A method for limiting aircraft traction and steering

Abstract

The invention discloses a method for limiting the towing steering of an aircraft, wherein a control system comprises a tractor control unit, an aircraft steering angle acquisition module and a steering angle limit value setting knob, wherein the aircraft steering angle acquisition module is used for acquiring the real-time steering angle of the aircraft, and the aircraft steering angle acquisition module is connected to the tractor control unit via a network cable; the steering angle limit value setting knob is used for setting the maximum steering angle limit value of the aircraft, and the steering angle limit value setting knob is connected to the tractor control unit via a multi-core cable, and when the aircraft tractor tows the aircraft for steering, the steering angle of the tractor can be controlled according to the real-time detected aircraft steering angle, thereby ensuring that the steering angle of the aircraft steering wheel group is within an allowable range.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation ground support equipment, and in particular relates to a method for limiting aircraft traction and steering. Background Art

[0002] When an aircraft is towed by a tractor on the ground, the rotation angle of the aircraft's steering landing gear must be controlled within a certain range and cannot exceed the allowable rotation range of the landing gear. Exceeding this range will damage the landing gear and cause an aircraft accident. Therefore, when the tractor is towing an aircraft, it is necessary to always pay attention to the steering angle of the aircraft's steering landing gear to ensure that the steering angle is within the allowable range.

[0003] The control of the steering angle of the tractor when towing an aircraft currently relies mainly on the operator controlling the vehicle to move along the trajectory or estimating the aircraft's steering angle through manual observation and then feeding back the observed steering angle value to the tractor operator, so that the operator can adjust the steering angle to ensure that the aircraft's steering angle is within the required range.

[0004] At present, the tractor control can only limit the steering angle of the tractor itself. When the tractor is docked with the aircraft, the steering angle of the tractor is not the steering angle of the aircraft, and the tractor control unit cannot obtain the steering angle of the aircraft. The tractor control unit cannot directly control and protect the steering angle of the aircraft. Summary of the invention

[0005] In order to solve the problem that a tractor control unit cannot directly control and protect the steering angle of an aircraft, the present invention provides a method for limiting aircraft traction steering, which can control the steering angle of the tractor according to the steering angle of the aircraft detected in real time.

[0006] The present invention adopts the following technical solution to solve the above technical problems. A method for limiting aircraft traction steering is characterized in that: the control system used includes a tractor control unit, an aircraft steering angle acquisition module and a steering angle limit value setting knob, wherein the aircraft steering angle acquisition module is used to collect the real-time steering angle of the aircraft, and the aircraft steering angle acquisition module is connected to the tractor control unit through a network cable; the steering angle limit value setting knob is used to set the maximum steering angle limit of the aircraft, and the steering angle limit value setting knob is connected to the tractor control unit through a multi-core wire; the specific control process is:

[0007] When the tractor is in a loaded condition of carrying an aircraft, the tractor will adjust the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor in real time according to the real-time steering angle of the aircraft collected by the aircraft steering angle collection module, so as to ensure that the actual steering angle ±A1 of the aircraft is controlled within the required range, that is, the aircraft's steering angle limit setting value ±A;

[0008] According to the aircraft's steering angle limit value, the actual steering angle value of the aircraft is divided into four areas, namely, the safety area, the warning area, the danger area, and the out-of-control area; the aircraft's steering angle limit value is set to ±A, the safety area range is -|A*0.6|~+|A*0.6|, the warning area range is ±(|A*0.6|~|A*0.8|), the danger area range is ±(|A*0.8|~|A*0.9|), and the out-of-control area range is >+|A*0.9| and <-|A*0.9|;

[0009] The steering angle limit value A can be freely set through the steering angle limit value setting knob. The absolute value adjustment range of the steering angle limit value A is 0 to 100°.

