Vehicle control method and device

Abstract

The present application relates to the technical field of vehicles, and discloses a vehicle control method and device. The method comprises the following steps: in response to the vehicle meeting an idle working condition condition, determining an idle basic supercharging pressure according to at least an idle speed and a throttle signal, and then correcting the idle basic supercharging pressure based on at least a real-time intake air temperature and a real-time atmospheric pressure to output an idle target supercharging pressure; and on the basis of at least the idle target supercharging pressure and an actual supercharging pressure, a first control mechanism is used to output a VGT control signal to drive a VGT actuator to execute a first vehicle control action. The present application no longer uses a traditional fixed cross-section turbine, but can at least utilize the VGT characteristics to execute corresponding vehicle control actions in the vehicle idle scene, so that the smoothness and power response of the vehicle in urban road driving can be improved, and the urban working condition fuel consumption can be reduced.

Description

Technical Field

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

[0002] In continuous driving scenarios on urban roads, especially in congested conditions, vehicles frequently experience situations such as "waiting at a red light - starting quickly at a green light - maintaining a constant speed while following other vehicles," or "waiting at a red light - starting and maintaining a constant speed while following other vehicles - overtaking," or "overtaking, releasing the accelerator and returning to a constant speed - stopping at a red light - starting quickly at a green light." Traditional turbocharging technology has at least the following drawbacks in this scenario: 1) Turbo lag and matching contradiction: Turbocharger design needs to balance low-speed response and high-speed power. Traditional fixed-section turbochargers must choose between "small section to improve low-speed response" and "large section to reduce high-speed exhaust back pressure," which cannot be satisfied simultaneously. In urban driving conditions, when drivers frequently accelerate rapidly, a small-section turbocharger can provide some low-speed torque, but the high exhaust back pressure leads to large engine pumping losses and poor fuel economy; conversely, if a large-section turbocharger is used, turbo lag is severe, resulting in sluggish acceleration response. 2) Plateau and Inefficient Zone Issues: Frequent start-stop and low-speed driving in urban areas cause the engine to operate in a low-speed, low-load range for extended periods. Under these conditions, the exhaust flow is small, the exhaust gas energy is insufficient, the turbocharger operating speed is low, the turbocharger efficiency drops significantly, the intake air volume in the cylinder is insufficient, combustion is incomplete, carbon deposits are easily generated, and exhaust emissions deteriorate. If this is combined with the low-pressure, thin air environment of plateaus, the oxygen content in the intake air is further reduced, the turbocharger drive energy continues to decay, and the problems of insufficient power, combustion degradation, and excessive emissions in the inefficient zone will be further aggravated. 3) Lack of continuous driving strategy: In the existing technology, there is a lack of intelligent control strategy that can effectively utilize VGT characteristics to maintain the engine in the high-efficiency range as much as possible while ensuring power response, so as to achieve "continuous" rather than "intermittent" driving for the ever-changing dynamic conditions of urban roads. Summary of the Invention

[0003] The purpose of this invention is to provide a vehicle control method and device that can at least improve the smoothness and power response of vehicles driving on urban roads, thereby reducing fuel consumption in urban conditions.

[0004] To address the aforementioned technical problems, in a first aspect, the present invention provides a vehicle control method, at least adaptable to vehicles equipped with a variable geometry turbocharger (VGT); the vehicle control method includes at least: In response to the vehicle meeting the idling conditions, the basic idle boost pressure is determined based at least on the idle speed and throttle signal, and then the basic idle boost pressure is corrected based at least on the real-time intake air temperature and real-time atmospheric pressure to output the target idle boost pressure. Based at least on the target boost pressure at idle and the actual boost pressure, a first control mechanism is used to output a VGT control signal to drive the VGT actuator to perform a first vehicle control action.

[0005] Optionally, the idling conditions are at least as follows: the vehicle is stationary, the throttle opening is 0, the engine speed is maintained at the idling speed, and the vehicle load does not exceed a preset load value.

[0006] Optionally, it may also include at least: In response to the vehicle meeting the preset steady-state operating conditions, the steady-state basic boost pressure is determined at least based on the engine speed and throttle opening, and then the steady-state basic boost pressure is corrected at least based on the real-time intake air temperature and the real-time atmospheric pressure to output the steady-state target boost pressure. Based at least on the steady-state target boost pressure and the actual boost pressure, a second control mechanism is used to output the VGT control signal to drive the VGT actuator to perform a second vehicle control action.

[0007] Optionally, the preset steady-state operating condition is at least that the user presses the accelerator pedal, and the rate of change of engine speed and / or the rate of change of throttle opening is lower than the corresponding rate of change threshold.

