System and method for automatically balancing fuel quantity in aircraft wing fuel tank

Abstract

The invention belongs to the technical field of aircraft wing fuel tank balance design, and particularly relates to an aircraft wing fuel tank fuel quantity automatic balance method which is implemented based on an aircraft wing fuel tank fuel quantity automatic balance system, a balance monitor automatically carries out balance according to set logic, manual work is not needed, and the balance efficiency is improved. The fuel quantity in three wing fuel tanks can be rapidly controlled within the average fuel quantity M + / -300kg in real time, the fuel quantity in the other wing fuel tank can be controlled within the average fuel quantity M + / -900kg, the precision can be controlled by adjusting the balance adjusting threshold H and the balance control threshold I, and the precision requirements of different airplanes for fuel imbalance control are met.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft wing fuel tank balancing design, and specifically relates to an automatic fuel balancing system and method in an aircraft wing fuel tank. Background Art

[0002] Large aircraft are generally equipped with multiple engines, and each group of engines is supplied with fuel by an independent fuel tank. The fuel tanks are usually symmetrically distributed in the left and right wings. It is generally designed that there are two wing fuel tanks in the left and right wings respectively.

[0003] Currently, in order to maintain the stability of the aircraft's center of gravity, cross-fuel supply or manual fuel transfer methods are often used to balance the fuel volume in each wing tank, so as to reduce the workload of flight control, reduce damage to the landing gear life during aircraft takeoff and landing, and avoid damage to aircraft structural components.

[0004] The cross-fueling method is used to balance the fuel volume in each wing tank. The balancing speed is slow, the fuel balance depends on the fuel supply pump, and requires tedious operations by the crew. The manual fuel transfer method is used to balance the fuel volume in each wing tank, which will consume a lot of crew energy and it is difficult to control the balancing accuracy.

[0005] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0006] The purpose of the present application is to provide a system and method for automatically balancing the amount of fuel in an aircraft wing tank, so as to overcome or alleviate at least one of the known technical defects.

[0007] The technical solution of this application is: On the one hand, a system for automatically balancing the amount of fuel in an aircraft wing tank is provided, comprising four balancing oil pumps, four balancing control valves, a balancing transfer pipeline, and a balancing monitor; Four balanced oil transfer pumps and balanced control valves are arranged in four wing oil tanks and are connected to balanced transfer pipelines through pipelines respectively; The balance monitor is connected to four balance oil pumps, a balance control valve, and a flight control system to obtain fuel-related parameters in the four wing tanks, thereby calculating the fuel quantity in the four wing tanks, and then balancing the fuel quantity in the four wing tanks by controlling the four balance oil pumps and the balance control valve switches and using the balance transfer pipeline.

[0008] On the one hand, a system for automatically balancing the amount of fuel in an aircraft wing tank is provided, comprising four balancing oil pumps, four balancing control valves, a balancing transfer pipeline, and a balancing monitor; Four balanced oil transfer pumps and balanced control valves are arranged in four wing oil tanks and are connected to balanced transfer pipelines through pipelines respectively; The balance monitor is connected to four balance oil pumps, a balance control valve, and a flight control system to obtain fuel-related parameters in the four wing tanks, thereby calculating the fuel quantity in the four wing tanks, and then balancing the fuel quantity in the four wing tanks by controlling the four balance oil pumps and the balance control valve switches and using the balance transfer pipeline.

