Enhanced electric buffer energy recovery system for fuel cell heavy truck

Abstract

The invention relates to an enhanced electric buffer energy recovery system for a fuel cell heavy truck, and the system comprises a CDC cabin domain controller which is used for transmitting an EV mode request or an enhanced electric buffer switch level to an enhanced electric buffer control module, and receiving a current enhanced electric buffer state fed back by the enhanced electric buffer control module; the sliding grade judgment module is connected with the enhanced electric buffer control module and used for sending the current sliding energy recovery grade of the vehicle to the enhanced electric buffer control module and receiving the current enhanced electric buffer state fed back by the enhanced electric buffer control module; and the vehicle speed calculation module is connected with the enhanced electric buffer control module and is used for sending the vehicle speed of the whole vehicle to the enhanced electric buffer control module. According to the method, energy is recycled to the maximum extent while the braking performance requirement is met, energy management is optimized, the driving range is increased, new hardware does not need to be added, and the vehicle cost and the self weight are not affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell heavy trucks, in particular to an enhanced electric buffer energy recovery system for fuel cell heavy trucks. BACKGROUND

[0002] The fuel heavy trucks on the market usually install a hydraulic retarder at the end of the gearbox when driving at high speed in mountainous areas, in order to avoid frequent use of the service brake causing brake overheating, degradation, and even burnout, which may cause safety accidents. The rotor is connected with the main shaft of the hydraulic retarder, and the output shaft of the gearbox drives the main shaft of the retarder through the intermediate gear to rotate. When braking is needed, the amount of oil between the rotor and the stator is controlled to control the damping of the rotor, thereby slowing down the rotation speed of the main shaft and the output shaft of the gearbox, and playing the role of vehicle speed reduction.

[0003] For some fuel cell heavy trucks, the capacity of the power battery is small, which cannot meet the energy storage demand of continuous energy recovery in long downhill working conditions. Therefore, a hydraulic retarder (such as Mercedes GENH2) is usually installed. However, the hydraulic retarder is only suitable for vehicles with central drive axles, and cannot be installed on fuel cell heavy trucks with integrated electric drive axles and distributed electric drive axles. The hydraulic retarder converts mechanical energy into heat energy and dissipates it into the air through a fan, without any energy recovery measures. Installing a large-capacity power battery will increase the cost of the battery and the self-weight of the vehicle. SUMMARY

[0004] In view of the above problems, the present application provides an enhanced electric buffer energy recovery system for fuel cell heavy trucks, which not only meets the braking performance requirements while maximizing energy recovery, optimizes energy management, and improves the driving range, but also does not require the addition of new hardware, and has no impact on the cost and self-weight of the vehicle.

[0005] In order to achieve the above-mentioned purposes and other related purposes, the technical scheme provided by the present application is as follows: An enhanced electric buffer energy recovery system for fuel cell heavy trucks, the system comprising: a CDC cockpit domain controller for sending an EV mode request or an enhanced electric buffer switch level to an enhanced electric buffer control module, and receiving the current enhanced electric buffer state feedback from the enhanced electric buffer control module; a coasting level determination module connected with the enhanced electric buffer control module, for sending the current coasting energy recovery level of the vehicle to the enhanced electric buffer control module, and receiving the current enhanced electric buffer state feedback from the enhanced electric buffer control module; a vehicle speed calculation module connected with the enhanced electric buffer control module, for sending the vehicle speed to the enhanced electric buffer control module; The coasting energy recovery torque calculation module is connected with the vehicle speed calculation module and the coasting level determination module, receives the vehicle speed and the current coasting energy recovery level, calculates the coasting recovery torque demand, outputs the information of the coasting recovery torque demand, and sends the information to the torque coordination module. The acceleration pedal determination module is connected with the enhanced electric brake control module, and is used to send the acceleration pedal opening degree information to the enhanced electric brake control module. The BMS battery management module is connected with the enhanced electric brake control module, and is used to send the total current information of the power battery to the enhanced electric brake control module. The EEM energy management module is connected with the enhanced electric brake control module, and is used to send the maximum available energy recovery torque value information to the enhanced electric brake control module. The vehicle power mode switching request module is connected with the enhanced electric brake control module, receives the current enhanced electric brake state information, and outputs the fuel-electric controller shutdown instruction. The fuel-electric controller is connected with the vehicle power mode switching request module and the enhanced electric brake control module, receives the fuel-electric controller shutdown instruction and the fuel-electric fan power request information, and outputs the fan speed request information and sends the information to the fuel-electric cooling fan.

[0006] Further, the enhanced electric brake switching level includes OFF-constant speed-1st gear-2nd gear-3rd gear-4th gear-5th gear-6th gear. The constant speed gear is used for automatically stabilizing the vehicle speed in the downhill working condition, and the 1st gear-6th gear can be used as the brake gear to control the vehicle speed under the premise of using the service brake.

[0007] Further, the system further includes an ADC intelligent driving domain controller connected with the enhanced electric brake control module, and used to send the ACC function running state to the enhanced electric brake control module. When the ACC function is activated, the EBS is requested to perform deceleration control in the downhill working condition, and the enhanced electric brake and the coasting energy recovery are exited at this time.

