An Automatic Judgment and Control Method for the Driving Mode of an Amphibious Vehicle

Abstract

The present invention provides a method for automatically judging and controlling the driving mode of an amphibious vehicle. Based on the wheel retraction state of the vehicle, the comparison of vehicle speed signals, and suspension parameter information, the actual driving environment of the vehicle is comprehensively judged. Then, according to the actual driving environment, the driving mode is adaptively matched and switched, and the switching timing of the driving mode is automatically and accurately controlled. It can ensure intelligent determination of the driving environment, automatic adaptation of the driving mode, and accurate control of the switching timing during the land / water driving and transition process of the amphibious vehicle. The mode selection switch is cancelled. Based on the conventional operation signals generated during the normal driving operation of the driver and the bus signal data fed back by each subsystem of the vehicle, the actual operating environment and state of the vehicle are intelligently judged, and the switching timing of the driving mode is accurately determined, ensuring that the vehicle fully exerts its driving ability and realizes safe driving, reducing the operation difficulty of the driver for power output control, and reducing the adverse consequences brought by misjudgment and misoperation.

Description

Technical Field

[0001] The present invention belongs to the field of special vehicles, and particularly relates to a method for automatically judging and controlling the driving mode of an amphibious vehicle. Background Art

[0002] With the development of military technology and the needs of modern warfare, the demand for multi-functional transport vehicles is increasing continuously. Amphibious vehicles have both the characteristics of land vehicle mobility and flexibility, and can directly travel on water surface, which has important strategic significance and has been developed rapidly.

[0003] The change of the driving state of an amphibious vehicle on land / water surface involves the conversion of driving mode, the conversion of steering system, the retraction and extension of tires, etc. Among them, the grasp of the conversion timing of the driving mode directly affects the operation efficiency and safety. If it is completely judged and operated by manual experience, it will increase the operation difficulty of the driver and is also prone to misjudgment, resulting in certain risks.

[0004] In view of this, there have been invention patents proposed to set "land / water surface / shoal" mode selection switches and corresponding control modules. The driver can achieve "one-key switching" through the selection button switch and cooperate with automatic control, which reduces the difficulty of manual operation. However, the timing of button selection still needs to be judged by manual experience. In addition, there are risks brought by "misoperation" buttons or "non-operation" buttons. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for judging and automatically controlling the driving mode of an amphibious vehicle. The method of the present invention can ensure intelligent judgment of the driving environment, automatic adaptation of the driving mode, and accurate control of the conversion timing during the driving and transition process of the amphibious vehicle on land / water surface. The manual mode selection switch is cancelled. Based only on the conventional operation signals generated during the normal driving operation of the driver and the bus signal data fed back by each subsystem of the vehicle, the actual operating environment and state of the vehicle can be intelligently judged, and the conversion timing of the driving mode can be accurately determined, ensuring that the vehicle can fully exert its driving ability and achieve safe driving, reducing the operation difficulty of the driver for power output control, and reducing the adverse consequences brought by misjudgment and misoperation.

[0006] In order to achieve the above technical features, the purpose of the present invention is realized as follows: A method for automatically judging and controlling the driving mode of an amphibious vehicle, which comprehensively judges the actual driving environment of the vehicle according to the wheel retraction and extension state, vehicle speed signal comparison, and suspension parameter information of the vehicle, and then adaptively matches and converts the driving mode according to the actual driving environment, and automatically and accurately controls the conversion timing of the driving mode.

