference numerals in the drawings denote functionally identical or similar elements. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0040] Among them, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention or simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0041] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0042] The specifically used word "exemplary" herein means "serving as an example, embodiment, or illustration". Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0043] In addition, for a better description of the present application, numerous specific details are given in the following detailed implementation manners. Those skilled in the art should understand that the present application can also be implemented without some specific details. In some instances, methods, means, elements, and circuits well-known to those skilled in the art are not described in detail so as to highlight the gist of the present application.

[0044] Refer to Figure 1, the lower limit fixing sensing device for the greenhouse cotton quilt in the embodiment of the present application includes: a fixing plate 230, a fixing box 250, a sensor 240, and a controller 210. The fixing plate 230 is a long strip structure, arranged along the rolling and spreading direction of the greenhouse cotton quilt 100. There are more than two fixing boxes 250, arranged along the length direction of the fixing plate 230. The controller 210 is electrically connected to the sensor 240. The sensor 240 is a mercury limit sensor 240, arranged inside the fixing box 250. More than two sensors 240 are connected in parallel. When the greenhouse cotton quilt 100 is in an unfolded state, any adjacent sensors 240 are spaced at the same preset angle.

[0045] In this embodiment, referring to Figure 1 and Figure 2 , two encountered sensors 240 are arranged on the fixing plate 230, and then the fixing plate 230 is attached to the greenhouse cotton quilt 100. As the greenhouse cotton quilt 100 unfolds and rolls up, it gradually becomes completely flat or gradually straight. The sensor 240 also shows different states as the fixing plate 230 bends or straightens, so that the state of the greenhouse cotton quilt 100 can be displayed. Among them, compared with the traditional lower limit sensing device of the greenhouse cotton quilt 100, the lower limit sensing and fixing device of the present application can be flexibly installed on the surface of the greenhouse cotton quilt 100. The fixing plate 230 can roll up and unfold together with the greenhouse cotton quilt 100, without being affected by the greenhouse itself or other factors, so that the true state of the greenhouse cotton quilt 100 can be obtained more accurately.

[0046] In a specific embodiment, referring to Figure 1 , the fixing plate 230 is a long strip structure, about 40 cm in length, and the fixing plate 230 is arranged along the rolling and spreading of the greenhouse cotton quilt 100, so that the fixing plate 230 can roll up or unfold together with the greenhouse cotton quilt 100. Among them, the fixing plate 230 is made of deformable material, such as stainless steel. After the fixing plate 230 is installed on the surface of the greenhouse cotton quilt 100, the bending shape of the fixing plate 230 is the same as that of the greenhouse cotton quilt 100. And the thickness of the fixing plate 230 should not be too thick to avoid breakage when the fixing plate 230 rolls up with the greenhouse panel. Therefore, the thickness of the fixing plate 230 can be set according to the thickness of the greenhouse cotton quilt to ensure that the fixing plate 230 can roll up with the greenhouse cotton quilt and will not break.

[0047] In this embodiment, on the plate surface of the fixing plate 230, a plurality of fixing holes 231 are opened along the length direction, for installing the fixing plate 230 on the surface of the greenhouse cotton quilt 100 and for fixing the sensor 240. Among them, the fixing holes 231 cover the surface of the fixing plate 230, which is convenient for adjusting the position of the sensor 240 and can firmly install the fixing plate 230 on the greenhouse cotton quilt 100. The fixing holes 231 are opened in at least two rows along the length direction of the fixing plate 230, and the adjacent fixing holes 231 are staggered.

[0048] Specifically, during the process of the fixing plate 230 being coiled and unrolled along with the greenhouse cotton quilt 100, the fixing plate 230 will deform from a spiral shape to a straight shape, and the spaced positions of the multiple sensors 240 provided on the fixing plate 230 are different, so as to ensure that when the fixing plate 230 is coiled into a spiral structure, the interval angles between any adjacent sensors 240 are equal.