[0008] Further, the system further includes an EBS electronic brake module connected with the enhanced electric brake control module, and used to send the ABS activation state information to the enhanced electric brake control module. When the ABS is activated, the enhanced electric brake and the coasting energy recovery are exited.

[0009] Further, when the vehicle speed is greater than a preset threshold, the vehicle has no failure in energy recovery, the charging power of the power battery meets the requirement, the opening degree of the accelerator pedal is zero, the adaptive cruise control (ACC) and the predictive cruise control (PACC) are not started, the enhanced electric coasting function in the enhanced electric coasting control module is activated, and the vehicle starts the following actions: the energy recovery in coasting is in the constant speed gear, the fuel cell is turned off, the running power of the electric fan is calculated according to the charging current and the SOC increasing rate of the power battery, and the air conditioning cold-heat hedging is activated, so that the energy consumption is performed by the PTC and the electric compressor under the premise of meeting the comfort of the cabin air conditioning.

[0010] Further, the conditions for exiting the enhanced electric coasting function in the enhanced electric coasting control module are as follows: in the activated state of the enhanced electric coasting, the enhanced electric coasting is turned off by pressing the enhanced electric coasting switch; the enhanced electric coasting is exited and the hydrogen cell is started when the user switches to the FEV mode; the vehicle is exited when the vehicle is stationary; the enhanced electric coasting is exited when the vehicle has a failure and cannot provide negative torque to support vehicle deceleration; and the enhanced electric coasting is exited when the ABS or the ESC function is activated.

[0011] Further, the current coasting energy recovery level of the vehicle includes: the first level is the coasting energy recovery level selected by the driver and needs to be stored; the second level is the coasting energy recovery level determined by the enhanced electric coasting switch; the third level is the constant speed gear; the fourth level is that the coasting energy recovery is turned off when the vehicle speed is greater than 10 km / h and the parking button is pressed; and the fifth level is that the coasting energy recovery is turned on.

[0012] Further, the current coasting energy recovery level of the vehicle further includes: the sixth level is that if the stored value in the non-volatile storage has not been set or cannot be read, the selected coasting energy recovery level should be set as the default value; the seventh level is that after the vehicle is started, once the driver actively selects the required coasting energy recovery level through the vehicle machine or the coasting level selector, the user-selected coasting energy recovery level should be set; the eighth level is that before the control unit is turned off, the stored coasting energy recovery level should be set as the current one and saved to the non-volatile storage; the ninth level is that a fixed coasting energy recovery level is used or the coasting energy recovery is prohibited when reversing; the tenth level is that the coasting energy recovery is prohibited when the ABS is activated; and the eleventh level is that the coasting energy recovery is stopped when the brake light request of the regenerative braking is stopped.

[0013] Further, the coasting energy recovery limitation reminder of the coasting level determination module is that the maximum recovery torque of the powertrain is less than the maximum recovery torque corresponding to the current coasting energy recovery level, and the absolute value of the minimum negative torque that the powertrain can generate is lower than the absolute value of the regenerative torque generated by the accelerator pedal.

[0014] Furthermore, the enhanced power buffer control module outputs power request data information for the gas-electric fan based on the total current information of the power battery.

[0015] The present invention has the following positive effects: 1. This invention improves the transmission efficiency of the drive system by using integrated electric drive axles and distributed electric drive axles in fuel cell heavy trucks compared to a central drive axle. At the same time, it can cover some mountain roads without using a hydraulic retarder, thus expanding the operating area and operating scenarios of the vehicle.

[0016] 2. This invention, through the cooperation between the CDC cockpit domain controller, coasting level determination module, vehicle speed calculation module, coasting energy recovery torque calculation module, and enhanced electric retarding control module, not only eliminates the need for additional hardware (such as a hydraulic retarder) and has no impact on vehicle cost or weight, but also maximizes energy recovery while meeting braking performance requirements, optimizes energy management, and improves driving range. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system framework of the present invention. Detailed Implementation

[0018] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0019] Example 1: As Figure 1 As shown, an enhanced energy recovery system for fuel cell heavy-duty trucks includes: The CDC cockpit domain controller is used to send EV mode requests or enhanced electric buffer switch levels to the enhanced electric buffer control module, and to receive the current enhanced electric buffer status from the enhanced electric buffer control module. The coasting level determination module is connected to the enhanced electric retardation control module and is used to send the current coasting energy recovery level of the vehicle to the enhanced electric retardation control module and receive the current enhanced electric retardation status fed back by the enhanced electric retardation control module. The vehicle speed calculation module is connected to the enhanced electric delay control module and is used to send the vehicle speed to the enhanced electric delay control module; The coasting energy recovery torque calculation module is connected to the vehicle speed calculation module and the coasting level determination module, respectively. It is used to receive the vehicle speed and the current coasting energy recovery level, calculate the coasting recovery torque requirement, output the coasting recovery torque requirement information and send it to the torque coordination module. An accelerator pedal determination module, connected with the enhanced regenerative braking control module, is configured to send accelerator pedal opening degree information to the enhanced regenerative braking control module. A BMS battery management module, connected with the enhanced regenerative braking control module, is configured to send total current information of the power battery to the enhanced regenerative braking control module. An EEM energy management module, connected with the enhanced regenerative braking control module, is configured to send maximum available energy recovery torque value information to the enhanced regenerative braking control module. A vehicle power mode switching request module, connected with the enhanced regenerative braking control module, is configured to receive current enhanced regenerative braking state information and output a fuel cell controller shutdown instruction. A fuel cell controller, connected with the vehicle power mode switching request module and the enhanced regenerative braking control module, is configured to receive the fuel cell controller shutdown instruction and fuel cell fan power request information, and output fan rotating speed request information and send the fan rotating speed request information to a fuel cell cooling fan.