[0007] The specific acquisition methods of the wheel retraction and extension state, vehicle speed signal comparison, and suspension parameter information are as follows:

[0008] When an amphibious vehicle is driving on land, the driver can realize the driving intention by controlling the accelerator pedal, automatic transmission handle, steering wheel and brake pedal just like operating a traditional vehicle. During the process of the vehicle entering the water or sailing on the water surface, the vehicle state characteristics will change as follows:

[0009] First, when driving on land, the wheels are in the lowered state and in contact with the ground; when sailing on water, in order to reduce the sailing resistance, the driver can actively control to retract the wheels to increase the sailing speed;

[0010] Second, when driving on land, the vehicle weight is supported by the wheels and the suspension. The pressure of each cylinder of the suspension subsystem and the working stroke of the suspension conform to the change range of land driving; after driving into the water, as the buoyancy of the vehicle body increases, the maximum pressure of each cylinder of the suspension subsystem decreases and the working stroke of the suspension changes, and the working stroke range of the suspension changes significantly; when manually controlling to retract the wheels during water surface sailing, the suspension subsystem enters the working state of water surface sailing and remains stable;

[0011] Third, when driving on land, the "vehicle speed" signal provided by the vehicle ABS system is consistent with the actual vehicle speed; after entering water surface sailing, the "vehicle speed" signal provided by the vehicle ABS system can no longer truly reflect the actual vehicle speed.

[0012] Based on the changes in the vehicle state characteristics in the above three aspects, the intelligent judgment of the actual driving environment is realized, and then the automatic adaptation matching of the driving mode and the accurate control of the conversion timing are realized.

[0013] The specific implementation steps of this method are as follows:

[0014] Step 1, upgrade the functions of the vehicle-related systems;

[0015] Step 2, judge the vehicle driving state on land and realize the conversion of the land driving state;

[0016] Step 3, judge the state of the vehicle after driving into the water and realize the conversion of the state of driving in water;

[0017] Step 4, judge the vehicle water surface sailing state and realize the conversion of the water surface sailing state.

[0018] The specific content of the function upgrade in the above Step 1 includes:

[0019] 1.1, the vehicle's vehicle control unit and each subsystem can share the vehicle's specified information in real time through the CAN bus according to the protocol;

[0020] 1.2, take the "vehicle speed" provided by the vehicle ABS subsystem as the first speed of the vehicle, and at the same time, introduce the "vehicle speed" based on the Beidou signal as the second speed of the vehicle;

[0021] 1.3. Input the accelerator pedal signal into the vehicle control unit, and then, after comprehensive calculation by the vehicle control unit, output it to the engine control unit.

[0022] 1.4. The power distributor and automatic transmission of the vehicle support changing the driving mode and gear in real time according to the request of the vehicle control unit.

[0023] Both the power distributor and the automatic transmission are installed on the amphibious vehicle. By controlling the left and right position movement of the two synchronizers of the power distributor, the four modes of "power interruption" mode, "wheel drive" mode output to the wheels through the automatic transmission, "jet pump drive" mode output through the jet pump, and "wheel-jet pump dual drive" are respectively realized; so as to adopt the "wheel drive" mode when driving on land, the "jet pump drive" mode when sailing on water, and the "wheel-jet pump dual drive" mode when in the transition state between land and water, to meet the vehicle power requirements; correctly select the above driving modes in different driving environments to improve the vehicle driving performance and protect the equipment from damage.

[0024] The specific content during driving on land in step 2 includes the following:

[0025] 2.1. The vehicle state meets the following three conditions: ① The wheels are in the lowered state; ② The first speed signal provided by the vehicle ABS subsystem is consistent with the second speed signal provided according to the Beidou signal; ③ The cylinder pressures of the suspension subsystem and the suspension working stroke conform to the land driving change range.

[0026] The vehicle control unit determines that it is in the land driving mode at this time, and the power distributor should always be in the "wheel drive" mode.

[0027] 2.2. When the vehicle speed = 0, after the driver starts the engine and the transmission shift lever is in the "D" gear position, the power is transmitted to the wheels for driving; as the vehicle speed increases, the power distributor still maintains the "wheel drive" mode, and the operation of the transmission system is the same as that of a traditional vehicle.

