Engine braking stepless regulation method, device, equipment and medium

Abstract

The invention relates to an engine braking stepless regulation method, device and equipment and a medium, and belongs to the technical field of engine braking. The method comprises the steps that a negative torque request and basic driving data sent when a vehicle is braked are obtained, and the required negative torque is determined according to the negative torque request; according to the basic driving data and the required negative torque, the engine braking starting state is determined; when the engine braking starting state is starting, and engine braking of the vehicle does not meet the required negative torque, a pneumatic supercharger is adjusted, and first engine braking torque is obtained; when the first engine braking torque meets the required negative torque, stepless adjustment of engine braking is completed, and the braking effect can be improved through engine braking and adjustment of a pneumatic supercharger; the engine braking torque of the vehicle is controlled according to the required negative torque, continuous and variable torque adjustment can be carried out, and then stepless adjustment of engine braking is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of engine braking, and in particular to a method, device, equipment and medium for steplessly adjusting engine braking. Background Art

[0002] Engine braking refers to the braking effect on the drive wheels through the compression resistance, internal friction and intake and exhaust resistance generated by the engine's compression stroke. When the driver gradually reduces the throttle opening and does not step on the clutch, the internal operating mechanism of the engine will generate resistance to help the vehicle slow down. This braking method not only relies on friction brakes, but also effectively reduces the driver's operating burden and improves fuel economy.

[0003] At present, stepless adjustment is generally achieved through hydraulic retarder, proportional exhaust brake valve + cylinder brake valve, which is expensive; the proportional exhaust brake torque is insufficient when used alone, and the braking effect is poor. When using engine brake alone, the braking torque is mainly related to the engine speed, and it is impossible to provide continuously variable torque adjustment.

[0004] Therefore, there is an urgent need to propose a method, device, equipment and medium for stepless adjustment of engine braking to solve the technical problems existing in the prior art of adjusting torque solely through exhaust braking or engine braking, resulting in poor braking effect and inability to perform continuously variable torque adjustment. Summary of the invention

[0005] In view of this, it is necessary to provide a method, device, equipment and medium for stepless adjustment of engine braking to solve the technical problems existing in the prior art of adjusting torque solely through exhaust braking or engine braking, resulting in poor braking effect and inability to perform continuously variable torque adjustment.

[0006] In order to solve the above problems, the present invention provides an engine brake stepless adjustment method, comprising: Acquire a negative torque request and basic driving data sent when the vehicle is braking, and determine a required negative torque according to the negative torque request; determining an engine brake activation state according to the basic driving data and the required negative torque; When the engine brake on state is on and the engine brake of the vehicle does not meet the required negative torque, adjusting the pneumatic supercharger to obtain a first engine brake torque; When the first engine braking torque satisfies the required negative torque, the stepless adjustment of the engine braking is completed.

[0007] In a possible implementation, the basic driving data includes a current engine speed; the engine brake on state includes an exhaust brake on state and an in-cylinder brake on state; and determining the engine brake on state according to the basic driving data and the required negative torque includes: determining the exhaust brake opening state according to the current engine speed and the required negative torque; When the exhaust brake on state is on and the exhaust brake on state does not satisfy the required negative torque, determining that the in-cylinder brake on state is on, and determining the exhaust brake on state is off; When the in-cylinder brake is turned on and does not satisfy the required negative torque, the in-cylinder brake turned on state and the exhaust brake turned on state are determined to be turned on.

[0008] In a possible implementation, the basic driving data includes an intake temperature of the pneumatic supercharger, an actual boost pressure error, and an altitude; and the adjusting the pneumatic supercharger to obtain the first engine braking torque includes: Determining an initial exhaust gas bypass opening feedforward term of the pneumatic supercharger according to the current engine speed and the required negative torque, and correcting the initial exhaust gas bypass opening feedforward term according to the altitude to obtain a target exhaust gas bypass opening feedforward term; determining an initial boost pressure of the pneumatic supercharger according to the current engine speed and the required negative torque, and correcting the initial boost pressure according to the altitude and the intake air temperature to obtain a target boost pressure; Performing closed-loop control calculation according to the target boost pressure and the actual boost pressure error to obtain a closed-loop term of the exhaust gas bypass opening of the pneumatic supercharger; Obtaining the exhaust gas bypass opening of the pneumatic supercharger according to the target exhaust gas bypass opening feedforward term and the exhaust gas bypass opening closed-loop term; The duty cycle is adjusted according to the exhaust bypass opening to obtain a first engine braking torque.

