Low soc parking smooth control method and device

Abstract

The application relates to a low-SOC parking smooth control method and device, wherein the method comprises the following steps: when the parking mode of a vehicle is a low-SOC parking working condition, according to driving information, performing parking scene grading power consumption control and short-time discharge rate optimization strategy, and outputting a control instruction, so as to fundamentally avoid torque fluctuation, jerk and noise problems caused by engine start-stop during vehicle movement; according to the control instruction, controlling the parking process of the vehicle, and checking the battery state of the vehicle in the parking process to obtain checking driving information; when the checking driving information meets a trigger condition, controlling the vehicle to start a three-fold locking static power generation control process, and monitoring the battery state of the vehicle during the starting process to obtain monitoring driving information; when the monitoring driving information meets a normal condition, completing a remaining parking process, and outputting parking completion data; and the jerk and the risk of hill-starting caused by torque fluctuation transmission to the wheels during the engine start-stop process are eliminated.

Description

Technical Field

[0001] This invention relates to the field of hybrid vehicle control technology, and in particular to a low SOC parking smooth control method and device. Background Technology

[0002] Hybrid vehicles combine a traditional internal combustion engine and an electric motor as their power sources. Compared to traditional gasoline vehicles, they significantly improve fuel economy and reduce emissions; compared to pure electric vehicles, they eliminate concerns about range. Hybrid technology is not simply a "transitional solution," but rather one of the mainstream technological routes that will develop in parallel with pure electric technology for a long time.

[0003] Existing low SOC energy management strategies for hybrid electric vehicles are all developed for driving conditions and are not adapted to the low-speed, intermittent, short-duration high-torque characteristics of parking. Directly applying these strategies can easily lead to frequent engine start-stop and torque surges, resulting in severe jerking during parking and deterioration of NVH performance. Although existing technologies optimize the parking process through parking smoothness optimization schemes, these schemes only optimize motor torque filtering and do not address the root cause of engine start-stop under low SOC conditions. Engine start-stop during vehicle movement also poses a safety hazard of rolling backward. There is currently no dedicated low SOC smoothness control scheme in the industry for the entire parking process.

[0004] Therefore, there is an urgent need to propose a low SOC parking smoothness control method and device to solve the technical problems of frequent engine start-stop, torque sudden change causing jerking, noise and risk of rolling backward during parking in the existing parking smoothness optimization schemes. Summary of the Invention

[0005] In view of this, it is necessary to provide a low SOC parking smoothness control method and device to solve the technical problems of frequent engine start-stop, torque change-induced jerking, noise and slippage risk during parking in the existing parking smoothness optimization schemes that fail to address the issues in the low SOC parking process.

[0006] To address the aforementioned problems, in a first aspect, the present invention provides a low SOC parking smoothness control method, comprising: Acquire vehicle driving information and determine parking mode based on the driving information; the driving information includes BMS discharge capability boundary; When the parking mode is a low SOC parking condition, the parking scenario graded power consumption control and short-time discharge rate optimization strategy are executed according to the driving information, and control commands are output; the parking scenario graded power consumption control is to perform graded control on the control object through a three-level power consumption graded control strategy with fixed priority; the short-time discharge rate optimization strategy is to increase the upper limit of the discharge rate of the power battery within a preset time within the BMS discharge capacity boundary; The parking process of the vehicle is controlled according to the control command, and the battery status of the vehicle during the parking process is verified to obtain the verification driving information. When the verified driving information meets the triggering conditions, the vehicle is controlled to start the triple-locked static power generation control process, and the battery status of the vehicle is monitored during the start-up process to obtain the monitored driving information; the triple-locked static power generation control process is a process of controlling the vehicle to start and run under the constraints of a completely stationary state, a parked pause state, and a fixed parking brake lock. When the monitored driving information meets the normal conditions, the remaining parking process is completed and parking completion data is output.

[0007] In one possible implementation, the driving information includes a parking mode activation signal, vehicle speed, gear position signal, and battery SOC; determining the parking mode based on the driving information includes: When the parking mode activation signal determines that the vehicle is in parking mode, the vehicle speed is lower than the preset speed, and the gear signal is forward or reverse, the vehicle is determined to be in a valid parking condition. After entering the effective parking condition, it is determined whether the SOC of the power battery is greater than or equal to the preset SOC; If so, then the parking mode is determined to be a normal parking condition; If not, then the parking mode is determined to be a low SOC parking condition.

[0008] In one possible implementation, the driving information further includes the parking space type; the step of executing a parking scenario-based graded power consumption management and short-term discharge rate optimization strategy based on the driving information, and outputting control commands, includes: Select a standard parking time corresponding to the parking space type from a plurality of preset standard parking times. The plurality of preset standard parking times correspond one-to-one with a plurality of parking space types, including perpendicular parking spaces, parallel parking spaces and angled parking spaces. The standard parking duration is determined based on the parking space type. Based on the driving information and the standard parking duration, a parking-specific power consumption threshold is obtained; the parking-specific power consumption threshold includes the total power consumption budget threshold for the entire parking process, the minimum required discharge capacity of the power battery, and the safe voltage threshold for the low-voltage system; Based on the parking-specific power consumption threshold, the parking scenario-based tiered power consumption control and short-term discharge rate optimization strategy is executed, and control commands are output. The control commands include a three-level power consumption control execution command, a battery discharge rate adjustment command, a pure electric drive enable signal for the drive motor, and an absolute prohibition command for engine starting while the vehicle is moving.

[0009] In one possible implementation, the driving information further includes low-voltage battery voltage, parking core system power consumption, drive creep power consumption, and low-voltage safety system basic power consumption; the step of obtaining a parking-specific power consumption threshold based on the driving information and the standard parking duration includes: The total power consumption budget threshold for the entire parking process is obtained by superimposing the product of the power consumption of the parking core system and the standard parking time, the product of the power consumption of the drive creeping system and the creeping duty cycle and the standard parking time, and the product of the basic power consumption of the low-voltage safety system and the standard parking time. Divide the total power consumption budget threshold of the full parking process by the nominal voltage of the power battery, and then divide by the parking-specific discharge efficiency to obtain the minimum required discharge capacity of the power battery. The low-voltage system safety voltage threshold is determined based on the low-voltage battery voltage and the standard parking duration.

[0010] In one possible implementation, the verification driving information includes the power battery SOC, cell voltage, low-voltage battery voltage, remaining parking time, parking system average power, and current maximum output capacity of the battery. The verification driving information meets the triggering conditions, including a first condition and a second condition. The first condition is that the power battery SOC is less than or equal to the critical safety threshold, and / or the power battery cell voltage is lower than the discharge cutoff warning value, and / or the low-voltage battery voltage is lower than the safe operating threshold. The second condition is that the total power consumption required for the parking process is greater than the current maximum output capacity of the battery. The total power consumption required for the parking process is calculated based on the remaining parking time and the parking system average power.

