In-cylinder direct injection driving system and in-cylinder direct injection driving pulse width adaptive regulation method

Abstract

This invention discloses an in-cylinder direct injection drive system and an adaptive control method for the pulse width of the in-cylinder direct injection drive. The in-cylinder direct injection drive system includes a multi-dimensional parameter acquisition unit, a control unit, a drive execution unit, and a closed-loop feedback unit. This application achieves synchronous real-time acquisition of four core parameters—in-cylinder temperature, humidity, fuel quantity, and engine speed—by placing temperature sensors, humidity sensors, fuel quantity sensors, and speed sensors at corresponding positions in each cylinder block, and deploying a speed sensor in conjunction with the engine crankshaft. The sensor deployment positions ensure acquisition accuracy, solving the problem of incomplete operating condition perception. Furthermore, the control unit's built-in algorithm, through a process of "signal preprocessing – multi-parameter fusion calculation – pulse width calibration – closed-loop feedback," introduces weighting coefficients to achieve multi-parameter collaborative analysis, dynamically adjusting the drive pulse width according to operating conditions, rather than using a fixed mapping table or a single threshold adjustment.

Description

Technical Field

[0001] This invention relates to the technical field of automotive power systems, specifically to a direct injection drive system and a direct injection drive pulse width adaptive control method. Background Technology

[0002] With the rapid development of the automotive industry towards energy conservation, environmental protection, and high efficiency, Gas Direct Injection (GDI) technology, as a core technology for improving engine fuel economy and reducing exhaust emissions, has been widely applied in various passenger and commercial vehicle engines. Currently, the core requirement of GDI injection drive systems is to achieve precise control of injection action. Drive pulse width, as a key parameter determining the injection quantity and timing, directly affects engine combustion efficiency, power performance, and exhaust emission levels. Therefore, drive pulse width control schemes have become a core focus of existing technology research. Existing solutions either only collect macroscopic parameters such as engine speed and throttle opening, without considering the impact of real-time in-cylinder environmental changes on injection performance; or they only collect a single in-cylinder parameter (such as temperature), failing to comprehensively reflect the actual operating conditions under the combined effects of multiple factors such as in-cylinder temperature, humidity, and injection quantity. This leads to a mismatch between drive pulse width adjustment and actual needs, resulting in problems such as injection quantity deviation and poor atomization, which in turn affect engine combustion efficiency. Summary of the Invention

[0003] This invention aims to at least solve the technical problem of mismatch between drive pulse width adjustment and actual needs in existing technologies. To this end, this invention provides a direct injection drive system and a direct injection drive pulse width adaptive control method.

[0004] According to a first aspect of the present invention, a direct injection drive system includes: The multi-dimensional parameter acquisition unit includes multiple temperature sensors, multiple humidity sensors, multiple fuel quantity sensors, and multiple speed sensors. The multiple temperature sensors are installed on the cylinder walls surrounding the injectors of each cylinder, and are used to acquire the instantaneous temperature inside the cylinder in real time. The multiple humidity sensors are installed on the cylinder walls surrounding the injectors of each cylinder, and are used to acquire the instantaneous humidity inside the cylinder in real time. The multiple fuel quantity sensors are installed at the fuel outlet of each injector, and are used to acquire the instantaneous fuel injection quantity and cumulative fuel injection quantity in real time. The multiple speed sensors are installed at the front end of the engine crankshaft, and are used to acquire the engine speed in real time. The control unit is configured as follows: Receive temperature, humidity, oil level, and speed signals acquired by the multi-dimensional parameter acquisition unit; Preprocess the received signal; The weight coefficients of each parameter are dynamically allocated according to the real-time operating conditions, and multi-parameter fusion calculation is performed. The driving pulse width control signal is generated based on the fusion calculation results; The drive pulse width is continuously calibrated by receiving closed-loop feedback signals. A drive execution unit includes a drive chip and a switching unit, wherein the switching unit controls the opening and closing of the fuel injector according to the drive pulse width control signal; The closed-loop feedback unit includes a sampling resistor connected in series in the fuel injection drive circuit, as well as the temperature sensor, humidity sensor, and fuel quantity sensor. The sampling resistor is used to monitor the fuel injection current or voltage status in real time. The temperature sensor, humidity sensor, and fuel quantity sensor transmit the actual in-cylinder temperature, humidity, and fuel injection quantity back to the control unit in real time, forming a closed-loop regulation.

