Multi-mode self-adaptive amphibious vehicle range extending system start-stop control method

Abstract

The invention relates to the field of extended-range hybrid electric vehicle control, and particularly discloses a multi-mode self-adaptive amphibious vehicle extended-range system start-stop control method, which comprises the following steps of: switching to a corresponding working mode according to a driving environment of a vehicle, the range extending system is adaptively adjusted to a power generation working condition or a stop working condition according to different working modes; the range extending system start-stop control module comprises a range extender starting module and a range extender stopping module, and the engine starting module is divided into a starter emergency starting mode and an ISG reverse dragging engine starting mode; task requirements of a driver can be met, operation states of all parts can be coordinated more sufficiently, energy output efficiency is improved, the range extending system is higher in starting and response speed and lower in oil consumption and emission in the starting process, meanwhile, the mode that an engine is started by a starter is reserved to cope with emergency situations, and the range extending system is suitable for popularization and application. And the stability and the reliability of the whole system are improved.

Description

Technical Field

[0001] The invention relates to the field of range-extended hybrid electric vehicle control, and in particular to a multi-mode adaptive start-stop control method for a range-extended system of an amphibious vehicle. Background Art

[0002] Amphibious vehicles are a unique means of transportation. The body is sealed and the chassis design takes both land and water into consideration. Land travel relies on the friction between the wheels and the ground, and the transmission system transmits the power of the engine or motor to the wheels for driving; water travel relies on devices such as propellers or water jets to generate thrust using the engine or motor. Its suspension system needs to adapt to different land and water environments. On land, it can reduce shock to ensure comfort and stability, and in water, it can adjust according to the change of buoyancy and withstand the impact of water in and out, so that it can travel on land and water. It can be used in military, rescue, tourism and other fields. In order to cope with complex and changeable driving needs, amphibious vehicles often use hybrid power for driving. When driving on land, hybrid power can avoid engine idling loss in pure electric mode in congested road conditions, and the engine can efficiently supply energy at high speed or long distances; when driving on water, the power source is flexibly allocated according to the speed and load, and the electric power assists low-speed navigation, while the engine ensures high-speed and heavy-load propulsion. At the same time, electric power can instantly release high torque to assist starting and acceleration on land and water, and the engine's continuous power output ensures long-distance driving. The two work together to optimize power performance and can effectively reduce emissions, which is in line with environmental protection trends.

[0003] The range-extending system control of the amphibious heavy-duty hybrid transport vehicle can effectively balance the workload between the engine and the battery-motor system, extend the service life of the engine and battery, ensure smooth and continuous power output, and ensure the reliability and stability of the vehicle; by adjusting the start and stop of the engine in different usage scenarios, it can effectively improve fuel utilization and reduce energy waste. At the same time, it can also optimize the battery charging state, ensure that the engine operates in the high-efficiency power generation range, extend the vehicle's cruising range, and optimize the vehicle's energy utilization in water and land environments.

[0004] The hybrid amphibious vehicle designed in patent CN113928064B mainly focuses on the overall structure, component layout, connection relationship and function realization of the hybrid amphibious vehicle, and does not elaborate on how to control its range extension system. In addition, the lack of the main drive motor may lead to limited peak torque output and insufficient power under extreme conditions. The control method of a hybrid excitation internal combustion power generation range extension system for electric vehicles disclosed in patent CN108407624A does not optimize the vehicle's starting process. The engine still uses a starter to start. Its starting torque is limited, the starting speed is relatively slow, and the fuel consumption is high during the starting process. However, a full-condition control method for a permanent magnet synchronous range extension system disclosed in patent CN108621809A only mentions the use of an ISG reverse-drag engine for starting, and does not design the use of the engine's own starter motor for starting. There is no backup starting means, which puts higher requirements on starting reliability, has high requirements on battery power and status, has a single point failure risk, and relies on the ISG motor and related systems. Summary of the invention

[0005] The object of the present invention is to provide a multi-mode adaptive start-stop control method for an amphibious vehicle range-extending system to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: Terminology explanation: ISG motor: ISG motor is a motor that integrates starter and generator functions. Its structure includes a stator, a rotor and a cooling system. It generates electricity through electromagnetic induction and Ampere force starting. It is used in the engine range extender system to generate electricity to supplement energy, start the engine and assist in power output.