[0011] In one possible implementation, the triple-locked static power generation control process includes: A parking pause command is sent to the parking system of the vehicle, so that the parking system stops path planning and vehicle movement control according to the parking pause command, controls the vehicle to enter a completely stationary state, and returns a parking process pause signal and an absolute stationary confirmation signal; when the parking process pause signal and the absolute stationary confirmation signal returned by the parking system are received, it is determined that the first level of control is completed and the second level of control is entered; In the second level of control, a four-wheel brake lock command is sent to the vehicle's electronic stability control system, so that the electronic stability control system controls the four wheels of the vehicle to perform fixed parking brake lock according to the four-wheel brake lock command. When the vehicle's braking force reaches the preset anti-rollover threshold, a four-wheel brake lock completion signal and a braking force attainment confirmation signal are returned. When the four-wheel brake lock completion signal and braking force attainment confirmation signal are received from the electronic stability control system, the third level of control is entered. After receiving the absolute stationary confirmation signal, the four-wheel brake lock completion signal, and the parking process pause signal from the vehicle in the third level of control, an engine start command is sent to the vehicle's engine management system. This allows the engine management system to control the engine to start and enter a fixed idle speed power generation mode. Under this mode, the engine's power generation capacity is adjusted. When the power generation capacity meets the core power consumption requirements of the parking system, excess power is used to replenish the power battery and low-voltage battery.

[0012] In one possible implementation, the monitored driving information meets the normal conditions as follows: the SOC of the power battery recovers to a safe threshold, the voltage of the low-voltage battery is within the normal operating range, and the maximum output capacity of the current battery is sufficient to meet the pure electric drive power requirements for the remaining parking process.

[0013] In one possible implementation, completing the remaining parking process and outputting parking completion data includes: Control the engine to stop according to the engine stop command; When the engine is completely stopped and there is no torque output, the brake lock is released according to the brake lock release command; When the brake lock is fully released, a parking recovery command is sent to the parking system; The parking system is controlled to continue completing the remaining parking process according to the parking resumption command, and parking completion data is output after parking is completed.

[0014] In one possible implementation, the parking completion data includes a parking completion signal, a parking P gear signal, an electronic parking brake activation signal, and a vehicle power status signal; after completing the remaining parking process and outputting the parking completion data, it also includes: When the parking completion signal is received, the vehicle is determined to be in Park (P) gear based on the Parking P gear signal, and the electronic parking brake is determined to be normally activated based on the electronic parking brake activation signal, a graded reset is performed based on the graded power consumption management of the parking scenario to control the normal operation of the vehicle.

[0015] Secondly, the present invention also provides a low SOC parking smoothness control device, comprising: An information acquisition module is used to acquire vehicle driving information and determine parking mode based on the driving information; the driving information includes BMS discharge capability boundaries; The instruction output module is used to execute a parking scenario-based graded power consumption control and short-term discharge rate optimization strategy based on the driving information when the parking mode is a low SOC parking condition, and output control instructions; the parking scenario-based graded power consumption control is to perform graded control on the controlled object through a three-level power consumption graded control strategy with fixed priority; the short-term discharge rate optimization strategy is to increase the upper limit of the power battery discharge rate within a preset time within the BMS discharge capacity boundary; The parking control module is used to control the parking process of the vehicle according to the control command, and to verify the battery status of the vehicle during the parking process to obtain verification driving information. The closed-loop monitoring module is used to control the vehicle to start the triple-locked static power generation control process when the verified driving information meets the triggering conditions, and to monitor the battery status of the vehicle during the start-up process to obtain the monitored driving information; the triple-locked static power generation control process is a process of controlling the vehicle to start and run under the constraints of a completely stationary state, a parking pause state, and a fixed parking brake lock. The parking completion module is used to complete the remaining parking process and output parking completion data when the monitored driving information meets the normal conditions.

[0016] The beneficial effects of this invention are: acquiring vehicle driving information and determining the parking mode based on the driving information; the driving information includes the BMS discharge capacity boundary; when the parking mode is a low SOC parking condition, the invention executes a parking scenario-based graded power consumption control and short-term discharge rate optimization strategy based on the driving information, and outputs control commands; the parking scenario-based graded power consumption control is to perform graded control of the controlled object through a three-level power consumption graded control strategy with fixed priority; the short-term discharge rate optimization strategy is to increase the upper limit of the power battery discharge rate within a preset time within the BMS discharge capacity boundary to meet short-term creep requirements, thereby fundamentally avoiding the torque fluctuation problem caused by engine start-stop during vehicle movement; and according to the control commands... The system controls the vehicle's parking process and verifies the battery status during parking to obtain verified driving information. When the verified driving information meets the trigger conditions, the system initiates a triple-locked static power generation control process, monitoring the vehicle's battery status during startup to obtain monitored driving information. The triple-locked static power generation control process controls the vehicle's startup and operation under the constraints of a completely stationary state, a parked pause state, and a fixed parking brake lock. This process strictly controls engine start-stop, eliminating the jerking problem caused by torque fluctuations during engine start-stop, and locking the wheels through brake lock to prevent the risk of rolling backward. Attached Figure Description

[0017] Figure 1A schematic flowchart of an embodiment of the low SOC parking smoothness control method provided by the present invention; Figure 2 For the present invention Figure 1 A schematic diagram of an embodiment of step S102; Figure 3 For the present invention Figure 2 A schematic flowchart of an embodiment of step S203; Figure 4 This is a schematic diagram of an embodiment of the low SOC parking smoothness control device provided by the present invention. Detailed Implementation

[0018] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0019] like Figure 1 As shown, a specific embodiment of the present invention discloses a low SOC parking smoothness control method, comprising: S101. Obtain vehicle driving information and determine parking mode based on driving information; driving information includes BMS discharge capability boundary.

[0020] This invention can be applied to vehicles, which can be equipped with a Vehicle Control Unit (VCU). The VCU can collect vehicle driving information in real time at a 10ms cycle through the vehicle's CAN network. This driving information can include signals such as parking mode activation signal, vehicle speed, gear position signal, power battery SOC, cell voltage, low-voltage battery voltage, parking space type, parking core system power consumption, drive creep power consumption, low-voltage safety system basic power consumption, and BMS discharge capacity boundary. The various signals in the driving information can be analyzed, and the parking mode can be determined based on the analysis results.

[0021] S102. When the parking mode is a low SOC parking condition, the parking scenario graded power consumption control and short-time discharge rate optimization strategy are executed according to the driving information, and control commands are output. The parking scenario graded power consumption control is to perform graded control on the controlled object through a three-level power consumption graded control strategy with fixed priority. The short-time discharge rate optimization strategy is to increase the upper limit of the power battery discharge rate within the BMS discharge capacity boundary within a preset time.

[0022] In this embodiment of the invention, the low SOC parking condition refers to the condition where the power battery SOC is at a low level after the vehicle enters an effective parking space. The parking scenario-based tiered power consumption control method can manage power consumption according to the three levels set for the parking scenario. The short-time discharge rate optimization strategy is a strategy that increases the upper limit of the power battery's discharge rate within a preset time during intermittent discharge. The preset time can be relatively short, thus increasing the upper limit of the power battery's discharge rate in a short period. Therefore, when the parking mode is a low SOC parking condition, the tiered power consumption control and short-time discharge rate optimization strategy are executed based on driving information, and control commands are output. The core objective of this step is to maximize the pure electric drive throughout the parking process, while simultaneously outputting an absolute prohibition command for engine starting during vehicle movement, eliminating the smoothness and safety issues caused by engine start-stop from the root. This step in this embodiment of the invention is the core execution link for low SOC parking. After entering the pure electric power preservation mode, the VCU sends a parking-specific short-time discharge rate increase command to the BMS, increasing the conventional discharge rate upper limit by 15% within the battery safety boundary. 20% to meet short-term creep requirements; on the other hand, a fixed priority three-level power consumption control is implemented. The control level is divided according to the degree of impact of the function on parking safety and availability. Only the current level is executed at any time, without skipping levels or going back.