[0020] In the embodiment, the enhanced regenerative braking switch levels include OFF-constant speed-1st gear-2nd gear-3rd gear-4th gear-5th gear-6th gear. The constant speed gear is used for automatically stabilizing vehicle speed in downhill working conditions, and the 1st gear-6th gear can be used as brake gears to control vehicle speed under the premise of using the accelerator pedal to brake.

[0021] In the embodiment, the system further includes an ADC intelligent driving domain controller, connected with the enhanced regenerative braking control module, configured to send ACC function running state to the enhanced regenerative braking control module. When the ACC function is activated, the EBS is requested to perform deceleration control in the downhill working condition, and the enhanced regenerative braking and the coasting energy recovery are exited at this time.

[0022] In the embodiment, the system further includes an EBS electronic brake module, connected with the enhanced regenerative braking control module, configured to send ABS activation state information to the enhanced regenerative braking control module. When the ABS is activated, the enhanced regenerative braking and the coasting energy recovery are exited.

[0023] In the embodiment, when the vehicle speed is greater than a preset threshold, the vehicle has no fault of unlimited energy recovery, the power battery charging power meets the requirement, the accelerator pedal opening degree information is zero, and the adaptive cruise ACC and the predictive cruise PACC functions are not started, the enhanced regenerative braking function in the enhanced regenerative braking control module is activated, and the vehicle starts the following actions: the coasting energy recovery should enter the constant speed gear, the fuel cell stack is closed, the running power of the fuel cell fan is calculated according to the power battery charging current and the SOC increasing rate, and the air conditioning cold and heat hedging is activated, so that the energy consumption is performed by the PTC and the electric compressor under the premise of meeting the comfort of the cabin air conditioner.

[0024] In the embodiment, the condition for exiting the enhanced regenerative braking function in the enhanced regenerative braking control module is that, in the enhanced regenerative braking activated state, the enhanced regenerative braking switch is pressed by the user to turn off the enhanced regenerative braking; the user switches to the FEV mode, the enhanced regenerative braking should be exited and the hydrogen stack should be started; the vehicle is stationary, the vehicle should exit the enhanced regenerative braking; the vehicle fails to provide negative torque to support vehicle deceleration, the enhanced regenerative braking should be exited; the vehicle ABS is activated or the ESC function is activated, the enhanced regenerative braking should be exited.

[0025] In the embodiment, the current vehicle coasting energy recovery level includes: the first level is the selected coasting energy recovery level that needs to be stored; the second level is the coasting energy recovery level determined by the enhanced regenerative braking switch level; the third level is the constant speed; the fourth level is that the coasting energy recovery is turned off when the vehicle speed is greater than 10 km / h and the parking button is pressed; the fifth level is that the coasting energy recovery is turned on from off.

[0026] In the embodiment, the current vehicle coasting energy recovery level further includes: the sixth level is that if the stored value in the non-volatile storage has not been set or cannot be read, the selected coasting energy recovery level should be set to the default value; the seventh level is that after the vehicle is started, once the driver actively selects the required coasting energy recovery level through the vehicle machine or the coasting level selector, the user-selected coasting energy recovery level should be set; the eighth level is that before the control unit is turned off, the stored coasting energy recovery level should be set to the current and saved to the non-volatile storage; the ninth level is that a fixed coasting energy recovery level is used or the coasting energy recovery is prohibited when reversing; the tenth level is that the coasting energy recovery is prohibited when the ABS is activated, and the eleventh level is that the coasting energy recovery is stopped when the brake light request of the regenerative braking is stopped.

[0027] In the embodiment, the coasting energy recovery limitation reminder of the coasting level determination module is that the maximum recovery torque of the powertrain in operation is less than the maximum recovery torque corresponding to the current coasting energy recovery level, and the absolute value of the minimum negative torque that the powertrain can generate is lower than the absolute value of the regenerative torque generated by the accelerator pedal.

[0028] In the embodiment, the enhanced regenerative braking control module outputs data information of the fuel-electric fan power request according to the total current information of the power battery.

[0029] Embodiment 2: On the basis of the enhanced regenerative braking energy recovery system for fuel cell heavy trucks in embodiment 1, the present application is further described and explained.

