A DPF passive regeneration control method, system and vehicle when coasting with a barrier

Abstract

The present application relates to the field of particle trap control, and discloses a DPF passive regeneration control method and system when coasting with gears and a vehicle, collects vehicle operation signals; determines whether the vehicle is in a coasting state with gears according to the vehicle operation signals; if the vehicle is in a coasting state with gears, collects the temperature upstream of the DPF; determines whether the temperature upstream of the DPF is less than a preset value, if yes, controls the engine to enter a temperature maintenance mode to maintain the exhaust temperature, otherwise, continuously collects the temperature upstream of the DPF. The present application controls the engine to enter a temperature maintenance mode to maintain the exhaust temperature when the vehicle is coasting with gears, avoids the problem that the exhaust temperature is reduced and the DPF passive regeneration function cannot be triggered due to coasting with gears, thereby affecting the fuel consumption and power of the vehicle.

Description

Technical Field

[0001] This invention relates to the field of particulate filter control, and more specifically to a DPF passive regeneration control method, system, and vehicle for coasting in gear. Background Technology

[0002] A DPF (Diesel Particulate Filter) filters particles in exhaust gas using the principle of physical filtration. The pores of the DPF carrier are blocked at alternating ends, forcing particles through the porous walls and diffusing and adhering to the pore walls, thus forming a filter. However, during the filtration process, as particles continuously accumulate in the DPF, it can cause an increase in the exhaust back pressure of the diesel engine, leading to a deterioration in diesel engine performance. Therefore, it is necessary to periodically remove particles from the DPF to restore it to its initial state and achieve DPF regeneration.

[0003] DPF regeneration methods are divided into active regeneration and passive regeneration. In actual operation, vehicles inevitably use coasting mode in gear. At this time, the engine is in reverse drag mode and does not inject fuel for combustion, causing the exhaust temperature to drop sharply. The exhaust temperature is too low to trigger the passive regeneration function of DPF, thus frequently triggering the active regeneration function of DPF, which seriously affects the vehicle's fuel consumption and power. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a DPF passive regeneration control method, system, and vehicle for coasting in gear. When the vehicle is coasting in gear, the engine is controlled to enter a heat preservation mode to maintain exhaust temperature, preventing the exhaust temperature from dropping and thus avoiding the failure to trigger the DPF passive regeneration function, which would otherwise affect the vehicle's fuel consumption and power.

[0005] In a first aspect, the technical solution of the present invention provides a DPF passive regeneration control method for coasting in gear, comprising the following steps: Collect vehicle operation signals; Determine whether the vehicle is in a coasting state based on the vehicle operation signal; If the vehicle is coasting in gear, the upstream temperature of the DPF is collected; Determine if the upstream temperature of the DPF is lower than the preset value. If so, control the engine to enter the heat preservation mode to maintain exhaust temperature; otherwise, continuously collect the upstream temperature of the DPF.

[0006] In one alternative implementation, the engine is a 6-cylinder diesel engine; Controlling the engine to enter a heat preservation mode to maintain exhaust temperature includes: Control the engine to execute a three-cylinder braking + three-cylinder ignition mode.

[0007] In one optional implementation, vehicle operation signals are collected, specifically including: Collect vehicle throttle signal, speed signal, acceleration signal and gear signal.

[0008] In an optional implementation, after controlling the engine to enter a heat preservation mode to maintain exhaust temperature, the following steps are also included: Check if the vehicle has exited the coasting mode; if so, control the engine to exit the warm-up mode.

[0009] In one optional implementation, detecting whether the vehicle has exited the coasting state in gear specifically includes: Detect whether an accelerator signal, brake pedal signal, or braking signal is received.