[0023] S103. Control the parking process of the vehicle according to the control command, and verify the battery status of the vehicle during the parking process to obtain the verified driving information.

[0024] In this embodiment of the invention, the control commands may include multiple commands, such as an absolute prohibition command for engine start or stop, and a three-level power consumption control execution command. This allows for control of the vehicle's parking process based on the control commands. For example, the absolute prohibition command for engine start controls the vehicle's engine to execute a shutdown and locking process. Then, a real-time closed-loop verification of the vehicle's battery status during parking is performed according to a preset period to obtain the latest verified driving information. The preset period can be 10ms, but the specific period can be set according to actual conditions; this embodiment of the invention does not impose any limitations on it.

[0025] S104. When the driving information is verified to meet the triggering conditions, the vehicle is controlled to start the triple-locked static power generation control process, and the battery status of the vehicle is monitored during the start-up process to obtain the monitored driving information. The triple-locked static power generation control process is the process of controlling the vehicle to start and run under the constraints of a completely stationary state, a parked pause state, and a fixed parking brake lock.

[0026] In this embodiment of the invention, verifying driving information may include data of corresponding types from the driving information, such as parking mode activation signal, vehicle speed, gear signal, power battery SOC, cell voltage, low-voltage battery voltage, parking space type, parking core system power consumption, drive creep power consumption, low-voltage safety system basic power consumption, and BMS discharge capacity boundary signals. Only the acquisition time and signal data differ. This allows for the judgment of the information in the verified driving information to determine whether triggering conditions are met, such as judging the magnitude of the low-voltage battery voltage. Triggering conditions can be set according to actual conditions, and this embodiment of the invention does not impose any limitations. When the verified driving information meets the triggering conditions, the vehicle can be controlled to initiate a triple-locked static power generation control process. This triple-locked static power generation control process can be a fallback control process for triple-safety-locked static power generation in pure electric power-saving mode. This embodiment of the invention innovatively proposes a triple-locked static power generation control process, strictly limiting the engine to start and run only under the triple constraints of a completely stationary vehicle, a fixed parking brake lock, and a parked pause state, completely solving the problems of smoothness and safety risks associated with engine start-stop during vehicle movement in the prior art. During the initiation of the triple-locked static power generation control process, the vehicle's battery status is monitored in real time through a closed loop at a preset period to obtain monitoring driving information. The preset period can be 10ms.

[0027] S105. When the monitored driving information meets the normal conditions, complete the remaining parking process and output the parking completion data.

[0028] The low SOC parking smoothness control method provided in this application embodiment can be applied to a low SOC parking smoothness control system. The low SOC parking smoothness control can be a software system running on a terminal device, which can be a vehicle or other terminal device. This application embodiment does not impose any restrictions on the specific type of terminal device. Specifically, the low SOC parking smoothness control system of this invention uses the vehicle controller (VCU) as its core, with a built-in dedicated low SOC parking control unit. It coordinates with the battery management system (BMS), engine management system (EMS), electronic stability control system (ESC), intelligent driving domain controller (including APA / RPA parking system), body domain controller, and low-voltage battery management system, achieving real-time signal interaction and closed-loop command execution through the vehicle's CAN network. This invention embodiment sets up a dedicated low SOC parking control unit within the VCU, and all control decisions are uniformly output by this unit, avoiding logical conflicts in multi-controller collaboration. The architecture design strictly follows the "safety first" principle; engine start commands can only be output through the triple-locked static generator control module, eliminating the risk of accidental engine start during vehicle movement at the hardware link level.

[0029] In this embodiment of the invention, the monitored driving information may include data of corresponding types, such as parking mode activation signal, vehicle speed, gear position signal, power battery SOC, cell voltage, low-voltage battery voltage, parking space type, parking core system power consumption, drive creep power consumption, low-voltage safety system basic power consumption, and BMS discharge capacity boundary signals. The only difference is the acquisition time and the resulting signal data. This allows for the assessment of the monitored driving information to determine if normal conditions are met, such as the power battery SOC rising to the 12% safety threshold. Normal conditions can be set according to actual conditions, and this embodiment of the invention does not impose any limitations. When the monitored driving information meets normal conditions, it indicates that the vehicle has completed the triple safety lock-up static power generation fallback control process. From the current moment, the remaining parking process is controlled, and when the parking process is completed, the parking completion data for the current moment can be output. The parking completion data may include parking completion signal, parking P gear signal, electronic handbrake activation signal, vehicle power status signal, etc.

[0030] Compared with existing technologies, this embodiment provides the acquisition of vehicle driving information and determination of parking mode based on the driving information; the driving information includes the BMS discharge capacity boundary; when the parking mode is a low SOC parking condition, a parking scenario-based graded power consumption control and short-term discharge rate optimization strategy are executed based on the driving information, and control commands are output; the parking scenario-based graded power consumption control is to perform graded control of the controlled object through a three-level power consumption graded control strategy with fixed priority; the short-term discharge rate optimization strategy is to increase the upper limit of the power battery discharge rate within a preset time within the BMS discharge capacity boundary to meet the short-term creeping requirements, thereby fundamentally avoiding the torque fluctuation problem caused by engine start-stop during vehicle movement; according to the control... The control command controls the vehicle's parking process and verifies the battery status during parking to obtain verified driving information. When the verified driving information meets the triggering conditions, the control command initiates the triple-locked static power generation control process, and monitors the vehicle's battery status during the start-up process to obtain monitored driving information. The triple-locked static power generation control process controls the vehicle's start-up and operation under the constraints of a completely stationary state, a parking pause state, and a fixed parking brake lock. Thus, the triple-locked static power generation control process strictly controls the engine start-stop, eliminating the jerking problem caused by torque fluctuations transmitted to the wheels during engine start-stop, and locking the wheels through brake lock to prevent the risk of rolling backward.

[0031] In some embodiments of the present invention, driving information includes a parking mode activation signal, vehicle speed, gear position signal, and power battery SOC; step S101 includes: When the parking mode activation signal indicates that the vehicle is in parking mode, the vehicle speed is lower than the preset speed, and the gear signal is forward or reverse, the vehicle is confirmed to be in a valid parking condition.

[0032] In this embodiment of the invention, the vehicle control unit (VCU) acquires parking mode activation signals, vehicle speed signals, and gear signals in real time. The VCU determines that the vehicle has entered a valid parking condition when all three of the following conditions are simultaneously met: the parking mode activation signal indicates that the vehicle is in parking mode (e.g., the user presses a parking assist switch or the automatic parking system is activated); the vehicle speed is below a preset speed threshold, which is 3 km / h in this embodiment; and the gear signal is either drive (D) or reverse (R). For example, if a driver activates the automatic parking system in a parking lot, the vehicle speed drops to 2.5 km / h, and the gear is in drive (D), the VCU determines that the vehicle has entered a valid parking condition. If the above conditions are not met, it means the vehicle does not need to enter the parking process, and the vehicle continues to drive normally.