[0005] A direct injection drive system according to an embodiment of the present invention has at least the following beneficial effects: This application achieves synchronous real-time acquisition of four core parameters—in-cylinder temperature, humidity, fuel injection quantity, and engine speed—by placing temperature, humidity, fuel quantity, and speed sensors at corresponding locations in each cylinder block, and deploying a speed sensor in conjunction with the engine crankshaft. The sensor deployment positions ensure accurate data acquisition, resolving the issue of incomplete operating condition perception. Furthermore, the control unit's built-in algorithm, through a process of "signal preprocessing - multi-parameter fusion calculation - pulse width calibration - closed-loop feedback," introduces weighting coefficients to achieve multi-parameter collaborative analysis. This allows for dynamic adjustment of the drive pulse width based on operating conditions, rather than using a fixed mapping table or a single threshold adjustment.

[0006] According to some embodiments of the present invention, the control unit is a microcontroller unit, which includes a Flash memory, a crystal oscillator circuit, and various types of interfaces; the Flash memory is used to store algorithm programs, historical data, and a preset in-cylinder operating condition reference model; the crystal oscillator circuit provides a clock signal for the MCU; the various types of interfaces include analog interfaces, digital interfaces, and frequency interfaces, which are adapted to the signal outputs of different sensors.

[0007] According to some embodiments of the present invention, the operation flow of the multi-parameter fusion adaptive control algorithm executed by the control unit is as follows: The temperature, humidity, oil level, and speed signals are filtered and normalized. The weighting coefficients of each parameter are automatically assigned according to the current engine operating conditions, which include cold start, warm-up, high load, and high humidity environment. The weighted parameters are input into the nonlinear control model to calculate the optimal driving pulse width. The pulse width is corrected by combining the actual fuel injection status fed back by the closed-loop feedback unit; The corrected pulse width is output to the drive execution unit, and feedback data for the next cycle is received.

[0008] According to some embodiments of the present invention, the weighting coefficients of each parameter are automatically allocated based on the current engine operating conditions and the weighting coefficients are adjusted online based on real-time operating conditions to achieve continuous and non-linear pulse width adjustment.

[0009] According to some embodiments of the present invention, the closed-loop feedback unit forms a dual closed-loop structure, comprising: Fuel injection drive current / time closed loop based on sampling resistor; A closed-loop combustion effect is based on feedback from temperature, humidity, and fuel level sensors.

[0010] According to some embodiments of the present invention, the fuel quantity sensor simultaneously provides the instantaneous fuel injection quantity and the cumulative fuel injection quantity; the control unit compensates for injector aging based on the cumulative fuel injection quantity, and performs real-time error correction based on the deviation between the instantaneous fuel injection quantity and the theoretical fuel injection quantity corresponding to the target pulse width.

[0011] According to some embodiments of the present invention, the power supply of each sensor in the multi-dimensional parameter acquisition unit is provided by an LDO circuit on the controller board, which steps down the 12V vehicle voltage to 5V to provide unified power supply for the sensors.

[0012] According to some embodiments of the present invention, the instantaneous humidity inside the cylinder collected by the humidity sensor is used as a feedforward control parameter to participate in the pulse width calculation of the control unit, in order to compensate for the influence of the in-cylinder water vapor concentration on the completeness of fuel combustion.

[0013] According to some embodiments of the present invention, the temperature sensor has a measurement range of -55℃ to 125℃ and an accuracy of ±0.5℃; The humidity sensor has a measurement range of 20%~90%RH and an accuracy of ±5%RH. The oil level sensor has a measurement range of 0~100mL / s and an accuracy of ±0.1mL / s; The speed sensor has a measurement range of 0~8000 r / min and an accuracy of ±10 r / min.

