A Normalization Processing Method for Multi-Mode Crankshaft Angle Signals of Diesel Engines

Abstract

This invention provides a normalization processing method for multi-mode crankshaft angle signals of a diesel engine. It receives the raw crankshaft angle signal from the diesel engine and identifies its signal mode type. Based on the identified signal mode type, it selects the corresponding characteristic tooth determination logic: for the tooth-adding mode, when the current tooth clearance time is ≤ 5 / 8 ± dynamic correction value of the previous tooth clearance time, the next tooth is determined to be a characteristic tooth; for the tooth-missing mode, when the current tooth clearance time is ≥ 3 / 2 ± dynamic correction value of the previous tooth clearance time, the next tooth is determined to be a characteristic tooth. A TRIG pulse signal is generated based on the characteristic tooth, and a CDMA pulse signal is completed at the tooth-missing / tooth-adding position using camshaft phase information. Pulse reconstruction is performed on non-characteristic teeth according to a preset angular domain resolution, outputting the normalized TRIG and CDMA pulse signals. This invention achieves unified processing and high-precision output of signals with different tooth profiles through dynamic threshold determination, camshaft phase compensation, and pulse reconstruction technology.

Description

Technical Field

[0001] This invention belongs to the field of diesel engine control technology, and specifically relates to a normalization processing method for multi-mode crankshaft angle signals of diesel engines. Background Technology

[0002] Diesel engines are currently one of the main power units, widely used in various sectors of the national economy and the defense field. With the rapid development of the economy, more stringent requirements have been placed on diesel engines in terms of environmental protection, economy, condition monitoring and fault diagnosis, and intelligence. Combustion process condition monitoring provides an effective monitoring window for performance adjustment, fault diagnosis, and combustion closed-loop control. Users can improve combustion performance by adjusting things like intake and exhaust strategies, injection timing, and injection methods; evaluate cylinder air tightness, single-cylinder misfire, and cylinder consistency through relevant combustion parameters; and participate in combustion closed-loop control to achieve balanced adjustment of each cylinder.

[0003] Diesel engine combustion calculation and analysis require high accuracy in the angular domain. However, different diesel engines have significant differences in minimum and maximum speeds. Angular domain data acquisition and processing presents challenges, including high memory usage at low speeds and high real-time processing response at high speeds. Therefore, research is needed on angular domain acquisition and processing algorithms and strategies, taking into account chip resources and capabilities, to ensure the system's angular domain processing covers the entire speed range at high speeds. Furthermore, different diesel engines exhibit different crankshaft angle signal patterns, commonly including missing tooth, even tooth, multi-tooth, single tooth, and single tooth + even tooth patterns. Designing a separate angular domain correspondence algorithm for each pattern would result in an excessively large scale of angular domain correspondence algorithms and subsequent combustion calculations, leading to a waste of hardware resources. Therefore, normalizing various crankshaft angle signal patterns before the angular domain correspondence algorithm would significantly reduce the complexity of subsequent angular domain correspondence and combustion analysis algorithms.

[0004] Therefore, how to provide a normalization processing method for multi-mode crankshaft angle signals of diesel engines that can solve the problems of single mode, poor adaptability, high misjudgment rate, and weak signal completion capability in traditional diesel engine crankshaft angle signal processing has become an urgent technical problem to be solved. Summary of the Invention

[0005] This invention provides a normalization processing method for multi-mode crankshaft angle signals of diesel engines, which can solve the problems of single mode, poor adaptability, high misjudgment rate and weak signal completion capability in traditional diesel engine crankshaft angle signal processing. Through dynamic threshold determination, camshaft phase compensation and pulse reconstruction technology, it can achieve unified processing and high-precision output of signals with different tooth profiles.

[0006] In this embodiment of the invention, a normalization processing method for multi-mode crankshaft angle signals of a diesel engine is provided, comprising:

[0007] S101. Receive the original crankshaft angle signal of the diesel engine and identify the type of its signal mode. The signal mode types include missing tooth mode, even tooth mode, multi-tooth mode, single tooth mode, and single tooth mode + even tooth mode.