[0010] Under loaded conditions, within the safety zone, the travel and steering of the tractor are not restricted, and all operating functions and ranges of the no-load state are maintained; that is, the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor are not interfered with and adjusted, and the tractor is still controlled according to the normal travel speed setting value V and steering angle setting value α of the tractor, that is, ;

[0011] Under load conditions, within the warning area, the actual speed setting value V1 of the tractor is not restricted and is controlled according to the normal travel speed setting value V; the actual steering angle setting value α1 decreases from the normal steering angle setting value α*100% to the normal steering angle setting value α*33% according to the actual steering angle A1 increasing from ±A*0.6 to ±A*0.8, that is, the actual speed setting value V1 and the actual steering angle setting value α1 within the warning area are calculated as follows:

[0012] ;

[0013] Under load conditions, in the dangerous area, the actual speed setting value V1 of the tractor is not restricted, and the travel control is performed according to the normal speed setting value V; the actual steering angle setting value α1 decreases from the normal steering angle setting value α*33% to 0 according to the change of the actual steering angle A1 from ±A*0.8 to ±A*0.9, that is, the actual speed setting value V1 and the actual steering angle setting value α1 in the dangerous area are calculated as follows:

[0014] ;

[0015] Under loaded conditions, once entering the out-of-control area, the tractor will stop working and maintain a stable stopped state. All operator operations will be invalid to avoid serious accidents caused by further operations or misoperations. That is, when in the out-of-control area, the actual speed setting value V1 of the forced tractor is set to 0, and the actual steering angle setting value α1 of the forced tractor is set to 0.

[0016] It is further defined that, under the loaded working condition, after entering the out-of-control area, after the operator carefully observes and confirms the on-site working conditions, when it is necessary to restore and correct the aircraft steering angle, the forced button on the tractor operation panel can be pressed. At this time, the tractor enters the forced working condition and can be operated. Under this condition, the actual speed setting value V1 and the actual steering angle setting value α1 are adjusted and set according to the normal speed setting value V*10% and the normal steering angle setting value α*10%; that is, under the loaded working condition, in the out-of-control area, after entering the forced working condition, the setting formulas of the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor are as follows: .

[0017] Further restrictions are made that, under load conditions, in the out-of-control area, after entering the forced condition, the tractor cannot continue to be forced to rotate in the out-of-control direction, and can only perform a slow steering angle correction in the non-out-of-control direction; that is, if the out-of-control direction of the tractor is +A, the actual steering angle setting value α1 of the tractor will not be allowed to be a positive number. ; If the out-of-control direction of the tractor is -A, the actual steering angle setting value α1 of the tractor shall not be negative. .

[0018] It is further defined that the control system also includes a photoelectric switch, which is used to identify whether the tractor is unloaded or loaded. When the photoelectric switch is triggered, it is in a loaded mode, and when the photoelectric switch is not triggered, it is in an unloaded mode. The photoelectric switch is connected to the tractor control unit through a multi-core wire.

[0019] It is further defined that the photoelectric switch is used to identify whether the tractor is currently in a loaded condition with an aircraft or an unloaded condition without an aircraft; when the tractor is docked with the aircraft's front lift, the aircraft's front lift blocks the photoelectric switch, causing the photoelectric switch to be triggered, and the tractor control unit identifies and determines that it is currently in a loaded condition; when the tractor is detached from the aircraft's front lift, the photoelectric switch is unblocked, the photoelectric switch is reset, and the tractor control unit identifies and determines that it is currently in an unloaded condition, and two sets of photoelectric switches are installed at the same time for identification and confirmation, and only when both sets of photoelectric switches are triggered is it considered to be a loaded condition.

[0020] It is further defined that the control system also includes an LED light bar, which is used to indicate the current steering angle and status of the aircraft, and the LED light bar is connected to the tractor control unit via a serial communication line.

[0021] It is further defined that a group of long LED light strips are arranged in the tractor panel area, the middle of the light strip is the dividing zero point in the left and right directions, and the lighting direction of the light strip is consistent with the direction in which the aircraft turns, that is, when the aircraft turns left, the light strip lights up from the middle dividing zero point to the left, and when the aircraft turns right, the light strip lights up from the middle dividing zero point to the right;

[0022] Under load conditions, the ratio of the length of the LED light bar that is lit from the middle to the left or right to the total length of the light bar corresponds to the ratio of the actual turning angle of the aircraft to the maximum allowable turning angle of the aircraft; that is, the midpoint of the light bar is set as 0, and the total length of the light bar is L, then the calculation formula for the length L1 of the lit part of the light bar is: ;

[0023] Under load conditions, when the actual turning angle of the aircraft is in the safe area, warning area, danger area, or out-of-control area, the LED light bar will light up in different colors, and the LED light bar will flash when it is in the out-of-control area.