[0014] According to a second aspect of the present invention, a direct injection drive pulse width adaptive control method is applied to the direct injection drive system described in any of the above claims, comprising the following steps: Multiple parameters inside the cylinder are simultaneously collected by temperature and humidity sensors installed on the cylinder wall around the injector, fuel quantity sensor installed at the fuel outlet of the injector, and speed sensor installed at the front end of the crankshaft. These multiple parameters include cylinder temperature, humidity, fuel injection quantity, and engine speed. The control unit preprocesses the collected multiple parameters, dynamically allocates the weight coefficients of each parameter according to the real-time operating conditions, performs fusion calculations, and generates the driving pulse width. The drive execution unit controls the injector to inject oil according to the drive pulse width through the switching unit; The sampling resistor monitors the fuel injection status in real time, while each sensor transmits the actual cylinder temperature, humidity, and fuel injection quantity back to the control unit. The control unit adjusts the weighting coefficient and driving pulse width for the next cycle based on the feedback data, forming a closed-loop adaptive control.

[0015] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the structure of a direct injection drive system. Figure 2 This is a schematic diagram of the BANK1 structure of the direct injection drive system. Figure 3 This is a schematic diagram of the BANK2 direct injection drive system. Figure 4 This is a schematic diagram of the BANK3 direct injection drive system. Figure 5 This is a flowchart of a method for adaptive pulse width control of in-cylinder direct injection drive. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0018] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0019] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0020] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0022] During direct injection, the injection quantity and atomization effect are not only affected by engine speed, but also closely related to in-cylinder temperature, humidity, and the actual injection quantity. In-cylinder temperature affects the fuel atomization speed, humidity affects the fuel combustion completeness, and the actual injection quantity reflects the injection execution deviation. Existing technologies, due to their limited parameter acquisition, cannot accurately capture instantaneous changes in in-cylinder operating conditions, leading to a mismatch between drive pulse width adjustment and actual needs, resulting in problems such as injection quantity deviation and poor atomization, which in turn affect engine combustion efficiency. Current dedicated drive chips lack comprehensive operating condition acquisition pins and cannot achieve the above functions. Therefore, this application proposes a direct injection drive system and a direct injection drive pulse width adaptive control method.

[0023] Reference Figures 1 to 4 This embodiment uses an inline 6-cylinder or V6 direct injection engine as the application scenario, with cylinders numbered 1 to 6. The fuel injection drive employs three independent drive channels: BANK1 drives cylinders 1 and 6, BANK2 drives cylinders 2 and 5, and BANK3 drives cylinders 3 and 4. The three banks have identical circuit structures and are independently controlled by the MCU, triggered sequentially according to the engine's power stroke order, typically 1-5-3-6-2-4. Each BANK circuit includes: a boost power supply node VBOOST, with all three groups sharing the same boost circuit output; high-side MOSFETs: Q1 for BANK1, Q4 for BANK2, and Q7 for BANK3; low-side parallel MOSFETs: Q2 / Q3 for BANK1, Q5 / Q6 for BANK2, and Q8 / Q9 for BANK3; gate resistors: R1 for BANK1, R2 for BANK2, and R3 for BANK3; a high-voltage detection node: VHS1 for BANK1, VHS2 for BANK2, and VHS3 for BANK3; and pulse width control signals GDI1, GDI2, and GDI3, respectively. The following detailed description uses BANK2 as a typical example; BANK1 and BANK3 have the same structure, only with increasing labeling.

[0024] Figure 1 In the process, the control unit MCU receives the AD signal, SPI communication signal, and safety shutdown control signal from the fuel injection drive chip, while the fuel injection drive chip receives the fuel injection pulse width control signal, FLAG control signal, SPI communication signal, clock signal, and safety shutdown control signal from the control unit MCU.

[0025] This system is deployed on a 6-cylinder GDI engine. The multi-dimensional parameter acquisition unit includes six temperature sensors, six humidity sensors, multiple fuel level sensors, and six speed sensors. The six temperature sensors and six humidity sensors are respectively installed on the cylinder walls surrounding the injectors of each cylinder. The temperature sensors are used to collect the instantaneous temperature inside the cylinder in real time, and the humidity sensors are used to collect the instantaneous humidity inside the cylinder in real time. The multiple fuel level sensors are installed at the fuel outlet of each injector and are sealed to the fuel line to prevent fuel leakage. The fuel level sensors are used to collect the instantaneous injection quantity and cumulative injection quantity in real time. The speed sensor is installed at the front end of the engine crankshaft, aligned with the crankshaft gear to ensure accurate speed measurement. The speed sensor is used to collect the engine speed in real time. The power supply unit includes a 12V vehicle battery, which powers the MCU through the PMIC, and an LDO step-down (12V→5V) power supply to the sensors. The signals from the temperature, humidity, fuel level, and speed sensors are acquired to the MCU port through a preprocessing circuit, which includes voltage divider resistors, current limiting resistors, and filter capacitors to ensure signal quality and sampling accuracy.