[0009] Optionally, in the above-mentioned automatic balancing system for the amount of fuel in the aircraft wing tanks, the balancing monitor balances the amount of fuel in the four wing tanks specifically as follows: Step 1: Calculate the fuel quantity in the four wing tanks to obtain the average fuel quantity M, and proceed to step 2; Step 2: determine whether there is a wing tank with low fuel level. If yes, proceed to step 3; if no, proceed to step 6, wherein a wing tank with low fuel level refers to a wing tank whose internal fuel level is less than the average fuel level M, and the amount of the internal fuel level is greater than the balance adjustment threshold H, and the duration is greater than the set time length S; Step 3: close the balancing oil pump in the wing tank with low fuel quantity, and open the balancing control valve in the wing tank with low fuel quantity, and proceed to step 4; Step 4: determine whether the fuel amount in the wing tank of low fuel amount is within the range of the average fuel amount M±balance control threshold I, and the duration is greater than the set time S. If so, proceed to step 5; if not, proceed to step 6; Step 5: Close the balance control valve in the wing tank with low fuel quantity and proceed to step 6; Step 6: Determine whether there is a wing tank with a high fuel amount. If yes, proceed to step 7; if no, proceed to step 8, wherein the wing tank with a high fuel amount refers to a wing tank whose internal fuel amount is greater than the average fuel amount M, and the amount of the internal fuel amount is greater than the balance adjustment threshold H, and the duration is greater than the set time length S; Step 7, close the balance control valve in the wing tank with high fuel quantity, and open the balance oil pump in the wing tank with high fuel quantity, and proceed to step 8; Step 8: Determine whether there are three wing tanks whose fuel amounts are within the range of the average fuel amount M±balance control threshold I, and the duration is greater than the set duration S. If so, close all balancing oil pumps and balancing control valves to complete the balancing of the fuel amount in the wing tanks. If not, proceed to step 4.

[0010] Optionally, in the above-mentioned automatic balancing system for the amount of fuel in the aircraft wing tank, the balance control threshold I<balance adjustment threshold H.

[0011] Optionally, in the above-mentioned automatic balancing system for the amount of fuel in the aircraft wing tank, the balancing adjustment threshold H is 300 kg.

[0012] Optionally, in the above-mentioned automatic balancing system for the amount of fuel in the aircraft wing tank, the set time length S is 1 second.

[0013] Optionally, in the above-mentioned automatic balancing system for the amount of fuel in the aircraft wing tank, the balancing control threshold value I is 200 kg.

[0014] On the other hand, a method for automatically balancing the amount of fuel in an aircraft wing tank is provided, which is implemented based on the above-mentioned automatic balancing system for the amount of fuel in an aircraft wing tank, and comprises: Step 1: Calculate the fuel quantity in the four wing tanks to obtain the average fuel quantity M, and proceed to step 2; Step 2: determine whether there is a wing tank with low fuel level. If yes, proceed to step 3; if no, proceed to step 6, wherein a wing tank with low fuel level refers to a wing tank whose internal fuel level is less than the average fuel level M, and the amount of the internal fuel level is greater than the balance adjustment threshold H, and the duration is greater than the set time length S; Step 3: close the balancing oil pump in the wing tank with low fuel quantity, and open the balancing control valve in the wing tank with low fuel quantity, and proceed to step 4; Step 4: determine whether the fuel amount in the wing tank with low fuel amount is within the range of the average fuel amount M±balance control threshold I, and the duration is greater than the set duration S. If so, proceed to step 5; if not, proceed to step 6, wherein the balance control threshold I<balance adjustment threshold H; Step 5: Close the balance control valve in the wing tank with low fuel quantity and proceed to step 6; Step 6: Determine whether there is a wing tank with a high fuel amount. If yes, proceed to step 7; if no, proceed to step 8, wherein the wing tank with a high fuel amount refers to a wing tank whose internal fuel amount is greater than the average fuel amount M, and the amount of the internal fuel amount is greater than the balance adjustment threshold H, and the duration is greater than the set time length S; Step 7, close the balance control valve in the wing tank with high fuel quantity, and open the balance oil pump in the wing tank with high fuel quantity, and proceed to step 8; Step 8: Determine whether there are three wing tanks whose fuel amounts are within the range of the average fuel amount M±balance control threshold I, and the duration is greater than the set duration S. If so, close all balancing oil pumps and balancing control valves to complete the balancing of the fuel amount in the wing tanks. If not, proceed to step 4.