[0010] Secondly, the technical solution of the present invention provides a DPF passive regeneration control system for vehicles coasting in gear, comprising: Detection unit: used to collect vehicle operation signals and DPF upstream temperature; Engine insulation module: Used to implement engine insulation mode; Electronic control unit: Used to determine whether the vehicle is in a coasting state based on the vehicle operation signal collected by the detection unit. If so, it triggers the detection unit to collect the upstream temperature of the DPF and determines whether the upstream temperature of the DPF is less than the preset value. If so, it triggers the engine insulation module to control the engine to enter the insulation mode to maintain the exhaust temperature.

[0011] In one optional implementation, the engine insulation module includes an in-cylinder braking system and a fuel supply system; the engine is a 6-cylinder diesel engine. Triggering the engine insulation module to control the engine to enter insulation mode and maintain exhaust temperature, specifically including: The system controls the in-cylinder braking system to execute the braking mode of three cylinders, while simultaneously controlling the fuel supply system to cut off fuel to the three cylinders in braking mode and ignite and inject fuel to the three cylinders in non-braking mode.

[0012] In one optional implementation, the detection unit includes a throttle signal sensor, a vehicle speed signal sensor, an acceleration signal sensor, a gear position signal sensor, and a DPF upstream temperature sensor. Vehicle operation signals include throttle signals collected by the throttle signal sensor, vehicle speed signals collected by the vehicle speed signal sensor, acceleration signals collected by the acceleration signal sensor, and gear signals collected by the gear position signal sensor; The upstream temperature sensor of the DPF is used to collect the upstream temperature of the DPF.

[0013] In an optional embodiment, the detection unit further includes a brake pedal signal sensor for acquiring brake pedal signals and a brake signal sensor for acquiring braking signals. The electronic control unit is also used to detect whether a throttle signal, brake pedal signal, or braking signal is received after the engine is put into the heat preservation mode to maintain exhaust temperature. If so, the engine is controlled to exit the heat preservation mode.

[0014] Thirdly, the technical solution of the present invention provides a vehicle equipped with the control system described in any one of the above claims.

[0015] The present invention provides a DPF passive regeneration control method, system, and vehicle for coasting in gear. Compared with the prior art, it has the following advantages: It collects vehicle operation signals to determine whether the vehicle is in a coasting state. In the coasting state, it first determines whether the upstream temperature of the DPF is lower than a preset value. If it is lower than the preset value, it indicates that the exhaust temperature does not meet the conditions for DPF passive regeneration. At this time, it controls the engine to enter a heat preservation mode. The engine is a 6-cylinder diesel engine, specifically a heat preservation mode of three-cylinder braking + three-cylinder ignition can be adopted. This ensures that the engine has no torque output while increasing the exhaust temperature, which can better maintain the DPF passive regeneration function and avoid DPF blockage. Attached Figure Description To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a passive regeneration control method for DPF during coasting with gear provided in an embodiment of the present invention.

[0017] Figure 2 This is a schematic block diagram of a DPF passive regeneration control system for coasting with gears provided in an embodiment of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0020] Figure 1 This is a schematic flowchart of a passive regeneration control method for DPF during coasting in gear, provided by an embodiment of the present invention. Figure 1 As shown, the method includes the following steps.

[0021] Step 101: Collect vehicle operation signals.

[0022] In this embodiment, throttle signal, vehicle speed signal, acceleration signal and gear signal can be collected.

[0023] Step 102: Determine whether the vehicle is in a coasting state based on the vehicle operation signal.

[0024] After collecting vehicle operation signals, it is determined whether the vehicle operation signals meet the conditions for coasting in gear. If so, it means that the vehicle is in a coasting state in gear. For example, if there is no throttle signal, the vehicle speed is less than a threshold, the acceleration is less than a threshold and the rate of change of acceleration decreases, and the gear is not in neutral, it means that the vehicle is in a coasting state in gear.

[0025] If the vehicle operation signal meets the conditions for coasting in gear, then step 103 is executed. That is, when the vehicle is in coasting mode, the engine does not inject fuel for combustion, leading to a decrease in exhaust temperature, which may affect the DPF passive regeneration function. Therefore, it is necessary to collect the upstream temperature T of the DPF for judgment, and then execute step 103.