[0007] Power battery: The power battery is an energy storage device that plays a key role in vehicle power systems such as engine range extension systems. It can store the electrical energy generated by generators (such as ISG motors), receive and store energy recovered by vehicle braking, and provide power to the drive motor when the vehicle needs power.

[0008] High-voltage distribution box: The high-voltage distribution box is a key component in the vehicle's high-voltage system. It has an input interface connected to the power battery and an output interface connected to various high-voltage electrical equipment. It contains a variety of circuit components. Its main functions are to distribute electrical energy, provide safety protection and perform status monitoring.

[0009] Transfer case: A transfer case is a power distribution device used in amphibious vehicles or water power equipment. It can selectively or simultaneously distribute engine power to different output components such as propellers and drive wheels through gears, clutches and other components to achieve power transmission in different driving conditions on water and land.

[0010] ACC: The vehicle's ACC gear is a gear position of the car's ignition switch. In this gear position, some of the vehicle's electrical equipment such as the radio, cigarette lighter, etc. can be powered on, but the engine and main power system are in an unstarted state.

[0011] VCU: VCU stands for Vehicle Control Unit, which is the core control component of electric vehicles or hybrid vehicles. It collects signals from various vehicle sensors and accurately controls the power distribution, energy management, safety monitoring and coordinated operation of various components based on preset algorithms to ensure efficient, stable and safe operation of the vehicle.

[0012] A multi-mode adaptive start-stop control method for an amphibious vehicle range extension system, the method comprising: Switch to the corresponding working mode according to the driving environment of the vehicle, and the range-extending system adaptively adjusts to the power generation condition or the stop condition according to the different working modes; The start-stop control of the range extender system includes a range extender start module and a range extender stop module, wherein in the range extender start module, when the fault level judgment module judges that there is no major fault in each component that affects the driving function of the whole vehicle, the high voltage power-on is completed, the whole vehicle sends an engine start request signal and there is no engine stop command, the engine start module can be entered; The engine starting module is divided into starter emergency starting mode and ISG reverse engine starting mode; the difference between the two mainly lies in whether the driver presses the emergency starting switch. When the driver presses the emergency starting switch, the starter emergency starting mode is entered, and when the emergency starting switch is turned off and the fault level judgment module outputs a signal allowing the ISG reverse starting engine, the ISG reverse engine starting mode can be entered only when the battery normally supplies power to the ISG.

[0013] As a further technical solution of the present invention, in the step of switching to a corresponding working mode according to the driving environment of the vehicle, the range extender system adaptively adjusts to a power generation condition or a stop condition according to different working modes: The working modes include land working mode, water working mode and beaching mode: After the vehicle's ACC gear is turned on, it will enter the state selection stage; when the land working mode switch is activated, the vehicle will enter the land working mode; if the vehicle is about to enter the water, the up and down beach mode switch should be activated, and the vehicle will switch from the land working mode to the up and down beach mode; after the vehicle successfully enters the water surface, the water working mode switch is activated again, and the vehicle will switch to the water working mode; these three main working modes can be further subdivided according to the status of each component. According to the differences in each driving condition and driving needs, the range extender will adapt to each working mode to enter the power generation condition or the shutdown condition.