[0028] The specific content when the vehicle drives into the water in step 3 includes the following:

[0029] 3.1. The vehicle state is judged around the land driving conditions in 2.1 of step 2. If: ① The wheels are in the lowered state; ② The first speed signal provided by the vehicle ABS subsystem is consistent with the second speed signal provided according to the Beidou signal; ③ The cylinder pressures of the suspension subsystem and the suspension stroke value conform to the land driving change range.

[0030] The vehicle control unit maintains the land driving mode; the power distributor maintains the "wheel drive" mode.

[0031] 3.2 When the vehicle state changes as the buoyancy of the water surface increases as follows: ① The first speed signal provided by the vehicle ABS subsystem and the second speed signal provided according to the Beidou signal show a difference due to wheel slip, reaching the set threshold; ② The pressures of each cylinder of the suspension subsystem and the suspension travel gradually exceed the change range during land travel.

[0032] After both conditions in 3.2 are met, the vehicle control unit determines that it has entered the amphibious environment. The automatic control system outputs an "idle speed signal for the accelerator pedal" to reduce the speed. The power distributor combines with "jet pump drive". After the action is completed, it resumes outputting the "actual position of the accelerator pedal". At this time, the "dual drive mode of wheels and jet pump" is achieved.

[0033] In the "dual drive mode of wheels and jet pump", the automatic transmission shift lever is in the "D" gear, and the wheels and the jet pump can output vehicle driving force simultaneously.

[0034] If the automatic transmission shift lever is in the "N" gear, the power distributor maintains the "wheel drive" mode, and the "jet pump drive" mode temporarily interrupts the power output. Since the automatic transmission responds to the "N" gear, the actual power of the vehicle is completely interrupted.

[0035] If the automatic transmission shift lever is in the "R" gear, both the wheels and the jet pump can output power. The wheels rotate in reverse with the drive of the transmission, and the reverse bucket above the jet pump drops, realizing the reversal of the jet pump water flow.

[0036] 3.3 When the vehicle is traveling in the "dual drive mode of wheels and jet pump", once it is determined that the vehicle operating state conditions meet the "land travel" conditions in 2.1, the control unit controls the power distributor to return to the "wheel drive" mode.

[0037] 3.4 When the vehicle is traveling in the "dual drive mode of wheels and jet pump", to further increase the traveling speed, after the driver issues the "retract the tires" command; the automatic control system will actively cooperate to control the engine speed to decrease, control the power distributor to disconnect the "jet pump drive" and the "wheel drive". After the "retract the tires" command is completed, the power distributor only combines with the "jet pump drive" and enters the water navigation state: At this time, ① The wheels are in the retracted state; ② When the Beidou signal feeds back the vehicle speed, the first speed signal provided by the vehicle ABS subsystem is 0; ③ The suspension subsystem enters a specific working state on the water surface and remains stable.

[0038] The specific contents during water navigation in step 4 include the following:

[0039] 4.1. When the following three conditions are met: ① the wheels are in the retracted state; ② when the Beidou signal feedback indicates vehicle speed, the first speed signal provided by the vehicle's ABS subsystem is 0; ③ the suspension subsystem enters a specific working state on the water surface and remains stable, the vehicle drive maintains the "jet pump drive". At this time, when the driver operates the transmission handle, it can still reflect the driving intention:

[0040] When the automatic transmission shift handle is in the "D" gear, the automatic control system controls the power distributor to only output forward power in the "jet pump drive" mode; while the "wheel drive" is interrupted, and the change of the automatic transmission gear has no impact on the drive;

[0041] When the automatic transmission shift handle is in the "N" gear, the automatic control system controls the "jet pump drive" of the power distributor to temporarily interrupt the output of power;

[0042] When the automatic transmission shift handle is in the "R" gear, the automatic control system controls the power distributor to perform the "jet pump drive" and the reverse bucket above the jet pump drops to achieve the reversal of the jet pump water flow;

[0043] 4.2. Under the water surface navigation state, after receiving the driver's "lower the wheels" command, after the control system cooperates to complete the tire lowering action, it controls the power distributor to engage the "wheel drive", that is, to restore to the "wheel-jet pump dual drive" mode;

[0044] 4.3. When the vehicle is traveling in the "wheel-jet pump dual drive" mode, once it is determined that the vehicle operating state conditions meet the aforementioned "land travel" conditions, the control unit controls the power distributor to switch to the "wheel drive" mode.