[0026] The control unit uses an MCU with a built-in dynamic weighted fusion algorithm to generate three independent pulse width control signals, GDI1, GDI2, and GDI3, which are output to the driver chips of BANK1, BANK2, and BANK3 respectively. The output fuel injection pulse width is controlled through multi-parameter fusion calculation. The fuel injection pulse width pin utilizes ATOM resources to ensure real-time waveform accuracy. The control unit is configured as follows: Receive temperature, humidity, oil level, and speed signals acquired by the multi-dimensional parameter acquisition unit; Preprocess the received signal; The weight coefficients of each parameter are dynamically allocated according to the real-time operating conditions, and multi-parameter fusion calculation is performed. The driving pulse width control signal is generated based on the fusion calculation results; The closed-loop feedback signal is received to continuously calibrate the drive pulse width.

[0027] The drive execution unit contains three identical drive channels BANK1, BANK2, and BANK3. Each channel contains an injection drive chip and a switching unit. The injection drive chip starts injection after receiving the injection pulse width signal, regulates the high-voltage and low-voltage conduction MOS output injection waveform, and monitors the injection status in real time through the low-side sampling resistor to achieve diagnostic and protection functions.

[0028] The closed-loop feedback unit includes sampling resistors for each BANK, as well as real-time feedback from all temperature, humidity, and fuel quantity sensors. During the fuel injection process, the closed-loop feedback unit collects signals from the temperature, humidity, fuel quantity, and speed sensors and sends them to the MCU. The MCU then adjusts the fuel injection pulse width in real time to achieve real-time adjustment.

[0029] The power supply unit, signal preprocessing unit, MCU algorithm control unit, driver chip unit, and closed-loop feedback unit are integrated on the control board.

[0030] The three-bank architecture enables precise group control of the six cylinders. Compared to a single injection drive chip driving all injectors, the three banks can independently adjust the drive current, sampling feedback, and aging compensation of each group of injectors, significantly reducing the impact of parasitic parameter differences in the drive circuit on injection consistency. Alternating triggering according to the power stroke sequence (e.g., GDI1→GDI2→GDI3→GDI1 cycle) allows sufficient time for the boost capacitor to recover, preventing VBOOST voltage drop exceeding 5% due to multiple injectors operating simultaneously. Multi-parameter acquisition combined with the three independent drives improves overall fuel economy and reduces injection quantity deviation between cylinders. In some other embodiments, a single drive chip can also be used.

[0031] This application achieves synchronous real-time acquisition of four core parameters—in-cylinder temperature, humidity, fuel injection quantity, and engine speed—by placing temperature, humidity, fuel quantity, and speed sensors at corresponding locations in each cylinder block, and deploying a speed sensor in conjunction with the engine crankshaft. The sensor deployment positions ensure accurate data acquisition, resolving the issue of incomplete operating condition perception. Furthermore, the control unit's built-in algorithm, through a process of "signal preprocessing - multi-parameter fusion calculation - pulse width calibration - closed-loop feedback," introduces weighting coefficients to achieve multi-parameter collaborative analysis. This allows for dynamic adjustment of the drive pulse width based on operating conditions, rather than using a fixed mapping table or a single threshold adjustment.

[0032] Furthermore, all six temperature sensors are ADT7310 (-55~125℃, ±0.5℃), all six humidity sensors are HIH-4030 (20~90%RH, ±5%RH), all six fuel level sensors are FS-100 (0~100mL / s, ±0.1mL / s), and the speed sensor is a Hall effect A3144 (0~8000r / min, ±10r / min). All sensors undergo consistency calibration before leaving the factory to ensure consistent output characteristics for the three banks. All sensors have uniform range accuracy, providing a consistent input reference for the independent control of the three banks and avoiding control deviations between banks due to sensor differences. The speed sensor, in conjunction with the crankshaft 60-tooth trigger wheel, accurately identifies the top dead center position of each cylinder, ensuring that the MCU triggers the corresponding bank's GDI signal at the correct time, avoiding injection phase misalignment.