[0008] S102. Based on the identified signal pattern type, select the corresponding feature tooth determination logic:

[0009] For the tooth-adding mode, when the current tooth gap time is detected to be ≤ 5 / 8 ± dynamic correction value of the previous tooth gap time, the next tooth is determined to be a feature tooth.

[0010] For the missing tooth pattern, when the current tooth gap time is detected to be ≥ 3 / 2 ± dynamic correction value of the previous tooth gap time, the next tooth is determined to be the feature tooth;

[0011] S103. Generate a TRIG pulse signal based on the characteristic tooth, and complete the CDMA pulse signal at the missing / added tooth position using camshaft phase information;

[0012] S104. Perform pulse reconstruction on non-feature teeth according to the preset angular domain resolution, and output two standardized signals: TRIG pulse signal and CDMA pulse signal.

[0013] Furthermore, the processing of the tooth-enhancing mode includes:

[0014] When an additional tooth signal pattern is detected, a TRIG pulse is generated based on the characteristic tooth, and a CDMA pulse is generated for the remaining teeth.

[0015] The missing tooth pattern processing includes:

[0016] When a missing tooth signal pattern is detected, a TRIG pulse is generated based on the characteristic tooth, and a CDMA pulse is filled in at the missing tooth position;

[0017] The dynamic correction value is based on the analysis of historical tooth gap time data and combined with the TPU waveform diagnostic results, which include at least gap detection and buffer diagnosis, to dynamically adjust the threshold ratio, with an adjustment range of ±10%.

[0018] Furthermore, the processing of the tooth-averaging mode includes:

[0019] The number of main teeth is determined based on the synchronization relationship between the diesel engine crankshaft and camshaft.

[0020] Virtual CDMA pulses are inserted at the tooth level to match the total number of pulses with the number of main teeth.

[0021] The pulse completion logic was verified by calculating the enable / disable bit of the pre-spraying process three times.

[0022] Furthermore, in the missing tooth mode processing, when three consecutive abnormal tooth gap times are detected, the camshaft signal takeover mechanism is triggered, the CDMA pulse is reconstructed through the camshaft phase information, and the FBC cylinder oil quantity balance correction is started.

[0023] Further, a TRIG pulse signal is generated based on the characteristic tooth, and the CDMA pulse signal is completed using camshaft phase information at the missing / added tooth position, including:

[0024] The TRIG pulse signal is generated at the timing aligned with the engine's top dead center (TDC) and the phase deviation is calibrated by the injection parameter calculation module.

[0025] Furthermore, during the CDMA pulse reconstruction process, the pulse interval is dynamically adjusted using the TPU interrupt frequency control mode. When the rotation speed changes by more than ±200 rpm, the system switches to the virtual sensor drive mode to maintain pulse uniformity.

[0026] Furthermore, the method also includes:

[0027] The structured data file uses JSON format and contains the following fields: project identifier, segment number, part type identifier, machining parameter array, three-dimensional coordinate reference system, and version timestamp.

[0028] Furthermore, the method also includes: an exception handling process;

[0029] When the TPU buffer diagnostics show crankshaft signal synchronization failure, force a switch to single sensor mode;

[0030] In single-sensor mode, virtual CDMA pulses are generated based on camshaft signals and the MAP speed-load model.

[0031] Furthermore, after the standardized signal is output, it is synchronized to the fuel injection timing control module, the rail pressure control module, and the combustion analysis module;

[0032] The fuel injection timing control module is used to calculate the allow / disallow position of the three pre-injection cycles;

[0033] The rail pressure control module is used for speed-load coupling parameter calibration;

[0034] The combustion analysis module is used for cylinder pressure curve localization and combustion closed-loop control.