[0014] As a further technical solution of the present invention, the onshore working mode can be divided into parking charging mode, energy recovery mode, silent driving mode, pure electric driving mode, pure oil navigation mode, power generation driving mode and hybrid driving mode; among which the parking charging mode, pure oil navigation mode, power generation driving mode and hybrid driving mode require the range extender to start and enter the power generation condition, and after the whole vehicle working mode is judged, a start command will be output to the range extender system: If the vehicle power demand is 0 and the vehicle speed is less than the parking setting speed, the SOC will be judged. When the battery SOC is less than the set value, the vehicle will enter the parking charging mode; If the vehicle's required power is not 0 and the vehicle speed is greater than the set speed, the required power will be judged; if the engine's maximum power is greater than the vehicle's required power, it will be judged whether the battery SOC is greater than the set SOC. If it is greater, the vehicle enters the pure oil cruising mode; if it is less than, the vehicle enters the power generation driving mode; if the engine's maximum power is less than the vehicle's required power, the vehicle enters the hybrid driving mode.

[0015] As a further technical solution of the present invention, water working mode: when the vehicle enters the water working mode, the system will first detect the switch of the silent mode. If the switch is turned on and the battery SOC is less than the set value, it will determine whether the hybrid mode switch is turned on together with the situation that the pure electric silent switch is not turned on; If the hybrid mode switch is on, continue to determine whether the battery SOC is greater than the set value; if it is greater than the set value, the vehicle enters the hybrid mode; if it is less than the set value, determine the required power and the maximum power of the engine together with the case where the hybrid mode switch is not on; If the maximum engine power is greater than the required power, the battery SOC is further determined to be greater than the set value. If it is less than the set value, the vehicle enters the power generation navigation mode; if it is greater than the set value, the vehicle enters the pure oil navigation mode; If the maximum engine power is less than the required power, the vehicle enters hybrid cruising mode; Among them, in the power generation navigation mode, pure oil navigation mode, and hybrid navigation mode, the range extender will adaptively start according to the requirements of the working mode.

[0016] As a further technical solution of the present invention, the up-and-down beach mode: when the vehicle selects the up-and-down beach mode, the system will evaluate whether the maximum output power of the engine is greater than the required power of the whole vehicle. If the engine output power is greater than the required power, the vehicle enters the pure oil beach mode; otherwise, the vehicle enters the hybrid beach mode; in both modes, the range extender start signal will be output to keep the range extender in operation.

[0017] As a further technical solution of the present invention, the starter emergency start mode: after entering the starter emergency start mode, the VCU requests the ISG to enter the idle speed. When the key is turned to the Start gear, the VCU outputs a start request switch signal to the ECU to control the starter relay to engage, and the engine starts, using speed control; then the VCU controls the ISG speed and engine synchronization. When the difference between the ISG speed and the engine speed is within the calibrated range, the VCU outputs a signal to the hydraulic controller to control the clutch to engage; after the clutch confirms engagement, the ISG is adjusted to the active discharge mode and no longer receives speed control instructions.

[0018] As a further technical solution of the present invention, ISG reverse drag engine starting mode: after entering the ISG reverse drag engine starting mode, first the VCU requests the ISG motor torque mode output and enters the low speed state; when the difference between the ISG speed and the engine speed is within the calibrated range, the VCU outputs a signal to the hydraulic controller to control the clutch to engage; based on the fluctuation of the ISG torque, it is determined whether the ISG is engaged, and when the clutch confirms the engagement, the ISG speed automatically and gradually increases to drag the engine into the idle speed; when the engine speed reaches the starting speed condition, the engine starts, and speed control is used to switch the ISG motor from the driving mode to the power generation mode.