[0024] When the tractor is in the no-load state, the LED light bar only lights up the lamp beads at the middle dividing point of the light bar, and the light color is blue;

[0025] When the tractor is in an unloaded state, or when the aircraft steering angle acquisition system fails, the LED light bars light up in sequence from left to right and then from right to left;

[0026] When the tractor is in the loaded state, when the aircraft steering angle acquisition system fails, the LED light bar lights up from left to right and then from right to left in sequence, and the steering angle alarm emits a long beeping interval, that is, an alarm tone every 3s, and returns to normal after the fault is eliminated.

[0027] It is further defined that the control system also includes a steering angle alarm, the steering angle alarm is used to provide an alarm status prompt of the actual steering angle of the aircraft, and the steering angle alarm is connected to the tractor control unit via a multi-core wire;

[0028] Under load conditions, in the warning area, the steering angle alarm emits a beep followed by a 1s intermittent tone to remind the operator that they are currently in the warning area and to pay attention to safe operation;

[0029] Under load conditions, in the danger zone, the steering angle alarm emits a continuous beeping sound to remind the operator that they are in the danger zone and to pay attention to safe operation;

[0030] Under loaded conditions, once entering the out-of-control area, the steering angle alarm will emit a long beep to remind the operator that they are currently in the out-of-control area and that emergency measures are required to avoid damage to the aircraft.

[0031] It is further defined that the control system also includes a display module, which is used to display relevant information of the aircraft steering angle, and the display module is connected to the tractor control unit via a serial communication line.

[0032] It is further defined that the control system also includes a communication module, which is used to send data and status information of the aircraft steering angle to a third party or a superior node, and the communication module is connected to the tractor control unit through a bus.

[0033] Compared with the prior art, the present invention has the following advantages and beneficial effects: when the aircraft tractor is towing an aircraft for steering, the steering angle of the tractor can be controlled according to the steering angle of the aircraft detected in real time, thereby ensuring that the steering angle of the aircraft steering wheel group is within the allowable range. DETAILED DESCRIPTION

[0034] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention. Example

[0035] The control system of the present invention comprises a tractor control unit, an aircraft steering angle acquisition module, a photoelectric switch, an LED light bar, a steering angle limit setting knob, a steering angle alarm, a display module and a communication module;

[0036] The aircraft steering angle acquisition module is used to collect the real-time steering angle of the aircraft. The aircraft steering angle acquisition module is connected to the tractor control unit through a network cable;

[0037] The photoelectric switch is used to identify whether the tractor is unloaded or loaded. When the photoelectric switch is triggered, it is in the loaded mode, and when the photoelectric switch is not triggered, it is in the unloaded mode. The photoelectric switch is connected to the tractor control unit through a multi-core wire.

[0038] The LED light bar is used to indicate the current aircraft steering angle and status. The LED light bar is connected to the tractor control unit through a serial communication line;

[0039] The steering angle limit setting knob is used to set the maximum steering angle limit of the aircraft. The steering angle limit setting knob is connected to the tractor control unit through a multi-core wire;

[0040] The steering angle alarm is used to provide an alarm status prompt of the actual steering angle of the aircraft. The steering angle alarm is connected to the tractor control unit through a multi-core wire;

[0041] The display module is used to display relevant information of the aircraft steering angle, and the display module is connected to the tractor control unit through a serial communication line;

[0042] The communication module is used to send data and status information of the aircraft steering angle to a third party or a superior node, and the communication module is connected to the tractor control unit through a bus.

[0043] The present invention collects the real-time steering angle of the aircraft, optimizes the steering control of the tractor according to the collected real-time steering angle of the aircraft, and further ensures that the steering angle of the aircraft steering wheel group is within an allowable range.

[0044] In the method, a photoelectric sensing switch is provided to identify whether the tractor is currently in a loaded condition with an aircraft or an unloaded condition without an aircraft. When the tractor is docked with the aircraft's front lift, the aircraft's front lift blocks the photoelectric switch, causing the photoelectric switch to be triggered, and the tractor control unit identifies and determines that the tractor is currently in a loaded condition. When the tractor is detached from the aircraft's front lift, the photoelectric switch is unblocked, the photoelectric switch is reset, and the tractor control unit identifies and determines that the tractor is currently in an unloaded condition.