[0009] In a possible implementation, the method further includes: When the first engine braking torque does not meet the required negative torque, determining a throttle opening term according to the current engine speed and the required negative torque; The intake air volume is adjusted according to the throttle opening item to obtain a second engine braking torque; When the second engine braking torque satisfies the required negative torque, the stepless adjustment of the engine braking is completed.

[0010] In a possible implementation, when the second engine braking torque satisfies the required negative torque, after the stepless adjustment of the engine braking is completed, the method further includes: When the second engine braking torque does not meet the required negative torque, determining an exhaust gas recirculation valve opening term according to the current engine speed and the required negative torque; adjusting the exhaust gas volume according to the exhaust gas recirculation valve opening item to obtain a third engine braking torque; The engine braking is continuously adjusted according to the third engine braking torque.

[0011] In a possible implementation, determining the exhaust brake opening state according to the current engine speed and the required negative torque includes: Determining whether the current engine speed is greater than a preset speed, and whether the required negative torque is greater than a preset negative torque; If so, determining that the exhaust brake opening state is on; If not, it is determined that the exhaust brake opening state is closed.

[0012] In a possible implementation, the correcting the initial exhaust gas bypass opening feedforward term according to the altitude to obtain a target exhaust gas bypass opening feedforward term includes: Correcting the initial exhaust bypass opening feedforward term according to the altitude to obtain a corrected exhaust bypass opening feedforward term; A target exhaust bypass opening degree feedforward term is obtained according to the initial exhaust bypass opening degree feedforward term and the corrected exhaust bypass opening degree feedforward term.

[0013] On the other hand, the present invention also provides an engine brake stepless adjustment device, comprising: A data acquisition module, used to acquire a negative torque request and basic driving data sent when the vehicle is braking, and determine a required negative torque according to the negative torque request; a state determination module, configured to determine an engine brake activation state according to the basic driving data and the required negative torque; a torque determination module, configured to adjust the pneumatic supercharger to obtain a first engine braking torque when the engine braking on state is on and the engine braking of the vehicle does not meet the required negative torque; The stepless adjustment module is used to complete the stepless adjustment of the engine braking when the first engine braking torque meets the required negative torque.

[0014] On the other hand, an embodiment of the present invention discloses a vehicle, comprising: a processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein the computer program, when executed by the processor, implements the various steps of the above-mentioned engine brake stepless adjustment method embodiment.

[0015] On the other hand, an embodiment of the present invention discloses a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the various steps of the above-mentioned engine brake stepless adjustment method embodiment are implemented.

[0016] The beneficial effects of the present invention are as follows: a negative torque request and basic driving data sent when a vehicle is braking are obtained, and a required negative torque is determined according to the negative torque request; an engine braking on state is determined according to the basic driving data and the required negative torque; when the engine braking on state is on and the engine braking of the vehicle does not meet the required negative torque, the pneumatic supercharger is adjusted to obtain a first engine braking torque; when the first engine braking torque meets the required negative torque, stepless adjustment of the engine braking is completed, and the braking effect can be increased by adjusting the engine braking and the pneumatic supercharger; the engine braking torque of the vehicle is controlled according to the required negative torque, and continuously variable torque adjustment can be performed, thereby realizing stepless adjustment of the engine braking. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic flow chart of an embodiment of the method for stepless adjustment of engine braking provided by the present invention; Figure 2 A schematic diagram of the structure of an embodiment of a process for determining a required negative torque provided by the present invention; Figure 3 For the present invention Figure 1 A schematic flow chart of an embodiment of step S102; Figure 4 For the present invention Figure 1 A schematic flow chart of an embodiment of step S103; Figure 5 A schematic flow chart of one embodiment of the engine brake stepless adjustment method provided by the present invention; Figure 6 A schematic flow chart of another embodiment of the method for steplessly adjusting engine brake provided by the present invention; Figure 7 A schematic structural diagram of an embodiment of the engine brake stepless adjustment device provided by the present invention; Figure 8 A schematic structural diagram of an embodiment of a vehicle provided by the present invention. DETAILED DESCRIPTION

[0018] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a 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 used to limit the scope of the present invention.