[0015] Optionally, in the above-mentioned method for automatically balancing the fuel amount in the aircraft wing tank, the balance adjustment threshold H is 300 kg.

[0016] Optionally, in the above-mentioned method for automatically balancing the amount of fuel in the aircraft wing tank, the time length S is set to 1 second.

[0017] Optionally, in the above-mentioned method for automatically balancing the fuel amount in the aircraft wing tank, the balance control threshold I is 200 kg.

[0018] This application has at least the following beneficial technical effects: Provided is a method for automatically balancing the amount of fuel in an aircraft wing tank. The method is implemented based on an automatic balancing system for the amount of fuel in an aircraft wing tank. A balancing monitor automatically performs balancing according to a set logic without manual work. The amount of fuel in three of the wing tanks can be quickly and in real time controlled within an average amount of fuel M±300kg, and the amount of fuel in another wing tank can be controlled within an average amount of fuel M±900kg. The accuracy can be controlled by adjusting a balance adjustment threshold H and a balance control threshold I, thereby meeting the accuracy requirements of different aircraft for fuel imbalance control. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of an automatic fuel balancing system in an aircraft wing tank provided by an embodiment of the present application; Figure 2 is a schematic diagram of a method for automatically balancing the amount of fuel in an aircraft wing tank provided in an embodiment of the present application; in: 1- wing fuel tank; 2- balance fuel pump; 3- balance control valve; 4- balance transfer pipeline; 5- balance monitor; 6- flight control system.

[0020] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0021] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0022] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0023] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0024] On one hand, the present application provides an automatic balancing system for the amount of fuel in an aircraft wing tank, wherein there are four wing tanks 1, which are symmetrically distributed in the left and right wings. The automatic balancing system for the amount of fuel in the aircraft wing tank includes four balancing oil pumps 2, four balancing control valves 3, a balancing transfer pipeline 4, and a balancing monitor 5. Figure 1 shown.

[0025] Four balanced oil pumps 2 and balanced control valves 3 are arranged in four wing oil tanks 1 and are connected to balanced transfer pipelines 4 through pipelines respectively.

[0026] The balance monitor 5 is connected to the four balance oil pumps 2, the balance control valve 3, and the flight control system 6, so as to obtain the fuel-related parameters in the four wing fuel tanks 1, such as temperature, pressure, liquid level, etc., so as to calculate the fuel quantity in the four wing fuel tanks 1, and then control the four balance oil pumps 2, the balance control valve 3 switch, and use the balance transfer pipeline 4 to quickly balance the fuel quantity in the four wing fuel tanks 1.

[0027] On the other hand, the present application provides a method for automatically balancing the amount of fuel in an aircraft wing tank, based on the automatic balancing system for the amount of fuel in an aircraft wing tank disclosed in the above embodiment. Figure 2 As shown, including: Step 1: Calculate the fuel quantity in the four wing fuel tanks 1, obtain the average fuel quantity M, and proceed to step 2.

[0028] Step 2: Determine whether there is a wing tank 1 with low fuel level. If yes, proceed to step 3; if no, proceed to step 6. The wing tank 1 with low fuel level refers to a wing tank 1 whose internal fuel level is less than the average fuel level M, and the amount of the internal fuel level is greater than the balance adjustment threshold H, and the duration is greater than the set time S. The balance adjustment threshold H can be specifically 300 kg, and the set time S can be specifically 1 second.

[0029] Step 3: close the balancing oil pump 2 in the wing oil tank 1 with low fuel level, and open the balancing control valve 3 in the wing oil tank 1 with low fuel level, and proceed to step 4.

[0030] Step 4: Determine whether the fuel quantity in the wing tank 1 with low fuel quantity is within the range of the average fuel quantity M±balance control threshold I, and the duration is greater than the set duration S. If yes, proceed to step 5; if not, proceed to step 6. The balance control threshold I<balance adjustment threshold H, which can be 200 kg.

[0031] Step 5: Close the balance control valve 3 in the wing tank 1 with low fuel quantity and proceed to step 6.