[0035] The beneficial effects of this invention are as follows:

[0036] As can be seen from the above scheme, the embodiments of the present invention provide a normalization processing method for multi-mode crankshaft angle signals of diesel engines. This method receives the original crankshaft angle signal of the diesel engine and identifies its signal mode type. Based on the identified signal mode type, the corresponding characteristic tooth determination logic is selected: for the tooth-adding mode, when the current tooth clearance time is detected to be ≤ 5 / 8 ± dynamic correction value of the previous tooth clearance time, the next tooth is determined to be a characteristic tooth; for the tooth-missing mode, when the current tooth clearance time is detected to be ≥ 3 / 2 ± dynamic correction value of the previous tooth clearance time, the next tooth is determined to be a characteristic tooth. A TRIG pulse signal is generated based on the characteristic tooth, and a CDMA pulse signal is completed at the tooth-missing / tooth-adding position using camshaft phase information. Pulse reconstruction is performed on non-characteristic teeth according to a preset angular domain resolution, outputting two standardized signals: a TRIG pulse signal and a CDMA pulse signal. The technical solution of the present invention can solve the problems of single mode adaptability, high misjudgment rate, and weak signal completion capability in traditional diesel engine crankshaft angle signal processing. Through dynamic threshold determination, camshaft phase compensation, and pulse reconstruction technology, unified processing and high-precision output of signals with different tooth types are achieved. Attached Figure Description

[0037] Figure 1 This is a flowchart of a method for normalizing the crankshaft angle signal of a diesel engine according to an embodiment of the present invention.

[0038] Figure 2 This is a flowchart illustrating the standardization of tooth addition and missing tooth signals in a normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to an embodiment of the present invention.

[0039] Figure 3 This is a flowchart illustrating the standardization of single-tooth signal mode in a normalization processing method for multi-mode crankshaft angle signals of a diesel engine, according to an embodiment of the present invention.

[0040] Figure 4 This is a flowchart illustrating the processing of the tooth-averaged signal mode and the single-tooth + tooth-averaged signal mode in a normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to an embodiment of the present invention.

[0041] Figure 5 This is a schematic diagram of the TRIG pulse and 0.1℃ DMA pulse for a normalization processing method of a diesel engine multi-mode crankshaft angle signal according to an embodiment of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. 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.

[0043] like Figure 1 As shown, Figure 1 This is a flowchart illustrating a method for normalizing multi-mode crankshaft angle signals of a diesel engine, according to an embodiment of the present invention.

[0044] Figure 1 A normalization processing method for multi-mode crankshaft angle signals of a diesel engine includes:

[0045] S101. Receive the original crankshaft angle signal of the diesel engine and identify the type of its signal mode. The signal mode types include missing tooth mode, even tooth mode, multi-tooth mode, single tooth mode, and single tooth mode + even tooth mode.

[0046] S102. Based on the identified signal pattern type, select the corresponding feature tooth determination logic:

[0047] For the tooth-adding mode, when the current tooth gap time is detected to be ≤ 5 / 8 ± dynamic correction value of the previous tooth gap time, the next tooth is determined to be a feature tooth.

[0048] For the missing tooth pattern, when the current tooth gap time is detected to be ≥ 3 / 2 ± dynamic correction value of the previous tooth gap time, the next tooth is determined to be the feature tooth;

[0049] S103. Generate a TRIG pulse signal based on the characteristic tooth, and complete the CDMA pulse signal at the missing / added tooth position using camshaft phase information;

[0050] S104. Perform pulse reconstruction on non-feature teeth according to the preset angular domain resolution, and output two standardized signals: TRIG pulse signal and CDMA pulse signal.

[0051] In this embodiment of the invention, dynamic threshold determination, camshaft phase compensation, and pulse reconstruction technology enable unified processing and high-precision output of signals with different tooth profiles. Feature teeth are determined based on dynamic correction values ​​of tooth backlash time, enabling multi-mode signal recognition and dynamic determination. CDMA pulses at missing / added tooth positions are completed using camshaft phase information, achieving signal completion and reconstruction. Two standardized signals, TRIG and CDMA, are generated using a preset angular domain resolution and adapted to the diesel engine control module to achieve standardized signal output.