[0008] Optionally, at least during the process of outputting the VGT control signal using the second control mechanism, layered opening constraint logic for the nozzle ring blades based on the engine speed is superimposed.

[0009] Optionally, the hierarchical opening constraint logic includes at least: When the engine speed is within the first speed range, the opening of the nozzle ring blade is constrained to be within the first opening range; When the engine speed is within the second speed range, the opening of the nozzle ring blade is constrained to be within the second opening range; When the engine speed is in the third speed range, the opening degree of the nozzle ring blade is constrained to be in the third opening degree range.

[0010] Optionally, it may also include at least: In response to the vehicle meeting preset transient operating conditions, the transient basic boost pressure is determined at least based on the engine speed and throttle opening, and then the transient basic boost pressure is corrected at least based on the real-time intake air temperature and the real-time atmospheric pressure to output the transient target boost pressure. Based at least on the transient target boost pressure and the actual boost pressure, a second control mechanism is used to output the VGT basic control signal; At least the throttle opening change rate and the engine speed change rate are collected, and the transient compensation amount is determined based on the throttle opening change rate and the engine speed change rate; The final VGT drive control signal is generated based at least on the VGT basic control signal and the transient compensation amount to drive the VGT actuator to perform a third vehicle control action.

[0011] Optionally, in response to a set sudden increase condition being met by the vehicle acceleration, the rate of change of the throttle opening, and / or the rate of change of the engine speed, the determination time of the transient compensation amount is pre-processed.

[0012] Optionally, the preset transient operating condition is at least that the user presses the accelerator pedal, and the rate of change of engine speed and / or the rate of change of throttle opening is not lower than the corresponding rate of change limit.

[0013] Based on the same concept, in a second aspect, the present invention also provides a vehicle control device for performing the vehicle control method described in any one of the first aspects; The vehicle control device includes at least: The pressure output module is used to determine the basic idle boost pressure based at least on the idle speed and throttle signal in response to the vehicle meeting the idle operating conditions, and then correct the basic idle boost pressure based at least on the real-time intake air temperature and real-time atmospheric pressure to output the target idle boost pressure. The action execution module is used to output a VGT control signal using a first control mechanism, based at least on the idle target boost pressure and the actual boost pressure, so as to drive the VGT actuator to perform a first vehicle control action.

[0014] The technical solution provided by this invention is at least applicable to vehicles equipped with a variable geometry turbocharger (VGT). When performing vehicle control, firstly, in response to the vehicle meeting idle operating conditions, the basic idle boost pressure is determined at least based on the idle speed and throttle signal. Then, the basic idle boost pressure is corrected at least based on real-time intake air temperature and real-time atmospheric pressure to output a target idle boost pressure. Further, based at least on the target idle boost pressure and the actual boost pressure, a first control mechanism outputs a VGT control signal to drive the VGT actuator to perform a first vehicle control action. Therefore, this invention no longer uses a traditional fixed-section turbocharger, but can at least utilize the characteristics of the VGT to perform corresponding vehicle control actions in the vehicle's idle scenario, improving the smoothness and power response of the vehicle during urban driving and helping to reduce fuel consumption in urban conditions. Attached Figure Description

[0015] Figure 1 This is a flowchart of a vehicle control method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a vehicle control device provided in an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0017] It should be noted that any symbols and / or numbers present in the specification that are not marked in the accompanying drawings are not reference numerals.

[0018] As mentioned in the background section, in continuous driving scenarios on urban roads, especially in congested conditions, vehicles frequently experience situations such as "waiting at a red light - starting quickly at a green light - following at a constant speed," or "waiting at a red light - starting and following at a constant speed - overtaking," or "overtaking, releasing the accelerator and returning to a constant speed - stopping at a red light - starting quickly at a green light." This involves cyclical switching between three operating conditions: idling, steady state, and transient state. Traditional turbocharging technology has at least the following drawbacks in this scenario: 1) Turbo lag and matching contradiction: Turbocharger design needs to balance low-speed response and high-speed power. Traditional fixed-section turbochargers must choose between "small section to improve low-speed response" and "large section to reduce high-speed exhaust back pressure," which cannot be satisfied simultaneously. In urban driving conditions, when drivers frequently accelerate rapidly, a small-section turbocharger can provide some low-speed torque, but the high exhaust back pressure leads to large engine pumping losses and poor fuel economy; conversely, if a large-section turbocharger is used, turbo lag is severe, resulting in sluggish acceleration response. 2) Plateau and Inefficient Zone Issues: Frequent start-stop and low-speed driving in urban areas cause the engine to operate in a low-speed, low-load range for extended periods. Under these conditions, the exhaust flow is small, the exhaust gas energy is insufficient, the turbocharger operating speed is low, the turbocharger efficiency drops significantly, the intake air volume in the cylinder is insufficient, combustion is incomplete, carbon deposits are easily generated, and exhaust emissions deteriorate. If this is combined with the low-pressure, thin air environment of plateaus, the oxygen content in the intake air is further reduced, the turbocharger drive energy continues to decay, and the problems of insufficient power, combustion degradation, and excessive emissions in the inefficient zone will be further aggravated. 3) Lack of continuous driving strategy: In the existing technology, there is a lack of intelligent control strategy that can effectively utilize VGT characteristics to control the engine operating point by actively adjusting the turbine geometry, so as to maintain the engine in the high-efficiency range as much as possible while ensuring power response, and achieve "continuous" rather than "intermittent" driving for the ever-changing dynamic conditions of urban roads.