[0019] As a further technical solution of the present invention, in the range extender shutdown module, when the oil level is lower than the minimum oil level threshold, the vehicle is in a parking charging state, the vehicle Ready signal is 0, or the driving component has a major fault that affects the vehicle's driving function, the vehicle will send an engine shutdown request signal; if the engine start request signal is 0 or the engine shutdown request signal is 1, then the range extender will enter the shutdown module at this time; After entering the shutdown module, the VCU will output the ISG clutch disconnection signal. When the clutch is confirmed to be disconnected, the VCU requests the ISG to enter the driving mode to supply power to the battery, and the battery supplies power to the accessory system, and requests the engine to be shut down; When the range extender is shut down, it will re-enter the initialization state.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present invention designs a multi-mode adaptive start-stop control method for the range-extending system in view of the complex driving environment of amphibious vehicles. Compared with the existing technology, the present invention can switch to the corresponding optimal working mode according to the driving environment of the vehicle, so that the range-extending system can be adaptively adjusted to the power generation condition or the stop condition according to the different working modes, so as to meet the driver's task requirements while more fully coordinating the operating status of each component and improving the energy output efficiency. At the same time, the starting condition of the range-extending system is optimized, and the ISG reverse engine starting mode is designed, so that the range-extending system starts and responds faster during the starting process, and has lower fuel consumption and emissions. At the same time, the mode of starting the engine with the starter is retained to deal with emergencies, which improves the stability and reliability of the overall system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention.

[0022] Figure 1 This is a schematic diagram of the structure of an amphibious heavy-duty hybrid vehicle.

[0023] Figure 2 The framework diagram of the start-stop control method for the multi-mode adaptive amphibious vehicle range-extending system.

[0024] Figure 3 This is the logic framework diagram for the output of the start signal of the range extender in the land working mode.

[0025] Figure 4 This is the logic framework diagram for the output of the start signal of the range extender in the water working mode.

[0026] Figure 5 This is the logic framework diagram of the output of the range extender start signal for the up-and-down beach mode.

[0027] Figure 6 This is the start-stop flow chart of the range extender.

[0028] Figure 7 This is the flow chart of the starter emergency start mode.

[0029] Figure 8 This is the flow chart of the ISG reverse engine start mode. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] like Figure 1 The figure shows a schematic diagram of the structure of an amphibious heavy-duty hybrid vehicle. Its main components include an engine, a clutch, an ISG motor, a high-voltage distribution box, a power battery, a drive motor, a hub motor, a transfer case, a wet clutch, a spray pump, etc. As the power module of the whole vehicle, the range extender, its control system needs to respond to the vehicle command in real time to switch modes and give feedback. The multi-mode adaptive start-stop control method of the amphibious vehicle range extender system designed for an amphibious heavy-duty hybrid vehicle of the present invention can adaptively switch to different vehicle working modes according to the driving conditions, and judge whether the range extender needs to participate in the work, and adjust the range extender to the corresponding working conditions in combination with the driver's operation information.

[0032] See also Figure 2 The embodiment of the present invention provides a multi-mode adaptive start-stop control method for an amphibious vehicle range extension system, the method comprising: Switch to the corresponding working mode according to the driving environment of the vehicle, and the range-extending system adaptively adjusts to the power generation condition or the stop condition according to the different working modes; The start-stop control of the range extender system includes a range extender start module and a range extender stop module, wherein in the range extender start module, when the fault level judgment module judges that there is no major fault in each component that affects the driving function of the whole vehicle, the high voltage power-on is completed, the whole vehicle sends an engine start request signal and there is no engine stop command, the engine start module can be entered; See also Figure 6 The engine start module is divided into a starter emergency start mode and an ISG reverse engine start mode; the difference between the two lies mainly in whether the driver presses the emergency start switch. When the driver presses the emergency start switch, the starter emergency start mode is entered, and when the emergency start switch is turned off and the fault level judgment module outputs a signal allowing the ISG reverse start engine, the ISG reverse engine start mode can be entered only when the battery normally supplies power to the ISG.