[0049] In this embodiment, referring to Figure 1 , the fixing box 250 is a square hollow structure, and one of its opposite sides is open, enabling the sensor 240 to be placed inside. Among them, the material of the fixing box 250 is relatively hard and not easily deformed, which can protect the sensor 240 placed inside from being damaged. Moreover, mounting holes are provided on the fixing box 250, which match the fixing holes 231 provided on the fixing plate 230, thereby fixedly installing the fixing box 250 and the fixing plate 230. Fixing installation of the fixing plate 230 and the fixing box 250, as well as the fixing box 250 and the sensor 240, can be achieved by using steel wires for winding.

[0050] In this embodiment, the sensor 240 of the present application is a mercury limit sensor 240, and the mercury limit sensor 240 is a sensor 240 with mercury as the sensitive element. This kind of sensor 240 has the advantages of high precision, good stability, fast response speed, etc. The working principle of the mercury limit sensor 240 is based on the conductivity and fluidity of mercury. When mercury contacts a liquid, due to the conductivity of the liquid, mercury will form a closed circuit, thereby outputting a signal. Specifically, the sensor 240 is fixedly installed inside the fixing box 250. During the process of the mercury limit sensor 240 being coiled and unrolled along with the fixing plate 230 and the greenhouse cotton quilt 100, the mercury inside the sensor 240 at this time will always be in a continuous alternation of disconnection and closure.

[0051] Among them, at least two or more mercury limit sensors 240 are provided on the fixing plate 230, and the angles between any adjacent mercury limit sensors 240 after the greenhouse cotton quilt 100 is rolled up are the same. Therefore, during the process of the mercury sensor 240 being coiled and unrolled along with the greenhouse cotton quilt 100, the flow directions of the mercury inside at least two mercury limit sensors 240 are always opposite, so that the connection states of at least two mercury limit sensors 240 are opposite, that is, during the process of the greenhouse cotton quilt 100 being coiled and unrolled, at least one mercury limit sensor 240 is always in a closed state.

[0052] In a specific embodiment, the installation directions of two or more mercury limit sensors 240 are the same, ensuring the consistency of the mercury limit sensors 240 when they are coiled and unrolled along with the greenhouse cotton quilt 100, and avoiding the situation where two symmetric mercury limit sensors 240 always maintain the same state.

[0053] In a specific embodiment, refer to Figure 1 , Figure 2 and Figure 3 , when the number of mercury limit sensors 240 is 3, and after the fixing plate 230 is rolled up with the greenhouse cotton quilt 100, the angles between the 3 mercury limit sensors 240 are equal, all being 120 degrees. When the greenhouse cotton quilt 100 is in the unrolled state, at least 1 of the 3 mercury limit sensors 240 is always in the closed state, indicating that the greenhouse cotton quilt 100 is in the rolling and paving state at this time. When the greenhouse cotton quilt 100 is fully spread out, the fixing plate 230 is in a straight state, and at this time, the states of the 3 mercury limit sensors 240 are the same, all being open, indicating that the greenhouse cotton quilt 100 is in the spread-out state at this time.

[0054] In this embodiment, since the installation directions of the 3 mercury limit sensors 240 are the same, only after the fixing plate 230 is fully spread out, the mercury moving positions inside the 3 mercury limit sensors 240 are the same, and the connection states at this time are also the same.

[0055] In this embodiment, refer to Figure 4 , the 3 mercury limit sensors 240 are respectively connected to the splitter 220 using the sub-signal lines 241, and the 3 mercury limit sensors 240 are connected in parallel, while the splitter 220 is connected to the controller 210 using the main signal line 211, and the controller 210 is signal-connected to the rolling machine of the greenhouse. When the greenhouse cotton quilt 100 is being rolled and paved, there is always one mercury limit sensor 240 that can communicate with the splitter 220, ensuring the path between the controller 210, the splitter 220, and the mercury limit sensors 240, so as to obtain the state of the greenhouse cotton quilt 100 at this time. When the greenhouse cotton quilt 100 is in the fully spread-out state, the 3 mercury limit sensors 240 are all in the open state, and at this time, the sensor 240 - splitter 220 - controller 210 is in an open circuit state, obtaining that the greenhouse cotton quilt 100 is in the flat-laid state at this time.