[0032] Step 6: Determine whether there is a wing tank 1 with a high fuel volume. If yes, proceed to step 7; if no, proceed to step 8. The wing tank 1 with a high fuel volume refers to a wing tank 1 whose internal fuel volume is greater than the average fuel volume M, and the amount of the internal fuel volume is greater than the balance adjustment threshold H, and the duration is greater than the set time S.

[0033] Step 7: close the balance control valve 3 in the wing tank 1 with a high fuel volume, and open the balance oil pump 2 in the wing tank 1 with a high fuel volume to proceed to step 8.

[0034] Step 8: Determine whether there are three wing tanks 1 whose fuel amounts are within the range of the average fuel amount M±balance control threshold I, and the duration is greater than the set duration S. If so, close all the balancing oil pumps 2 and balancing control valves 3 to complete the balancing of the fuel amount in the wing tanks 1. If not, proceed to step 4.

[0035] In a specific example, the four wing fuel tanks 1 are fuel tank No. 1, fuel tank No. 2, fuel tank No. 3, and fuel tank No. 4, respectively, and the internal fuel amounts are 11000kg, 10000kg, 90000kg, and 10000kg, respectively. The automatic fuel amount balancing method in the aircraft wing fuel tank disclosed in the above embodiment is used for balancing, as follows: a. Calculate the amount of fuel in the four wing tanks 1 and obtain the average fuel amount M = 10000 kg.

[0036] b. It is determined that the No. 3 fuel tank is the wing fuel tank 1 with low fuel level.

[0037] c. Close the balancing oil pump 2 in the No. 3 oil tank, and open the balancing control valve 3 in the No. 3 oil tank.

[0038] d. It is determined that the fuel quantity in the No. 3 fuel tank is not within the average fuel quantity M±balance control threshold value I=200kg.

[0039] e. Determine that fuel tank No. 1 is wing tank 1 with a high fuel quantity.

[0040] f. Close the balancing control valve 3 in the No. 1 tank and open the balancing oil pump 2 in the No. 1 tank. At this time, the fuel in the No. 1 tank will be transferred to the No. 3 tank through the balancing transfer pipeline 4.

[0041] g. It is determined that there are no three wing tanks 1 whose fuel amounts are within the range of the average fuel amount M±balance control threshold value I, and the duration is greater than the set duration S=1s. Because the duration is too short, the fuel in tank No. 1 needs to be transferred to tank No. 3 through the balance transfer pipeline 4 until the fuel amount in tank No. 1 reaches 10300kg. The fuel amounts in tank No. 1, tank No. 2, tank No. 3, and tank No. 4 are 10300kg, 10000kg, 9700kg, and 10000kg respectively. All balance oil pumps 2 and balance control valves 3 are closed, and the balance monitor 5 reports "the fuel is balanced".

[0042] In another specific example, the four wing fuel tanks 1 are fuel tank No. 1, fuel tank No. 2, fuel tank No. 3, and fuel tank No. 4, respectively, and the internal fuel amounts are 11000 kg, 9000 kg, 120000 kg, and 8000 kg, respectively. The automatic fuel amount balancing method in the aircraft wing fuel tank disclosed in the above embodiment is used for balancing, specifically as follows: a. Calculate the amount of fuel in the four wing tanks 1 and obtain the average fuel amount M = 10000 kg.

[0043] b. Determine that the No. 2 and No. 4 fuel tanks are wing tank 1 with low fuel levels.

[0044] c. Close the balancing oil pump 2 in the No. 2 and No. 4 oil tanks, and open the balancing control valve 3 in the No. 2 and No. 4 oil tanks.

[0045] d. Determine whether the fuel quantity in the No. 2 and No. 4 fuel tanks is within the average fuel quantity M ± the balance control threshold value I = 200 kg.

[0046] e. Determine that No. 1 and No. 3 fuel tanks are wing fuel tanks 1 with high fuel quantity.