[0030] As shown in Figure 1 , an enhanced regenerative braking energy recovery system for fuel cell heavy trucks, the system comprises: CDC cockpit domain controller, configured to send an EV mode request or an enhanced regenerative braking level to the enhanced regenerative braking control module, and receive a current enhanced regenerative braking state fed back by the enhanced regenerative braking control module; A coasting level determination module, connected with the enhanced regenerative braking control module, configured to send a current coasting energy recovery level of the vehicle to the enhanced regenerative braking control module, and receive the current enhanced regenerative braking state fed back by the enhanced regenerative braking control module; A vehicle speed calculation module, connected with the enhanced regenerative braking control module, configured to send a vehicle speed to the enhanced regenerative braking control module; A coasting energy recovery torque calculation module, connected with the vehicle speed calculation module and the coasting level determination module, configured to receive the vehicle speed and the current coasting energy recovery level, calculate a coasting recovery torque demand, and output information of the coasting recovery torque demand and send the information to the torque coordination module; An accelerator pedal determination module, connected with the enhanced regenerative braking control module, configured to send an accelerator pedal opening degree information to the enhanced regenerative braking control module; A BMS battery management module, connected with the enhanced regenerative braking control module, configured to send a total current information of the power battery to the enhanced regenerative braking control module; An EEM energy management module, connected with the enhanced regenerative braking control module, configured to send a maximum available energy recovery torque value information to the enhanced regenerative braking control module; A vehicle power mode switching request module, connected with the enhanced regenerative braking control module, configured to receive the current enhanced regenerative braking state information, and output a fuel cell controller shutdown instruction; A fuel cell controller, connected with the vehicle power mode switching request module and the enhanced regenerative braking control module, configured to receive the fuel cell controller shutdown instruction and a fuel cell fan power request information, and output a fan rotating speed request information and send the information to a fuel cell cooling fan.

[0031] In the embodiment, the working flow of the system of the application comprises: 1. Setting a regenerative braking level adjustment switch, the switch gears are set as OFF-constant speed-1st gear-2nd gear-3rd gear-4th gear-5th gear-6th gear, the constant speed gear is used for automatically stabilizing the vehicle speed in downhill working conditions, and the 1st gear-6th gear can be used as braking gears to control the vehicle speed under the premise of using the service brake pedal to brake; 2. Setting an enhanced regenerative braking switch, the switch is activated in long downhill working conditions, the vehicle can consume part of the electric energy through the high-voltage electrical appliances while recovering energy, so as to avoid the power battery being fully charged too fast and the energy recovery being closed, 3. When the enhanced regenerative braking is activated, the vehicle automatically shuts down the fuel cell to avoid consuming hydrogen while recovering energy; 4. The operation power of the fuel cell fan can be controlled according to the battery charging rate in the energy recovery process, so as to avoid the power battery energy from being reduced; 5, The enhanced electric brake vehicle electric brake level defaults to enter constant speed gear, so that the user one-key operation in downhill working condition, and the man-machine interaction is more friendly; 6, Avoiding misentry into enhanced electric brake function in flat road driving, causing abnormal closing of fuel cell stack affecting vehicle driving power demand, and needing accurate identification of downhill working condition and activation in coasting process; At the same time, when ABS is activated, the enhanced electric brake and coasting energy recovery are exited to avoid vehicle instability on low adhesion road surface (such as icy road surface in winter); 7, The enhanced electric brake is also automatically closed when the power battery SOC is too low to avoid affecting the vehicle power; 8, When the enhanced electric brake is activated, the user presses the enhanced electric brake switch again to close the enhanced electric brake; 9, When the user switches the FEV switch to identify that the user wants to start the fuel cell, the enhanced electric brake is automatically closed; 10, When the ACC function is activated, the EBS will request deceleration control in downhill working condition, at which time the enhanced electric brake and coasting energy recovery are exited.

[0032] In this embodiment, the coasting energy recovery level adjustment should have a constant speed gear. When the vehicle is downhill, the vehicle can automatically adjust the motor feedback torque according to the speed at the activation time to stabilize the vehicle speed at the speed expected by the user (for example, when the vehicle needs to descend at a speed of 60 km / h, only the speed is adjusted to 60 km / h through the accelerator pedal or brake pedal, and then the constant speed gear is activated through the coasting energy recovery level adjustment, and the vehicle will automatically control the motor braking torque to control the vehicle speed at 60 km / h); When the vehicle constant speed gear is activated, the instrument should prompt the user to enter the constant speed; If the vehicle energy recovery capability is limited (such as high battery SOC, motor over-temperature, etc.) during the vehicle downhill constant speed control process, the vehicle cannot maintain constant speed, and the instrument should prompt the user.

[0033] In this embodiment, the vehicle should have a coasting energy recovery one-key closing switch: 1, When the coasting energy recovery activation switch is pressed in the coasting energy recovery closed state, the vehicle defaults to enter the constant speed gear, and automatically adjusts the motor braking torque according to the current vehicle speed; 2, When the coasting energy recovery switch is pressed in the coasting energy recovery activated state (such as the current coasting energy recovery level is 5), the vehicle should close the coasting energy recovery, and set the current coasting energy recovery level to 0.

[0034] In this embodiment, the vehicle should provide different coasting energy recovery level selection switches to meet the user's deceleration demand, for example, the slope increases in long downhill road section, and the driver wants to reduce the speed, and opening the coasting energy recovery and increasing the coasting energy recovery level can effectively reduce the speed.

[0035] In this embodiment, the precondition is: vehicle power mode = "Driving"; the vehicle is in driving state (e.g. the vehicle speed is greater than 30km / h); the battery SOC is in a reasonable range (the allowed charging power meets the highest level requirement of regenerative braking).