[0019] like Figure 1 As shown, a specific embodiment of the present invention discloses a method for steplessly adjusting engine braking, comprising: S101, obtaining a negative torque request and basic driving data sent when the vehicle is braking, and determining a required negative torque according to the negative torque request; S102, determining the engine brake on state according to basic driving data and required negative torque; S103, when the engine brake on state is on and the engine brake of the vehicle does not meet the required negative torque, adjusting the pneumatic supercharger to obtain a first engine brake torque; S104: When the first engine braking torque meets the required negative torque, the stepless adjustment of the engine braking is completed.

[0020] It should be understood that when the vehicle is driven downhill at a constant speed, the auxiliary brake needs to be continuously adjustable to provide the required negative torque according to the change in vehicle speed. ‌ The stepless adjustment of vehicle engine braking refers to the stepless change of braking effect by continuously and smoothly adjusting the engine speed and torque. ‌ This adjustment method is different from the traditional fixed gear adjustment. It can be adjusted arbitrarily and smoothly within a range, rather than in a jumpy manner. Figure 2 As shown, Figure 2 The process of determining the required negative torque includes the auxiliary brake handle request, the retarder controller request, the transmission controller request, and the EBS controller request. Among them, the retarder, transmission, and EBS directly request the torque percentage. When the auxiliary brake handle is not in a constant speed gear, different handle gears correspond to fixed torque percentage requirements; when the auxiliary brake handle is in a constant speed gear, the vehicle speed when the accelerator is released is used as the target speed, and closed-loop control is performed based on the difference between the target vehicle speed and the actual vehicle speed. The torque percentage calculated above is multiplied by a fixed reference torque value to obtain each negative torque request source, and the required negative torque is obtained through TSC1 arbitration.

[0021] In a specific embodiment of the present invention, according to the required negative torque after arbitration of the whole vehicle, the engine brake (including the cylinder brake valve or the switch exhaust brake valve), throttle, exhaust gas recirculation valve, pneumatic supercharger and other actuators participate, and the throttle, exhaust gas recirculation valve, pneumatic supercharger and other actuators are fully utilized to control the intake volume in the engine cylinder, so as to expand the range of engine brake torque adjustment. When the EECU receives the negative torque request of the vehicle, the required negative torque can be determined according to the negative torque request, and the basic driving data of each module on the vehicle can be obtained. The basic driving data and the required negative torque can then be looked up in a table to determine the engine brake opening state, for example: a mapping table is looked up according to the current engine speed and the required negative torque, and the table value determines whether the engine brake is turned on. For example: when the current engine speed or the required negative torque is low, the engine brake opening state is not turned on; when the current engine speed is greater than the preset speed (for example, 800rpm) and the required negative torque is greater than the preset negative torque (for example, -200Nm), the engine brake opening state is turned on, and in other cases, the exhaust brake opening state is determined to be closed. Then the engine brake opening state can be judged. When the engine brake opening state is closed, the process ends and waits for the next negative torque request to be received; when the engine brake opening state is on, it is judged whether the required negative torque can be maintained by turning on the engine brake alone. If yes, the engine brake is determined to be on, and the engine brake torque is adjusted by the engine brake to complete the stepless adjustment of the engine brake; if not, when the engine brake opening state is on, the pneumatic supercharger is adjusted again, and the duty cycle is adjusted by adjusting the opening of the pneumatic supercharger, and then the engine brake torque is adjusted to obtain the first engine brake torque after adjustment, and then it can be judged whether the first engine brake torque meets the required negative torque (that is, whether turning on the engine brake and the pneumatic supercharger is sufficient to maintain the required negative torque of the whole vehicle). If yes, the engine brake torque condition can be completed by turning on the engine brake and the pneumatic supercharger, and then the stepless adjustment of the engine brake is realized. If not, the engine brake torque can be adjusted again by other devices, and the acquisition returns to S101. The specific process can be set according to the actual situation, and the embodiment of the present invention is not limited here.

[0022] Compared with the prior art, the present embodiment provides a method for obtaining a negative torque request and basic driving data sent when a vehicle is braking, and determining a required negative torque according to the negative torque request; determining an engine braking on-state according to the basic driving data and the required negative torque; when the engine braking on-state is on and the engine braking of the vehicle does not meet the required negative torque, adjusting the pneumatic supercharger to obtain a first engine braking torque; when the first engine braking torque meets the required negative torque, completing stepless adjustment of the engine braking, and adjusting the engine braking and the pneumatic supercharger to increase the braking effect; controlling the engine braking torque of the vehicle according to the required negative torque, and performing continuously variable torque adjustment, thereby achieving stepless adjustment of the engine braking.