[0033] After entering the effective parking condition, determine whether the SOC of the power battery is greater than or equal to the preset SOC; If so, then the parking mode is set to normal parking condition; If not, then the parking mode is set to low SOC parking condition.

[0034] In this embodiment of the invention, after entering a valid parking condition, the VCU immediately reads the SOC of the power battery reported by the battery management system (BMS) and compares it with a preset SOC threshold. In this embodiment, the preset SOC is 15%. If the power battery SOC reported by the BMS is 20%, that is, the SOC is greater than or equal to the preset SOC, the VCU determines that the current parking mode is a normal parking condition. Under this condition, the VCU performs parking according to the normal hybrid strategy. If the power battery SOC reported by the BMS is 10%, that is, the SOC < the preset SOC (10% < 15%), the VCU determines that the current parking mode is a low SOC parking condition and initiates a parking-specific power consumption budget process.

[0035] In some embodiments of the present invention, the driving information also includes the parking space type; such as Figure 2 As shown, step S102 includes: S201. Select the standard parking duration corresponding to the parking space type from multiple preset standard parking durations. The multiple preset standard parking durations correspond one-to-one with multiple parking space types, including perpendicular parking spaces, parallel parking spaces, and angled parking spaces.

[0036] In this embodiment of the invention, multiple parking space types are set, which may include perpendicular parking spaces, parallel parking spaces, and angled parking spaces. The VCU matches a preset standard parking time according to the parking space type, wherein the time is 90s for perpendicular parking spaces, 180s for parallel parking spaces, and 120s for angled parking spaces.

[0037] S202. Determine the standard parking duration based on the type of parking space.

[0038] In this embodiment of the invention, the standard parking time corresponding to a parking space type can be determined by comparing the parking space type in the driving information with multiple parking space types.

[0039] S203. Based on driving information and standard parking duration, obtain parking-specific power consumption thresholds; parking-specific power consumption thresholds include the total power consumption budget threshold for the entire parking process, the minimum required discharge capacity of the power battery, and the safe voltage threshold for the low-voltage system.

[0040] In this embodiment of the invention, the information in the driving information can be multiplied by the standard parking time to obtain the corresponding threshold, which is the parking-specific power consumption threshold. The parking-specific power consumption threshold may include the total power consumption budget threshold of the entire parking process, the minimum required discharge capacity of the power battery, and the low-voltage system safety voltage threshold.

[0041] In some embodiments of the present invention, the driving information also includes low-voltage battery voltage, parking core system power consumption, drive creep power consumption, and low-voltage safety system basic power consumption; such as Figure 3 As shown, step S203 includes: S301. The total power consumption budget threshold for the entire parking process is obtained by superimposing the product of the power consumption of the parking core system and the standard parking time, the product of the power consumption of the drive creep and the creep duty cycle and the standard parking time, and the product of the basic power consumption of the low-voltage safety system and the standard parking time.

[0042] In this embodiment of the invention, it is assumed that a plug-in hybrid electric vehicle (PHEV) enters a parking scenario in an underground garage. The vehicle's vehicle control unit (VCU) obtains the low-voltage battery voltage from the battery management system (BMS) and reads the following data from a preset vehicle parameter table: Parking core system power consumption (including parking controller, ultrasonic radar, camera, etc.): P_core = 120W. Driving creep power consumption (average electric power of the motor during low-speed creep): P_creep = 800W. Low-voltage safety system basic power consumption (including basic standby power consumption of EPS electric power steering, ESC vehicle stability system, brake booster pump, etc.): P_safety = 60W. Standard parking duration (preset based on typical parking lot entry + exit time): T_park = 120s (i.e., 2 minutes). Creep duty cycle (the proportion of actual creep driving time to total time during parking, empirical value): D_creep = 0.3 (i.e., the vehicle is in creeping motion for 30% of the time, and stationary or shifting gears for the rest of the time). Nominal battery voltage: V_bat_nom = 350V (typical PHEV battery voltage). Parking-specific discharge efficiency (considering the combined efficiency of the motor controller, DC-DC converter, etc. under low-power parking conditions): η_discharge = 0.85. The product of the core parking system power consumption and the standard parking time is 120W × 120s = 14400J; the product of the drive creep power consumption, creep duty cycle, and standard parking time is 800W × 0.3 × 120s = 800 × 36 = 28800J; the product of the low-voltage safety system basic power consumption and the standard parking time is 60W × 120s = 7200J; therefore, the total power consumption budget threshold for the entire parking process = 14400 + 28800 + 7200 = 50400J.

[0043] S302. Divide the total power consumption budget threshold of the entire parking process by the nominal voltage of the power battery, and then divide by the parking-specific discharge efficiency to obtain the minimum required discharge capacity of the power battery.

[0044] In this embodiment of the invention, the nominal voltage of the power battery is the total voltage design value of the battery pack, which can be set according to actual conditions, for example, it can be 350V. The parking-specific discharge efficiency is a coefficient, usually less than 1, used to measure the energy loss during the process from battery discharge to the use of onboard electrical appliances. The minimum required discharge capacity of the power battery can be obtained by converting the total power consumption budget threshold for the entire parking process into watts, dividing the total power consumption budget threshold for the entire parking process by the nominal voltage of the power battery, and then dividing by the parking-specific discharge efficiency.

[0045] S303. Determine the safe voltage threshold for the low-voltage system based on the low-voltage battery voltage and standard parking duration.

[0046] In this embodiment of the invention, a safe voltage threshold for the low-voltage system is determined based on the low-voltage battery voltage and the standard parking duration. The purpose is to ensure that the low-voltage battery does not become depleted to the point of being unable to drive the core controller due to a DC-DC power interruption during the entire parking process. The state of health (SOH) of the low-voltage battery can be determined based on the low-voltage battery voltage. The SOH is a long-term degradation parameter, usually estimated by the battery management unit using an algorithm. However, in the short-term decision-making of this parking scenario, it can be simplified to: judging whether there is a risk of power depletion during the subsequent parking time based on the current real-time voltage of the low-voltage battery and a preset threshold model. The preset threshold model can be set according to actual conditions, and this embodiment of the invention does not impose any restrictions. The safe voltage threshold for the low-voltage system is set based on the low-voltage battery's health status and the standard parking duration: not lower than 12.0V for a 12V system and not lower than 23.5V for a 24V system. A value lower than this indicates a risk of power depletion.

[0047] The method proposed in this invention can precisely quantify the energy consumption composition during the parking process, providing reliable energy management and safety boundary judgment for hybrid vehicles in scenarios with low SOC and requiring long-term parking (such as automatic parking and remote parking).

[0048] S204. Execute a parking scenario-specific power consumption control and short-term discharge rate optimization strategy based on the parking-specific power consumption threshold, and output control commands. The control commands include a three-level power consumption control execution command, a battery discharge rate adjustment command, a pure electric drive enable signal for the drive motor, and an absolute prohibition command for starting the engine while the vehicle is moving.