[0045] By sharing the transmission handle signal, the driver's driving intention on the water surface is identified, so as to match the corresponding drive mode.

[0046] As described above, the control system automatically judges and switches the drive mode between land / water and transition modes through tire status, vehicle speed signal comparison, and suspension parameters. The advantages of this method are as follows:

[0047] 1. The judgment and control method of the present invention makes full use of the advantage of the whole vehicle information sharing of the amphibious vehicle, actively judges the timing of the conversion between land and water driving modes, makes up for the lack of driver experience, improves the rationality of the conversion between land and water driving modes of the amphibious vehicle, and thus improves the success rate and safety of the conversion between land and water driving modes.

[0048] 2. In the present invention, during the land / water driving process, the accelerator pedal signal and the transmission handle signal are shared, and there is no need to add an operation unit for water surface driving, which simplifies the system setting and the driver's operation difficulty. If the steering wheel signal is used to replace the rudder signal, the operation method during water surface navigation is further simplified and more in line with the vehicle driving habit. Detailed implementation mode

[0049] The following is a further description in combination with specific embodiments.

[0050] Generally speaking, in order for an amphibious vehicle to adapt to the driving states on land / water, a power distributor is configured. Both the power distributor and the automatic transmission are mounted on the amphibious vehicle. By controlling the left and right position movements of the two synchronizers of the power distributor, four modes are respectively realized: the "power interruption" mode, the "wheel drive" mode output to the wheels through the automatic transmission, the "jet pump drive" mode output through the jet pump, and the "wheel-jet pump dual drive" mode. So as to adopt the "wheel drive" mode when driving on land, the "jet pump drive" mode when sailing on water, and the "wheel-jet pump dual drive" mode when in the transitional state between land and water, to meet the vehicle power requirements. Correctly select the above drive modes in different driving environments to improve the vehicle driving performance and protect the equipment from damage.

[0051] When the amphibious vehicle is driving on land, the driver operates it like a traditional vehicle, and realizes the driving intention by controlling the accelerator pedal, the automatic transmission handle, the steering wheel and the brake pedal. During the process of the vehicle entering the water or sailing on water, the vehicle state characteristics will change as follows:

[0052] First, when driving on land, the wheels are in the lowered state and in contact with the ground; when sailing on water, in order to reduce the sailing resistance, the driver can actively control to retract the wheels to increase the sailing speed.

[0053] Second, when driving on land, the vehicle weight is supported by the wheels and the suspension. The pressure of each cylinder of the suspension subsystem and the suspension working stroke conform to the change range of driving on land; after driving into the water, as the buoyancy of the vehicle body increases, the maximum pressure of each cylinder of the suspension subsystem decreases and the suspension working stroke changes, and the suspension working stroke range changes significantly; when the wheels are manually controlled to retract during water sailing, the suspension subsystem enters the water sailing working state and remains stable.

[0054] Third, when driving on land, the "vehicle speed" signal provided by the vehicle ABS system coincides with the actual vehicle speed; after entering water sailing, the "vehicle speed" signal provided by the vehicle ABS system can no longer truly reflect the actual vehicle speed.

[0055] Based on the above three aspects of vehicle state characteristic changes, the present invention provides a method for automatically judging and controlling the drive mode of an amphibious vehicle, which comprehensively judges the actual driving environment of the vehicle according to the wheel retraction state, the comparison of the vehicle speed signal and the suspension parameter information of the vehicle, and then adaptively matches and converts the drive mode according to the actual driving environment, and automatically and accurately controls the conversion timing of the drive mode.