[0033] In this embodiment, the step of switching to a corresponding working mode according to the driving environment of the vehicle, and the range-extending system adaptively adjusting to a power generation condition or a stop condition according to different working modes: The working modes include land working mode, water working mode and beaching mode: After the vehicle's ACC gear is turned on, it will enter the state selection stage; when the land working mode switch is activated, the vehicle will enter the land working mode; if the vehicle is about to enter the water, the up and down beach mode switch should be activated, and the vehicle will switch from the land working mode to the up and down beach mode; after the vehicle successfully enters the water surface, the water working mode switch is activated again, and the vehicle will switch to the water working mode; these three main working modes can be further subdivided according to the status of each component. According to the differences in each driving condition and driving needs, the range extender will adapt to each working mode to enter the power generation condition or the shutdown condition.

[0034] See also Figure 3 In this embodiment, the onshore working mode can be divided into parking charging mode, energy recovery mode, silent driving mode, pure electric driving mode, pure oil navigation mode, power generation driving mode and hybrid driving mode; among which the parking charging mode, pure oil navigation mode, power generation driving mode and hybrid driving mode require the range extender to start and enter the power generation condition. After the whole vehicle working mode is judged, a start command will be output to the range extender system: If the vehicle power demand is 0 and the vehicle speed is less than the parking setting speed, the SOC will be judged. When the battery SOC is less than the set value, the vehicle will enter the parking charging mode; If the vehicle's required power is not 0 and the vehicle speed is greater than the set speed, the required power will be judged; if the engine's maximum power is greater than the vehicle's required power, it will be judged whether the battery SOC is greater than the set SOC. If it is greater, the vehicle enters the pure oil cruising mode; if it is less than, the vehicle enters the power generation driving mode; if the engine's maximum power is less than the vehicle's required power, the vehicle enters the hybrid driving mode.

[0035] See also Figure 4 In this embodiment, the water working mode: when the vehicle enters the water working mode, the system will first detect the switch of the silent mode. If the switch is turned on and the battery SOC is less than the set value, it will determine whether the hybrid mode switch is turned on together with the situation that the pure electric silent switch is not turned on; If the hybrid mode switch is on, continue to determine whether the battery SOC is greater than the set value; if it is greater than the set value, the vehicle enters the hybrid mode; if it is less than the set value, determine the required power and the maximum power of the engine together with the case where the hybrid mode switch is not on; If the maximum engine power is greater than the required power, the battery SOC is further determined to be greater than the set value. If it is less than the set value, the vehicle enters the power generation navigation mode; if it is greater than the set value, the vehicle enters the pure oil navigation mode; If the maximum engine power is less than the required power, the vehicle enters hybrid cruising mode; Among them, in the power generation navigation mode, pure oil navigation mode, and hybrid navigation mode, the range extender will adaptively start according to the requirements of the working mode.

[0036] See also Figure 5 In this embodiment, the up-and-down beach mode: when the vehicle selects the up-and-down beach mode, the system will evaluate whether the maximum output power of the engine is greater than the required power of the whole vehicle. If the engine output power is greater than the required power of the whole vehicle, the vehicle enters the pure oil beach mode; otherwise, the vehicle enters the hybrid beach mode; in both modes, the range extender start signal will be output to keep the range extender in operation.

[0037] See also Figure 7 In this embodiment, the starter emergency start mode: after entering the starter emergency start mode, the VCU requests the ISG to enter the idle speed. When the key is turned to the Start gear, the VCU outputs a start request switch signal to the ECU to control the starter relay to engage, and the engine starts, using speed control; then the VCU controls the ISG speed and engine synchronization. When the difference between the ISG speed and the engine speed is within the calibrated range, the VCU outputs a signal to the hydraulic controller to control the clutch to engage; after the clutch confirms engagement, the ISG is adjusted to the active discharge mode and no longer receives speed control instructions.

[0038] See also Figure 8 In this embodiment, the ISG reverse-drag engine start mode: after entering the ISG reverse-drag engine start mode, the VCU first requests the ISG motor torque mode output and enters the low-speed state, and the speed is controlled to be about 300 revolutions per minute; when the difference between the ISG speed and the engine speed is within the calibrated range, the VCU outputs a signal to the hydraulic controller to control the clutch to engage; based on the fluctuation of the ISG torque, it is determined whether the ISG is engaged. When the clutch confirms the engagement, the ISG speed automatically and gradually increases to drag the engine into the idle speed, about 700 revolutions per minute; when the engine speed reaches the starting speed condition, the engine starts, and speed control is used to switch the ISG motor from the driving mode to the power generation mode.