[0023] In some embodiments of the present invention, before step S102, the method further includes: The throttle opening is set to fully open, the exhaust gas recirculation valve opening is set to fully closed, and the duty cycle of the pneumatic supercharger is set to a preset value.

[0024] In a specific embodiment of the present invention, when the EECU receives a negative torque request from the vehicle, the engine brake is controlled not to be turned on, the throttle opening is fully opened, the exhaust gas recirculation valve opening (EGR) is fully closed, and the pneumatic supercharger duty cycle is a preset value, which can be 0.

[0025] In some embodiments of the present invention, the basic driving data includes the current engine speed; the engine brake on state includes the exhaust brake on state and the cylinder brake on state; Figure 3 As shown, step S102 includes: S301, determining an exhaust brake opening state according to a current engine speed and a required negative torque; S302, when the exhaust brake on state is on and the exhaust brake on state does not satisfy the required negative torque, determining that the in-cylinder brake on state is on, and determining the exhaust brake on state to be off; S303: When the in-cylinder brake is turned on but the required negative torque cannot be satisfied, the in-cylinder brake turn-on state and the exhaust brake turn-on state are determined to be turned on.

[0026] In a specific embodiment of the present invention, the engine brake on state may include an exhaust brake on state and an in-cylinder brake on state. When the EECU receives a negative torque request for the whole vehicle, the required negative torque is taken as a target, and the exhaust brake on state is calculated according to the current engine speed and the required negative torque. When the exhaust brake on state is on, and turning on the exhaust brake alone is sufficient to maintain the required negative torque of the whole vehicle (when turning on the exhaust brake satisfies the required negative torque), only the exhaust brake is used; when turning on the exhaust brake alone is insufficient to maintain the required negative torque of the whole vehicle (when turning on the exhaust brake does not satisfy the required negative torque), the in-cylinder brake on state is turned on, and the exhaust brake on state is determined to be off; when turning on the in-cylinder brake alone is sufficient to maintain the required negative torque of the whole vehicle (when turning on the in-cylinder brake satisfies the required negative torque), only the in-cylinder brake is used; when turning on the in-cylinder brake alone is insufficient to maintain the required negative torque of the whole vehicle (when turning on the in-cylinder brake does not satisfy the required negative torque), the in-cylinder brake on state and the exhaust brake on state are determined to be on, that is, the in-cylinder brake and the exhaust brake are used at the same time.

[0027] In some embodiments of the present invention, step S301 includes: Determine whether the current engine speed is greater than a preset speed, and whether the required negative torque is greater than a preset negative torque; If so, it is determined that the exhaust brake opening state is on; If not, it is determined that the exhaust brake opening state is closed.

[0028] In a specific embodiment of the present invention, a mapping table is searched according to the current engine speed and the required negative torque, and the table value determines whether the engine brake is turned on. For example, when the current engine speed or the required negative torque is low, the exhaust brake is turned off; when the current engine speed is greater than a preset speed (such as 800rpm) and the required negative torque is greater than a preset negative torque (such as -200Nm), the exhaust brake is turned on; in other cases, the exhaust brake is turned off.

[0029] In some embodiments of the present invention, the basic driving data includes the air intake temperature of the pneumatic supercharger, the actual boost pressure error and the altitude; Figure 4 As shown, step S103 includes: S401, determining an initial exhaust gas bypass opening feedforward item of the pneumatic supercharger according to the current engine speed and the required negative torque, and correcting the initial exhaust gas bypass opening feedforward item according to the altitude to obtain a target exhaust gas bypass opening feedforward item; S402, determining an initial boost pressure of the pneumatic supercharger according to the current engine speed and the required negative torque, and correcting the initial boost pressure according to the altitude and the intake air temperature to obtain a target boost pressure; S403, performing closed-loop control calculation according to the target boost pressure and the actual boost pressure error to obtain a closed-loop item of the exhaust gas bypass opening of the pneumatic supercharger; S404, obtaining the exhaust gas bypass opening of the pneumatic supercharger according to the target exhaust gas bypass opening feedforward term and the exhaust gas bypass opening closed-loop term; S405: Adjust the duty cycle according to the exhaust gas bypass opening to obtain a first engine braking torque.

