Feeding trough liquid level detection and water supplementing control device and method

Abstract

The invention provides a manger liquid level detection and water supplement control device and method.The device comprises a controller and a metal probe, the controller is provided with a detection port connected with the metal probe, the metal probe stands above a manger through a support, the lower end of the metal probe extends into the manger, and the detection port is connected with the metal probe. Meanwhile, the top end of the metal probe is used as an electric sampling point connected with the detection port; the method comprises the following operations that the controller is provided with a water supplementing threshold value K1 and a water stopping threshold value K2, and K1 is larger than K2; the detection port is configured to sequentially execute the following steps in each sampling period: continuously outputting a low level for T1 time so as to lower the voltage of an electric sampling point; stopping outputting the low level, and reading the voltage value Vs of the electric sampling point after T2 time; the controller judges after obtaining the voltage value Vs; when the Vs is greater than or equal to K1, the controller starts the water replenishing valve; and when Vs is smaller than or equal to K2, the controller shuts down the water replenishing valve.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of feeding detection and control in aquaculture, in particular to a trough liquid level detection and water replenishment control device and method. BACKGROUND

[0002] In an intelligent farm, the drinking water level in the feeding trough is monitored, and water is replenished automatically when it is below a threshold value to ensure that the livestock has sufficient drinking water. A common detection method is to place a metal probe in the trough, and the upper controller determines whether the trough is short of water according to the potential change of the metal probe, and then controls the start / stop of the water replenishment valve.

[0003] The metal probe is erected above the trough by a support, and its outer surface is covered with an insulating shell, so that the metal probe and the support are not conductive under normal circumstances. Only when the liquid surface in the trough contacts the exposed part of the metal probe does a loop form, thereby causing a corresponding potential change.

[0004] However, due to reasons such as animals bending to eat and scale growth, conductive media such as feed and scale may adhere to the insulating shell. Over time, the exposed part of the metal probe may be connected to the support, even if the metal probe does not contact the liquid surface in the trough, a micro-conductive loop may be formed, which may cause a potential change, thereby causing the controller to determine that the trough is full of water even though it is short of water. SUMMARY

[0005] The present application provides a trough liquid level detection and water replenishment control device and method to solve the problem of inaccurate liquid level detection in the prior art. The specific technical means are as follows.

[0006] A trough liquid level detection and water replenishment control device includes a controller and a metal probe. The controller is provided with a detection port connected to the metal probe, which controls the start / stop of the water replenishment valve according to the signal feedback from the metal probe. The metal probe is erected above the trough by a support and has its lower end extending into the trough. The top end of the metal probe is an electrical sampling point connected to the detection port, and a DC bias voltage is provided at the electrical sampling point.

[0007] The controller is provided with a water replenishment threshold K1 and a water stop threshold K2, where K1 is greater than K2.

[0008] The detection port is configured to sequentially execute the following operations in each sampling period:

[0009] Operation S1: output a low level for T1 time to pull down the voltage of the electrical sampling point;

[0010] Operation S2: stop outputting the low level and read the voltage value Vs of the electrical sampling point after T2 time;

[0011] One sampling period is T1+T2;

[0012] The controller judges after obtaining the voltage value Vs:

[0013] When Vs is greater than or equal to K1, the controller starts the water replenishment valve;

[0014] When Vs is less than or equal to K2, the controller stops the water replenishment valve.

[0015] Further, the detection port is configured to sequentially execute in each sampling period:

[0016] Operation S0, output high level for T0 time;

[0017] Operation S1, output low level for T1 time to pull down the voltage of the electric sampling point;

[0018] Operation S2, stop outputting low level and read the voltage value Vs of the electric sampling point after T2 time;

[0019] One sampling period is T0+T1+T2.

[0020] Further, a detection circuit is provided between the detection port and the metal probe, the detection circuit comprising a biasing resistor R1 and a sampling resistor R2, one end of the biasing resistor R1 being connected to a direct current source VCC and the other end being connected to the electric sampling point, thereby providing the direct current biasing voltage; one end of the sampling resistor R2 being connected to the electric sampling point and the other end being connected to the detection port.