[0056] Refer to Figure 5 , the lower limit fixing sensing control method for the greenhouse cotton quilt 100 in the embodiment of the present application includes the following steps:

[0057] S100. When it is necessary to roll and pave the greenhouse cotton quilt 100, the rolling machine starts to roll and pave the greenhouse cotton quilt 100;

[0058] S200. After the greenhouse cotton quilt 100 is rolled and paved to the position of the lower limit fixing sensing device, it drives the fixing plate 230 to spread out towards the bottom of the greenhouse, and the multiple sensors 240 spread out together with the fixing plate 230 and disconnect from the controller 210;

[0059] S300. After the rolling machine receives the disconnection signal from the controller 210, the rolling machine stops rolling and paving the greenhouse cotton quilt 100.

[0060] In this embodiment, for the rolling and unrolling of the greenhouse cotton quilt 100, first, start the rolling machine, so that the rolling machine controls the greenhouse cotton quilt 100 to roll and unroll towards the bottom of the greenhouse to cover the top of the greenhouse. The greenhouse cotton quilt 100 continues to roll and unroll on the greenhouse. When it rolls and unrolls to the installation position of the lower limit fixed sensing device, it will drive the fixing plate 230 on the surface of the greenhouse cotton quilt 100 to be laid flat together. During the process of laying the fixing plate 230 flat, more than two mercury limit sensors 240 are gradually disconnected, so that the controller 210 - splitter 220 - sensor 240 is disconnected. When the controller 210 is disconnected from the mercury limit sensor 240, the controller 210 will send a disconnection signal to the rolling machine, so that the rolling machine obtains the signal that the greenhouse cotton quilt 100 has reached the lower limit.

[0061] In a specific embodiment, the number of mercury limit sensors 240 is more than two, and when the greenhouse cotton quilt 100 is in a rolled state, the mercury limit sensors 240 on the fixing plate 230 are equally spaced from the adjacent mercury limit sensors 240. Therefore, when the greenhouse cotton quilt 100 is rolling and unrolling and has not reached the lower limit, the state of at least one mercury limit sensor 240 is different from the states of other mercury limit sensors 240, and multiple mercury limit sensors 240 are connected in parallel, so that the controller 210 - splitter 220 - sensor 240 always maintains a conductive state, and the rolling machine always executes the rolling and unrolling command of the greenhouse cotton quilt 100. When the greenhouse cotton quilt 100 is rolled and unrolled to the lower limit, the fixing plate 230 is laid flat together, and more than two mercury limit sensors 240 are all in the same disconnected state, so that the controller 210 - splitter 220 - sensor 240 always maintains an open circuit state, and the rolling machine stops the rolling and unrolling of the greenhouse cotton quilt 100.

[0062] In a specific embodiment, the lower limit fixed sensing device is arranged at the bottom position of the greenhouse cotton quilt 100 and is 40 cm - 50 cm away from the edge position, which can prevent the lower limit sensing device from being on the ground after the rolling and unrolling of the greenhouse cotton quilt 100 is completed.

[0063] In this embodiment, a delay device is arranged inside the rolling machine to delay the stop of the rolling machine. Specifically, the mercury limit sensor 240 is arranged at the bottom of the greenhouse cotton quilt 100 and there is still a distance from the edge position of the greenhouse cotton quilt 100. If the rolling machine stops when the greenhouse cotton quilt 100 is at the lower limit, there is still part of the greenhouse not covered. Therefore, this application arranges a delay device inside the rolling machine, so as to delay the stop of the rolling machine and make the rolling machine control the greenhouse cotton quilt 100 to continue rolling and unrolling. Among them, the delay time set by the delay device can be set according to the rolling and unrolling speed of the rolling machine, so that after the greenhouse cotton quilt 100 is rolled and unrolled to the bottom of the greenhouse and completely covered, the rolling and unrolling of the rolling machine is stopped.