[0019] In view of this, the inventor proposes the following technical concept: 1. Technical problem to be solved: 1) Solve the problem of sluggish power response and slow acceleration of traditional turbocharged engines in urban traffic congestion; 2) To address the problem of high fuel consumption and poor emissions caused by the engine frequently operating in the inefficient range under continuous driving conditions on urban roads; 3) A smart strategy is proposed to achieve continuous, smooth and efficient driving on urban roads by actively optimizing VGT control under the dynamic working conditions of changing urban roads, thus solving the shortcomings of the current strategy.

[0020] 2. Proposed technical objectives: 1) Significantly improves the smoothness and power response of urban driving: By anticipating the driver's operating intentions, the VGT blade opening can be adjusted in advance to build up an appropriate pressure reserve in the turbocharger before acceleration is required, thereby eliminating or significantly reducing turbo lag, making the vehicle respond more quickly when overtaking and achieving a more linear power output. 2) Effectively reduces fuel consumption in urban driving conditions: By precisely controlling VGT (Vehicle GT), the engine operating point is brought as close as possible to the optimal BSFC (Body-Based Fuel Consumption Rate) range. For example, during start-stop, constant speed, and overtaking acceleration, the VGT vanes are adjusted to a specific opening in advance to reduce exhaust back pressure and pumping losses, achieving more economical operation. This creates a "continuous driving" experience, transforming the intermittent driving mode of congested urban roads into a smoother, more consistent "energy flow" management. Through VGT control strategies, the vehicle can adapt to speed fluctuations more smoothly, reducing unnecessary rapid acceleration and deceleration, and improving ride comfort. 3) Improved emissions performance: Due to more complete combustion and a better engine operating point, it helps reduce HC, CO and particulate matter emissions.

[0021] Based on the above technical concepts Figure 1 This is a flowchart of a vehicle control method provided by an embodiment of the present invention. This embodiment is applicable to at least any control optimization scenario for a vehicle equipped with a VGT. The vehicle control method can be, but is not limited to, executed by the vehicle control device in this embodiment as the execution subject, which can be implemented in software and / or hardware. Figure 1 As shown, the vehicle control method includes at least the following steps: S1. In response to the vehicle meeting the idling conditions, determine the basic idle boost pressure based at least on the idle speed and throttle signal, and then correct the basic idle boost pressure based at least on the real-time intake air temperature and real-time atmospheric pressure to output the target idle boost pressure.

[0022] The idling conditions can be determined based on the actual vehicle configuration. In one specific implementation, the idling conditions may optionally include at least the vehicle being stationary, the throttle opening being 0, the engine speed being maintained at idle speed, and the vehicle load not exceeding a preset load value. It is understood that the preset load value can be close to 0.

[0023] S2. At least based on the target boost pressure at idle and the actual boost pressure, a first control mechanism is used to output a VGT control signal to drive the VGT actuator to perform a first vehicle control action.

[0024] The idling condition corresponds to the condition when a vehicle is waiting at a red light.

[0025] For example, step S2 can be specifically described as follows: At least based on the target boost pressure at idle and the actual boost pressure, the steady-state pressure difference is eliminated, and a VGT control signal is output to drive the VGT actuator to increase the opening.

[0026] More specifically, for the situation of waiting at a red light: 1) Judgment conditions: The vehicle is stationary, the vehicle speed and throttle opening are 0, the engine speed is maintained at idle speed, and the overall vehicle load is close to 0; 2) VGT Control Logic: The ECU can obtain the basic boost pressure at idle speed by looking up a table through the basic boost pressure MAP based on the idle speed and throttle signal (e.g., zero throttle signal). Further, it can be corrected by combining real-time intake air temperature and real-time atmospheric pressure (i.e., the aforementioned correction of the basic boost pressure at idle speed based at least on real-time intake air temperature and real-time atmospheric pressure) and then output the target boost pressure at idle speed. Further, the difference between the target boost pressure at idle speed and the actual boost pressure is calculated, and then a PI controller is used to carry out closed-loop regulation. The proportional element quickly converges the deviation, the integral element eliminates the steady-state pressure error, and the derivative regulation is canceled (i.e., the aforementioned first control mechanism). The controller output signal (i.e., the aforementioned VGT control signal) is amplified and then drives the VGT actuator to adjust the nozzle ring blades to the fully open state, reduce the idle exhaust back pressure, stabilize the engine idle intake air volume, and achieve smooth and low-loss operation at idle speed (i.e., the aforementioned first vehicle control action).