[0039] As a further technical solution of the present invention, in the range extender shutdown module, when the oil level is lower than the minimum oil level threshold, the vehicle is in a parking charging state, the vehicle Ready signal is 0, or the driving component has a major fault that affects the vehicle's driving function, the vehicle will send an engine shutdown request signal; if the engine start request signal is 0 or the engine shutdown request signal is 1, then the range extender will enter the shutdown module at this time; After entering the shutdown module, the VCU will output the ISG clutch disconnection signal. When the clutch is confirmed to be disconnected, the VCU requests the ISG to enter the driving mode to supply power to the battery, and the battery supplies power to the accessory system, and requests the engine to be shut down; When the range extender is shut down, it will re-enter the initialization state.

[0040] It should be noted that, in this article, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0041] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A multi-mode adaptive start-stop control method for an amphibious vehicle range-extending system, characterized in that: The method comprises: Switch to the corresponding working mode according to the driving environment of the vehicle, and the range-extending system adaptively adjusts to the power generation condition or the stop condition according to the different working modes; The start-stop control of the range extender system includes a range extender start module and a range extender stop module, wherein in the range extender start module, when the fault level judgment module judges that there is no major fault in each component that affects the driving function of the whole vehicle, the high voltage power-on is completed, the whole vehicle sends an engine start request signal and there is no engine stop command, the engine start module can be entered; The engine starting module is divided into starter emergency starting mode and ISG reverse engine starting mode; the difference between the two mainly lies in whether the driver presses the emergency starting switch. When the driver presses the emergency starting switch, the starter emergency starting mode is entered, and when the emergency starting switch is turned off and the fault level judgment module outputs a signal allowing the ISG reverse starting engine, the ISG reverse engine starting mode can be entered only when the battery normally supplies power to the ISG.

2. A multi-mode adaptive start-stop control method for an amphibious vehicle range-extending system according to claim 1, characterized in that: The step of switching to a corresponding working mode according to the driving environment of the vehicle, and the range-extending system adaptively adjusting to a power generation condition or a stop condition according to different working modes: The working modes include land working mode, water working mode and beaching mode: After the vehicle's ACC gear is turned on, it will enter the state selection stage; when the land working mode switch is activated, the vehicle will enter the land working mode; if the vehicle is about to enter the water, the up and down beach mode switch should be activated, and the vehicle will switch from the land working mode to the up and down beach mode; after the vehicle successfully enters the water surface, the water working mode switch is activated again, and the vehicle will switch to the water working mode; these three working modes are further subdivided according to the status of each component. According to the differences in each driving condition and driving needs, the range extender will adapt to each working mode to enter the power generation condition or the shutdown condition.

3. A multi-mode adaptive start-stop control method for an amphibious vehicle range-extending system according to claim 2, characterized in that: The onshore working modes are divided into parking charging mode, energy recovery mode, silent driving mode, pure electric driving mode, pure oil navigation mode, power generation driving mode and hybrid driving mode; among which the parking charging mode, pure oil navigation mode, power generation driving mode and hybrid driving mode require the range extender to start and enter the power generation condition. After the whole vehicle working mode is judged, a start command will be output to the range extender system: If the vehicle power demand is 0 and the vehicle speed is less than the parking setting speed, the SOC will be judged. When the battery SOC is less than the set value, the vehicle will enter the parking charging mode; If the vehicle's required power is not 0 and the vehicle speed is greater than the set speed, the required power will be judged; if the engine's maximum power is greater than the vehicle's required power, it will be judged whether the battery SOC is greater than the set SOC. If it is greater, the vehicle enters the pure oil cruising mode; if it is less than, the vehicle enters the power generation driving mode; if the engine's maximum power is less than the vehicle's required power, the vehicle enters the hybrid driving mode.