[0064] In a specific embodiment, refer toFigure 3 During the rolling and unrolling process of the greenhouse quilt 100, it is necessary to roll and unroll the entire greenhouse quilt 100 on the greenhouse simultaneously, so the rolling and unrolling speed is low. If the number of mercury limit sensors 240 provided on the fixed plate 230 is small, it may occur that the greenhouse quilt 100 is in the process of rolling towards the bottom of the greenhouse, and due to the low rolling and unrolling speed, the mercury limit sensors 240 are all in the disconnected state. At this time, the controller 210 will send a disconnection signal to the rolling machine, causing the rolling machine to stop the rolling of the greenhouse quilt 100 towards the bottom of the greenhouse. Therefore, in this application, a disconnection prevention device is connected to the controller 210, and the disconnection prevention time is set to 5 seconds. If all the mercury limit sensors 240 are in the disconnected state when the greenhouse quilt 100 has not reached the lower limit, the disconnection prevention device keeps the controller 210 connected. After 5 seconds, the mercury limit sensors 240 will be in communication with the controller 210.

[0065] Specifically, when the greenhouse quilt 100 is rolled towards the bottom of the greenhouse, the mercury inside two or more mercury limit sensors 240 is in the disconnected state. When the controller 210 - splitter 220 - sensor 240 is in an open - circuit state, the controller 210 will not send a disconnection signal to the rolling machine within 5 seconds, and at this time, the greenhouse quilt 100 continues to roll towards the bottom of the greenhouse. If within 5 seconds, at least one mercury limit sensor 240 closes, making the controller 210 - splitter 220 - sensor 240 in a conducting state, the greenhouse quilt 100 continues to roll. If after 5 seconds, all the mercury limit sensors 240 are still in the disconnected state, indicating that the greenhouse quilt 100 has reached the lower limit, the controller 210 will send a disconnection signal to the rolling machine, causing the rolling machine to stop the rolling of the greenhouse quilt 100.

[0066] In this embodiment, the fixed box 250 is a square - shaped shell structure with openings on opposite sides. On either side, a steel wire is passed through the fixing hole 231 and the side wall, so as to install and fix the fixed box 250 to the fixed plate 230. Among them, the opening directions on both sides of the fixed box 250 are perpendicular to the length direction of the fixed plate 230. When installing the mercury limit sensor 240 inside the fixed box 250, the sub - signal line 241 connected to the mercury limit sensor 240 passes through any one of the openings on the side of the fixed box 250 and is connected to the splitter 220.

[0067] In a specific embodiment, for the installation of the mercury limit sensor 240 on the fixing plate 230, when the greenhouse cotton quilt 100 is in a laid state, the fixing plate 230 is arranged along the rolling and unrolling direction of the greenhouse cotton quilt 100, such that the length direction of the fixing plate 230 is the same as the rolling and unrolling direction of the greenhouse cotton quilt 100. At this time, the fixing plate 230 is in a straight state. The mercury limit sensor 240 is installed in the fixing box 250 on the fixing plate 230, and is connected to the splitter 220 using the sub-signal wire 241. It is necessary to ensure that all the mercury limit sensors 240 are in an off state at this time.

[0068] Rolling and unrolling process of the greenhouse cotton quilt 100: Start the rolling machine, and the rolling machine controls the greenhouse cotton quilt 100 to roll towards the bottom of the greenhouse at a constant speed. At this time, the controller 210 - splitter 220 - sensor 240 is in a conductive state. During the rolling and unrolling process of the greenhouse cotton quilt 100, the fixing plate 230 gradually changes from a spiral shape to a straight shape. When it is completely deformed into a straight shape, the mercury positions inside the multiple mercury limit sensors 240 are the same, and all are in an off state. At this time, the controller 210 - splitter 220 - sensor 240 is in an open circuit state. After 5 seconds, the controller 210 - splitter 220 - sensor 240 is still in an open circuit state, and the controller 210 sends a disconnection signal to the rolling machine. After receiving the disconnection signal, the delay device controls the rolling machine to delay closing. At this time, the rolling machine continues to roll the greenhouse cotton quilt 100 according to the preset time.