[0030] In some embodiments of the present invention, step S401 includes: The initial exhaust gas bypass opening degree feedforward term is corrected according to the altitude to obtain a corrected exhaust gas bypass opening degree feedforward term; A target exhaust bypass opening degree feedforward term is obtained according to the initial exhaust bypass opening degree feedforward term and the corrected exhaust bypass opening degree feedforward term.

[0031] In a specific embodiment of the present invention, the basic driving data may also include the intake temperature of the pneumatic supercharger, the actual boost pressure error and the altitude. When the engine braking alone is not sufficient to maintain the required negative torque, the engine braking torque is adjusted by adjusting the duty cycle of the pneumatic supercharger to obtain the first engine braking torque after adjustment. Specifically, the initial exhaust bypass opening feedforward item of the pneumatic supercharger under the engine braking condition is calculated according to the engine speed and the negative torque demand, and then the initial exhaust bypass opening feedforward item is corrected by the altitude to obtain the corrected initial exhaust bypass opening feedforward item, and then the initial exhaust bypass opening feedforward item is added to the corrected initial exhaust bypass opening feedforward item to obtain the target exhaust bypass opening feedforward item; the exhaust bypass opening closed-loop item of the pneumatic supercharger under the engine braking condition is calculated according to the engine speed and the negative torque demand. The initial boost pressure / exhaust manifold demand pressure is calculated based on the speed and negative torque demand (the boost pressure closed loop is preferred, and the exhaust manifold pressure sensor is used when there is no boost pressure sensor), and the initial boost pressure is corrected according to the altitude and intake temperature to obtain the corrected boost pressure. The initial boost pressure is then added to the corrected boost pressure to obtain the target boost pressure. A closed-loop control calculation is then performed based on the error between the target boost pressure and the actual boost pressure to obtain the closed-loop item of the exhaust gas bypass opening of the pneumatic supercharger; the exhaust gas bypass opening of the pneumatic supercharger is calculated based on the feedforward item and closed-loop item of the exhaust gas bypass opening of the pneumatic supercharger under engine braking conditions, and the duty cycle is adjusted based on the exhaust gas bypass opening to obtain the first engine braking torque. When there is no boost pressure sensor or exhaust manifold pressure sensor, only the feedforward item is considered.

[0032] In some embodiments of the present invention, the method further comprises: When the first engine braking torque does not meet the required negative torque, determining a throttle opening term according to the current engine speed and the required negative torque; The intake air volume is adjusted according to the throttle opening term to obtain a second engine braking torque; When the second engine braking torque meets the required negative torque, the stepless adjustment of the engine braking is completed.

[0033] In a specific embodiment of the present invention, when the engine brake and the pneumatic supercharger are not sufficient to maintain the required negative torque (when the first engine brake torque does not meet the required negative torque), the throttle opening item is determined according to the current engine speed and the required negative torque, and then the altitude correction is performed. The engine brake torque is adjusted by adjusting the intake volume through the throttle opening item to obtain the second engine brake torque. When the engine brake and the pneumatic supercharger are turned on and the throttle is sufficient to maintain the required negative torque (when the second engine brake torque meets the required negative torque), the stepless adjustment of the engine brake is completed.

[0034] In some embodiments of the present invention, when the second engine braking torque meets the required negative torque, after the stepless adjustment of the engine braking is completed, the method further includes: When the second engine braking torque does not meet the required negative torque, determining an exhaust gas recirculation valve opening term according to the current engine speed and the required negative torque; The exhaust gas volume is adjusted according to the exhaust gas recirculation valve opening item to obtain a third engine braking torque; The engine brake is adjusted steplessly according to the third engine brake torque.

[0035] In a specific embodiment of the present invention, when turning on the engine brake and the pneumatic supercharger and the throttle is not sufficient to maintain the required negative torque (when the second engine braking torque does not meet the required negative torque), the exhaust gas recirculation valve opening item under the engine braking condition is calculated based on the engine speed and the negative torque demand, the exhaust gas recirculation valve opening item is determined, and then the altitude correction is performed. The exhaust gas volume is adjusted by adjusting the exhaust gas recirculation valve opening item to adjust the engine braking torque to the third engine braking torque, and then the stepless adjustment of the engine braking is completed according to the third engine braking torque.