[0036] Scenario description: 1. The user presses the "enhanced electric brake switch"; 2. The instrument displays the enhanced electric brake function opening indicator light (long downhill indicator light); 3. The vehicle automatically adjusts the regenerative braking level to the constant speed gear, and displays the corresponding level on the instrument; 4. The vehicle automatically closes the fuel cell stack; 5. Start the fuel cell cooling fan synchronously, and dynamically adjust the cooling fan power according to the change of the power battery charging rate (e.g. if the power battery charging rate is high after starting the enhanced electric brake, increase the fuel cell fan power, and if the power battery charging rate is low, decrease the fuel cell fan power to 0); 6. If the feedback power is limited during the enhanced electric brake operation, the user is prompted on the instrument, so that the user can use the service brake to stabilize the vehicle speed downhill.

[0037] User turns off the enhanced electric brake: 1. The user turns off the enhanced electric brake switch during the enhanced electric brake operation; 2. Turn off the enhanced electric brake, and adjust the regenerative braking level to the level before the enhanced electric brake is activated.

[0038] Power battery power is too low to exit the enhanced electric brake: 1. If the power battery SOC is lower than the set value, the enhanced electric brake is exited; 2. The instrument enhanced electric brake indicator light is turned off; 3. Synchronously adjust the regenerative braking level to the level before the enhanced electric brake is activated.

[0039] In this embodiment, during the vehicle sliding process without the user stepping on the pedal, the user presses the enhanced electric brake switch, and the enhanced electric brake function should be activated under the following operating conditions: 1. The vehicle speed is greater than a threshold value (e.g. 30km / h TBD); 2. The vehicle has no fault of limited energy recovery, 3. The power battery charging power meets; 4. The user does not step on the accelerator pedal; 5. The adaptive cruise control ACC and predictive cruise control PACC functions are not turned on; After the enhanced electric brake function is activated, the vehicle will start the following actions: 1. The regenerative braking should enter the constant speed gear, 2. Close the fuel cell stack, 3. Calculate the running power of the fuel cell fan according to the recharging current of the power battery and the SOC increasing rate; 4. Activate the air conditioning cold and hot hedging, so as to meet the comfort of the cabin air conditioning under the premise of using PTC and electric compressor for energy consumption.

[0040] In this embodiment, the enhanced electric buffer energy recovery is enhanced: exit the enhanced electric buffer 1. In the enhanced electric buffer activation state, the user can turn off the enhanced electric buffer by pressing the enhanced electric buffer switch; 2. The user switches to FEV mode, and should exit the enhanced electric buffer and start the hydrogen stack; 3. The vehicle is stationary (such as the vehicle speed is reduced to 5km / h TBD), and the vehicle should exit the enhanced electric buffer; 4. When the vehicle fails to provide negative torque to support vehicle deceleration, the enhanced electric buffer should be exited; 5. The enhanced electric buffer should be exited when the vehicle ABS is activated or the ESC function is activated.

[0041] In this embodiment, the pedal torque demand includes: PedalTorqueDemand_01, set the torque demand according to the accelerator pedal position; PedalTorqueDemand_02, adjust the pedal torque demand according to the current vehicle speed and driving direction; PedalTorqueDemand_03, adjust the torque demand according to the current logical gear; PedalTorqueDemand_04, provide negative torque demand when the accelerator pedal is not pressed in forward gear; If the vehicle is driving in the required driving direction (the vehicle is driving forward, and the logical gear sigCurGear is in forward gear), AcceleratorTorqueDetermination should calculate the negative torque demand sigAccrTqDmdAct to indicate the requested torque opposite to the required driving direction indicated by the logical gear sigCurGear. (The accelerator pedal is not pressed); PedalTorqueDemand_05, set the torque demand to 0 when the accelerator pedal is not pressed in reverse gear; PedalTorqueDemand_06, avoid vehicle shaking when coasting energy recovery; PedalTorqueDemand_07, adjust the pedal torque demand according to the coasting recovery level; If the vehicle speed sigWhlBasdVehSpd is greater than a certain value, AcceleratorTorqueDeter mination should adjust the torque demand sigAccrTqDmdAct according to the actual coasting recovery level and the actual moving direction sigVehMovgDir; Pedal torque demand_08, coasting energy recovery constant speed torque calculation If the current coasting energy recovery level PCU_CoastLvlUsrSeld = "Constant Speed", the Accelerator Torque Determination should calculate the coasting recovery torque demand sigAccrTqDmdAct according to the vehicle speed SigVehSpd at the moment when the constant speed gear is opened, and control the vehicle speed around the target vehicle speed, increase the vehicle speed to reduce the coasting recovery torque demand sigAccrTqDmdAct; Reduce the vehicle speed to increase the coasting energy recovery torque demand sigAccrTqDmdAct until O; If the constant speed cannot be maintained, PCU_EERConSpeLim = "Constant Speed Limited" should be set, prompting the user.