[0045] At the same time, in order to ensure the recognition accuracy of the photoelectric switch, two sets of photoelectric switches are installed for identification and confirmation. Only when both sets of photoelectric switches are triggered, it is considered to be a load condition.

[0046] Under no-load conditions, the tractor operates normally in full state, that is, the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor are not restricted, and it is still controlled according to the normal travel speed setting value V and steering angle setting value α of the tractor, that is, ;

[0047] When it is identified that the tractor is in a loaded condition of carrying an aircraft, the tractor will adjust the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor in real time according to the collected real-time steering angle of the aircraft, so as to ensure that the actual steering angle ±A1 of the aircraft is controlled within the required range, that is, the aircraft's steering angle limit setting value ±A;

[0048] The present invention divides the actual steering angle value of the aircraft into four areas according to the steering angle limit value of the aircraft, namely, a safe area, a warning area, a dangerous area, and an out-of-control area; the steering angle limit value of the aircraft is set to ±A, the safe area ranges from -|A*0.6| to +|A*0.6|, the warning area ranges from ±(|A*0.6| to |A*0.8|), the dangerous area ranges from ±(|A*0.8| to |A*0.9|), and the out-of-control area ranges from >+|A*0.9| to <-|A*0.9|;

[0049] The method is equipped with a steering angle limit value setting adjustment knob, through which the steering angle limit value A can be freely set, and the absolute value adjustment range of the steering angle limit value A is 0 to 100 degrees;

[0050] Under loaded conditions, within the safety zone, the travel and steering of the tractor are not restricted, and all operating functions and ranges of the no-load state are maintained; that is, the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor are not interfered with and adjusted, and the tractor is still controlled according to the normal travel speed setting value V and steering angle setting value α of the tractor, that is, .

[0051] Under load conditions, within the warning area, the actual speed setting value V1 of the tractor is not restricted and is controlled according to the normal travel speed setting value V; the actual steering angle setting value α1 decreases from the normal steering angle setting value α*100% to the normal steering angle setting value α*33% according to the actual steering angle A1 increasing from ±A*0.6 to ±A*0.8. That is, the actual speed setting value V1 and the actual steering angle setting value α1 within the warning area are calculated as follows:

[0052]

[0053] Under load conditions, in the warning area, the steering angle alarm emits a beep followed by a 1s intermittent tone to remind the operator that they are currently in the warning area and to pay attention to safe operation;

[0054] Under load conditions, in the dangerous area, the actual speed setting value V1 of the tractor is not restricted, and the travel control is performed according to the normal speed setting value V; the actual steering angle setting value α1 changes from the normal steering angle setting value α*33% to 0 according to the change of the actual steering angle A1 from ±A*0.8 to ±A*0.9. That is, the calculation of the actual speed setting value V1 and the actual steering angle setting value α1 in the dangerous area is as follows:

[0055]

[0056] Under load conditions, in the danger zone, the steering angle alarm emits a continuous beeping sound to remind the operator that they are in the danger zone and to pay attention to safe operation;

[0057] Under load conditions, once entering the out-of-control area, the tractor will stop working and maintain a stable stop state. The operator's operation is invalid to avoid further operation or misoperation causing serious accidents. That is, when in the out-of-control area, the actual speed setting value V1 of the forced tractor is 0, and the actual steering angle setting value α1 of the forced tractor is 0.

[0058] Under loaded conditions, once the aircraft enters the out-of-control area, the steering angle alarm will emit a long beep to remind the operator that the aircraft is in the out-of-control area and needs emergency treatment to avoid damage to the aircraft.

[0059] Under loaded working condition, after entering the out-of-control area, after the operator carefully observes and confirms the on-site working condition, if it is necessary to restore and correct the aircraft steering angle, the forced button on the tractor operation panel can be pressed. At this time, the tractor enters the forced working condition and can be operated. Under this condition, the actual speed setting value V1 and the actual steering angle setting value α1 are adjusted and set according to the normal speed setting value V*10% and the normal steering angle setting value α*10%; that is, under loaded working condition, in the out-of-control area, after entering the forced working condition, the setting formula of the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor is as follows: .