[0027] For example, the target boost pressure at idle speed is calculated at least in the following ways: P_Boost_Tgt=P_Boost_Base×Fac_Tamb×Fac_Pamb; In the above formula, P_Boost_Tgt represents the target boost pressure at idle, P_Boost_Base represents the basic boost pressure at idle, Fac_Tamb represents the intake air temperature correction coefficient, and Fac_Pamb represents the atmospheric pressure correction coefficient. It is understood that the intake air temperature correction coefficient and the atmospheric pressure correction coefficient can be obtained through pre-experimental calibration or determined by looking up a table.

[0028] Furthermore, a PI controller is used to implement closed-loop regulation of the boost pressure. The proportional element quickly converges the pressure deviation, the integral element eliminates steady-state error, and the derivative term is eliminated. When the actual boost pressure is continuously higher than the target pressure, the PI controller output continuously drops to the lower limit. This output is then amplified to drive the VGT actuator, causing the nozzle ring blades to adjust to the fully open position, reducing the turbine's work and thus lowering the boost pressure.

[0029] It is known that, under idling conditions: the operation is downgraded to PI (differential D term is turned off), and the differential term is not enabled; Operating characteristics: The target boost pressure is fixed, and the operating conditions change gradually; Requirements: Only steady-state pressure deviation needs to be eliminated, control disturbances should be avoided first, and dynamic damping function should be sacrificed.

[0030] For operating conditions where the actual boost pressure is greater than the target boost pressure (e < 0, negative deviation): 1. The proportional term immediately produces a negative output, attempting to reduce the boost pressure; 2. When a negative deviation persists, the integral term accumulates downwards continuously; 3. The PI output continues to decrease, eventually reaching the lower limit of the controller output; 4. The lower limit of the controller output is calibrated to the VGT nozzle ring fully open position.

[0031] Based on the aforementioned technical solution, the control process for a vehicle in a steady-state condition (which can correspond to conditions such as constant speed following) will be explained below.

[0032] In another specific implementation, optionally, it also includes at least: In response to the vehicle meeting the preset steady-state operating conditions, the steady-state basic boost pressure is determined at least based on the engine speed and throttle opening, and then the steady-state basic boost pressure is corrected at least based on the real-time intake air temperature and real-time atmospheric pressure to output the steady-state target boost pressure. Based at least on the steady-state target boost pressure and the actual boost pressure, a second control mechanism is used to output VGT control signals to drive the VGT actuator to perform a second vehicle control action.

[0033] For example, based at least on the steady-state target boost pressure and the actual boost pressure, a second control mechanism outputs a VGT control signal to drive the VGT actuator to perform a second vehicle control action, which can be specifically as follows: Based on at least the steady-state target boost pressure and the actual boost pressure, a boost closed-loop feedback regulation is performed, and a VGT control signal is output to drive the VGT actuator to adjust the opening degree according to the boost pressure deviation.

[0034] In another specific implementation, optionally, the preset steady-state operating condition is at least that the user presses the accelerator pedal, and the rate of change of engine speed and / or the rate of change of throttle opening is lower than the corresponding rate of change threshold.

[0035] In another specific implementation, optionally, at least during the process of outputting the VGT control signal using the second control mechanism, a layered opening constraint logic for the nozzle ring blades based on engine speed is superimposed.

[0036] In yet another specific implementation, the hierarchical opening constraint logic optionally includes at least: When the engine speed is within the first speed range, the opening of the constraint nozzle ring blade is within the first opening range; When the engine speed is within the second speed range, the opening of the constraint nozzle ring blade is within the second opening range; When the engine speed is in the third speed range, the opening degree of the constraint nozzle ring blade is in the third opening degree range.

[0037] For steady-state operating conditions (such as constant-speed following scenarios): 1) Judgment conditions: The driver smoothly and lightly presses the accelerator, the engine speed and / or throttle opening are stable, and the rate of change of engine speed and / or throttle opening is less than the calibration threshold (i.e., the rate of change of engine speed is less than the calibration threshold of the rate of change of engine speed, and / or the rate of change of throttle opening is less than the calibration threshold of the opening). 2) VGT control logic: The ECU can collect throttle opening and engine speed signals, and output the steady-state basic boost pressure by looking up the corresponding basic boost pressure MAP. The real-time intake air temperature and atmospheric pressure are sent to the feedforward correction unit to perform environmental compensation correction on the steady-state basic boost pressure, and calculate the target boost pressure for the current operating condition (i.e., the aforementioned steady-state target boost pressure, the calculation method of which can be consistent with the aforementioned idle target boost pressure).