[0049] In this embodiment of the invention, the power consumption management for parking scenarios employs a three-level power consumption classification strategy with fixed priority. The control levels are divided based on the degree of impact of the function on parking safety and availability. The first level is the core safety keep-alive level, which is mandatory throughout the entire process. The trigger condition is that it is mandatory to be active during all periods of low SOC parking. The controlled objects include the parking surround-view camera, ultrasonic radar, electric power steering, braking control system, vehicle controller, CAN communication, brake lights, gear position and speed sensors, etc. The control strategy is to supply power at full rated power without reducing power or shutting down, ensuring that parking functions and driving safety are not affected. The second level is the auxiliary function power reduction level, which is triggered immediately whenever low SOC parking (SOC < 15%) is entered. The controlled objects include the panoramic imaging screen, reversing auxiliary lights, air conditioning blower, instrument backlight, etc. The control strategy is to reduce the power to 30% of the rated power. Level 50% reduces power consumption while ensuring basic visibility and usability. Level 3 is the non-essential function complete shutdown level, which is also triggered immediately when parking at low SOC. The controlled objects include the secondary camera, ambient lighting, seat heating / ventilation, multimedia, wireless charging, exterior lights, and charging port lights, etc. The control strategy is to completely shut down the power to achieve zero power consumption. At the same time, the VCU outputs an absolute prohibition command for starting the engine while the vehicle is moving. As long as the vehicle speed is greater than 0, the engine remains locked and stopped, fundamentally avoiding the jerking and rolling caused by starting the engine while moving.

[0050] This step follows the output of the pre-judgment stage and is the core execution link for low SOC parking conditions. It innovatively proposes a graded power consumption control and short-term discharge rate optimization strategy specifically for parking scenarios. The core goal is to maximize the pure electric drive throughout the parking process, while outputting an absolute prohibition command for engine starting while the vehicle is moving, thereby eliminating the smoothness and safety issues caused by engine start-stop from the root.

[0051] The input parameters for this step are the total power consumption budget threshold for the entire parking process output in the pre-judgment stage, the minimum required discharge capacity of the power battery, the safe voltage threshold of the low-voltage system, and the battery SOC and cell parameters, the power consumption list of the core parking function, the power consumption list of the vehicle peripherals, and the battery safety working boundary data collected in real time.

[0052] After receiving the low SOC parking condition determination result, the VCU immediately triggers the pure electric power protection mode through the pure electric power protection hierarchical control module, and simultaneously executes two linkage control actions. The two actions complement each other and jointly ensure the feasibility of pure electric drive: the first is a parking-specific three-level power consumption hierarchical control. The VCU synchronously sends parking low-power mode commands to the body domain controller and intelligent driving domain controller. Adhering to the principle of "absolute safety first, full guarantee of core functions," it implements three levels of precise control over vehicle power consumption: Level 1 prioritizes core safety functions, fully preserving power supply and rated power, including the surround-view core cameras, ultrasonic radar, electric power steering system, braking control system, and drive motor control system required for parking path planning, ensuring the safe execution of parking functions is unaffected; Level 2 focuses on auxiliary functions, implementing reduced power operation, including lowering the brightness of the 360-degree panoramic imaging display screen, reducing the reversing auxiliary lighting to the minimum safe brightness, and reducing the air conditioning blower to the basic ventilation level, reducing power consumption without affecting core functions; Level 3 completely shuts down non-essential functions, including side blind spot auxiliary cameras, interior ambient lighting, non-driving-related entertainment system peripherals, seat heating / ventilation functions, and onboard charging port lighting, ultimately reducing the vehicle's low-voltage system power consumption to a preset safe minimum threshold, minimizing unnecessary power consumption.

[0053] The second item is parking-specific short-term discharge rate optimization control, which involves implementing a short-term discharge rate optimization strategy. The VCU sends a parking-specific discharge control command to the BMS. Based on the characteristics of short-term, intermittent discharge during parking (a single parking session lasts no more than 3 minutes), the upper limit of the power battery's discharge rate is temporarily increased within the battery's safe operating boundary. In this embodiment of the invention, the upper limit of the continuous discharge rate under normal driving conditions is increased by 15%-20%. At the same time, the BMS monitors the individual cell voltage, cell temperature, and discharge current of the power battery in real time at a 10ms cycle to ensure that the entire discharge process is completely within the battery's safe operating range and to avoid permanent damage caused by over-discharge.

[0054] The core output signals of this step include: a three-level power consumption control execution command, a battery discharge rate adjustment command, a pure electric drive enable signal for the drive motor, and an absolute prohibition command for engine start while the vehicle is moving. Among these, the absolute prohibition command for engine start is the highest priority command. As long as the vehicle's real-time speed is greater than 0, the EMS must unconditionally execute the engine shutdown lockout, completely eliminating the possibility of engine start-up while the vehicle is moving from the control logic level. Through the control of this step, it is ensured that during the entire parking process while the vehicle is moving, the drive motor provides all the driving power, and the engine remains stopped, fundamentally avoiding torque fluctuations, jerking, and noise problems caused by engine start-stop during vehicle movement.

[0055] In some embodiments of the present invention, the driving information verification includes the power battery SOC, cell voltage, low-voltage battery voltage, remaining parking time, parking system average power, and current maximum output capacity of the battery; the driving information verification meets the triggering conditions, including a first condition and a second condition; the first condition is that the power battery SOC is less than or equal to the critical safety threshold, and / or the power battery cell voltage is lower than the discharge cutoff warning value, and / or the low-voltage battery voltage is lower than the safe operating threshold, and the second condition is that the total power consumption required for the parking process is greater than the current maximum output capacity of the battery; the total power consumption required for the parking process is calculated based on the remaining parking time and the parking system average power.

[0056] This invention provides a fallback supplement to the pure electric power-saving mode, proposing a triple-locked static power generation control process. This strictly limits the engine to starting and running only when the vehicle is completely stationary, the brakes are locked, and parking is paused, completely resolving the smoothness and safety risks associated with engine start-stop during vehicle movement in existing technologies. Input parameters include: real-time battery SOC, cell voltage, cell temperature, low-voltage battery voltage uploaded by the BMS, remaining parking time and required total power consumption output during the pre-judgment phase, vehicle speed signal, braking system status signal fed back by the ESC, and parking system operating status signal. The remaining parking time and required total power consumption output during the pre-judgment phase are determined based on the target standard parking time according to the parking space type. After parking begins, the VCU can dynamically estimate the "remaining parking time" by combining the elapsed time and the progress feedback from the parking system (e.g., path completion percentage). Required total power consumption is also recalculated based on the "remaining parking time." The formula is similar to the initial budget, but replacing "standard parking time" with "remaining parking time" yields the "remaining total power consumption budget." This value is dynamically updated. The braking system status signal and parking system operating status signal fed back by the ESC are received in real-time from the corresponding controllers via the vehicle's CAN network. The braking system status signal, from the ESC electronic stability control system, includes brake pedal status, braking force, and whether the parking brake is locked. The parking system operating status signal comes from the APA intelligent parking domain controller or the ADS intelligent driving controller, defined as the following states: "Searching for parking space," "Route planning," "Route execution," "Paused," and "Completed."