[0026] Of course, if the coasting adjustment is not satisfied, then step S101 continues.

[0027] Step 103: Collect the upstream temperature T of the DPF.

[0028] When the vehicle operation signal meets the conditions for coasting in gear, it is necessary to further collect the upstream temperature of the DPF to determine whether the vehicle's gear operation mode affects the passive regeneration function of the DPF.

[0029] S104. Determine whether the upstream temperature of the DPF is less than the preset value. If so, proceed to step S105; otherwise, continue to proceed to step S103.

[0030] When the upstream temperature T of the DPF is less than the preset value T1 for passive regeneration of the DPF, the engine can be controlled to enter the heat preservation mode (three-cylinder braking + three-cylinder ignition) to maintain the exhaust temperature. When the upstream temperature of the DPF is not less than the preset value T1 for passive regeneration of the DPF, the passive regeneration of the DPF can proceed normally without controlling the engine to enter the heat preservation mode. Instead, the upstream temperature T of the DPF will continue to be monitored.

[0031] S105 controls the engine to enter the heat preservation mode to maintain exhaust temperature.

[0032] In one specific embodiment, the engine is a 6-cylinder diesel engine. The heat preservation mode refers to a three-cylinder braking + three-cylinder ignition mode. The in-cylinder braking system controls the first three or the last three cylinders to be in braking mode, while the remaining three cylinders are in non-braking mode. The fuel supply system coordinates to de-fuel the three cylinders in braking mode and ignite the three cylinders in non-braking mode, with the ignition cylinder injecting fuel. For example, the first three cylinders brake while the last three cylinders ignite.

[0033] The heat preservation mode is the working mode actually calibrated during the DPF passive regeneration calibration test. Specifically, the three-cylinder braking MAP and three-cylinder fuel injection MAP are calibrated according to the DPF passive regeneration temperature threshold at different engine speeds. The braking torque and positive power torque cancel each other out, the engine has no torque output, and the upstream temperature of the DPF is raised to the temperature required for DPF passive regeneration. This satisfies the temperature requirements of DPF passive regeneration without affecting the vehicle's coasting in gear.

[0034] S106: Detect whether the vehicle has exited the coasting mode; if so, control the engine to exit the warm-up mode.

[0035] This embodiment determines whether to exit the coasting mode by collecting throttle signal, brake pedal signal, and braking signal. When a throttle signal, brake pedal signal, or braking signal is collected, it indicates that the vehicle will no longer maintain the coasting mode and the engine needs to be controlled to exit the warm-up mode in order to avoid affecting the normal operation of the engine.

[0036] In this embodiment, vehicle operation signals are collected; it is determined whether the vehicle operation signals meet the conditions for coasting in gear; if the vehicle operation signals meet the conditions for coasting in gear, the upstream temperature T of the DPF is collected; it is determined whether the temperature T is less than the preset value T1 for passive regeneration of the DPF; if the temperature T is less than the preset value T1 for passive regeneration of the DPF, the engine is controlled to enter the heat preservation mode (three-cylinder braking + three-cylinder ignition) to maintain the exhaust temperature; otherwise, the upstream temperature T of the DPF continues to be collected; the engine is controlled to enter the heat preservation mode (three-cylinder braking + three-cylinder ignition) to maintain the exhaust temperature; when a throttle signal, brake pedal signal, or braking signal is collected, the heat preservation mode is exited. Therefore, when the vehicle is coasting in gear and the exhaust temperature does not meet the conditions for passive regeneration of the DPF, the heat preservation mode of three-cylinder braking + three-cylinder ignition is used to increase the exhaust temperature while ensuring that the engine has no torque output, which can better maintain the passive regeneration function of the DPF and avoid DPF clogging.

[0037] The foregoing has described in detail an embodiment of a passive regeneration control method for DPF during coasting in gear. Based on the passive regeneration control method for DPF during coasting in gear described in the above embodiment, this invention also provides a passive regeneration control system for DPF during coasting in gear corresponding to the method.