[0069] The embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technologies in the market, or to enable other ordinary technical personnel in the technical field to understand the disclosed embodiments.

Claims

1. A lower limit fixed sensing device for greenhouse quilts, which is suitable for being arranged on greenhouse quilts, and is characterized in that Comprising: A fixing plate, a fixing box, a sensor and a controller; The fixing plate is in a long strip structure and is arranged along the rolling and spreading direction of the greenhouse cotton quilt; There are more than two fixing boxes, which are arranged along the length direction of the fixing plate; The controller is electrically connected to the sensor; The sensor is a mercury limit sensor, which is arranged inside the fixing box. More than two of the sensors are connected in parallel. When the greenhouse cotton quilt is in an unfolded state, any adjacent sensors are spaced at the same preset angle.

2. The lower limit fixing sensing device for greenhouse quilts according to claim 1, characterized in that, More than two of the sensors are installed in the same direction.

3. The lower limit fixing sensing device for the greenhouse cotton quilt according to claim 1, characterized in that, The fixing plate is made of deformable material; The fixing plate is in surface contact with the greenhouse cotton quilt.

4. The lower limit fixing sensing device for the greenhouse cotton quilt according to claim 3, characterized in that, A plurality of mounting holes are formed in the plate surface of the fixing plate along the length direction; The fixing plate is wound and connected with the greenhouse cotton quilt wire; The fixing box is wound and connected with the fixing plate wire.

5. The lower limit fixing sensing device for the greenhouse cotton quilt according to claim 1, characterized in that, The lower limit fixing sensing device is arranged at the rolling and spreading end of the greenhouse cotton quilt; The lower limit fixing sensing device is spaced from the rolling and spreading end of the greenhouse cotton quilt by a preset distance.

6. The lower limit fixed sensing device for the greenhouse cotton quilt according to claim 1, characterized in that, Further comprising: A splitter; The controller, the splitter and the sensor are electrically connected in sequence.

7. The lower limit fixing sensing device for the greenhouse cotton quilt according to claim 6, characterized in that, Further comprising: A main signal line and branch signal lines; Both ends of the main signal line are electrically connected to the controller and the splitter respectively; The number of the branch signal lines corresponds to the number of the sensors one by one, and both ends of the branch signal lines are electrically connected to the splitter and the sensor respectively.

8. A lower limit fixed sensing control method for a greenhouse cotton quilt, which uses the lower limit fixed sensing device described in any one of claims 1-9 to perform rolling and unrolling control on the greenhouse cotton quilt, characterized in that, Including the following steps: When it is necessary to roll and spread the greenhouse cotton quilt, the rolling machine starts to roll and spread the greenhouse cotton quilt; After the greenhouse cotton quilt is rolled and spread to the position of the lower limit fixing sensing device, it drives the fixing plate to spread towards the bottom of the greenhouse. A plurality of the sensors spread together with the fixing plate and disconnect from the controller; After receiving the disconnection signal from the controller, the rolling machine stops rolling and spreading the greenhouse cotton quilt.

9. A lower limit fixing sensing control method for greenhouse quilts, characterized in that, When the greenhouse cotton quilt is in an unfolded state, at least one of the sensors is in a connected state; When the greenhouse cotton quilt is in a spread state, more than two of the sensors are all in a disconnected state.

10. A lower limit fixed sensing control method for greenhouse cotton quilts, characterized in that, Further comprising: After receiving the disconnection signal from the controller, the rolling machine delays the closing.

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