[0033] Specifically, the temperature sensor has a measurement range of -55℃ to 125℃ and an accuracy of ±0.5℃; the humidity sensor has a measurement range of 20% to 90%RH and an accuracy of ±5%RH; the oil level sensor has a measurement range of 0 to 100mL / s and an accuracy of ±0.1mL / s; and the speed sensor has a measurement range of 0 to 8000r / min and an accuracy of ±10r / min.

[0034] Furthermore, the three independent PWM outputs allow for individual adjustment of the injection pulse width of the three banks, adapting to the compensation needs of different cylinders due to variations in intake manifold length and individual injectors. The dynamic phase adjustment function supports injection timing optimization for variable valve timing engines at different speeds / loads. The multi-channel ADC combined with DMA enables synchronous acquisition of 6×3 parameters, completing one round every 1ms, providing real-time data for the dynamic weighting algorithm.

[0035] Furthermore, the MCU incorporates a built-in BP neural network model. This model shares the same network structure across three banks, but the input parameters are processed by bank group. The inputs for each bank are: the average temperature and average humidity of the two cylinders within that bank, their respective fuel quantity feedback (and global engine speed). The algorithm independently runs a complete "preprocessing → weight allocation → fusion calculation → calibration → feedback" process for each bank, outputting the pulse widths of GDI1, GDI2, and GDI3 respectively. During dynamic weight allocation, if the operating environment of cylinders 1 and 6 corresponding to BANK1 differs from that of BANK2, the MCU will automatically assign different weight coefficients to different banks. For example, during cold starts, BANK1, which is closer to the thermostat, heats up faster, and its temperature weight gradually decreases, while the temperature weight of the more distant BANK3 remains higher for a longer period.

[0036] The three banks independently calculate weights and pulse widths, achieving cylinder-level adaptive control, which is more precise than unified control of all cylinders. Cylinders closer to the radiator warm up slowly during cold starts; independent weight allocation allows for a higher temperature compensation weight for these banks, preventing excessively lean misfires. Conversely, cylinders closer to the center of the engine warm up quickly, allowing their temperature weight to be reduced earlier, preventing excessively rich carbon buildup. The shared structure of the BP network reduces MCU memory usage, while independent inputs and outputs enable differentiated control.

[0037] Furthermore, each BANK has an independent inner current loop and a shared outer current loop. Inner loop: The sampling resistors of BANK1 and BANK2 independently acquire the injection current waveform of their respective BANKs. The MCU polls the ADC values ​​of the three BANKs every 10μs, independently adjusting the duty cycle of the corresponding PWM to ensure that the actual peak current of each BANK is stabilized at 12A±0.5A. Outer loop: After each working cycle, the MCU calculates the combustion efficiency index of each cylinder based on the accumulated temperature, humidity, and fuel quantity of each of the six cylinders, and then backpropagates to correct the weight parameters and pulse width reference of the BANK to which that cylinder belongs in the next cycle. The correction values ​​of the three BANKs are stored and take effect independently. The three independent inner loops of the BANKs ensure the accuracy of the total drive current of the two injectors in each group, avoiding inconsistencies in the actual opening voltage due to differences in wiring harness impedance. The independent outer loop achieves closed-loop compensation between cylinders. For example, if the fuel injection quantity of cylinder 6 is low due to carbon deposits (even if the total current of BANK2 is normal, the distribution between the two cylinders is uneven), the fuel quantity sensor detects that the fuel injection quantity of this cylinder is too low. The outer loop will add an extra correction factor for the next fuel injection of BANK2. Specifically, it can be achieved by fine-tuning the PWM duty cycle of BANK2 or prompting the user for maintenance.