[0036] A specific embodiment of the present invention, as Figure 5 As shown, when the EECU receives a negative torque request from the vehicle, the required negative torque is used as the target. At this time, the throttle is controlled to be fully open, the EGR is fully closed, and the duty cycle of the pneumatic supercharger is 0. The engine brake opening state is calculated according to the current engine speed and the negative torque demand.

[0037] When turning on the engine brake alone is not enough to maintain the required negative torque, the engine braking torque is adjusted by adjusting the duty cycle of the pneumatic supercharger. The pneumatic supercharger exhaust bypass opening feedforward item under engine braking conditions is calculated based on the engine speed and negative torque demand, and then the altitude correction is performed; the pneumatic supercharger exhaust bypass opening closed-loop item under engine braking conditions calculates the target boost pressure / exhaust manifold required pressure based on the engine speed and negative torque demand (preferentially based on the boost pressure closed loop, and the exhaust manifold pressure sensor is used when there is no boost pressure sensor), the target boost pressure is corrected according to the altitude and intake temperature, and the closed-loop control calculation is performed based on the error between the target boost pressure and the actual boost pressure; the pneumatic supercharger exhaust bypass opening is calculated based on the pneumatic supercharger exhaust bypass opening feedforward item and closed-loop item under engine braking conditions, and only the feedforward item is considered when there is no boost pressure sensor or exhaust manifold pressure sensor.

[0038] When the engine brake and pneumatic supercharger are not enough to maintain the required negative torque, the engine brake torque is adjusted by adjusting the intake air volume through the throttle. The throttle opening item under engine brake conditions is calculated based on the engine speed and negative torque demand, and then the altitude correction is performed.

[0039] When the engine brake and pneumatic supercharger and throttle are not enough to maintain the required negative torque, the engine brake torque is adjusted by adjusting the exhaust gas volume through exhaust gas recirculation. The exhaust gas recirculation valve opening item under engine braking conditions is calculated based on the engine speed and negative torque demand, and then corrected for altitude.

[0040] A specific embodiment of the present invention, as Figure 6 As shown, when there are both a switch-type engine brake valve and a switch-type exhaust brake valve: When the EECU receives a negative torque request from the vehicle, the required negative torque is used as the target. At this time, the engine brake is controlled not to be turned on, the throttle is fully open, the EGR is fully closed, and the duty cycle of the pneumatic supercharger is 0. The exhaust brake opening state is calculated according to the current engine speed and negative torque demand.

[0041] When the exhaust brake alone is sufficient to maintain the required negative torque, only the exhaust brake is used; when the exhaust brake alone is insufficient to maintain the required negative torque, the cylinder brake is turned on; when the cylinder brake alone is sufficient to maintain the required negative torque, only the cylinder brake is used; when the engine brake alone is insufficient to maintain the required negative torque, both the cylinder brake and the exhaust brake are used; The engine braking torque is adjusted by adjusting the duty cycle of the pneumatic supercharger. The feedforward item of the pneumatic supercharger exhaust bypass opening under engine braking conditions is calculated based on the engine speed and negative torque demand, and then the altitude correction is performed; the closed-loop item of the pneumatic supercharger exhaust bypass opening under engine braking conditions calculates the target boost pressure / exhaust manifold demand pressure based on the engine speed and negative torque demand (the boost pressure closed loop is preferred, and the exhaust manifold pressure sensor is used when there is no boost pressure sensor), the target boost pressure is corrected according to the altitude and intake temperature, and the closed-loop control calculation is performed based on the error between the target boost pressure and the actual boost pressure; the pneumatic supercharger exhaust bypass opening is calculated based on the feedforward item and closed-loop item of the pneumatic supercharger exhaust bypass opening under engine braking conditions, and only the feedforward item is considered when there is no boost pressure sensor or exhaust manifold pressure sensor.

[0042] When the engine brake and pneumatic supercharger are not enough to maintain the required negative torque, the engine brake torque is adjusted by adjusting the intake air volume through the throttle. The throttle opening item under engine brake conditions is calculated based on the engine speed and negative torque demand, and then the altitude correction is performed.

[0043] When the engine brake and pneumatic supercharger and throttle are not enough to maintain the required negative torque, the engine brake torque is adjusted by adjusting the exhaust gas volume through exhaust gas recirculation. The exhaust gas recirculation valve opening item under engine braking conditions is calculated based on the engine speed and negative torque demand, and then corrected for altitude.