[0047] f. Close the balancing control valve 3 in the No. 1 and No. 3 fuel tanks, and open the balancing oil pump 2 in the No. 1 and No. 3 fuel tanks. At this time, the fuel in the No. 1 and No. 3 fuel tanks will be transferred to the No. 2 and No. 4 fuel tanks through the balancing transfer pipeline 4.

[0048] g. It is determined that there are no three wing tanks 1 whose fuel amounts are within the range of the average fuel amount M±balancing control threshold value I, and the duration is greater than the set duration S=1s. Because the duration is too short, the fuel in tanks 1 and 3 still needs to be transferred to tanks 2 and 4 through the balancing transfer pipeline 4. After the fuel amount in tank 2 reaches 9800kg, the balancing control valve 3 in tank 2 is closed. After the fuel amount in tank 1 reaches 10300kg, the balancing oil pump 2 in tank 2 is closed. After the fuel amount in tank 3 reaches 10300kg, the balancing oil pump 2 in tank 3 is closed. At this time, the fuel amount in tank 4 is 9600kg. All balancing oil pumps 2 and balancing control valves 3 are closed, and the balancing monitor 5 reports "the fuel is balanced".

[0049] The automatic balancing method for the amount of fuel in an aircraft wing tank disclosed in the above embodiment is implemented based on the automatic balancing system for the amount of fuel in an aircraft wing tank disclosed in the above embodiment. The balancing monitor 5 automatically performs balancing according to the set logic without manual operation. The amount of fuel in three of the wing tanks 1 can be quickly and real-time controlled within the average fuel amount M±300kg, and the amount of fuel in the other wing tank 1 can be controlled within the average fuel amount M±900kg. The accuracy can be controlled by adjusting the balance adjustment threshold H and the balance control threshold I to meet the accuracy requirements of different aircraft for fuel imbalance control.

[0050] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. An automatic fuel balancing system in an aircraft wing tank, characterized in that: It comprises four balanced oil pumps (2), four balanced control valves (3), a balanced transfer pipeline (4), and a balanced monitor (5); Four balanced oil transfer pumps (2) and balanced control valves (3) are arranged in four wing oil tanks (1) and are respectively connected to balanced transfer pipelines (4) through pipelines; The balance monitor (5) is connected to the four balance oil pumps (2), the balance control valve (3), and the flight control system (6) so as to obtain the relevant parameters of the fuel in the four wing oil tanks (1), thereby being able to calculate the amount of fuel in the four wing oil tanks (1), and then being able to balance the amount of fuel in the four wing oil tanks (1) by controlling the switches of the four balance oil pumps (2) and the balance control valve (3) and utilizing the balance transfer pipeline (4).

2. The automatic fuel balancing system in the aircraft wing tank according to claim 1, characterized in that: The balance monitor (5) balances the fuel quantity in the four wing fuel tanks (1) as follows: Step 1: Calculate the fuel quantity in the four wing fuel tanks (1) to obtain the average fuel quantity M, and proceed to step 2; Step 2: determine whether there is a wing fuel tank (1) with low fuel level. If yes, proceed to step 3; if no, proceed to step 6, wherein the wing fuel tank (1) with low fuel level refers to a wing fuel tank (1) whose internal fuel level is less than the average fuel level M, whose internal fuel level is greater than the balance adjustment threshold H, and whose duration is greater than the set time length S; Step 3, closing the balancing oil pump (2) in the wing oil tank (1) with low fuel quantity, and opening the balancing control valve (3) in the wing oil tank (1) with low fuel quantity, and proceeding to step 4; Step 4: determine whether the fuel quantity in the low-fuel wing tank (1) is within the range of the average fuel quantity M±balance control threshold value I, and whether the duration is greater than a set time length S; if so, proceed to step 5; if not, proceed to step 6; Step 5, close the balance control valve (3) in the wing tank (1) with low fuel quantity, and proceed to step 6; Step 6: Determine whether there is a wing fuel tank (1) with a high fuel quantity. If yes, proceed to step 7; if no, proceed to step 8, wherein the wing fuel tank (1) with a high fuel quantity refers to a wing fuel tank (1) whose internal fuel quantity is greater than the average fuel quantity M, whose amount is greater than the balance adjustment threshold H, and whose duration is greater than the set time length S; Step 7, close the balance control valve (3) in the wing tank (1) with a high fuel volume, and open the balance oil pump (2) in the wing tank (1) with a high fuel volume, and proceed to step 8; Step 8: Determine whether the fuel amount in any of the three wing fuel tanks (1) is within the range of the average fuel amount M±balance control threshold value I, and the duration is greater than the set duration S. If so, close all the balancing fuel pumps (2) and balancing control valves (3) to complete the balancing of the fuel amount in the wing fuel tanks (1). If not, proceed to step 4.