[0038] Furthermore, the control unit is a microcontroller unit, which includes a Flash memory, a crystal oscillator circuit, and various types of interfaces; the Flash memory is used to store algorithm programs, historical data, and preset in-cylinder operating condition reference models; the crystal oscillator circuit provides clock signals for the MCU; the various types of interfaces include analog interfaces, digital interfaces, and frequency interfaces, which are adapted to the signal outputs of different sensors.

[0039] Furthermore, each fuel quantity sensor independently outputs instantaneous flow rate. The MCU accumulates the cumulative fuel injection quantity of each injector and stores it in six different addresses in Flash. Aging compensation is performed on a cylinder-by-cylinder basis: when the cumulative fuel injection quantity of cylinder 3 reaches 10000L, only a 1% pulse width compensation is added to that cylinder, without affecting cylinder 4. Real-time deviation detection is also performed on a cylinder-by-cylinder basis: if the instantaneous fuel injection quantity of a cylinder deviates from the target value by >0.2mL / s, the next PWM duty cycle of the BANK to which that cylinder belongs is immediately corrected. If the BANK drives two cylinders simultaneously, the correction will affect both cylinders at the same time. However, the channel balancing function of the drive chip can be further fine-tuned based on the feedback from the fuel quantity sensors of the two cylinders, or the difference can be minimized by selecting and matching injectors.

[0040] When the injector in cylinder 6 wears faster than that in cylinder 1, and if cylinder 2 is closer to the exhaust gas recirculation (EGR) inlet and experiences more carbon buildup, the system can be configured with different compensation coefficients for cylinders 1 and 6. This extends the effective lifespan of the injector assembly and reduces maintenance frequency.

[0041] Furthermore, the power supply for each sensor in the multi-dimensional parameter acquisition unit is provided by an LDO circuit on the controller board. This LDO circuit steps down the 12V vehicle voltage to 5V to provide a unified power supply for the sensors. A unified 5V power supply ensures that the reference voltages of the six temperature sensors and six humidity sensors are consistent, avoiding AD conversion value deviations due to power supply differences. The star topology ensures that the sensor power supply circuit for each bank is independent, so a sudden change in the sensor load of one bank will not affect the sensor signal quality of other banks.

[0042] Furthermore, the instantaneous in-cylinder humidity collected by the humidity sensor is used as a feedforward control parameter and participates in the pulse width calculation of the control unit to compensate for the impact of in-cylinder water vapor concentration on fuel combustion completeness. Three sets of independent humidity feedforwards solve the problem of uneven humidity between cylinder banks—for a V6 engine, the different intake manifold lengths and crankcase ventilation arrangements of the left and right cylinder banks may lead to higher humidity in one bank. Traditional single humidity sensors cannot distinguish this, while this system achieves zoned feedforward compensation through independent humidity sensors for each cylinder.

[0043] Reference Figure 2 The present invention also provides an embodiment of an adaptive pulse width control method for direct injection drive, applied to any of the above-described direct injection drive systems, comprising the following steps: Step S100: Simultaneously collect multiple parameters inside the cylinder by using temperature and humidity sensors installed on the cylinder wall around the injector, fuel quantity sensor installed at the fuel outlet of the injector, and speed sensor installed at the front end of the crankshaft. The multiple parameters include cylinder temperature, humidity, fuel injection quantity, and engine speed. Step S200: The control unit preprocesses the collected multiple parameters, dynamically allocates the weight coefficients of each parameter according to the real-time operating conditions, performs fusion calculation, and generates the drive pulse width; Step S300: The drive execution unit controls the injector to inject oil according to the drive pulse width through the switching unit; Step S400: The sampling resistor monitors the fuel injection status in real time, and at the same time, each sensor transmits the actual cylinder temperature, humidity and fuel injection quantity back to the control unit. Step S500: The control unit corrects the weighting coefficient and drive pulse width for the next cycle based on the feedback data to form a closed-loop adaptive control.