[0060] Under load conditions, in the out-of-control area, after entering the forced condition, the tractor cannot continue to rotate in the out-of-control direction, and can only make a slow steering angle correction in the non-out-of-control direction; that is, if the out-of-control direction of the tractor is +A, the actual steering angle setting value α1 of the tractor will not be allowed to be a positive number. ; If the out-of-control direction of the tractor is -A, the actual steering angle setting value α1 of the tractor shall not be negative. .

[0061] A set of long LED light strips are arranged in the tractor panel area. The middle of the light strip is the dividing zero point in the left and right directions. The lighting direction of the light strip is consistent with the direction in which the aircraft turns. That is, when the aircraft turns left, the light strip lights up from the middle dividing zero point to the left, and when the aircraft turns right, the light strip lights up from the middle dividing zero point to the right.

[0062] Under load conditions, the ratio of the length of the LED light bar that is lit from the middle to the left or right to the total length of the light bar corresponds to the ratio of the actual turning angle of the aircraft to the maximum allowable turning angle of the aircraft; that is, the midpoint of the light bar is set as 0, and the total length of the light bar is L, then the calculation formula for the length L1 of the lit part of the light bar is: .

[0063] Under load conditions, when the actual turning angle of the aircraft is within the safe area, the LED light bar lights up in blue (the color can be changed freely);

[0064] Under load conditions, when the actual turning angle of the aircraft is within the warning area, the LED light bar lights up in yellow (can be changed freely);

[0065] Under load conditions, when the actual turning angle of the aircraft is within the danger zone, the LED light bar lights up in red (can be changed freely);

[0066] Under load conditions, when the actual steering angle of the aircraft is within the out-of-control area, the LED light bar lights up in red (can be changed freely) and flashes (the flashing interval can be set freely);

[0067] When the tractor is in the no-load state, the LED light bar only lights up the lamp beads at the middle dividing point of the light bar, and the light color is blue;

[0068] When the tractor is in an unloaded state and the aircraft steering angle acquisition system fails, the LED light bar lights up from left to right and then from right to left in sequence, and the steering angle alarm does not work. The light bar returns to normal after the fault is eliminated;

[0069] When the tractor is in the loaded state, when the aircraft steering angle acquisition system fails, the LED light bar lights up from left to right and then from right to left in turn, and the steering angle alarm emits a long interval (3s interval) beeping alarm prompt tone, and returns to normal after the fault is eliminated;

[0070] The present invention has an external interface, which can be connected to a display module to display the current loading state of the tractor, the real-time steering angle of the aircraft and other related state information of the traction steering control of the aircraft.

[0071] The present invention improves the operating convenience of the equipment by automatically identifying the loading state of the tractor, and eliminates the interference factors of the loading state identification for accurately controlling the actual steering angle of the aircraft.

[0072] The present invention divides the area of ​​the actual steering angle of the aircraft to make the protection of the actual steering angle of the aircraft more stable and reliable. The tractor operation is unrestricted and operates normally in the safe area; different sound warnings are given in the warning area and the danger area, and the actual steering angle setting value is proportionally reduced to zero; the walking and steering operations of the tractor are restricted in the out-of-control area to ensure the safety of the aircraft; in the out-of-control area, when the operator needs to make adjustments to repair the current state, there is a forced operation mode. In the forced operation mode, the actual travel speed setting value and the actual steering angle setting value of the tractor are proportionally reduced to 10% of the normal value, so that the tractor is operated slowly to fully ensure the operation accuracy and the safety of the aircraft;

[0073] The present invention is also equipped with an LED light bar, through which the direction of the aircraft's steering angle, the magnitude of the steering angle, and the regional status of the steering angle can be visually viewed;

[0074] The present invention also has a steering angle alarm, which can directly distinguish the current actual steering angle alarm state through sound and give the operator a clear sound prompt;

[0075] The method can also be connected to an external display module to display the aircraft steering angle value, steering angle status and other related steering control information in text information;

[0076] The present invention also has wireless and wired communication functions, and can transmit the aircraft steering angle value and steering angle status and other related steering control status information to a third party or a master control system for monitoring and display through communication (TCP / RS485 / MODBUS485 / CAN);

[0077] The present invention provides the operator with comprehensive instructions and prompts in the form of sound and light, and at the same time ensures through internal control logic that the actual turning angle of the aircraft does not exceed the limit value, thereby ensuring the safety of the aircraft's turning.