[0042] In this embodiment, the coasting level determination includes: Coasting level determination_01, the coasting energy recovery level selected by the driver needs to be stored; The selected coasting energy recovery level sigCoastLvlUsrSeld should be set to the recovery level parCoastLvlSaved from the non-volatile storage after the vehicle is started, before the driver actively selects a new level sigHmiCoastLvlReq; Coasting level determination 02, combined switch coasting energy recovery level determination; 1. When receiving the coasting energy recovery level signal SCM_CoastLvlReq of the combination switch Req = 0x1: When the energy recovery gear is increased by one gear, the coasting level determination is increased by one gear based on the current level, and is sent through the signal sigCoastLvlUsrSeld; 2. When receiving the coasting energy recovery level signal SCM_CoastLvlReq of the combination switch Req = 0x2: When the energy recovery gear is reduced by one gear, the coasting level determination is reduced by one gear based on the current level, and is sent through the signal sigCoastLvlUsrSeld; 3. When receiving the coasting energy recovery level signal SCM_CoastLvlReq of the combination switch to increase or decrease the gear, the gear should be switched according to the following order, Increase gear: OFF - Constant Speed - Level1 - Level2 - Level3 - Level4 - Level5 - Level6; Downshift: Level 6—Level 5—Level 4—Level 3—Level 2—Level 1—Constant Speed—OFF; hint: The coasting level determination requires arbitration between the coasting energy recovery level input SCM_CoastLvlReq of the combination switch and the coasting level selection CDC_HmiCoastLvlReq of the central control screen; The highest level of coasting energy recovery is level 6, the lowest level is constant speed, and level 0 disables coasting energy recovery. The energy recovery level switch signal on the combination switch is a self-reset signal. It sends 3 corresponding signals after each dialing and then returns to 0x0. Gliding level assessment 03, constant speed gear 1. When coasting energy recovery is off (PCU_CoastLvlUsrSeld=OFF), if SCM_CoastLvlReq=0x1: Energy recovery level increased by one level is received, the system should enter constant speed mode and set the current coasting energy recovery level PCU_CoastLvlUsrSeld="constant speed". Glide Level Assessment_04: Glide Energy Recovery Off Vehicles should disable coasting energy recovery and set the current coasting energy recovery level PCU_CoastLvlUsrSeld to "OFF" if the following conditions are met: 1. Vehicle speed PCU_VehSpd is greater than 10km / h (standardized value); 2. Received that the parking button has been pressed (sigPrkSwtSt == "Applied"); Gliding level assessment 05, gliding energy recovery changed from off to on. When coasting energy recovery is off (PCU_CoastLvlUsrSeld is set to "OFF"), and the parking button is pressed (sigPrkSwtSt=="Applied") and the current vehicle speed is PCU_ If VehSpd is greater than 10 km / h (calibrated value), then set the current coasting energy recovery level PCU_. CoastLvlUsrSeld = "Constant speed"; Glide level determination_06, unable to read memory value, default value used. If the non-volatile storage value parCoastLvlSaved has not been set or cannot be read, then the selected coast energy recovery level sigCoastLvlUsrSeld should be set to the default value parCoastLvlDft.

[0043] Hint: The described situation can occur at the first vehicle start or in case of a par CoastLvlSaved is deleted due to a memory error; Coast Level Decision 07, Set coast energy recovery level sigCoastLvlUsrSeld according to user selection Coast Level Decision 07, Set coast energy recovery level sigCoastLvlUsrSeld according to user selection Coast Level Decision 08, Store current coast energy recovery level Coast Level Decision 08, Store current coast energy recovery level Coast Level Decision 08, Store current coast energy recovery level Coast Level Decision 09, Use fixed coast energy recovery level or disable coast energy recovery during reverse For reverse driving, only a fixed specified coast level can be used. (If desired, the coast function during reverse driving can be disabled.) Coast Level Decision 10, Disable coast energy recovery when ABS is active If ABS is active (sigABSActv = "ABS active") or has a fault (sigABSFullyOper = "Not Fully Operational"), coast energy recovery should be deactivated (torque target request set to 0). Coast Level Decision 10, Disable coast energy recovery when ABS is active If ABS is active (sigABSActv = "ABS active") or has a fault (sigABSFullyOper = "Not Fully Operational"), coast energy recovery should be deactivated (torque target request set to 0). Coast Level Decision 11, Brake light illumination request during regenerative braking When all the following conditions are met within a debounce time (200 ms TBD), the PCU should request brake light illumination by setting the signal BrkLiReqRegen = 1: • Gear is in D • Accelerator pedal position ≤ 25% (pending) Motor total torque applied ≤ M * (A - Ar) * R / Ratio (M: vehicle mass; A: deceleration threshold (0.13G, TBD) Ar: resistance deceleration (not including road slope) R: wheel radius Ratio: actual torque ratio) • Vehicle deceleration > 0.13G (TBD) When all the following conditions are met, PCU shall reset BrkLiReqRegen to 0: • Vehicle deceleration < 0.07G (TBD).