[0056] The specific implementation steps of this method are as follows:

[0057] Step 1, perform functional upgrades on vehicle-related systems:

[0058] 1.1, The vehicle's overall control unit and each subsystem can share vehicle-specified information in real time via the CAN bus according to the protocol;

[0059] 1.2, Take the "vehicle speed" provided by the vehicle's ABS subsystem as the first speed of the vehicle. At the same time, introduce the "vehicle speed" based on Beidou signals as the second speed of the vehicle;

[0060] 1.3, Input the accelerator pedal signal into the vehicle's overall control unit, and then, after comprehensive calculation by the overall control unit, output it to the engine control unit;

[0061] 1.4, The vehicle's power distributor and automatic transmission support changing the drive mode and gear position in real time according to the request of the overall control unit.

[0062] Step 2, determine the vehicle's land driving state and implement the conversion of the land driving state:

[0063] 2.1, The vehicle state meets the following three conditions: ① The wheels are in the lowered state; ② The first speed signal provided by the vehicle's ABS subsystem is consistent with the second speed signal provided based on Beidou signals; ③ The cylinder pressures of the suspension subsystem and the suspension working stroke conform to the land driving change range;

[0064] The overall control unit of the vehicle determines that it is in the land driving mode at this time, and the power distributor should always be in the "wheel drive" mode;

[0065] 2.2, When the vehicle speed = 0, after the driver starts the engine and the transmission shift lever is in the "D" gear position, the power is transmitted to the wheels for driving; as the vehicle speed increases, the power distributor still maintains the "wheel drive" mode, and the operation of the transmission system is the same as that of a traditional vehicle.

[0066] Step 3, determine the state of the vehicle after driving into water and implement the conversion of the water driving state:

[0067] 3.1, The vehicle state is judged around the land driving conditions in 2.1 of Step 2. If: ① The wheels are in the lowered state; ② The first speed signal provided by the vehicle's ABS subsystem is consistent with the second speed signal provided based on Beidou signals; ③ The cylinder pressures of the suspension subsystem and the suspension stroke value conform to the land driving change range;

[0068] The overall control unit of the vehicle maintains the land driving mode; the power distributor maintains the "wheel drive" mode;

[0069] 3.2 When the vehicle state changes as the buoyancy of the water surface increases as follows: ① The first speed signal provided by the vehicle's ABS subsystem and the second speed signal provided according to the Beidou signal show a difference with wheel slip and reach the set threshold; ② The pressures of each cylinder of the suspension subsystem and the suspension stroke gradually exceed the change range during land driving.

[0070] After both conditions in 3.2 are satisfied, the vehicle control unit determines that it has entered the amphibious environment. The automatic control system outputs an "idle speed signal for the accelerator pedal" to reduce the speed. The power distributor combines with "jet pump drive". After the action is completed, it resumes outputting the "actual position of the accelerator pedal". At this time, the "dual drive mode of wheels and jet pump" is realized.

[0071] In the "dual drive mode of wheels and jet pump", the automatic transmission shift lever is in the "D" gear, and the wheels and the jet pump can output vehicle driving force simultaneously.

[0072] If the automatic transmission shift lever is in the "N" gear, the power distributor maintains the "wheel drive" mode, and the "jet pump drive" mode temporarily interrupts the power output. Since the automatic transmission responds to the "N" gear, the actual power of the vehicle is completely interrupted.

[0073] If the automatic transmission shift lever is in the "R" gear, both the wheels and the jet pump can output power. The wheels reverse with the drive of the transmission, and the reverse bucket above the jet pump drops, realizing the water flow reversal of the jet pump.

[0074] 3.3 When the vehicle is driving in the "dual drive mode of wheels and jet pump", once it is determined that the vehicle operating state conditions meet the "land driving" conditions in 2.1, the control unit controls the power distributor to return to the "wheel drive" mode.