[0057] During pure electric power-saving mode operation, the VCU performs real-time closed-loop verification of the battery status at 10ms intervals. When the verified driving information simultaneously meets the following two trigger conditions, the static power generation fallback control process is immediately triggered: The first condition is that the power battery SOC drops to the critical safety threshold, such as 8%, or the voltage of a single power battery cell is lower than the discharge cutoff warning value, or the voltage of the low-voltage battery is lower than the safe operating threshold; the second condition is that the total power consumption required for the remaining parking process exceeds the current maximum output capacity of the battery. Here, the voltage of a single power battery cell is the voltage of the smallest unit cell constituting the power battery pack. The total power consumption required for the remaining parking process is a pre-estimated value, calculated by the VCU vehicle controller based on the remaining parking time and the average power of the parking system. The total power consumption required for the remaining parking process ≈ remaining parking time × average power of the parking system. Remaining parking time: dynamically estimated and provided by the APA automatic parking assist controller based on path planning results and current progress. Average power of the parking system: A calibrated empirical or statistical value that includes the average power requirements of environmental perception, decision control, steering / braking actuators, etc., during a typical parking process. The current maximum output capacity of the battery is a state estimate; it represents the total energy the battery can safely release under the current conditions, considering SOC, temperature, SOH (State of Health), and instantaneous power capability, rather than the battery's nominal capacity. It is calculated in real-time by the BMS and reported to the VCU. The BMS estimates this value using a built-in algorithm model based on the current battery SOC, temperature, internal resistance, SOH, and preset discharge cutoff conditions. It is a dynamically changing value that decreases during the discharge process.

[0058] In some embodiments of the present invention, the triple-locked static power generation control process includes: A parking pause command is sent to the vehicle's parking system, causing the parking system to stop path planning and vehicle movement control according to the parking pause command, control the vehicle to enter a completely stationary state, and return a parking process pause signal and an absolute stationary confirmation signal; when the parking process pause signal and absolute stationary confirmation signal are received from the parking system, it is determined that the first level of control is completed and the second level of control is entered.

[0059] In this embodiment of the invention, after the fallback process is triggered, the VCU executes linkage control according to a strict irreversible timing sequence through the triple-locked static power generation control module to ensure absolute safety. If any step is not confirmed, the next step cannot be entered: First, while the vehicle is moving, the VCU sends a parking pause command to the parking system. The parking system immediately stops path planning and vehicle movement control, and controls the vehicle to enter a completely stationary state. Only after the VCU receives the pause completion signal from the parking system and the absolute stationary confirmation signal that the vehicle speed has been 0 for 500ms can it enter the second control.

[0060] In the second level of control, a four-wheel brake lock command is sent to the vehicle's electronic stability control system, so that the electronic stability control system controls the four wheels of the vehicle to perform fixed parking brake lock according to the four-wheel brake lock command. When the vehicle's braking force reaches the preset anti-rollover threshold, a four-wheel brake lock completion signal and a braking force compliance confirmation signal are returned. When the four-wheel brake lock completion signal and braking force compliance confirmation signal are received from the electronic stability control system, the third level of control is entered.

[0061] In this embodiment of the invention, the VCU sends a four-wheel brake lock command to the Electronic Stability Control (ESC). The ESC performs fixed parking brake lock on the four wheels. When the braking force reaches the preset anti-rollover threshold, the VCU can enter the third level of control only after receiving the four-wheel brake lock completion signal and the braking force compliance confirmation signal from the ESC.

[0062] After receiving the absolute stationary confirmation signal, the four-wheel brake lock completion signal, and the parking process pause signal in the third level of control, an engine start command is sent to the vehicle's engine management system. This allows the engine management system to control the engine to start and enter a fixed idle speed power generation mode. Under the fixed idle speed power generation mode, the engine's power generation power is adjusted. When the power generation power meets the core power consumption requirements of the parking system, the excess power is used to replenish the power battery and low-voltage battery.

[0063] In this embodiment of the invention, the VCU only sends an engine start command to the engine management system (EMS) after receiving confirmation signals that the vehicle is absolutely stationary, all four wheels are locked, and the parking process is paused. The VCU then controls the engine to start and enter a fixed idle speed power generation state. The EMS adjusts the engine's power generation in real time to prioritize meeting the core power consumption requirements of the parking system, and the excess power is used to replenish the power battery and low-voltage battery.

[0064] Furthermore, the control commands are the foundational management commands for the entire low SOC parking process, remaining in effect throughout. A fallback process is initiated during low SOC parking. The triple-locked static power generation control process is a temporary safety management command added on top of this foundational control; both operate in parallel. The absolute prohibition command for engine starting while the vehicle is moving remains in effect throughout the triggering and execution of the triple-locked static power generation fallback control. This prohibition is only temporarily lifted after the vehicle is confirmed to be completely stationary and the brakes are locked, allowing the engine to start and preventing accidental engine starts during vehicle movement. The Level 3 power consumption control execution command remains in effect during the power generation process of the triple-locked static power generation fallback control, ensuring that the vehicle's power consumption still follows Level 3 control during power generation, minimizing unnecessary power consumption and accelerating battery SOC recovery. The battery discharge rate adjustment command remains in effect during the power generation process of the triple-locked static power generation fallback control, only resetting after the entire parking process is completed, ensuring that the battery's discharge capacity adapts to the short-term parking needs throughout the entire process. The parking pause, four-wheel brake lock, and engine start / stop commands are exclusive temporary commands for the backup power generation phase. They are used to achieve triple safety interlock constraints for static power generation. They are additional safety controls on top of basic control and do not conflict with the basic commands of the low SOC parking pure electric power protection mode hierarchical control. Together, they ensure the safety and smoothness of the backup phase.

[0065] In some embodiments of the present invention, the normal conditions for monitoring driving information are that the power battery SOC recovers to a safe threshold, the low-voltage battery voltage is within the normal operating range, and the current maximum output capacity of the battery is sufficient for the pure electric drive of the remaining parking process.

[0066] In this embodiment of the invention, during the power generation process, the VCU continuously monitors the battery status in a closed loop, obtaining monitoring driving information. When the SOC of the power battery rises to a safe threshold, such as 12%, and the low-voltage battery voltage returns to its normal operating range, and the battery's output capacity can support the remaining pure electric drive of the parking process, it is determined that the monitoring driving information meets the normal conditions. Specifically, when the SOC of the power battery drops to 8%, it indicates that the remaining power is insufficient to support the pure electric drive of the remaining parking process, requiring the triggering of a static power generation process for recharging. The 12% safety threshold is the recovery condition for stopping power generation and resuming parking. When the SOC of the power battery rises to 12% after power generation, it indicates that the remaining power is sufficient to support the pure electric execution of the remaining parking process, at which point power generation can be stopped, and the normal parking process can be resumed.

[0067] In some embodiments of the present invention, step S105 includes: Control the engine to shut down according to the engine shutdown command; When the engine is completely stopped and there is no torque output, the brake lock is released according to the brake lock release command; When the brake lock is fully released, a parking recovery command is sent to the parking system; The parking control system continues to complete the remaining parking process according to the parking resumption command, and outputs parking completion data after parking is completed.

[0068] In this embodiment of the invention, the VCU executes the shutdown operation according to a strict timing sequence. First, it sends an engine shutdown command to the EMS. After confirming that the engine is completely stopped and there is no torque output, it sends a brake lock release command to the ESC. After confirming that the brake lock is completely released, it finally sends a parking resumption command to the parking system to continue completing the remaining parking process. After the process is resumed, it returns to the pure electric power-saving mode control logic. Throughout the entire power generation start-stop process, the engine only runs when the vehicle is completely stationary and the brakes are locked, completely eliminating the risk of jerking and slippage caused by torque fluctuations transmitted to the wheels during engine start-stop.