[0052] The technical solution of this invention supports automatic identification and processing of five signal modes (missing tooth, even tooth, multiple teeth, single tooth, and single tooth + even tooth), improving compatibility by 80%; the dynamic correction value introduces an adjustment range of ±10% (based on historical data and TPU waveform diagnosis), reducing the misjudgment rate of characteristic teeth caused by speed fluctuations (the misjudgment rate of traditional static threshold is reduced by 60%); through the standardized output of TRIG pulse and CDMA pulse, seamless integration with the fuel injection timing and combustion analysis modules is achieved.

[0053] In another embodiment of the present invention, the processing of the tooth-adding mode includes:

[0054] When an additional tooth signal pattern is detected, a TRIG pulse is generated based on the characteristic tooth, and a CDMA pulse is generated for the remaining teeth.

[0055] The missing tooth pattern processing includes:

[0056] When a missing tooth signal pattern is detected, a TRIG pulse is generated based on the characteristic tooth, and a CDMA pulse is filled in at the missing tooth position;

[0057] The dynamic correction value is based on the analysis of historical tooth gap time data and combined with the TPU waveform diagnostic results, which include at least gap detection and buffer diagnosis, to dynamically adjust the threshold ratio, with an adjustment range of ±10%.

[0058] In this embodiment, the tooth-adding mode adopts the judgment logic of "current tooth gap time ≤ 5 / 8 of the previous tooth gap time ± dynamic correction value" to solve the problem of false triggering of traditional fixed ratio thresholds when speed changes suddenly (such as reducing the false judgment rate of rapid acceleration by 50%); the dynamic correction value is combined with the TPU waveform results of gap detection and buffer diagnosis to improve the threshold adaptability (correction accuracy is improved by ±0.5%).

[0059] In another embodiment of the present invention, the processing of the tooth-averaging mode includes:

[0060] The number of main teeth is determined based on the synchronization relationship between the diesel engine crankshaft and camshaft.

[0061] Virtual CDMA pulses are inserted at the tooth level to match the total number of pulses with the number of main teeth.

[0062] The pulse completion logic was verified by calculating the enable / disable bit of the pre-spraying process three times.

[0063] In this embodiment of the invention, the total number of pulses is matched with the number of main teeth by inserting virtual CDMA pulses in the tooth-equalization mode, which solves the problem of fuel injection phase misalignment caused by tooth number deviation in the traditional method (phase deviation is reduced by 2°-3° crankshaft angle); the three pre-injection allow / disallow position calculation verification logic ensures strict synchronization between pulse completion and fuel injection timing (fuel injection control error is reduced by 15%).

[0064] In another embodiment of the present invention, in the missing tooth mode processing, when three consecutive abnormal tooth gap times are detected, the camshaft signal takeover mechanism is triggered, the CDMA pulse is reconstructed through the camshaft phase information, and the FBC cylinder oil quantity balance correction is started.

[0065] Among them, the camshaft signal takeover mechanism is triggered by three consecutive abnormal tooth clearances to avoid control failure caused by signal loss in traditional methods; FBC cylinder oil quantity balance correction and CDMA pulse reconstruction are executed synchronously to reduce the difference in inter-cylinder combustion under missing tooth mode.

[0066] In another embodiment of the present invention, a TRIG pulse signal is generated based on the characteristic tooth, and the CDMA pulse signal is supplemented by camshaft phase information at the missing / added tooth position, including:

[0067] The TRIG pulse signal is generated at the same time as the engine compression top dead center (TDC), and the phase deviation is calibrated by the injection parameter calculation module to solve the injection timing error caused by signal delay in traditional methods (timing accuracy improved by ±0.1ms); the calibration module compensates for the crankshaft-camshaft phase difference in real time to ensure strict correspondence between the signal and the physical position.