[0044] The embodiment of the present invention has good compatibility, determines the priority action sequence of each actuator, and is compatible with different configurations; the principle of adjusting the intake boost pressure by a pneumatic supercharger is utilized, and the duty cycle of the pneumatic supercharger is adjusted in a closed loop according to the boost pressure or the exhaust manifold pressure; the throttle valve and the exhaust gas recirculation valve are used to assist in open loop regulation to avoid mutual interference among the pneumatic supercharger, the throttle valve, and the exhaust gas recirculation valve actuators; the pneumatic supercharger, the throttle valve, and the exhaust gas recirculation valve are used in combination to achieve stepless adjustment of the engine braking torque from 0 to the maximum capacity.

[0045] In order to better implement the engine brake stepless adjustment method in the embodiment of the present invention, based on the engine brake stepless adjustment method, the embodiment of the present invention also provides an engine brake stepless adjustment device, such as Figure 7 As shown, the engine brake stepless adjustment device 700 includes: The data acquisition module 701 is used to acquire the negative torque request and basic driving data sent when the vehicle is braking, and determine the required negative torque according to the negative torque request; A state determination module 702, for determining an engine brake on state according to basic driving data and required negative torque; The torque determination module 703 is used to adjust the pneumatic supercharger to obtain a first engine braking torque when the engine braking start state is on and the engine braking of the vehicle does not meet the required negative torque; The stepless adjustment module 704 is used to complete the stepless adjustment of the engine braking when the first engine braking torque meets the required negative torque.

[0046] The engine brake stepless adjustment device 700 provided in the above embodiment can implement the technical solution described in the above engine brake stepless adjustment method embodiment. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above engine brake stepless adjustment method embodiment, which will not be repeated here.

[0047] like Figure 8 As shown, the present invention also provides a vehicle 800. The vehicle 800 includes a processor 801, a memory 802 and a display 803. Figure 8 Only some of the components of vehicle 800 are shown, but it should be understood that implementation of all of the components shown is not a requirement, and more or fewer components may alternatively be implemented.

[0048] In some embodiments, the memory 802 may be an internal storage unit of the vehicle 800, such as a hard disk or memory of the vehicle 800. In other embodiments, the memory 802 may also be an external storage device of the vehicle 800, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., equipped on the vehicle 800.

[0049] Furthermore, the memory 802 may include both an internal storage unit of the vehicle 800 and an external storage device. The memory 802 is used to store application software installed in the vehicle 800 and various data.

[0050] In some embodiments, the processor 801 may be a central processing unit (CPU), a microprocessor or other data processing chip, and is used to run program codes or process data stored in the memory 802, such as the engine brake stepless adjustment method of the present invention.

[0051] In some embodiments, the display 803 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 803 is used to display information of the vehicle 800 and to display a visual user interface. The components 801-803 of the vehicle 800 communicate with each other via a system bus.

[0052] In some embodiments of the present invention, when the processor 801 executes the engine brake stepless adjustment program in the memory 802, the following steps may be implemented: Obtaining a negative torque request and basic driving data sent when the vehicle is braking, and determining a required negative torque according to the negative torque request; Determine the engine brake on state according to basic driving data and required negative torque; When the engine brake on state is on and the engine brake of the vehicle does not meet the required negative torque, the pneumatic supercharger is adjusted to obtain a first engine brake torque; When the first engine braking torque meets the required negative torque, the stepless adjustment of the engine braking is completed.

[0053] It should be understood that: when the processor 801 executes the engine brake stepless adjustment program in the memory 802, in addition to the above functions, other functions can also be realized. For details, please refer to the description of the corresponding method embodiment above.

[0054] Furthermore, the embodiment of the present invention does not specifically limit the type of the vehicle 800 mentioned, and the vehicle 800 may be a commercial vehicle, an off-road vehicle, or other vehicles.

[0055] Accordingly, an embodiment of the present application also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, the engine braking stepless adjustment method steps or functions provided in the above-mentioned method embodiments can be implemented.

[0056] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0057] The engine brake stepless adjustment method, device, equipment and medium provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for stepless adjustment of engine braking, characterized in that: include: Acquire a negative torque request and basic driving data sent when the vehicle is braking, and determine a required negative torque according to the negative torque request; determining an engine brake activation state according to the basic driving data and the required negative torque; When the engine brake on state is on and the engine brake of the vehicle does not meet the required negative torque, adjusting the pneumatic supercharger to obtain a first engine brake torque; When the first engine braking torque satisfies the required negative torque, the stepless adjustment of the engine braking is completed.