[0021] Further, the detection circuit further comprises a zener diode D1 and a filter capacitor C1 connected in parallel to each other, the positive electrode of the zener diode D1 being grounded and the negative electrode being connected to the electric sampling point or the detection port.

[0022] Further, a self-restoring fuse unit RA is further connected in series between the electric sampling point and the sampling resistor R2.

[0023] A trough liquid level detection and water replenishment control method, comprising the following operations:

[0024] A metal probe is erected above the trough and the upper end of the metal probe is used as an electric sampling point, and a direct current biasing voltage is provided at the electric sampling point;

[0025] A water replenishment threshold K1 and a water stop threshold K2 are provided, wherein K1 is greater than K2;

[0026] The detection port of the controller is connected to the electric sampling point and periodic sampling is performed, wherein in each sampling period, the following operations are sequentially executed:

[0027] Operation S1, output low level for T1 time, to pull down the voltage of the electric sampling point;

[0028] Operation S2, stop outputting low level and read the voltage value Vs of the electric sampling point after T2 time;

[0029] One sampling cycle is T1+T2;

[0030] The controller judges after obtaining the voltage value Vs:

[0031] When Vs is greater than or equal to K1, the controller starts the water supplement valve;

[0032] When Vs is less than or equal to K2, the controller stops the water supplement valve.

[0033] Further, in each sampling cycle, the following operations are sequentially performed:

[0034] Operation S0, output high level for T0 time;

[0035] Operation S1, output low level for T1 time, to pull down the voltage of the electric sampling point;

[0036] Operation S2, stop outputting low level and read the voltage value Vs of the electric sampling point after T2 time;

[0037] One sampling cycle is T0+T1+T2.

[0038] Compared with the prior art, the beneficial effects of the present application are:

[0039] 1) By using the two-stage sampling scheme of "pulling down first and then reading" for the electric sampling point, the problem of micro-conduction loop between the metal probe and the bracket caused by animals arching food and the like is solved, and the misjudgment situation that the controller determines water fullness although there is water shortage in the trough is avoided.

[0040] 2) By using the three-stage sampling scheme of "pulling up first, then pulling down, and then reading" for the electric sampling point, in addition to solving the micro-conduction problem, pulling up the voltage of the electric sampling point can electrolyze the oxidation layer on the surface side of the metal probe, ensuring the electrical contact performance of the metal probe; at the same time, reasonably setting the time duration of the pulled-up high level can effectively control the loss of the metal probe and prolong its service life. However, pulling up the voltage of the electric sampling point for T0 time promotes electrolysis, but the voltage sampling value will be larger, so even if there is water in the feeding trough, it will be misjudged as water shortage, resulting in the water supplement valve always supplementing water. Therefore, by pulling down the voltage in the subsequent T1 time, the problem is overcome, and the two actions of "pulling up" and "pulling down" complement each other, providing an ideal environment for the subsequent sampling reading operation in T2 time, ensuring the accuracy of the reading. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 Figure 1 is a structural schematic diagram of a trough liquid level detection and water replenishment control device.

[0042] Figure 2 Figure 2 is a schematic diagram of a trough liquid level detection equivalent circuit (non-micro-conduction state).

[0043] Figure 3 Figure 3 is a schematic diagram of a trough liquid level detection equivalent circuit (micro-conduction state).

[0044] Figure 4 Figure 4 is a voltage waveform diagram of an electrical sampling point (two-section sampling).

[0045] Figure 5 Figure 5 is a voltage waveform diagram of an electrical sampling point (three-section sampling).

[0046] Figure 6 Figure 6 is a schematic diagram of a grounding circuit.

[0047] Figure 7 Figure 7 is a schematic diagram of a push-pull circuit. DETAILED DESCRIPTION

[0048] The application will be further described in conjunction with the accompanying drawings:

[0049] Referring to the accompanying Figure 1 , the trough liquid level detection and water replenishment control device comprises a controller 1, a metal probe 2 and a detection circuit 3. The controller 1 is provided with a detection port 101 connected with the metal probe 2, which controls the start / stop of a water replenishment valve according to the signal fed back by the metal probe 2.