[0038] The actual boost pressure generated by the engine is collected, and the difference between it and the target boost pressure is calculated to obtain the pressure deviation. The deviation signal is input to the PID controller to carry out boost closed-loop feedback regulation (i.e., the aforementioned second control mechanism). The PID output control signal is amplified by the power amplifier and driven by the driver to drive the VGT nozzle ring actuator, which adjusts the blade opening to change the turbine flow area. The engine boost state changes synchronously, and the actual boost pressure is transmitted back in real time to form a complete closed-loop control loop.

[0039] During the adjustment of VGT driven by PID output, the engine speed layered opening constraint logic is superimposed: the working interval can be divided into three segments with 3000r / min and 4000r / min as the dividing threshold, so as to realize the full speed domain VGT opening partition limit control (i.e. the aforementioned layered opening constraint logic of nozzle ring blade based on engine speed). When the engine speed is below 3000 r / min (i.e., the aforementioned first speed range), the nozzle ring blade opening is constrained to a relatively small opening of 30% to 50% (i.e., the aforementioned first opening range), which quickly establishes boost pressure through the throttling effect and improves low-speed torque. When the speed is in the range of 3000 r / min to 4000 r / min (i.e., the aforementioned second speed range), the blade opening is limited to a medium to large range of 50% to 90% (i.e., the aforementioned second opening range) to balance boost response and exhaust pumping losses. When the speed is above 4000 r / min (i.e., the aforementioned third speed range), the nozzle ring blade is directly controlled to be fully open (i.e., the aforementioned third opening range) to maximize the exhaust flow cross-sectional area and reduce high-speed exhaust back pressure loss. In this way, the boost power performance and exhaust flow efficiency are optimized in layers across the entire speed range.

[0040] More specifically, PID control is used during steady-state driving to balance dynamic tracking, eliminate steady-state error, and suppress pressure overshoot oscillation; Operating conditions: continuous load changes, frequent acceleration and deceleration, and frequent changes in target boost pressure; Requirements: It must be able to achieve steady-state stability with no static error, while also preventing pressure spikes / drops and suppressing oscillations.

[0041] 1) Actual boost pressure < target boost pressure Pressure deviation (e>0) is continuously fed into the PID controller. Proportional adjustment (P): Immediately outputs a positive adjustment amount based on the current deviation, and instantly issues a command to close the VGT blades to quickly reduce the pressure difference; Differential term (D): At this time, the deviation e is increasing. The differential term outputs reverse damping to limit the adjustment force, prevent VGT from being closed too much at once, and avoid subsequent overshoot during boost. Integral stage (I): As long as the deviation is not zero, the integral value continues to accumulate upwards, and the control command is gradually increased. As the VGT blades gradually close, the turbine exhaust gas flow cross-section decreases, increasing the energy the turbine can absorb from the exhaust gas, and the boost pressure continues to rise; the actual pressure continuously approaches the target pressure. 2) The actual boost pressure is greater than the target pressure. When the negative deviation is fed into the PID controller, the proportional circuit immediately outputs a negative command to drive the VGT blades to open wider and reduce boost pressure. During the rapid pressure drop, the deviation continues to decrease, and term D generates positive damping to prevent excessive VGT opening and excessive pressure drop. The pressure gradually approaches the target, and the deviation continues to shrink; the effect of D gradually disappears. The residual small negative deviation is continuously accumulated downwards by the integral and output, continuously increasing VGT; Ultimately, the actual pressure matches the target pressure, the P and D outputs return to zero, the integral remains constant, and a stable steady state is reached.

[0042] Based on the aforementioned technical solution, the control process for vehicles in transient operating conditions (which can correspond to overtaking, starting from a green light and driving quickly, etc.) will be explained below.

[0043] In yet another specific implementation, optionally, it may include at least: In response to the vehicle meeting the preset transient operating conditions, the transient basic boost pressure is determined at least based on the engine speed and throttle opening, and then the transient basic boost pressure is corrected at least based on the real-time intake air temperature and real-time atmospheric pressure to output the transient target boost pressure. At least based on the transient target boost pressure and the actual boost pressure, a second control mechanism is used to output the VGT basic control signal; At least the throttle opening change rate and engine speed change rate should be collected, and the transient compensation amount should be determined based on the throttle opening change rate and engine speed change rate. The final VGT drive control signal is generated based at least on the VGT basic control signal and transient compensation amount to drive the VGT actuator to perform the third vehicle control action.