[0075] 3.4 When the vehicle is driving in the "dual drive mode of wheels and jet pump", to further increase the driving speed, after the driver issues the "retract tires" command; the automatic control system will actively cooperate to control the engine speed to decrease, control the power distributor to disconnect the "jet pump drive" and the "wheel drive". After the "retract tires" command is completed, the power distributor only combines with the "jet pump drive" and enters the water navigation state: At this time, ① The wheels are in the retracted state; ② When the Beidou signal feedbacks vehicle speed, the first speed signal provided by the vehicle's ABS subsystem is 0; ③ The suspension subsystem enters a specific working state on the water surface and remains stable.

[0076] The specific contents during water navigation in step 4 include the following:

[0077] 4.1. When the following three conditions are met: ① the wheels are in the retracted state; ② when the Beidou signal feedback indicates vehicle speed, the first speed signal provided by the vehicle's ABS subsystem is 0; ③ the suspension subsystem enters a specific working state on the water surface and remains stable, the vehicle drive maintains "jet pump drive". At this time, when the driver operates the transmission handle, it can still reflect the driving intention:

[0078] When the automatic transmission shift handle is in the "D" gear, the automatic control system controls the power distributor to only output forward power in the "jet pump drive" mode; while the "wheel drive" is interrupted, and the change of the automatic transmission gear has no effect on the drive.

[0079] When the automatic transmission shift handle is in the "N" gear, the automatic control system controls the "jet pump drive" of the power distributor to temporarily interrupt the power output.

[0080] When the automatic transmission shift handle is in the "R" gear, the automatic control system controls the power distributor to perform "jet pump drive" and the reverse bucket above the jet pump drops to reverse the water flow of the jet pump.

[0081] 4.2. In the water navigation state, after receiving the driver's "lower the wheels" command, after the control system cooperates to complete the tire lowering action, it controls the power distributor to engage the "wheel drive", that is, it returns to the "wheel-jet pump dual drive" mode.

[0082] 4.3. When the vehicle is driving in the "wheel-jet pump dual drive" mode, once it is determined that the vehicle operating state conditions meet the aforementioned "land driving" conditions, the control unit controls the power distributor to switch to the "wheel drive" mode.

[0083] As described above, the control system automatically judges the land / water and transition modes and switches the drive mode through tire status, vehicle speed signal comparison, and suspension parameters. It makes full use of the advantage of the whole vehicle information sharing of the amphibious vehicle, actively judges the timing of the land and water driving mode conversion, makes up for the lack of driver experience, improves the rationality of the land and water driving mode conversion of the amphibious vehicle, and thus improves the success rate and safety of the land and water driving mode conversion.

Claims

1. An automatic judgment and control method for the driving mode of an amphibious vehicle, characterized in that, Based on the retraction state of the vehicle's wheels, the comparison of vehicle speed signals, and suspension parameter information, comprehensively judge the actual driving environment of the vehicle, and then adaptively match and convert the driving mode according to the actual driving environment, and automatically and accurately control the conversion timing of the driving mode; The specific acquisition methods of the wheel retraction state, vehicle speed signal comparison, and suspension parameter information are as follows: When an amphibious vehicle is driving on land, the driver operates it like a traditional vehicle, realizing the driving intention by controlling the accelerator pedal, automatic transmission handle, steering wheel, and brake pedal. During the process of the vehicle entering the water or sailing on the water surface, the vehicle state characteristics will change as follows: First, when driving on land, the wheels are in the lowered state and in contact with the ground; when sailing on water, to reduce the sailing resistance, the driver can actively control the wheels to retract to increase the sailing speed; Second, when driving on land, the vehicle weight is supported by the wheels and the suspension. The pressure of each cylinder of the suspension subsystem and the suspension working stroke conform to the change range of land driving; after driving into the water, as the buoyancy of the vehicle body increases, the maximum pressure of each cylinder of the suspension subsystem decreases and the suspension working stroke changes, and the suspension working stroke range changes significantly; when manually controlling the wheels to retract during water surface sailing, the suspension subsystem enters the water surface sailing working state and remains stable; Third, when driving on land, the "vehicle speed" signal provided by the vehicle's ABS system is consistent with the actual vehicle speed; after entering water surface sailing, the "vehicle speed" signal provided by the vehicle's ABS system can no longer truly reflect the actual vehicle speed; Based on the changes in the vehicle state characteristics in the above three aspects, realize the intelligent judgment of the actual driving environment, and then realize the automatic adaptive matching of the driving mode and the accurate control of the conversion timing.