[0044] Specific implementation: After the 6-cylinder GDI engine starts, the control unit, including the MCU, executes the following cycle: Step 1: The crankshaft speed sensor triggers an interrupt every 6° to update the current crankshaft angle and speed, and predicts the next cylinder that needs to be injected, according to the power sequence 1-5-3-6-2-4; Step 2: When it is predicted that the second cylinder will be injected, activate BANK2 1ms in advance, and read the instantaneous values ​​of temperature, humidity, and fuel quantity of that cylinder, as well as the cumulative value of fuel quantity fed back by BANK2. Step 3: The MCU dynamically allocates weighting coefficients based on the current speed, temperature / humidity of cylinder 2, and historical accumulated data of BANK23. For example, if cylinder 2 is located at the end of the intake port, the humidity weight is slightly higher. Step 4: Input the weighted parameters into the BP network to calculate the optimal pulse width for the BANK. The GDI signals of the three BANKs are staggered in time, and each group updates the PWM duty cycle during its own injection window. The calculation of the optimal pulse width for the BANK specifically includes: cylinders 2 and 4. Since BANK2 drives two cylinders simultaneously, the pulse width of GDI2 needs to be set according to the target injection quantity of cylinder 2. Cylinder 4 will also be controlled by GDI2 during its power stroke, but the pulse width is recalculated before each injection. Therefore, the PWM duty cycle of GDI2 will dynamically change according to the cylinder to be injected. That is, each cylinder calculates its pulse width independently, but shares the same PWM hardware, which is achieved through time slot multiplexing. Step 5: The MCU sets the PWM duty cycle to output GDI2, and the driver chip turns on the second cylinder injector according to the Peak & Hold timing sequence.

[0045] Step 6: The sampling resistor provides real-time feedback of the current waveform. Within 5μs after the current fuel injection ends, the MCU completes the inner loop correction calculation and adjusts the PWM duty cycle for the next fuel injection.

[0046] Step 7: When the working cycle of cylinder 2 ends, the outer ring adjusts the weight parameters and pulse width reference of cylinder 4 in the next cycle based on the cumulative value of the oil quantity sensor of cylinder 2 and the theoretical value.

[0047] Step 8: Switch to the corresponding BANK in the power stroke order 1→5→3→6→2→4 (Cylinder 1 corresponds to BANK1, Cylinder 5 corresponds to BANK2, Cylinder 3 corresponds to BANK3, Cylinder 6 corresponds to BANK1, Cylinder 2 corresponds to BANK2, Cylinder 4 corresponds to BANK3), and repeat steps 1 to 7.

[0048] The cyclic scheduling strategy for three banks and six cylinders fully utilizes the MCU's timer and PWM multiplexing capabilities. Through time slot multiplexing, each PWM hardware can sequentially serve two cylinders within the same bank, saving hardware resources while ensuring independent calculation and correction of the pulse width for each cylinder. The inner loop correction can be completed between two injections within the same bank, achieving dynamic adjustment cylinder by cylinder; the outer loop correction optimizes long-term consistency step by step, based on the working cycle.

[0049] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0050] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A direct injection drive system, characterized in that, include: The multi-dimensional parameter acquisition unit includes multiple temperature sensors, multiple humidity sensors, multiple fuel quantity sensors, and multiple speed sensors. The multiple temperature sensors are installed on the cylinder walls surrounding the injectors of each cylinder, and are used to acquire the instantaneous temperature inside the cylinder in real time. The multiple humidity sensors are installed on the cylinder walls surrounding the injectors of each cylinder, and are used to acquire the instantaneous humidity inside the cylinder in real time. The multiple fuel quantity sensors are installed at the fuel outlet of each injector, and are used to acquire the instantaneous fuel injection quantity and cumulative fuel injection quantity in real time. The multiple speed sensors are installed at the front end of the engine crankshaft, and are used to acquire the engine speed in real time. The control unit is configured as follows: Receive temperature, humidity, oil level, and speed signals acquired by the multi-dimensional parameter acquisition unit; Preprocess the received signal; The weight coefficients of each parameter are dynamically allocated according to the real-time operating conditions, and multi-parameter fusion calculation is performed. The driving pulse width control signal is generated based on the fusion calculation results; The drive pulse width is continuously calibrated by receiving closed-loop feedback signals. A drive execution unit includes a drive chip and a switching unit, wherein the switching unit controls the opening and closing of the fuel injector according to the drive pulse width control signal; The closed-loop feedback unit includes a sampling resistor connected in series in the fuel injection drive circuit, as well as the temperature sensor, humidity sensor, and fuel quantity sensor. The sampling resistor is used to monitor the fuel injection current or voltage status in real time. The temperature sensor, humidity sensor, and fuel quantity sensor transmit the actual in-cylinder temperature, humidity, and fuel injection quantity back to the control unit in real time, forming a closed-loop regulation.