[0044] In another specific implementation, optionally, when the vehicle acceleration, throttle opening rate of change and / or engine speed rate of change meet the set sudden increase condition, the determination time of the transient compensation amount is pre-processed.

[0045] In another specific implementation, optionally, the preset transient operating condition is at least that the user presses the accelerator pedal, and the rate of change of engine speed and / or the rate of change of throttle opening is not lower than the corresponding rate of change limit.

[0046] More specifically, for transient conditions (such as overtaking, starting quickly from a green light, etc.): 1) Judgment conditions: The driver presses the accelerator pedal deeply, the load and speed increase rapidly, and the rate of change of engine speed / throttle opening is greater than or equal to the calibration threshold. 2) VGT Control Logic: The ECU can acquire throttle opening and engine speed signals, look up the corresponding basic boost pressure MAP to obtain the transient basic boost pressure, and then introduce real-time atmospheric pressure and intake air temperature to complete feedforward correction, outputting the transient target boost pressure; it can also acquire the actual boost pressure at the engine output, calculate the deviation between it and the transient target boost pressure, and send it to the PID controller to complete the boost closed-loop feedback regulation. Simultaneously, it can acquire the throttle opening change rate and engine speed change rate, and obtain the transient compensation amount through a dynamic feedforward MAP lookup table. This dynamic feedforward compensation signal (i.e., the aforementioned transient compensation amount) is multiplied and superimposed with the PID controller output signal to jointly generate the final VGT drive control amount (i.e., the aforementioned final VGT drive control signal); the control signal is amplified by a power amplifier and sent to the driver to drive the VGT nozzle ring to adjust its opening, thereby changing the engine intake boost state, forming a complete feedforward and feedback composite control closed loop.

[0047] When the driver accelerates rapidly and the rate of change of throttle / speed increases suddenly, the dynamic feedforward MAP can output compensation commands 0.5s to 1s in advance, actively controlling the VGT blades to close and reduce the turbine flow cross section, accumulating exhaust energy in advance and increasing the turbo pre-boost reserve; after the driver fully depresses the accelerator, there is already sufficient boost pressure difference inside the turbine, which greatly reduces the turbo lag phenomenon and the power response follows instantly.

[0048] Under this composite control, the engine intake airflow increases rapidly and synchronously during acceleration, resulting in complete combustion in the cylinder. At the same time, it eliminates the problems of excessive fuel injection caused by turbo lag and power gap in traditional pure feedback control. On the basis of improving transient power response, it optimizes transient air-fuel ratio and suppresses the fuel consumption and emission deterioration caused by transient rich fuel.

[0049] More specifically, scenario simulation can be as follows: 1. The driver rapidly and deeply presses the accelerator, causing a sudden increase in the rate of throttle change; 2. The dynamic feedforward logic immediately identifies transient operating conditions, outputs compensation commands to the feedforward MAP, and proactively closes the VGT blades in advance; the turbine flow cross section is reduced, exhaust energy is accumulated in advance, and pre-boost reserve is established (intervention 0.5s~1s in advance). Feedforward action occurs when the boost pressure deviation has not yet been fully established and the PID controller has not yet activated significantly. 3. As intake demand increases, the target boost pressure rises sharply; after a short delay, the actual boost pressure lags behind, resulting in a positive pressure deviation (e>0). 4. PID closed-loop formal intervention: The P-item output is fast, further reducing VGT and minimizing pressure deviation; The differential D provides damping to prevent overboost and overshoot. The I integral accumulates continuously, ensuring steady-state zero steady-state error; 5. The boost pressure rises rapidly and approaches the target; after the throttle stabilizes, the throttle change rate returns to zero → the transient feedforward compensation of the dynamic feedforward MAP gradually decays and exits. 6. The system transitions to steady state, relying solely on basic MAP and PID to maintain stable boost pressure.

[0050] For example, when the driver accelerates rapidly, with a throttle change rate >20% / s and the engine is in a preset low-to-medium speed range, transient feedforward control is activated; the maximum feedforward compensation corresponds to an additional 20% reduction in the relative opening of the VGT. After reaching the transient hold duration, the feedforward compensation amount decays to 0 according to a set slope, smoothly exiting the pre-adjustment. The throttle change threshold of 20% / s, the maximum compensation opening of 20%, and the slope decay time are all calibrable parameters.

[0051] Therefore, based on the above operating conditions, a cyclical switching (i.e., continuously repeating the three operating conditions) can be performed: The system operates on three modes: "waiting for a red light - starting quickly at a green light - following at a constant speed," or "waiting for a red light - starting and following at a constant speed - overtaking," or "releasing the accelerator after overtaking and returning to a constant speed - stopping at a red light - starting quickly at a green light." These modes continuously alternate between idling, steady-state, and transient conditions throughout the entire urban commuting route, with all three VGT control strategies participating.