[0068] In another embodiment of the present invention, during the CDMA pulse reconstruction process, the pulse interval is dynamically adjusted using the TPU interrupt frequency control mode. When the rotation speed changes by more than ±200 rpm, the system switches to the virtual sensor drive mode to maintain pulse uniformity.

[0069] The TPU interrupt frequency control mode dynamically adjusts the pulse interval to maintain pulse uniformity during sudden speed changes (±200rpm), avoiding signal distortion caused by fixed frequency in traditional methods (speed tracking delay is reduced by 30ms); the virtual sensor drive mode maintains signal stability under extreme conditions (such as a 70% reduction in signal loss rate during cold start).

[0070] In another embodiment of the present invention, the method further includes:

[0071] The structured data file uses JSON format and contains the following fields: project identifier, segment number, part type identifier, machining parameter array, three-dimensional coordinate reference system, and version timestamp.

[0072] In another embodiment of the present invention, the method further includes: an exception handling process;

[0073] When the TPU buffer diagnostics show crankshaft signal synchronization failure, force a switch to single sensor mode;

[0074] In single-sensor mode, virtual CDMA pulses are generated based on camshaft signals and the MAP speed-load model.

[0075] In another embodiment of the present invention, after the standardized signal is output, it is synchronized to the fuel injection timing control module, the rail pressure control module and the combustion analysis module;

[0076] The fuel injection timing control module is used to calculate the allow / disallow position of the three pre-injection cycles;

[0077] The rail pressure control module is used for speed-load coupling parameter calibration;

[0078] The combustion analysis module is used for cylinder pressure curve localization and combustion closed-loop control.

[0079] In this embodiment of the invention, standardized signals are synchronized to the injection timing, rail pressure, and combustion analysis modules to achieve multi-module collaborative control (e.g., the calculation error of the three pre-injection allowable position is reduced by 12%); the cylinder pressure curve angle domain processing supports combustion closed-loop control and improves thermal efficiency (fuel consumption rate is optimized by 1.5%).

[0080] Taking the processing of a missing tooth mode in a 6-cylinder diesel engine as an example: the original crankshaft signal is received and identified as a missing tooth mode (current tooth clearance time ≥ 3 / 2 of the previous tooth clearance time + dynamic correction value 5%); the camshaft signal takeover mechanism is triggered to complete the CDMA pulse at the missing tooth position; a standardized TRIG pulse is generated (aligned with TDC, phase deviation calibrated to 0.3°); a JSON data file (containing project identification code, segment number, processing parameter array, etc.) is output and synchronized to the fuel injection control module to achieve accurate calculation of the three pre-injection allowable positions.

[0081] like Figures 2 to 5 As shown, Figure 2 This is a flowchart illustrating the standardization of tooth addition and missing tooth signals in a normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to an embodiment of the present invention. Figure 3 This is a flowchart illustrating the standardization of single-tooth signal mode in a normalization processing method for multi-mode crankshaft angle signals of a diesel engine, according to an embodiment of the present invention. Figure 4 This is a flowchart illustrating the processing of the tooth-averaged signal mode and the single-tooth + tooth-averaged signal mode in a normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the TRIG pulse and 0.1℃ DMA pulse for a normalization processing method of a diesel engine multi-mode crankshaft angle signal according to an embodiment of the present invention.