2. The engine brake stepless adjustment method according to claim 1, characterized in that: The basic driving data includes the current engine speed; the engine brake on state includes the exhaust brake on state and the cylinder brake on state; The determining the engine brake on state according to the basic driving data and the required negative torque includes: determining the exhaust brake opening state according to the current engine speed and the required negative torque; When the exhaust brake on state is on and the exhaust brake on state does not satisfy the required negative torque, determining that the in-cylinder brake on state is on, and determining the exhaust brake on state is off; When the in-cylinder brake is turned on and does not satisfy the required negative torque, the in-cylinder brake turned on state and the exhaust brake turned on state are determined to be turned on.

3. The engine brake stepless adjustment method according to claim 2, characterized in that: The basic driving data includes the intake temperature of the pneumatic supercharger, the actual boost pressure error and the altitude; the pneumatic supercharger is adjusted to obtain the first engine braking torque, including: Determining an initial exhaust gas bypass opening feedforward term of the pneumatic supercharger according to the current engine speed and the required negative torque, and correcting the initial exhaust gas bypass opening feedforward term according to the altitude to obtain a target exhaust gas bypass opening feedforward term; determining an initial boost pressure of the pneumatic supercharger according to the current engine speed and the required negative torque, and correcting the initial boost pressure according to the altitude and the intake air temperature to obtain a target boost pressure; Performing closed-loop control calculation according to the target boost pressure and the actual boost pressure error to obtain a closed-loop term of the exhaust gas bypass opening of the pneumatic supercharger; Obtaining the exhaust gas bypass opening of the pneumatic supercharger according to the target exhaust gas bypass opening feedforward term and the exhaust gas bypass opening closed-loop term; The duty cycle is adjusted according to the exhaust bypass opening to obtain a first engine braking torque.

4. The engine brake stepless adjustment method according to claim 2, characterized in that: The method further comprises: When the first engine braking torque does not meet the required negative torque, determining a throttle opening term according to the current engine speed and the required negative torque; The intake air volume is adjusted according to the throttle opening item to obtain a second engine braking torque; When the second engine braking torque satisfies the required negative torque, the stepless adjustment of the engine braking is completed.

5. The method for steplessly adjusting engine brake according to claim 4, characterized in that: When the second engine braking torque satisfies the required negative torque, after the stepless adjustment of the engine braking is completed, the method further includes: When the second engine braking torque does not meet the required negative torque, determining an exhaust gas recirculation valve opening term according to the current engine speed and the required negative torque; adjusting the exhaust gas volume according to the exhaust gas recirculation valve opening item to obtain a third engine braking torque; The engine braking is continuously adjusted according to the third engine braking torque.

6. The engine brake stepless adjustment method according to claim 2, characterized in that: The step of determining the exhaust brake opening state according to the current engine speed and the required negative torque includes: Determining whether the current engine speed is greater than a preset speed, and whether the required negative torque is greater than a preset negative torque; If so, determining that the exhaust brake opening state is on; If not, it is determined that the exhaust brake opening state is closed.

7. The method for steplessly adjusting engine brake according to claim 3, characterized in that: The step of correcting the initial exhaust gas bypass opening feedforward term according to the altitude to obtain a target exhaust gas bypass opening feedforward term includes: Correcting the initial exhaust bypass opening feedforward term according to the altitude to obtain a corrected exhaust bypass opening feedforward term; A target exhaust bypass opening degree feedforward term is obtained according to the initial exhaust bypass opening degree feedforward term and the corrected exhaust bypass opening degree feedforward term.

8. An engine brake stepless adjustment device, characterized in that: include: A data acquisition module, used to acquire a negative torque request and basic driving data sent when the vehicle is braking, and determine a required negative torque according to the negative torque request; a state determination module, configured to determine an engine brake activation state according to the basic driving data and the required negative torque; a torque determination module, configured to adjust the pneumatic supercharger to obtain a first engine braking torque when the engine braking on state is on and the engine braking of the vehicle does not meet the required negative torque; The stepless adjustment module is used to complete the stepless adjustment of the engine braking when the first engine braking torque meets the required negative torque.

9. A vehicle, characterized in that: include: A processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein when the computer program is executed by the processor, the steps of the engine brake stepless adjustment method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the engine brake stepless adjustment method according to any one of claims 1 to 7 are implemented.

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