[0052] The technical solution provided in this embodiment is at least applicable to vehicles equipped with a variable geometry turbocharger (VGT). When performing vehicle control, firstly, in response to the vehicle meeting idle operating conditions, the basic idle boost pressure is determined at least based on the idle speed and throttle signal. Then, the basic idle boost pressure is corrected at least based on real-time intake air temperature and real-time atmospheric pressure to output a target idle boost pressure. Further, based at least on the target idle boost pressure and the actual boost pressure, a first control mechanism outputs a VGT control signal to drive the VGT actuator to perform a first vehicle control action. Therefore, this embodiment no longer uses a traditional fixed-section turbocharger, but can at least utilize the characteristics of the VGT to perform corresponding vehicle control actions in the vehicle's idle scenario, improving the smoothness and power response of the vehicle during urban driving and helping to reduce fuel consumption in urban conditions.

[0053] Figure 2 This is a schematic diagram of a vehicle control device provided in an embodiment of the present invention. This embodiment is applicable to at least any control optimization scenario for a vehicle equipped with a VGT. The vehicle control device can be implemented in software and / or hardware. Figure 2 As shown, the vehicle control device includes at least: The pressure output module 110 is used to determine the basic idle boost pressure based at least on the idle speed and throttle signal in response to the vehicle meeting the idle operating conditions, and then correct the basic idle boost pressure based at least on the real-time intake air temperature and real-time atmospheric pressure to output the target idle boost pressure. The action execution module 120 is used to output a VGT control signal using a first control mechanism, based at least on the idle target boost pressure and the actual boost pressure, so as to drive the VGT actuator to perform a first vehicle control action.

[0054] Optionally, the idling conditions are at least as follows: the vehicle is stationary, the throttle opening is 0, the engine speed is maintained at the idle speed, and the vehicle load does not exceed the preset load value.

[0055] Optionally, it may also include at least a steady-state control module 130; The steady-state control module 130 is specifically used for: In response to the vehicle meeting the preset steady-state operating conditions, the steady-state basic boost pressure is determined at least based on the engine speed and throttle opening, and then the steady-state basic boost pressure is corrected at least based on the real-time intake air temperature and real-time atmospheric pressure to output the steady-state target boost pressure. Based at least on the steady-state target boost pressure and the actual boost pressure, a second control mechanism is used to output VGT control signals to drive the VGT actuator to perform a second vehicle control action.

[0056] Optionally, the preset steady-state operating conditions are at least that the user presses the accelerator pedal, and the rate of change of engine speed and / or the rate of change of throttle opening is lower than the corresponding rate of change threshold.

[0057] Optionally, the steady-state control module 130 is also specifically used for: At least during the process of outputting the VGT control signal using the second control mechanism, a layered opening constraint logic for the nozzle ring blades based on engine speed is superimposed.

[0058] Optionally, the hierarchical opening constraint logic includes at least: When the engine speed is within the first speed range, the opening of the constraint nozzle ring blade is within the first opening range; When the engine speed is within the second speed range, the opening of the constraint nozzle ring blade is within the second opening range; When the engine speed is in the third speed range, the opening degree of the constraint nozzle ring blade is in the third opening degree range.

[0059] Optionally, it may also include at least a transient control module 140; The transient control module 140 is specifically used for: In response to the vehicle meeting the preset transient operating conditions, the transient basic boost pressure is determined at least based on the engine speed and throttle opening, and then the transient basic boost pressure is corrected at least based on the real-time intake air temperature and real-time atmospheric pressure to output the transient target boost pressure. At least based on the transient target boost pressure and the actual boost pressure, a second control mechanism is used to output the VGT basic control signal; At least the throttle opening change rate and engine speed change rate should be collected, and the transient compensation amount should be determined based on the throttle opening change rate and engine speed change rate. The final VGT drive control signal is generated based at least on the VGT basic control signal and transient compensation amount to drive the VGT actuator to perform the third vehicle control action.

[0060] Optionally, the transient control module 140 is also specifically used for: When the vehicle acceleration, throttle opening rate of change and / or engine speed rate of change meet the set sudden increase conditions, the determination time of the transient compensation amount is pre-processed.

[0061] Optionally, the preset transient operating conditions are at least that the user presses the accelerator pedal, and the rate of change of engine speed and / or the rate of change of throttle opening is not lower than the corresponding rate of change limit.