[0038] Figure 2This is a schematic block diagram of a DPF passive regenerative control system for coasting with gears provided in an embodiment of the present invention, as shown in the figure. Figure 2 As shown, the system in this embodiment includes a detection unit, an engine insulation module, and an electronic control unit.

[0039] Detection unit: Used to collect vehicle operation signals and upstream temperature of DPF.

[0040] Engine insulation module: Used to implement engine insulation mode.

[0041] Electronic control unit: Used to determine whether the vehicle is in a coasting state based on the vehicle operation signal collected by the detection unit. If so, it triggers the detection unit to collect the upstream temperature of the DPF and determines whether the upstream temperature of the DPF is less than the preset value. If so, it triggers the engine insulation module to control the engine to enter the insulation mode to maintain the exhaust temperature.

[0042] The engine is a 6-cylinder diesel engine, and the engine insulation module includes an in-cylinder braking system and a fuel supply system.

[0043] The in-cylinder braking system enables a three-cylinder braking mode, which is used to generate braking torque and increase exhaust temperature.

[0044] The fuel supply system can realize three-cylinder fuel cut-off / three-cylinder fuel injection function, which is used to cut off fuel to the brake cylinder and inject fuel to the ignition cylinder in the heat preservation mode.

[0045] Trigger the engine insulation module to control the engine to enter the insulation mode to maintain exhaust temperature. Specifically, this includes controlling the in-cylinder braking system to execute the braking mode of three cylinders, and simultaneously controlling the fuel supply system to cut off fuel to the three cylinders in the braking mode and ignite and inject fuel to the three cylinders in the non-braking mode.

[0046] In this embodiment, the detection unit includes a throttle signal sensor, a vehicle speed signal sensor, an acceleration signal sensor, a gear position signal sensor, and a DPF upstream temperature sensor. Vehicle operating signals include the throttle signal collected by the throttle signal sensor, the vehicle speed signal collected by the vehicle speed signal sensor, the acceleration signal collected by the acceleration signal sensor, and the gear position signal collected by the gear position signal sensor. The DPF upstream temperature sensor is used to collect the temperature upstream of the DPF.

[0047] The detection unit also includes a brake pedal signal sensor for acquiring brake pedal signals and a brake signal sensor for acquiring braking signals.

[0048] Correspondingly, the electronic control unit is also used to detect whether a throttle signal, brake pedal signal, or braking signal is received after the engine is controlled to enter the heat preservation mode to maintain exhaust temperature. If so, the engine is controlled to exit the heat preservation mode.

[0049] Electronic control units can be ECUs, but are not limited to them. They will not be elaborated on here, but are all within the scope of protection of this application.

[0050] The detection unit collects vehicle operation signals; the electronic control unit determines whether the vehicle operation signals meet the conditions for coasting in gear; if the vehicle operation signals meet the conditions for coasting in gear, the detection unit collects the upstream temperature T of the DPF; the electronic control unit determines whether the temperature T is less than the preset value T1 for passive regeneration of the DPF; if the temperature T is less than the preset value T1 for passive regeneration of the DPF, the engine is controlled to enter the heat preservation mode (three-cylinder braking + three-cylinder ignition) to maintain the exhaust temperature; if the temperature T is not less than the preset value T1 for passive regeneration of the DPF, the system returns to collecting the upstream temperature T of the DPF; the electronic control unit controls the engine to enter the heat preservation mode (three-cylinder braking + three-cylinder ignition) to maintain the exhaust temperature; maintaining a reasonable exhaust temperature while ensuring no torque output from the engine can better maintain the passive regeneration function of the DPF and avoid DPF clogging; when a throttle signal, brake pedal signal, or braking signal is collected, the electronic control unit controls the engine to exit the heat preservation mode to avoid affecting the normal operation of the engine.

[0051] This invention also provides a vehicle equipped with the control system described above.

[0052] The above-disclosed embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any non-creative variations that can be conceived by those skilled in the art, as well as any improvements and modifications made without departing from the principles of the present invention, should fall within the protection scope of the present invention.