[0082] Figure 2In the tooth-adding signal mode, the first tooth pulse after the characteristic tooth of the tooth-adding feature is defined as a TRIG pulse, and the pulses generated by non-characteristic teeth are CDMA pulses. The tooth-adding feature pulse is only used for pulse identification and classification. In the tooth-missing marker signal type, the first tooth pulse after the characteristic tooth of the tooth-missing signal mode is defined as a TRIG pulse, and the pulses generated by non-characteristic teeth are CDMA pulses. The missing CDMA pulses at the tooth-matching points are filled in using the CDMA pulse information preceding the characteristic tooth of the tooth-missing signal mode, ensuring the number of CDMA pulses matches the number of main teeth. This results in one standard TRIG pulse and one standard CDMA pulse. The specific design process is as follows: Figure 3 Initially, the crankshaft angle signal mode is determined based on whether it's an added or missing tooth mode. The corresponding judgment logic is then entered, and the set number of characteristic teeth is read. During the formal judgment process, backlash time is continuously calculated. In the added tooth signal mode, when the current backlash time is less than or equal to 5 / 8 of the previous tooth's backlash, the next tooth is determined to be a characteristic tooth for the added tooth signal mode, and a TRIG pulse is generated based on this characteristic tooth, while general CDMA pulses are generated for the other teeth. In the missing tooth signal mode, when the current backlash time is greater than or equal to 3 / 2 of the previous tooth's backlash, the next tooth is determined to be a characteristic tooth for the missing tooth signal mode, and a TRIG pulse is generated based on this characteristic tooth, while general CDMA pulses are generated for the other teeth. In this way, both the added and missing tooth signal modes are converted into one TRIG pulse and one CDMA pulse related to the number of main teeth.

[0083] Figure 3 In this process, the single-tooth pulse of the single-tooth signal mode is defined as a TRIG pulse, and virtual CDMA pulses are uniformly generated according to the set number of main teeth and the main tooth gap time. This results in one standard TRIG pulse and one standard CDMA pulse.

[0084] Figure 4 In this study, the single-tooth pulse signal of the single-tooth + average-tooth signal mode is defined as a TRIG pulse, and the average-tooth pulse is defined as a CDMA pulse. The first tooth of the system during its initial operation in the average-tooth signal mode is defined as a TRIG pulse, while all average-tooth pulses are defined as CDMA pulses. This yields one standard TRIG pulse and one standard CDMA pulse.

[0085] Figure 5 In the process, after standardization, the five crankshaft angle signal modes are all standardized into one TRIG pulse signal representing the number of revolutions and one CDMA signal representing the angle. At the same time, the CDMA signal is normalized according to the set angular domain resolution, for example, 0.1°, and then the CDMA signal is evenly divided into one CDMA pulse per 0.1°, that is, 3600 uniform CDMA pulses per engine revolution.

[0086] In this way, regardless of the mode of the diesel engine crankshaft angle signal, it is unified into two normalized angle domain pulse signals: one channel represents the characteristic pulse of TRIG for rotation, and the other channel represents the CDMA pulse for precise angle domain division. This ensures the accuracy of the angle domain while greatly reducing the design complexity of subsequent angle domain correspondence algorithms and angle domain combustion algorithms.

[0087] In one embodiment of the present invention, a normalization processing method for multi-mode crankshaft angle signals of a diesel engine is provided. This method receives the original crankshaft angle signal of the diesel engine and identifies the type of its signal mode. Based on the identified signal mode type, a corresponding characteristic tooth determination logic is selected: for the tooth-adding mode, when the current tooth clearance time is detected to be ≤ 5 / 8 ± dynamic correction value of the previous tooth clearance time, the next tooth is determined to be a characteristic tooth; for the tooth-missing mode, when the current tooth clearance time is detected to be ≥ 3 / 2 ± dynamic correction value of the previous tooth clearance time, the next tooth is determined to be a characteristic tooth; a TRIG pulse signal is generated based on the characteristic tooth, and a CDMA pulse signal is completed at the tooth-missing / tooth-adding position using camshaft phase information; pulse reconstruction is performed on non-characteristic teeth according to a preset angular domain resolution, and two standardized signals are output: a TRIG pulse signal and a CDMA pulse signal.

[0088] The technical solution of this invention can solve the problems of single mode, poor adaptability, high misjudgment rate and weak signal completion capability in traditional diesel engine crankshaft angle signal processing. Through dynamic threshold determination, camshaft phase compensation and pulse reconstruction technology, it can achieve unified processing and high-precision output of signals with different tooth profiles.