[0062] The technical solution provided in this embodiment is at least applicable to vehicles equipped with a variable geometry turbocharger (VGT). When performing vehicle control, firstly, in response to the vehicle meeting idle operating conditions, the basic idle boost pressure is determined at least based on the idle speed and throttle signal. Then, the basic idle boost pressure is corrected at least based on real-time intake air temperature and real-time atmospheric pressure to output a target idle boost pressure. Further, based at least on the target idle boost pressure and the actual boost pressure, a first control mechanism outputs a VGT control signal to drive the VGT actuator to perform a first vehicle control action. Therefore, this embodiment no longer uses a traditional fixed-section turbocharger, but can at least utilize the characteristics of the VGT to perform corresponding vehicle control actions in the vehicle's idle scenario, improving the smoothness and power response of the vehicle during urban driving and helping to reduce fuel consumption in urban conditions.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vehicle control method, characterized in that, It is compatible with vehicles equipped with Variable Geometry Turbochargers (VGT). The vehicle control method includes at least: In response to the vehicle meeting the idling conditions, the basic idle boost pressure is determined based at least on the idle speed and throttle signal, and then the basic idle boost pressure is corrected based at least on the real-time intake air temperature and real-time atmospheric pressure to output the target idle boost pressure. Based at least on the target boost pressure at idle and the actual boost pressure, a first control mechanism is used to output a VGT control signal to drive the VGT actuator to perform a first vehicle control action.

2. The vehicle control method according to claim 1, characterized in that, The idling conditions are at least as follows: the vehicle is stationary, the throttle opening is 0, the engine speed is maintained at the idling speed, and the vehicle load does not exceed the preset load value.

3. The vehicle control method according to claim 1, characterized in that, It also includes at least: In response to the vehicle meeting the preset steady-state operating conditions, the steady-state basic boost pressure is determined at least based on the engine speed and throttle opening, and then the steady-state basic boost pressure is corrected at least based on the real-time intake air temperature and the real-time atmospheric pressure to output the steady-state target boost pressure. Based at least on the steady-state target boost pressure and the actual boost pressure, a second control mechanism is used to output the VGT control signal to drive the VGT actuator to perform a second vehicle control action.

4. The vehicle control method according to claim 3, characterized in that, The preset steady-state operating conditions are at least when the user presses the accelerator pedal, and the rate of change of engine speed and / or the rate of change of throttle opening is lower than the corresponding rate of change threshold.

5. The vehicle control method according to claim 3, characterized in that, At least during the process of outputting the VGT control signal using the second control mechanism, layered opening constraint logic of the nozzle ring blades based on the engine speed is superimposed.

6. The vehicle control method according to claim 5, characterized in that, The hierarchical opening constraint logic includes at least the following: When the engine speed is within the first speed range, the opening of the nozzle ring blade is constrained to be within the first opening range; When the engine speed is within the second speed range, the opening of the nozzle ring blade is constrained to be within the second opening range; When the engine speed is in the third speed range, the opening degree of the nozzle ring blade is constrained to be in the third opening degree range.

7. The vehicle control method according to claim 1, characterized in that, It also includes at least: In response to the vehicle meeting preset transient operating conditions, the transient basic boost pressure is determined at least based on the engine speed and throttle opening, and then the transient basic boost pressure is corrected at least based on the real-time intake air temperature and the real-time atmospheric pressure to output the transient target boost pressure. Based at least on the transient target boost pressure and the actual boost pressure, a second control mechanism is used to output the VGT basic control signal; At least the throttle opening change rate and the engine speed change rate are collected, and the transient compensation amount is determined based on the throttle opening change rate and the engine speed change rate; The final VGT drive control signal is generated based at least on the VGT basic control signal and the transient compensation amount to drive the VGT actuator to perform a third vehicle control action.

8. The vehicle control method according to claim 7, characterized in that, When the vehicle acceleration, the rate of change of the throttle opening, and / or the rate of change of the engine speed meet the set sudden increase conditions, the determination time of the transient compensation amount is pre-processed.

9. The vehicle control method according to claim 7, characterized in that, The preset transient operating conditions are at least that the user presses the accelerator pedal, and the rate of change of engine speed and / or the rate of change of throttle opening is not lower than the corresponding rate of change limit.

10. A vehicle control device, characterized in that, Used to perform the vehicle control method according to any one of claims 1-9; The vehicle control device includes at least: The pressure output module is used to determine the basic idle boost pressure based at least on the idle speed and throttle signal in response to the vehicle meeting the idle operating conditions, and then correct the basic idle boost pressure based at least on the real-time intake air temperature and real-time atmospheric pressure to output the target idle boost pressure. The action execution module is used to output a VGT control signal using a first control mechanism, based at least on the idle target boost pressure and the actual boost pressure, so as to drive the VGT actuator to perform a first vehicle control action.

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