2. The direct injection drive system according to claim 1, characterized in that, The control unit is a microcontroller unit, which includes a Flash memory, a crystal oscillator circuit, and various types of interfaces. The Flash memory is used to store algorithm programs, historical data, and preset in-cylinder operating condition reference models. The crystal oscillator circuit provides clock signals to the MCU. The various types of interfaces include analog interfaces, digital interfaces, and frequency interfaces, which are adapted to the signal outputs of different sensors.

3. The direct injection drive system according to claim 1, characterized in that, The operation flow of the multi-parameter fusion adaptive control algorithm executed by the control unit is as follows: The temperature, humidity, oil level, and speed signals are filtered and normalized. The weighting coefficients of each parameter are automatically assigned according to the current engine operating conditions, which include cold start, warm-up, high load, and high humidity environment. The weighted parameters are input into the nonlinear control model to calculate the optimal driving pulse width. The pulse width is corrected by combining the actual fuel injection status fed back by the closed-loop feedback unit; The corrected pulse width is output to the drive execution unit, and feedback data for the next cycle is received.

4. The direct injection drive system according to claim 3, characterized in that, The weighting coefficients of each parameter are automatically allocated according to the current engine operating conditions and then adjusted online based on real-time operating conditions to achieve continuous and non-linear pulse width regulation.

5. The direct injection drive system according to claim 1, characterized in that, The closed-loop feedback unit forms a dual closed-loop structure, including: Fuel injection drive current / time closed loop based on sampling resistor; A closed-loop combustion effect is based on feedback from temperature, humidity, and fuel level sensors.

6. The direct injection drive system according to claim 1, characterized in that, The fuel quantity sensor provides both instantaneous and cumulative fuel injection quantities. The control unit compensates for injector aging based on the cumulative fuel injection quantity and performs real-time error correction based on the deviation between the instantaneous fuel injection quantity and the theoretical fuel injection quantity corresponding to the target pulse width.

7. The direct injection drive system according to claim 1, characterized in that, The power supply for each sensor in the multi-dimensional parameter acquisition unit is provided by the LDO circuit on the controller board. The LDO circuit steps down the 12V vehicle voltage to 5V to provide unified power to the sensors.

8. The direct injection drive system according to claim 1, characterized in that, The instantaneous humidity inside the cylinder collected by the humidity sensor is used as a feedforward control parameter and participates in the pulse width calculation of the control unit to compensate for the influence of the in-cylinder water vapor concentration on the completeness of fuel combustion.

9. The direct injection drive system according to claim 1, characterized in that: The temperature sensor has a measurement range of -55℃ to 125℃ and an accuracy of ±0.5℃. The humidity sensor has a measurement range of 20%~90%RH and an accuracy of ±5%RH. The oil level sensor has a measurement range of 0~100mL / s and an accuracy of ±0.1mL / s; The speed sensor has a measurement range of 0~8000 r / min and an accuracy of ±10 r / min.

10. A method for adaptive pulse width control of direct injection drive, applied to the direct injection drive system according to any one of claims 1 to 9, characterized in that, Includes the following steps: Multiple parameters inside the cylinder are simultaneously collected by temperature and humidity sensors installed on the cylinder wall around the injector, fuel quantity sensor installed at the fuel outlet of the injector, and speed sensor installed at the front end of the crankshaft. These multiple parameters include cylinder temperature, humidity, fuel injection quantity, and engine speed. The control unit preprocesses the collected multiple parameters, dynamically allocates the weight coefficients of each parameter according to the real-time operating conditions, performs fusion calculations, and generates the driving pulse width. The drive execution unit controls the injector to inject oil according to the drive pulse width through the switching unit; The sampling resistor monitors the fuel injection status in real time, while each sensor transmits the actual cylinder temperature, humidity, and fuel injection quantity back to the control unit. The control unit adjusts the weighting coefficient and driving pulse width for the next cycle based on the feedback data, forming a closed-loop adaptive control.

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