[0050] The metal probe 2 is erected above a trough 5 through a support 4 and has its lower end extended into the trough 5. The top end of the metal probe 2 is an electrical sampling point 201 connected with the detection port 101, and its outer surface is covered with an insulating shell 202, and its lower end is exposed. The detection circuit 3 comprises a biasing resistor R1 and a sampling resistor R2. One end of the biasing resistor R1 is connected with a direct current source VCC, and the other end is connected with the electrical sampling point 201, thereby providing a direct current bias voltage. One end of the sampling resistor R2 is connected with the electrical sampling point 201, and the other end is connected with the detection port 101.

[0051] The controller 1 is provided with a water replenishment threshold K1 and a water stop threshold K2, wherein K1 is greater than K2. After obtaining the voltage value Vs of the electrical sampling point 201, the controller 1 judges: when Vs is greater than or equal to K1, the water replenishment valve is started; and when Vs is less than or equal to K2, the water replenishment valve is stopped.

[0052] Referring to the accompanying Figure 2, and the equivalent resistance of the water body (water and feed mixed) is defined as Rt, the resistance of the bias resistor is R1, and the direct current bias voltage is Vcc, so when the metal probe 2 contacts the liquid surface (equivalent to grounding), the voltage of the electric sampling point 201 is:

[0053] Vs=Vcc*Rt / (R1+Rt);

[0054] According to the comparison result of Vs and K1, K2, water supplement or water cut control is realized.

[0055] However, due to the existence of the conductive medium 6 between the metal probe 2 and the support 4 caused by the animal arching and the like, the metal probe 2 is equivalent to being grounded through the support 4, thereby forming a micro-conduction loop; see Fig. 2. Figure 3 The equivalent resistance of the conductive medium 6 is Rk, and through voltage division with R1, the electric sampling point 201 will have a micro-conduction voltage Vb; this micro-conduction voltage Vb will be different due to the degree of micro-conduction (impedance) and will increase with time accumulation, similar to the characteristics of a capacitor, which is usually between 0.5-5V; so when the metal probe 2 contacts the liquid surface, the voltage of the electric sampling point 201 is:

[0056] Vs=Vb+(Vcc-Vb)*Rt / (R1+Rt);

[0057] Due to the existence and accumulation of the micro-conduction voltage Vb, the actual obtained Vs will also decrease, which will lead to that even if the metal probe 2 does not touch the liquid surface, Vs may be less than the water cut threshold K2, resulting in false judgment of water cut.

[0058] In view of this, the trough liquid level detection and water supplement control method is implemented in the above-mentioned device, and the detection port 101 is configured to sequentially perform the following operations in each sampling period:

[0059] Operation S1, output low level for T1 time, for pulling down the voltage of the electric sampling point 201;

[0060] Operation S2, stop outputting low level and read the voltage value Vs of the electric sampling point 201 after T2 time;

[0061] Referring to Fig. 3, Figure 4, a sampling period is T1+T2, the electric sampling point 201 is pulled down to smooth the micro-conduction voltage Vb in the time T1, and then the voltage value of the electric sampling point 201 is climbed to the stable interval for sampling in the time T2, wherein the time T1 and T2 are valued according to actual test and voltage climbing waveform. Thus, through the two-stage sampling scheme of "pulling down first and then reading" of the electric sampling point 201, the micro-conduction voltage Vb is smoothed before each sampling action, so that the voltage at the electric sampling point 201 can truly feedback the contact condition of the metal probe 2 with the liquid surface, and the problem of the micro-conduction loop between the metal probe 2 and the support 4 caused by the animal arching food and the like is solved, and the misjudgment situation that the controller judges water full although there is lack of water in the tank is avoided.