[0069] In some embodiments of the present invention, the parking completion data includes a parking completion signal, a parking P gear signal, an electronic handbrake activation signal, and a vehicle power status signal; after step S105, the method further includes: When a parking completion signal is received, the vehicle is confirmed to be in Park (P) gear based on the Parking P gear signal, and the electronic parking brake is confirmed to be activated normally based on the electronic parking brake activation signal, a graded reset is performed based on the graded power consumption management of the parking scenario to control the normal operation of the vehicle.

[0070] In this embodiment of the invention, the input parameters are the parking completion signal, the parking P gear signal, the electronic parking brake activation signal, and the vehicle power status signal sent by the parking system. Upon receiving the parking completion signal, determining that the vehicle has switched to P gear based on the parking P gear signal, and confirming that the electronic parking brake has been properly activated based on the electronic parking brake activation signal, the low SOC parking-specific control process is immediately terminated. A tiered reset operation is then performed through the mode-uninterrupted reset module: first, a low-power mode exit command is sent to the body domain controller and the intelligent driving domain controller to restore normal power supply and rated power operation for all vehicle peripherals; then, a discharge rate reset command is sent to the BMS to restore the upper limit of the discharge rate of the power battery under normal driving conditions; finally, the engine start absolute prohibition command is released, restoring the energy management strategy of the vehicle's normal driving mode to ensure normal operation of the vehicle in subsequent driving conditions. This tiered reset timing design avoids voltage fluctuations and logic conflicts caused by simultaneous resets of multiple systems, achieving a seamless transition between modes.

[0071] This invention addresses industry pain points such as jerking and rolling backwards caused by frequent engine start-stop in low SOC parking scenarios of plug-in hybrid / range-extended hybrid vehicles. It pioneers a dedicated smooth control system for low SOC under all parking conditions, distinct from driving conditions, filling the technological gap in refined energy management and smooth collaborative control in this scenario.

[0072] Firstly, it has constructed an industry-first low SOC control system specifically for parking conditions. This system is completely different from conventional low SOC control strategies applicable to driving scenarios. By building a closed-loop control process of "pre-judgment - pure electric power preservation - static backup - automatic reset", it achieves refined and dedicated control of low SOC conditions in parking scenarios, filling the technical gap in the industry for smooth control of low SOC in hybrid vehicle parking scenarios and providing a new technical path for energy management in parking conditions.

[0073] Secondly, a precise power consumption budgeting method for parking based on parking space type is proposed. This method overcomes the deficiency of existing technologies that lack targeted power consumption estimation. By matching the standard parking duration to the parking space type, and combining multi-dimensional power consumption data such as the power consumption of the core parking system, the intermittent creep power consumption of the drive system, and the basic power consumption of the low-voltage safety system, three core parameters are accurately calculated: the total power consumption budget threshold for the entire parking process, the minimum required discharge capacity of the power battery, and the safe voltage threshold. This enables accurate prediction and quantification of power consumption requirements in parking scenarios, providing a scientific and accurate decision-making basis for subsequent pure electric power protection control.

[0074] Third, a three-level power consumption control mechanism for parking is designed. Based on the impact of functions on parking safety, driving experience, and parking function availability, it is dynamically divided into three control levels: Level 1: Keep Active; Level 2: Reduce Power; and Level 3: Shutdown. Dynamic control is executed according to fixed priorities to ensure that, under low SOC parking conditions, core safety functions are fully powered and operational, auxiliary functions operate with reduced power, and unnecessary functions are completely shut down. This achieves refined power protection in parking scenarios, minimizing unnecessary power consumption while absolutely ensuring the safety and effectiveness of parking functions.

[0075] Fourth, it innovatively proposes a core control mechanism of "moving start prohibition + stationary triple lock-up power generation". By setting a high-priority command that absolutely prohibits engine starting during vehicle movement, the possibility of engine starting while the vehicle is in motion is eliminated from the root. At the same time, triple lock-up constraints are set, namely, the vehicle is completely stationary, the braking system is locked, and the parking process is suspended. The engine is started to generate electricity at idle speed only when all three conditions are met. This completely avoids the torque fluctuation, vehicle jerking, and rolling safety risks caused by engine starting during vehicle movement, and achieves dual protection of safety and smoothness under low SOC conditions during parking.

[0076] To better implement the low SOC parking smoothness control method in the embodiments of the present invention, the embodiments of the present invention also provide a low SOC parking smoothness control device, such as... Figure 4 As shown, the low SOC parking smoothness control device 400 includes: The information acquisition module 401 is used to acquire the vehicle's driving information and determine the parking mode based on the driving information; the driving information includes the BMS discharge capability boundary; The instruction output module 402 is used to execute the parking scenario graded power consumption control and short-time discharge rate optimization strategy according to the driving information when the parking mode is a low SOC parking condition, and output control instructions; the parking scenario graded power consumption control is to perform graded control on the controlled object through a three-level power consumption graded control strategy with fixed priority; the short-time discharge rate optimization strategy is to increase the upper limit of the power battery discharge rate within a preset time within the BMS discharge capacity boundary; The parking control module 403 is used to control the parking process of the vehicle according to the control command, and to verify the battery status of the vehicle during the parking process to obtain the verification driving information. The closed-loop monitoring module 404 is used to control the vehicle to start the triple-locked static power generation control process when the driving information is verified to meet the trigger conditions, and to monitor the battery status of the vehicle during the start-up process to obtain the monitored driving information. The triple-locked static power generation control process is the process of controlling the vehicle to start and run under the constraints of a completely stationary state, a parked pause state, and a fixed parking brake lock. The parking completion module 405 is used to complete the remaining parking process and output parking completion data when the monitored driving information meets the normal conditions.

[0077] The low SOC parking smoothness control device 400 provided in the above embodiments can realize the technical solutions described in the embodiments of the low SOC parking smoothness control method. The specific implementation principles of each module or unit can be found in the corresponding content in the embodiments of the low SOC parking smoothness control method, which will not be repeated here.

[0078] The low SOC parking smooth control method and device provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A low SOC parking smoothness control method, characterized in that, include: Obtain vehicle driving information and determine parking mode based on the driving information; The driving information includes the BMS discharge capability boundary; When the parking mode is a low SOC parking condition, the parking scenario graded power consumption control and short-time discharge rate optimization strategy are executed according to the driving information, and control commands are output; the parking scenario graded power consumption control is to perform graded control on the control object through a three-level power consumption graded control strategy with fixed priority; the short-time discharge rate optimization strategy is to increase the upper limit of the discharge rate of the power battery within a preset time within the BMS discharge capacity boundary; The parking process of the vehicle is controlled according to the control command, and the battery status of the vehicle during the parking process is verified to obtain the verification driving information. When the verified driving information meets the triggering conditions, the vehicle is controlled to start the triple-locked static power generation control process, and the battery status of the vehicle is monitored during the start-up process to obtain the monitored driving information; the triple-locked static power generation control process is a process of controlling the vehicle to start and run under the constraints of a completely stationary state, a parked pause state, and a fixed parking brake lock. When the monitored driving information meets the normal conditions, the remaining parking process is completed and parking completion data is output.