Claims

1. A passive regenerative DPF control method for coasting in gear, characterized in that, Includes the following steps: Collect vehicle operation signals; Determine whether the vehicle is in a coasting state based on the vehicle operation signal; If the vehicle is coasting in gear, the upstream temperature of the DPF is collected; Determine if the upstream temperature of the DPF is lower than the preset value. If so, control the engine to enter the heat preservation mode to maintain the exhaust temperature. Otherwise, continuously collect the upstream temperature of the DPF. The engine is a 6-cylinder diesel engine; Controlling the engine to enter a heat preservation mode to maintain exhaust temperature includes: Control the engine to execute a three-cylinder braking + three-cylinder ignition mode; The collection of vehicle operation signals specifically includes: Collect vehicle throttle signal, vehicle speed signal, acceleration signal and gear signal; After controlling the engine to enter the heat preservation mode to maintain exhaust temperature, the following steps are also included: Check if the vehicle has exited the coasting mode; if so, control the engine to exit the warm-up mode. The heat preservation mode is the working mode actually calibrated during the DPF passive regeneration calibration test. The three-cylinder braking MAP and three-cylinder fuel injection MAP are calibrated according to the DPF passive regeneration temperature threshold at different engine speeds. The braking torque and positive power torque cancel each other out, the engine has no torque output, and the upstream temperature of the DPF is raised to the temperature required for DPF passive regeneration.

2. The DPF passive regeneration control method for coasting in gear according to claim 1, characterized in that, Checking whether the vehicle has exited the coasting mode in gear includes: Detect whether an accelerator signal, brake pedal signal, or braking signal is received.

3. A DPF passive regenerative control system for coasting with gears, characterized in that, include, Detection unit: used to collect vehicle operation signals and DPF upstream temperature; Engine insulation module: Used to implement engine insulation mode; Electronic control unit: Used to determine whether the vehicle is in a coasting state based on the vehicle operation signal collected by the detection unit. If so, it triggers the detection unit to collect the upstream temperature of DPF and determine whether the upstream temperature of DPF is less than the preset value. If so, it triggers the engine insulation module to control the engine to enter the insulation mode to maintain the exhaust temperature. The engine insulation module includes an in-cylinder braking system and a fuel supply system; The engine is a 6-cylinder diesel engine; Triggering the engine insulation module to control the engine to enter insulation mode and maintain exhaust temperature, specifically including: The system controls the in-cylinder braking system to execute the braking mode of three cylinders, and at the same time controls the fuel supply system to cut off fuel to the three cylinders in the braking mode and ignite and inject fuel to the three cylinders in the non-braking mode. The detection unit includes a throttle signal sensor, a vehicle speed signal sensor, an acceleration signal sensor, a gear position signal sensor, and a DPF upstream temperature sensor; Vehicle operation signals include throttle signals collected by the throttle signal sensor, vehicle speed signals collected by the vehicle speed signal sensor, acceleration signals collected by the acceleration signal sensor, and gear signals collected by the gear position signal sensor; The upstream temperature sensor of the DPF is used to collect the upstream temperature of the DPF. The detection unit also includes a brake pedal signal sensor for acquiring brake pedal signals and a brake signal sensor for acquiring braking signals; The electronic control unit is also used to detect whether a throttle signal, brake pedal signal, or braking signal is received after the engine is put into the heat preservation mode to maintain exhaust temperature. If so, the engine is put out of the heat preservation mode. The heat preservation mode is the working mode actually calibrated during the DPF passive regeneration calibration test. The three-cylinder braking MAP and three-cylinder fuel injection MAP are calibrated according to the DPF passive regeneration temperature threshold at different engine speeds. The braking torque and positive power torque cancel each other out, the engine has no torque output, and the upstream temperature of the DPF is raised to the temperature required for DPF passive regeneration.

4. A vehicle, characterized in that, It is equipped with the control system described in claim 3.

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