4. A multi-mode adaptive start-stop control method for an amphibious vehicle range-extending system according to claim 2, characterized in that: Water working mode: When the vehicle enters the water working mode, the system will first detect the switch of the silent mode. If the switch is turned on and the battery SOC is less than the set value, it will determine whether the hybrid mode switch is turned on together with the situation that the pure electric silent switch is not turned on; If the hybrid mode switch is on, continue to determine whether the battery SOC is greater than the set value; if it is greater than the set value, the vehicle enters the hybrid mode; if it is less than the set value, determine the required power and the maximum power of the engine together with the case where the hybrid mode switch is not on; If the maximum engine power is greater than the required power, the battery SOC is further determined to be greater than the set value. If it is less than the set value, the vehicle enters the power generation navigation mode; if it is greater than the set value, the vehicle enters the pure oil navigation mode; If the maximum engine power is less than the required power, the vehicle enters hybrid cruising mode; Among them, in the power generation navigation mode, pure oil navigation mode, and hybrid navigation mode, the range extender will adaptively start according to the requirements of the working mode.

5. A multi-mode adaptive start-stop control method for an amphibious vehicle range-extending system according to claim 4, characterized in that: Up and down beach mode: When the vehicle selects the up and down beach mode, the system will evaluate whether the maximum output power of the engine is greater than the required power of the vehicle. If the engine output power is greater than the required power of the vehicle, the vehicle enters the pure oil beach mode; otherwise, the vehicle enters the hybrid beach mode; in both modes, the range extender start signal will be output to keep the range extender in operation.

6. A multi-mode adaptive start-stop control method for an amphibious vehicle range-extending system according to claim 1, characterized in that: Starter emergency start mode: After entering the starter emergency start mode, the VCU requests the ISG to enter the idle speed. When the key is turned to the Start gear, the VCU outputs a start request switch signal to the ECU to control the starter relay to engage, and the engine starts, using speed control; then the VCU controls the ISG speed and engine synchronization. When the difference between the ISG speed and the engine speed is within the calibrated range, the VCU outputs a signal to the hydraulic controller to control the clutch to engage; after the clutch confirms engagement, the ISG is adjusted to active discharge mode and no longer receives speed control commands.

7. A multi-mode adaptive start-stop control method for an amphibious vehicle range-extending system according to claim 1, characterized in that: ISG reverse-drag engine start mode: After entering the ISG reverse-drag engine start mode, the VCU first requests the ISG motor torque mode output and enters the low-speed state; when the difference between the ISG speed and the engine speed is within the calibrated range, the VCU outputs a signal to the hydraulic controller to control the clutch engagement; the ISG is judged whether it is engaged based on the fluctuation of the ISG torque, and when the clutch is confirmed to be engaged, the ISG speed automatically increases step by step to drag the engine into the idle speed; when the engine speed reaches the starting speed condition, the engine starts, and speed control is used to switch the ISG motor from drive mode to power generation mode.

8. The multi-mode adaptive start-stop control method of an amphibious vehicle range-extending system according to claim 1, characterized in that: In the range extender shutdown module, when the fuel level is lower than the minimum fuel level threshold, the vehicle is in the parking charging state, the vehicle Ready signal is 0, or the driving component has a major fault that affects the normal driving function of the vehicle, the vehicle will send a request engine shutdown signal; if the engine start request signal is 0 or the engine shutdown request signal is 1, then the range extender will enter the shutdown module; After entering the shutdown module, the VCU will output the ISG clutch disconnection signal. When the clutch is confirmed to be disconnected, the VCU requests the ISG to enter the driving mode to supply power to the battery, and the battery supplies power to the accessory system, and requests the engine to be shut down; When the range extender is shut down, it will re-enter the initialization state.

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