[0062] In addition, since the metal probe 2 is in the energized state for a long time, an insulating oxide layer is generated on the needle tip surface which often contacts the liquid surface, which not only reduces the feedback sensitivity of the metal probe 2, but also causes the liquid surface to overflow the part above the metal probe 2 needle tip to form an electric circuit; after a long time, the part of the metal probe 2 which newly contacts the liquid surface will form an oxide layer, so that the actual liquid level detection point position is gradually higher, and the water full overflow situation is easily caused.

[0063] Therefore, in another embodiment of the trough liquid level detection and water replenishment control method of the present application, the detection port is configured to sequentially perform the following operations in each sampling period:

[0064] Operation S0, output high level for T0 time;

[0065] Operation S1, output low level for T1 time, to pull down the voltage of the electric sampling point;

[0066] Operation S2, stop outputting low level and read the voltage value Vs of the electric sampling point after T2 time.

[0067] Referring to the accompanying drawings Figure 5, a sampling period is T0+T1+T2, the voltage of the electric sampling point 201 is pushed high in the time T0, so as to promote the metal probe 2 to carry out electrolysis reaction; the electric sampling point 201 is pulled low in the time T1 to flatten the micro-conduction voltage Vb, and then the voltage value of the electric sampling point 201 is climbed to the stable interval through the time T2 to carry out sampling, wherein the times T0, T1 and T2 are valued according to actual test and voltage climbing waveform. Thus, through the three-stage sampling scheme of “pulling high first, pulling low second and reading third” of the electric sampling point 201, in addition to solving the micro-conduction problem, the push-pull pull-up voltage of the electric sampling point 201 can make the oxidation layer on the surface side of the metal probe 2 be electrolyzed, so as to ensure the electrical contact performance of the metal probe 2; meanwhile, since the electrolysis reaction is also a kind of loss of the metal probe 2, therefore, the time duration of the pull-up level is reasonably set, so as to effectively control the loss of the metal probe 2 and prolong the service life thereof. And the voltage of the electric sampling point 201 is pulled up in the time T0, although the electrolysis is promoted, the voltage sampling value will be large, so that even if there is water in the feeding tank 5, it will be misjudged as water shortage, so as to cause the water supplement valve to always supplement water. Therefore, the electric sampling point 201 is pulled down in the subsequent time T1, which just overcomes the problem, the two actions of “pulling high” and “pulling low” are mutually complementary, and provide an ideal environment for the sampling reading operation in the subsequent time T2, so as to ensure the accuracy of reading.

[0068] In the above embodiment, the “pulling high” and “pulling low” operations of the electric level of the detection port 101 can be realized by the controller 1 (a programmable processing chip) to the configuration of the ADC port thereof, and only the electric level state of the detection port 101 in different time periods in the sampling period needs to be defined. In the main chip selection and design of the controller 1, the main chip generally has an analog-digital conversion unit (namely, the ADC port), and of course, an independent analog-digital conversion chip can also be used to realize the same, which is not described herein.

[0069] In addition, the “pulling high” and “pulling low” operations of the electric level of the detection port 101 can also be realized by a separate physical circuit, for example:

[0070] Referring to the attached Figure 6 , the pull-down of the electric level of the detection port 101 is set by the transistor Q1, the base of the transistor Q1 is connected to the controller 1, the emitter thereof is grounded, and the collector thereof is connected to the detection port 101, when the transistor Q1 is turned on, the detection port 101 is grounded, so as to pull down the electric level of the electric sampling point 201 connected thereto.

[0071] Referring to the attached Figure 7 , the pull-up of the electric level of the detection port 101 is realized by the push-pull circuit composed of the transistors Q2 and Q3, the input end of the push-pull circuit is connected to the controller 1, and the output end of the push-pull circuit is connected to the detection port 101, so as to reversely push up the electric level of the electric sampling point 201 connected thereto.

[0072] Referring to the attachedFigure 2 In order to improve the anti-interference and anti-surge performance of the detection circuit, the detection circuit is further provided with a parallel connection of a voltage stabilizing diode D1 and a filter capacitor C1, the positive electrode of the voltage stabilizing diode D1 is grounded, and the negative electrode is connected to the electric sampling point 201. Moreover, a self-restoring fuse unit RA is further connected in series between the electric sampling point 201 and the sampling resistor R2, which is disconnected when the current is too large, so as to avoid damage to the controller caused by overcurrent, overload, overheating or short circuit and the like.