[0044] In this embodiment, the coasting energy recovery limited warning includes: Coasting energy recovery limited warning_01, the maximum recovery torque that the powertrain can operate at is less than the maximum recovery torque corresponding to the current coasting energy recovery level; Coasting energy recovery limited warning_02, the absolute value of the minimum negative torque (sigTqMinVeh) that the powertrain can generate is lower than the absolute value of the regenerative torque generated by the accelerator pedal; If the coasting energy recovery is activated, and the absolute value of the minimum negative torque (sigTqMinVeh) that the powertrain can generate is lower than the absolute value of the regenerative torque generated by the accelerator pedal under the current vehicle speed and the current set coasting recovery level, VehicleTorqueCoordination shall provide the driver with information about the limited powertrain capability sigElecPtLimdDecelSt.

[0045] In this embodiment, the exit enhanced electric brake includes: Enhanced electric brake active state, meet any one of the following conditions, fctL3EnhancedElectric Retarder shall exit enhanced electric brake, and set the current enhanced electric brake state PCU_EERSts= 0x0: Not Active: — Enhanced electric brake switch CDC_EERSwt=0x1: OFF is received; Or — The driver's EV mode request sigElecVehModReq is "Not active"; Or — The vehicle is stationary (PCU_VehSpd < 5 km / h) TBD; Or The power battery SOC is lower than the threshold (BMS_BattActSOC is less than 30% calibration); Or ABS activation (sigABSActv = "ABS active") or failure (sigABSFully Oper = "Not Fully Operational"), or Coast energy recovery is off PCU_CoastLvlUsrSeld is "OFF" or ACC function is on (ADC_ACCSt!= 0x0: OFF).

[0046] In this embodiment, the vehicle power mode switching request, start-up condition judgment If the following start-up conditions are met, the vehicle power mode coordination function sends a fuel cell start-up condition judgment sigFuCellStrtPrecndnChk = "True" · Fuel cell status sigFCUStsCod!= "init value" or "Error" or "Factory" (for Yutong G20+ stack, fuel cell status sigFCUStsCod!= "Fault" or "Vehicle Fault") · Power mode request sigVehPrpnModReq = "Request FEV mode" · Bidirectional DCDC is in running state BRDCDC_StsFdbk = "Running state"; · Vehicle state sigVehSts = "Drive / RemoteDrive" or (Vehicle state sigVehSts = "HV On" && High-voltage battery SOC sigBattActSOC < parElecVeh ModHvBattSocLowMin); · No charge prohibition fuel cell operation request sigChrgnFuCellCtrl!= "Request To Shutdown" · Battery pack peak discharge power greater than stack start-up power sigAllwblPlsDcha Pwr > parFuCellStrPwr · Hydrogen cylinder high pressure average pressure HMS_HP greater than parHSocMin; · No close hydrogen cylinder valve instruction sigReqClsHBVlv!= "Request"; • The maximum allowed fuel cell power request sigFcPwrReqMax is greater than the minimum operating power of the fuel cell system FCU_CurMinPwr for a duration ParTimerforFCPwrReqMax LessThanMinFuelPwr: • The enhanced electric reserve is in the inactive state sigEERSts = "Inactive"; • The vehicle mode sigVehMod = "Normal Mode"; Otherwise, the power mode coordination should send the fuel cell start-up decision sigFuCellStrtP recndnChk = "False". Note: 1. The maximum allowed fuel cell power request sigFcPwrReqMax is the maximum fuel cell output power that can be consumed by the high voltage battery and high voltage components, which is calculated by summing the high voltage auxiliary power sigHvAuxPwrAct, the maximum allowed high voltage battery charging power sigHvBattPMaxChrgSho, and the motor power request (sigEgyCoornIvtrPwrGenReq in generator mode, sigEgyCoornIvtrPwrMotReq in drive mode).

[0047] 2. The hydrogen tank high pressure average pressure HMS_HP fluctuates, and a hysteresis interval should be set. If the hydrogen tank high pressure average pressure HMS_HP is greater than 3.3 Mpa for 1 S, start-up; if the hydrogen tank high pressure average pressure HMS_HP is less than 3 Mpa for 5 S, shut down.

[0048] In summary, the application not only meets the braking performance requirements while recovering energy to the maximum extent, optimizing energy management, and improving the driving range, but also does not need to increase new hardware, and has no influence on the vehicle cost and self weight.

[0049] The above detailed implementation does not constitute a limitation on the protection scope of the present disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. An enhanced energy recovery system for fuel cell heavy-duty trucks, characterized in that, The system includes: The CDC cockpit domain controller is used to send EV mode requests or enhanced electric buffer switch levels to the enhanced electric buffer control module, and to receive the current enhanced electric buffer status from the enhanced electric buffer control module. The coasting level determination module is connected to the enhanced electric retardation control module and is used to send the current coasting energy recovery level of the vehicle to the enhanced electric retardation control module and receive the current enhanced electric retardation status fed back by the enhanced electric retardation control module. The vehicle speed calculation module is connected to the enhanced electric delay control module and is used to send the vehicle speed to the enhanced electric delay control module; The coasting energy recovery torque calculation module is connected to the vehicle speed calculation module and the coasting level determination module, respectively. It is used to receive the vehicle speed and the current coasting energy recovery level, calculate the coasting recovery torque requirement, output the coasting recovery torque requirement information and send it to the torque coordination module. An accelerator pedal determination module, connected to the enhanced electric dam control module, is used to send accelerator pedal opening information to the enhanced electric dam control module. The BMS battery management module is connected to the enhanced current buffer control module and is used to send the total current information of the power battery to the enhanced current buffer control module. The EEM energy management module is connected to the enhanced electric delay control module and is used to send the maximum available energy recovery torque value information to the enhanced electric delay control module. The vehicle power mode switching request module is connected to the enhanced electric delay control module and is used to receive the current enhanced electric delay status information and output the fuel cell controller shutdown command. The gas turbine controller is connected to the vehicle power mode switching request module and the enhanced electric delay control module, respectively. It is used to receive the gas turbine controller's reactor shutdown command and the gas turbine fan power request information, output the fan speed request information and send it to the gas turbine cooling fan.