2. The automatic judgment and control method for the driving mode of an amphibious vehicle according to claim 1, characterized in that, The specific implementation steps of this method are as follows: Step 1, upgrade the functions of the vehicle-related systems; Step 2, judge the vehicle's land driving state and realize the conversion of the land driving state; Step 3, judge the state of the vehicle after driving into the water and realize the conversion of the state of driving in the water; Step 4, judge the vehicle's water surface sailing state and realize the conversion of the water surface sailing state.

3. The automatic judgment and control method for the driving mode of an amphibious vehicle according to claim 2, wherein The specific content of the function upgrade in Step 1 includes: 1.1, the vehicle's vehicle control unit and each subsystem can share the vehicle's specified information in real time through the CAN bus according to the protocol; 1.2, regard the "vehicle speed" provided by the vehicle's ABS subsystem as the first speed of the vehicle, and at the same time, introduce the "vehicle speed" based on the Beidou signal as the second speed of the vehicle; 1.3, input the accelerator pedal signal into the vehicle control unit, and then output it to the engine control unit after comprehensive calculation by the vehicle control unit; 1.4, the vehicle's power distributor and automatic transmission support changing the driving mode and gear in real time according to the request of the vehicle control unit.

4. The automatic judgment and control method for the driving mode of an amphibious vehicle according to claim 3, wherein Both the power distributor and the automatic transmission are installed on the amphibious vehicle. By controlling the left and right position movements of the two synchronizers of the power distributor, four modes are respectively realized: the "power interruption" mode, the "wheel drive" mode output to the wheels through the automatic transmission, the "jet pump drive" mode output through the jet pump, and the "wheel-jet pump dual drive" mode. So as to adopt the "wheel drive" mode when driving on land, the "jet pump drive" mode when sailing on water, and the "wheel-jet pump dual drive" mode in the transitional state between land and water to meet the vehicle's power requirements. Correctly select the above drive modes in different driving environments to improve the vehicle's driving performance and protect the equipment from damage.

5. The automatic judgment and control method for the driving mode of an amphibious vehicle according to claim 4, characterized in that, The following specific contents are included when driving on land in step 2: 2.

1. The vehicle state meets the following three conditions: ① The wheels are in the lowered state; ② The first speed signal provided by the vehicle's ABS subsystem is consistent with the second speed signal provided according to the Beidou signal; ③ The cylinder pressures of the suspension subsystem and the suspension working stroke conform to the change range of land driving. The vehicle control unit judges that it is in the land driving mode at this time, and the power distributor should always be in the "wheel drive" mode. 2.

2. When the vehicle speed = 0, after the driver starts the engine and the transmission shift lever is in the "D" gear position, the power is transmitted to the wheels for driving. As the vehicle speed increases, the power distributor still maintains the "wheel drive" mode, and the operation of the transmission system is the same as that of a traditional vehicle.

6. The automatic judgment and control method for the driving mode of an amphibious vehicle according to claim 4, characterized in that, The following specific contents are included when the vehicle drives into the water in step 3: 3.

1. The vehicle state is judged around the land driving conditions in 2.1 of step 2. If: ① The wheels are in the lowered state; ② The first speed signal provided by the vehicle's ABS subsystem is consistent with the second speed signal provided according to the Beidou signal; ③ The cylinder pressures of the suspension subsystem and the suspension stroke value conform to the change range of land driving. The vehicle control unit maintains the land driving mode; the power distributor maintains the "wheel drive" mode. 3.