[0078] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for limiting aircraft traction and steering, characterized in that: The control system used includes a tractor control unit, an aircraft steering angle acquisition module and a steering angle limit value setting knob, wherein the aircraft steering angle acquisition module is used to collect the real-time steering angle of the aircraft, and the aircraft steering angle acquisition module is connected to the tractor control unit through a network cable; the steering angle limit value setting knob is used to set the maximum steering angle limit of the aircraft, and the steering angle limit value setting knob is connected to the tractor control unit through a multi-core cable; the specific control process is: When the tractor is in a loaded condition of carrying an aircraft, the tractor will adjust the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor in real time according to the real-time steering angle of the aircraft collected by the aircraft steering angle collection module, so as to ensure that the actual steering angle ±A1 of the aircraft is controlled within the required range, that is, the aircraft's steering angle limit setting value ±A; According to the aircraft's steering angle limit value, the actual steering angle value of the aircraft is divided into four areas, namely, the safety area, the warning area, the danger area, and the out-of-control area; the aircraft's steering angle limit value is set to ±A, the safety area range is -|A*0.6|~+|A*0.6|, the warning area range is ±(|A*0.6|~|A*0.8|), the danger area range is ±(|A*0.8|~|A*0.9|), and the out-of-control area range is >+|A*0.9| and <-|A*0.9|; The steering angle limit value A can be freely set through the steering angle limit value setting knob. The absolute value adjustment range of the steering angle limit value A is 0 to 100°. Under the loaded condition, within the safety zone, the travel and steering of the tractor are not restricted, and all the operating functions and ranges of the no-load state are maintained, that is, the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor are not interfered with and adjusted, and are still controlled according to the normal speed setting value V and the normal steering angle setting value α of the tractor, that is, Under load conditions, within the warning zone, the actual speed setting value V1 of the tractor is not restricted and is controlled according to the normal speed setting value V. The actual steering angle setting value α1 decreases from the normal steering angle setting value α*100% to the normal steering angle setting value α*33% according to the actual steering angle A1 increasing from ±A*0.6 to ±A*0.

8. That is, the actual speed setting value V1 and the actual steering angle setting value α1 within the warning zone are calculated as follows: V1 = V; Under load conditions, in the danger zone, the actual speed setting value V1 of the tractor is not restricted, and the travel control is performed according to the normal speed setting value V. The actual steering angle setting value α1 decreases from the normal steering angle setting value α*33% to 0 according to the change of the actual steering angle A1 from ±A*0.8 to ±A*0.

9. That is, the actual speed setting value V1 and the actual steering angle setting value α1 in the danger zone are calculated as follows: V1 = V; Under loaded conditions, once entering the out-of-control zone, the tractor will stop working and maintain a stable stopped state. All operator operations will be invalid to avoid serious accidents caused by further operations or misoperations. That is, when in the out-of-control zone, the actual speed setting value V1 of the forced tractor is set to 0, and the actual steering angle setting value α1 of the forced tractor is set to 0.

2. The method for limiting aircraft traction and steering according to claim 1, characterized in that: Under loaded working condition, after entering the out-of-control zone, after the operator carefully observes and confirms the on-site working condition, if it is necessary to restore and correct the aircraft steering angle, the forced button on the tractor operation panel can be pressed. At this time, the tractor enters the forced working condition and can be operated. Under this condition, the actual speed setting value V1 and the actual steering angle setting value α1 are adjusted and set according to the normal speed setting value V*10% and the normal steering angle setting value α*10%. That is, under loaded working condition, in the out-of-control zone, after entering the forced working condition, the setting formula of the actual speed setting value V1 and the actual steering angle setting value α1 of the tractor is as follows:

3. The method for limiting aircraft traction and steering according to claim 2, characterized in that: Under load conditions, in the out-of-control zone, after entering the forced condition, the tractor cannot continue to rotate in the out-of-control direction, and can only make a slow steering angle correction in the non-out-of-control direction; that is, if the out-of-control direction of the tractor is +A, the actual steering angle setting value α1 of the tractor will not be allowed to be a positive number. If the uncontrolled direction of the tractor is -A, the actual steering angle setting value α1 of the tractor shall not be negative.