3. The automatic fuel balancing system in the aircraft wing tank according to claim 2, characterized in that: Balance control threshold I<balance adjustment threshold H.

4. The automatic fuel balancing system in the aircraft wing tank according to claim 3, characterized in that: The balance adjustment threshold H is 300kg.

5. The automatic fuel balancing system in the aircraft wing tank according to claim 4, characterized in that: Set the duration S to 1s.

6. The automatic fuel balancing system in the aircraft wing tank according to claim 5, characterized in that: The balance control threshold I is taken as 200kg.

7. A method for automatically balancing the amount of fuel in an aircraft wing tank, characterized in that: The automatic balancing system for the amount of fuel in the aircraft wing tank according to claim 1 is implemented, comprising: Step 1: Calculate the fuel quantity in the four wing fuel tanks (1) to obtain the average fuel quantity M, and proceed to step 2; Step 2: determine whether there is a wing fuel tank (1) with low fuel level. If yes, proceed to step 3; if no, proceed to step 6, wherein the wing fuel tank (1) with low fuel level refers to a wing fuel tank (1) whose internal fuel level is less than the average fuel level M, whose internal fuel level is greater than the balance adjustment threshold H, and whose duration is greater than the set time length S; Step 3, closing the balancing oil pump (2) in the wing oil tank (1) with low fuel quantity, and opening the balancing control valve (3) in the wing oil tank (1) with low fuel quantity, and proceeding to step 4; Step 4: determine whether the fuel quantity in the wing tank (1) with low fuel quantity is within the range of the average fuel quantity M±balance control threshold value I, and whether the duration is greater than the set duration S; if so, proceed to step 5; if not, proceed to step 6, wherein the balance control threshold value I<balance adjustment threshold value H; Step 5, close the balance control valve (3) in the wing tank (1) with low fuel quantity, and proceed to step 6; Step 6: Determine whether there is a wing fuel tank (1) with a high fuel quantity. If yes, proceed to step 7; if no, proceed to step 8, wherein the wing fuel tank (1) with a high fuel quantity refers to a wing fuel tank (1) whose internal fuel quantity is greater than the average fuel quantity M, whose amount is greater than the balance adjustment threshold H, and whose duration is greater than the set time length S; Step 7, close the balance control valve (3) in the wing tank (1) with a high fuel volume, and open the balance oil pump (2) in the wing tank (1) with a high fuel volume, and proceed to step 8; Step 8: Determine whether the fuel amount in any of the three wing fuel tanks (1) is within the range of the average fuel amount M±balance control threshold value I, and the duration is greater than the set duration S. If so, close all the balancing fuel pumps (2) and balancing control valves (3) to complete the balancing of the fuel amount in the wing fuel tanks (1). If not, proceed to step 4.

8. The method for automatically balancing the amount of fuel in an aircraft wing tank according to claim 7, characterized in that: The balance adjustment threshold H is 300kg.

9. The method for automatically balancing the amount of fuel in an aircraft wing tank according to claim 8, characterized in that: Set the duration S to 1s.

10. The method for automatically balancing the amount of fuel in an aircraft wing tank according to claim 9, characterized in that: The balance control threshold I is taken as 200kg.

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