[0073] The above preferred embodiments should be regarded as examples of the embodiments of the application, and any technical deduction, replacement, improvement and the like made similarly, approximately or based on the embodiments of the application should be regarded as the protection scope of the patent.

Claims

1. A trough liquid level detection and water replenishment control device, comprising a controller and a metal probe, the controller is provided with a detection port connected with the metal probe, and the controller controls the start / stop of a water replenishment valve according to the signal fed back by the metal probe, characterized in that, The metal probe is erected above the feeding trough by a support and has its lower end extended into the feeding trough, and the top end of the metal probe is an electric sampling point connected with the detection port, and a direct current bias voltage is provided at the electric sampling point; The controller is provided with a water supplement threshold K1 and a water stop threshold K2, wherein K1 is greater than K2; The detection port is configured to sequentially perform the following operations in each sampling period: Operation S1: output low level for T1 time to pull down the voltage of the electric sampling point; Operation S2: stop outputting low level and read the voltage value Vs of the electric sampling point after T2 time; One sampling period is T1+T2; After obtaining the voltage value Vs, the controller judges: When Vs is greater than or equal to K1, the controller starts the water supplement valve; When Vs is less than or equal to K2, the controller stops the water supplement valve.

2. The trough level detection and water replenishment control apparatus according to claim 1, characterized by The detection port is configured to sequentially perform the following operations in each sampling period: Operation S0: output high level for T0 time; Operation S1: output low level for T1 time to pull down the voltage of the electric sampling point; Operation S2: stop outputting low level and read the voltage value Vs of the electric sampling point after T2 time; One sampling period is T0+T1+T2.

3. The trough level detection and water replenishment control apparatus according to claim 1, characterized by A detection circuit is arranged between the detection port and the metal probe, and the detection circuit comprises a bias resistor R1 and a sampling resistor R2, one end of the bias resistor R1 is connected with a direct current source VCC, the other end is connected with the electric sampling point, thereby providing the direct current bias voltage; one end of the sampling resistor R2 is connected with the electric sampling point, and the other end is connected with the detection port.

4. The trough level detection and water replenishment control apparatus according to claim 3, wherein The detection circuit further comprises a voltage stabilizing diode D1 and a filter capacitor C1 which are connected in parallel, the positive electrode of the voltage stabilizing diode D1 is grounded, and the negative electrode is connected with the electric sampling point or the detection port.

5. The trough level detection and water replenishment control apparatus according to claim 4, wherein A self-recovery fuse unit RA is further connected in series between the electric sampling point and the sampling resistor R2.

6. A trough level detection and water replenishment control method, characterized by, The following operations are included: Erect a metal probe above the feeding trough and take the upper end of the metal probe as an electric sampling point, and provide a direct current bias voltage at the electric sampling point; A water supplement threshold K1 and a water stop threshold K2 are provided, wherein K1 is greater than K2; The detection port of the controller is connected with the electric sampling point and performs periodic sampling, wherein the following operations are sequentially performed in each sampling period: Operation S1: output low level for T1 time to pull down the voltage of the electric sampling point; Operation S2: stop outputting low level and read the voltage value Vs of the electric sampling point after T2 time; One sampling period is T1+T2; After obtaining the voltage value Vs, the controller judges: When Vs is greater than or equal to K1, the controller starts the water supplement valve; When Vs is less than or equal to K2, the controller stops the water supplement valve.

7. The trough level detection and water replenishment control method according to claim 6, characterized in that, The following operations are sequentially performed in each sampling period: Operation S0: output high level for T0 time; Operation S1: output low level for T1 time to pull down the voltage of the electric sampling point; Operation S2: stop outputting low level and read the voltage value Vs of the electric sampling point after T2 time; One sampling period is T0+T1+T2.

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