2. When the vehicle state changes with the increase of the buoyancy on the water surface as follows: ① The first speed signal provided by the vehicle's ABS subsystem and the second speed signal provided according to the Beidou signal show a difference due to wheel slip and reach the set threshold; ② The cylinder pressures of the suspension subsystem and the suspension stroke gradually exceed the change range of land driving. After both conditions in 3.2 are met, the vehicle control unit judges to enter the amphibious environment, and the automatic control system outputs an "idle speed signal of the accelerator pedal" to reduce the speed. The power distributor combines the "jet pump drive". After the action is completed, it resumes outputting the "actual position of the accelerator pedal". At this time, the "wheel-jet pump dual drive" mode is realized. In the "wheel-jet pump dual drive" mode, the automatic transmission shift lever is in the "D" gear, and the wheels and the jet pump can output vehicle driving force at the same time. If the automatic transmission shift lever is in the "N" gear, the power distributor maintains the "wheel drive" mode, and the "jet pump drive" mode temporarily interrupts the power output. Since the automatic transmission responds to the "N" gear, the actual power of the vehicle is completely interrupted. When the shift lever of the automatic transmission is in the "R" gear, both the wheels and the spray pump can output power. The wheels rotate reversely driven by the transmission, and the reverse bucket above the spray pump drops, realizing the reversal of the water flow of the spray pump. 3.3 When the vehicle is traveling in the "wheel-spray pump dual-drive" mode, once it is determined that the vehicle operating state conditions meet the "land travel" conditions in 2.1, the control unit controls the power distributor to return to the "wheel drive" mode. 3.4 When the vehicle is traveling in the "wheel-spray pump dual-drive" mode, to further increase the driving speed, after the driver issues the "retract tires" command; the automatic control system will actively cooperate to control the engine speed to decrease, control the power distributor to disconnect the "spray pump drive" and the "wheel drive". After the "retract tires" command is completed, the power distributor only engages the "spray pump drive" and enters the water navigation state: At this time, ① the wheels are in the retracted state; ② when the Beidou signal feedbacks vehicle speed, the first speed signal provided by the vehicle ABS subsystem is 0; ③ the suspension subsystem enters a specific working state on the water and remains stable.

7. The automatic judgment and control method for the driving mode of an amphibious vehicle according to claim 4, characterized in that The following are the specific contents during water navigation in step 4: 4.1 When the three conditions of ① the wheels are in the retracted state; ② when the Beidou signal feedbacks vehicle speed, the first speed signal provided by the vehicle ABS subsystem is 0; ③ the suspension subsystem enters a specific working state on the water and remains stable are met, the vehicle drive maintains the "spray pump drive". At this time, when the driver operates the transmission lever, it can still reflect his driving intention: When the shift lever of the automatic transmission is in the "D" gear, the automatic control system controls the power distributor to only output forward power through the "spray pump drive"; while the "wheel drive" is interrupted, and the change of the automatic transmission gear has no effect on the drive. When the shift lever of the automatic transmission is in the "N" gear, the automatic control system controls the "spray pump drive" of the power distributor to temporarily interrupt the output of power. When the shift lever of the automatic transmission is in the "R" gear, the automatic control system controls the power distributor to perform the "spray pump drive" and the reverse bucket above the spray pump drops, realizing the reversal of the water flow of the spray pump. 4.2 During the water navigation state, after receiving the driver's "lower the wheels" command, after the control system cooperates to complete the tire lowering action, it controls the power distributor to engage the "wheel drive", that is, to return to the "wheel-spray pump dual-drive" mode. 4.3 When the vehicle is traveling in the "wheel-spray pump dual-drive" mode, once it is determined that the vehicle operating state conditions meet the aforementioned "land travel" conditions, the control unit controls the power distributor to switch to the "wheel drive" mode.

8. The automatic judgment and control method for the driving mode of an amphibious vehicle according to claim 4, characterized in that, By sharing the transmission lever signal, the driver's water driving intention is identified, so as to match the corresponding drive mode.