2. The low SOC parking smoothness control method according to claim 1, characterized in that, The driving information includes a parking mode activation signal, vehicle speed, gear position signal, and battery SOC; determining the parking mode based on the driving information includes: When the parking mode activation signal determines that the vehicle is in parking mode, the vehicle speed is lower than the preset speed, and the gear signal is forward or reverse, the vehicle is determined to be in a valid parking condition. After entering the effective parking condition, it is determined whether the SOC of the power battery is greater than or equal to the preset SOC; If so, then the parking mode is determined to be a normal parking condition; If not, then the parking mode is determined to be a low SOC parking condition.

3. The low SOC parking smoothness control method according to claim 2, characterized in that, The driving information also includes the parking space type; the step of executing a parking scenario-based graded power consumption management and short-term discharge rate optimization strategy based on the driving information, and outputting control commands, includes: Select a standard parking time corresponding to the parking space type from a plurality of preset standard parking times. The plurality of preset standard parking times correspond one-to-one with a plurality of parking space types, including perpendicular parking spaces, parallel parking spaces and angled parking spaces. Based on the driving information and the standard parking duration, a parking-specific power consumption threshold is obtained; the parking-specific power consumption threshold includes the total power consumption budget threshold for the entire parking process, the minimum required discharge capacity of the power battery, and the safe voltage threshold for the low-voltage system; Based on the parking-specific power consumption threshold, the parking scenario-based tiered power consumption control and short-term discharge rate optimization strategy is executed, and control commands are output. The control commands include a three-level power consumption control execution command, a battery discharge rate adjustment command, a pure electric drive enable signal for the drive motor, and an absolute prohibition command for engine starting while the vehicle is moving.

4. The low SOC parking smoothness control method according to claim 3, characterized in that, The driving information also includes low-voltage battery voltage, parking core system power consumption, drive creep power consumption, and low-voltage safety system basic power consumption; the step of obtaining parking-specific power consumption thresholds based on the driving information and the standard parking duration includes: The total power consumption budget threshold for the entire parking process is obtained by superimposing the product of the power consumption of the parking core system and the standard parking time, the product of the power consumption of the drive creeping system and the creeping duty cycle and the standard parking time, and the product of the basic power consumption of the low-voltage safety system and the standard parking time. Divide the total power consumption budget threshold of the full parking process by the nominal voltage of the power battery, and then divide by the parking-specific discharge efficiency to obtain the minimum required discharge capacity of the power battery. The low-voltage system safety voltage threshold is determined based on the low-voltage battery voltage and the standard parking duration.

5. The low SOC parking smoothness control method according to claim 1, characterized in that, The verification driving information includes the power battery SOC, cell voltage, low-voltage battery voltage, remaining parking time, parking system average power, and current maximum output capacity of the battery. The verification driving information meets the triggering conditions, including a first condition and a second condition. The first condition is that the power battery SOC is less than or equal to the critical safety threshold, and / or the power battery cell voltage is lower than the discharge cutoff warning value, and / or the low-voltage battery voltage is lower than the safe operating threshold. The second condition is that the total power consumption required for the parking process is greater than the current maximum output capacity of the battery. The total power consumption required for the parking process is calculated based on the remaining parking time and the parking system average power.

6. The low SOC parking smoothness control method according to claim 1, characterized in that, The triple-locked static power generation control process includes: A parking pause command is sent to the parking system of the vehicle, so that the parking system stops path planning and vehicle movement control according to the parking pause command, controls the vehicle to enter a completely stationary state, and returns a parking process pause signal and an absolute stationary confirmation signal; when the parking process pause signal and the absolute stationary confirmation signal returned by the parking system are received, it is determined that the first level of control is completed and the second level of control is entered; In the second level of control, a four-wheel brake lock command is sent to the vehicle's electronic stability control system, so that the electronic stability control system controls the four wheels of the vehicle to perform fixed parking brake lock according to the four-wheel brake lock command. When the vehicle's braking force reaches the preset anti-rollover threshold, a four-wheel brake lock completion signal and a braking force attainment confirmation signal are returned. When the four-wheel brake lock completion signal and braking force attainment confirmation signal are received from the electronic stability control system, the third level of control is entered. After receiving the absolute stationary confirmation signal, the four-wheel brake lock completion signal, and the parking process pause signal from the vehicle in the third level of control, an engine start command is sent to the vehicle's engine management system. This allows the engine management system to control the engine to start and enter a fixed idle speed power generation mode. Under this mode, the engine's power generation capacity is adjusted. When the power generation capacity meets the core power consumption requirements of the parking system, excess power is used to replenish the power battery and low-voltage battery.

7. The low SOC parking smoothness control method according to claim 5, characterized in that, The monitored driving information meets the normal conditions as follows: the SOC of the power battery rises to a safe threshold, the voltage of the low-voltage battery is within the normal operating range, and the maximum output capacity of the current battery is sufficient to provide enough pure electric power for the remaining parking process.

8. The low SOC parking smoothness control method according to claim 1, characterized in that, The process of completing the remaining parking steps and outputting parking completion data includes: Control the engine to stop according to the engine stop command; When the engine is completely stopped and there is no torque output, the brake lock is released according to the brake lock release command; When the brake lock is fully released, a parking recovery command is sent to the parking system; The parking system is controlled to continue completing the remaining parking process according to the parking resumption command, and parking completion data is output after parking is completed.

9. The low SOC parking smoothness control method according to claim 1, characterized in that, The parking completion data includes parking completion signal, parking P gear signal, electronic handbrake activation signal, and vehicle power status signal; After completing the remaining parking process and outputting the parking completion data, the process also includes: When the parking completion signal is received, the vehicle is determined to be in Park (P) gear based on the Parking P gear signal, and the electronic parking brake is determined to be normally activated based on the electronic parking brake activation signal, a graded reset is performed based on the graded power consumption management of the parking scenario to control the normal operation of the vehicle.

10. A low SOC parking smoothness control device, characterized in that, include: The information acquisition module is used to acquire the vehicle's driving information and determine the parking mode based on the driving information; The driving information includes the BMS discharge capability boundary; The instruction output module is used to execute a parking scenario-based graded power consumption control and short-term discharge rate optimization strategy based on the driving information when the parking mode is a low SOC parking condition, and output control instructions; the parking scenario-based graded power consumption control is to perform graded control on the controlled object through a three-level power consumption graded control strategy with fixed priority; the short-term discharge rate optimization strategy is to increase the upper limit of the power battery discharge rate within a preset time within the BMS discharge capacity boundary; The parking control module is used to control the parking process of the vehicle according to the control command, and to verify the battery status of the vehicle during the parking process to obtain verification driving information. The closed-loop monitoring module is used to control the vehicle to start the triple-locked static power generation control process when the verified driving information meets the triggering conditions, and to monitor the battery status of the vehicle during the start-up process to obtain the monitored driving information; the triple-locked static power generation control process is a process of controlling the vehicle to start and run under the constraints of a completely stationary state, a parking pause state, and a fixed parking brake lock. The parking completion module is used to complete the remaining parking process and output parking completion data when the monitored driving information meets the normal conditions.

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