4. The method for limiting aircraft traction and steering according to claim 1, characterized in that: The control system also includes a photoelectric switch, which is used to identify whether the tractor is unloaded or loaded. When the photoelectric switch is triggered, it is in a loaded mode, and when the photoelectric switch is not triggered, it is in an unloaded mode. The photoelectric switch is connected to the tractor control unit through a multi-core wire.

5. The method for limiting aircraft traction and steering according to claim 4, characterized in that: The photoelectric switch is used to identify whether the tractor is currently in a loaded working condition with an aircraft or an unloaded working condition without an aircraft. When the tractor is docked with the aircraft's front lift, the aircraft's front lift blocks the photoelectric switch, causing the photoelectric switch to be triggered, and the tractor control unit identifies and determines that it is currently in a loaded working condition. When the tractor is detached from the aircraft's front lift, the photoelectric switch is unblocked, the photoelectric switch is reset, and the tractor control unit identifies and determines that it is currently in an unloaded working condition. Two sets of photoelectric switches are installed at the same time for identification and confirmation. Only when both sets of photoelectric switches are triggered can it be considered to be a loaded working condition.

6. The method for limiting aircraft traction and steering according to claim 1, characterized in that: The control system also includes an LED light bar, which is used to indicate the current steering angle and state of the aircraft. The LED light bar is connected to the tractor control unit via a serial communication line.

7. The method for limiting aircraft traction and steering according to claim 6, characterized in that: A set of long LED light strips are arranged in the tractor panel area. The middle of the light strip is the dividing zero point in the left and right directions. The lighting direction of the light strip is consistent with the direction in which the aircraft turns. That is, when the aircraft turns left, the light strip lights up from the middle dividing zero point to the left, and when the aircraft turns right, the light strip lights up from the middle dividing zero point to the right. Under load conditions, the ratio of the length of the LED light bar that is lit from the middle to the left or right to the total length of the light bar corresponds to the ratio of the actual turning angle of the aircraft to the maximum allowable turning angle of the aircraft; that is, the midpoint of the light bar is set as 0, and the total length of the light bar is L, then the calculation formula for the length L1 of the lit part of the light bar is: Under load conditions, when the actual turning angle of the aircraft is in the safe zone, warning zone, danger zone, or out-of-control zone, the LED light bar will light up in different colors, and the LED light bar will flash when it is in the out-of-control zone. When the tractor is in the no-load state, the LED light bar only lights up the lamp beads at the middle dividing point of the light bar, and the light color is blue; When the tractor is in an unloaded state, or when the aircraft steering angle acquisition system fails, the LED light bars light up in sequence from left to right and then from right to left; When the tractor is in the loaded state, when the aircraft steering angle acquisition system fails, the LED light bar lights up from left to right and then from right to left in sequence, and the steering angle alarm emits a long beeping interval, that is, an alarm tone every 3s, and returns to normal after the fault is eliminated.

8. The method for limiting aircraft traction and steering according to claim 1, characterized in that: The control system also includes a steering angle alarm, which is used to provide an alarm status prompt of the actual steering angle of the aircraft, and the steering angle alarm is connected to the tractor control unit via a multi-core wire; Under load conditions, in the warning zone, the steering angle alarm emits a beep followed by a 1s intermittent tone to remind the operator that they are currently in the warning zone and to pay attention to safe operation; Under load conditions, in the danger zone, the steering angle alarm emits a continuous beeping sound to remind the operator that he is currently in the danger zone and to pay attention to safe operation; Under loaded conditions, once entering the out-of-control zone, the steering angle alarm will emit a long beep to remind the operator that they are currently in the out-of-control zone and that emergency measures are required to avoid damage to the aircraft.

9. The method for limiting aircraft traction and steering according to claim 1, characterized in that: The control system also includes a display module, which is used to display relevant information of the aircraft steering angle. The display module is connected to the tractor control unit via a serial communication line.

10. The method for limiting aircraft traction and steering according to claim 1, characterized in that: The control system further comprises a communication module, which is used to send data and status information of the aircraft steering angle to a third party or a superior node, and the communication module is connected to the tractor control unit via a bus.

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