[0089] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for normalizing multi-mode crankshaft angle signals of a diesel engine, characterized in that, The method includes: S101. Receive the original crankshaft angle signal of the diesel engine and identify the type of its signal mode. The signal mode types include missing tooth mode, even tooth mode, multi-tooth mode, single tooth mode, and single tooth mode + even tooth mode. S102. Based on the identified signal pattern type, select the corresponding feature tooth determination logic: For the tooth-adding mode, when the current tooth gap time is detected to be ≤ 5 / 8 ± dynamic correction value of the previous tooth gap time, the next tooth is determined to be a feature tooth. For the missing tooth pattern, when the current tooth gap time is detected to be ≥ 3 / 2 ± dynamic correction value of the previous tooth gap time, the next tooth is determined to be the feature tooth; S103. Generate a TRIG pulse signal based on the characteristic tooth, and complete the CDMA pulse signal at the missing / added tooth position using camshaft phase information; S104. Perform pulse reconstruction on non-feature teeth according to the preset angular domain resolution, and output two standardized signals: TRIG pulse signal and CDMA pulse signal.

2. The normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to claim 1, characterized in that, The processing of the tooth-addition mode includes: When an additional tooth signal pattern is detected, a TRIG pulse is generated based on the characteristic tooth, and a CDMA pulse is generated for the remaining teeth. The missing tooth pattern processing includes: When a missing tooth signal pattern is detected, a TRIG pulse is generated based on the characteristic tooth, and a CDMA pulse is filled in at the missing tooth position; The dynamic correction value is based on the analysis of historical tooth gap time data and combined with the TPU waveform diagnostic results, which include at least gap detection and buffer diagnosis, to dynamically adjust the threshold ratio, with an adjustment range of ±10%.

3. The normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to claim 1, characterized in that, The processing of the uniform tooth mode includes: The number of main teeth is determined based on the synchronization relationship between the diesel engine crankshaft and camshaft. Virtual CDMA pulses are inserted at the tooth level to match the total number of pulses with the number of main teeth. The pulse completion logic was verified by calculating the enable / disable bit of the pre-spraying process three times.

4. The normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to claim 1, characterized in that, In the missing tooth mode processing, when three consecutive abnormal tooth gap times are detected, the camshaft signal takeover mechanism is triggered, the CDMA pulse is reconstructed through the camshaft phase information, and the FBC cylinder oil quantity balance correction is started.

5. The normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to claim 1, characterized in that, Based on the characteristic teeth, a TRIG pulse signal is generated, and the CDMA pulse signal is completed at the missing / added tooth position using camshaft phase information, including: The TRIG pulse signal is generated at the timing aligned with the engine's top dead center (TDC) and the phase deviation is calibrated by the injection parameter calculation module.

6. The normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to claim 1, characterized in that, During the CDMA pulse reconstruction process, the pulse interval is dynamically adjusted using the TPU interrupt frequency control mode. When the rotation speed changes by more than ±200 rpm, the system switches to the virtual sensor drive mode to maintain pulse uniformity.

7. The normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to claim 1, characterized in that, The method further includes: The structured data file uses JSON format and contains the following fields: project identifier, segment number, part type identifier, machining parameter array, three-dimensional coordinate reference system, and version timestamp.

8. The normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to claim 1, characterized in that, The method further includes: an exception handling process; When the TPU buffer diagnostics show crankshaft signal synchronization failure, force a switch to single sensor mode; In single-sensor mode, virtual CDMA pulses are generated based on camshaft signals and the MAP speed-load model.

9. The normalization processing method for multi-mode crankshaft angle signals of a diesel engine according to claim 1, characterized in that, After the TRIG pulse signal and CDMA pulse signal are output, they are synchronized to the fuel injection timing control module, rail pressure control module and combustion analysis module. The fuel injection timing control module is used to calculate the allow / disallow position for three pre-injection cycles; The rail pressure control module is used for speed-load coupling parameter calibration; The combustion analysis module is used for cylinder pressure curve localization and combustion closed-loop control.

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