2. The enhanced energy recovery system for fuel cell heavy-duty trucks according to claim 1, characterized in that: The enhanced electric slow switch levels include OFF-constant speed-1-2-3-4-5-6. The constant speed level is used to automatically stabilize the vehicle speed in downhill conditions, and levels 1-6 can be used as braking levels to control the vehicle speed while using the driving pedal to brake.

3. The enhanced energy recovery system for fuel cell heavy-duty trucks according to claim 1, characterized in that, The system also includes an ADC intelligent driving domain controller, which is connected to the enhanced electric retardation control module. It is used to send the ACC function operation status to the enhanced electric retardation control module. When the ACC function is activated, it will request EBS to perform deceleration control in downhill conditions. At this time, the enhanced electric retardation and coasting energy recovery will be discontinued.

4. The enhanced energy recovery system for fuel cell heavy-duty trucks according to claim 1, characterized in that, The system also includes an EBS electronic braking module, which is connected to the enhanced electric braking control module and is used to send ABS activation status information to the enhanced electric braking control module, and to deactivate enhanced electric braking and coasting energy recovery when ABS is activated.

5. The enhanced energy recovery system for fuel cell heavy-duty trucks according to claim 1, characterized in that: When the vehicle speed exceeds a preset threshold, there is a fault in the vehicle's unlimited energy recovery, the power battery charging power is sufficient, the accelerator pedal opening information is zero, and the adaptive cruise control (ACC) and predictive cruise control (PACC) functions are not activated, the enhanced energy recovery function in the enhanced energy recovery control module is activated, and the vehicle will initiate all of the following actions: coasting energy recovery should enter constant speed mode, the fuel cell stack should be turned off, the operating power of the fuel cell fan should be calculated based on the power battery recharge current and the SOC increase rate, and the air conditioning cooling and heating counter-current should be activated, thereby utilizing the PTC and electric compressor for energy consumption while meeting the cabin air conditioning comfort requirements.

6. The enhanced energy recovery system for fuel cell heavy-duty trucks according to claim 1, characterized in that, The conditions for exiting the enhanced power buffer function in the enhanced power buffer control module are as follows: when the enhanced power buffer is active, the user can turn off the enhanced power buffer by pressing the enhanced power buffer switch; when the user switches to FEV mode, the enhanced power buffer should be exited and the hydrogen stack should be started. If the vehicle is stationary, the enhanced electric buffer should be disengaged. When a vehicle malfunctions and is unable to provide negative torque to support vehicle deceleration, the enhanced electric buffer should be disengaged. Enhanced electric slowdown should be discontinued when the vehicle's ABS or ESC functions are activated.

7. The enhanced energy recovery system for fuel cell heavy-duty trucks according to claim 1, characterized in that, The current coasting energy recovery level of the vehicle includes: the first level is the coasting energy recovery level selected by the driver, which needs to be stored; the second level is the coasting energy recovery level determination of the enhanced electric slow switch level; the third level is constant speed; the fourth level is when the vehicle speed is greater than 10km / h and the parking button is pressed, coasting energy recovery is turned off; the fifth level is coasting energy recovery from off to on.

8. The enhanced energy recovery system for fuel cell heavy-duty trucks according to claim 7, characterized in that, The current coasting energy recovery level of the vehicle also includes: Level 6, if the stored value in non-volatile memory has not been set or cannot be read, then the selected coasting energy recovery level should be set to the default value; Level 7, after the vehicle is started, once the driver actively selects the required coasting energy recovery level through the vehicle system or coasting level selector, then the user-selected coasting energy recovery level should be set; Level 8, before the control unit is turned off, the stored coasting energy recovery level should be set to the current level and saved to non-volatile memory; Level 9, using a fixed coasting energy recovery level or disabling coasting energy recovery when reversing; Level 10, disabling coasting energy recovery when ABS is activated; and Level 11, the brake lights illuminate during regenerative braking to request the cessation of coasting energy recovery.

9. The enhanced energy recovery system for fuel cell heavy-duty trucks according to claim 1, characterized in that, The coasting level determination module's coasting energy recovery limitation warning indicates that the maximum recovery torque of the power system is less than the maximum recovery torque corresponding to the current coasting energy recovery level, and the absolute value of the minimum negative torque that the power system may generate is lower than the absolute value of the regenerative torque generated by the accelerator pedal.

10. The enhanced energy recovery system for fuel cell heavy-duty trucks according to claim 1, characterized in that: The enhanced power buffer control module outputs power request data for the gas-electric fan based on the total current information of the power battery.

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