A single-rotor engine ignition control strategy

Abstract

This invention discloses an ignition control strategy for a single-rotor engine, belonging to the field of engine electronic control technology. Addressing the problems of long flame propagation paths in the narrow combustion chambers of single-rotor engines, insufficient adaptability of existing ignition control methods, poor combustion stability, and difficulty in balancing power and emissions, this invention collects parameters such as engine speed, load, eccentric shaft angle, and rotor phase to identify the current compression stroke working chamber and determine the target ignition window. It then queries a basic ignition MAP and, after operating condition correction, obtains the L-spark plug target advance angle and T-spark plug target delay angle. Based on six operating conditions—starting, idling, economy, power, anti-knock, and emissions optimization—a TL-spark plug collaborative control mode is selected, and ignition is executed within the target window. Parameters are updated for the next cycle based on combustion feedback. This invention achieves dynamic adaptive optimization of the ignition strategy across all operating conditions, improving combustion efficiency and operational reliability, while balancing power, economy, and emissions performance. It is suitable for engineering applications in single-rotor engine electronic control systems.

Description

Technical Field

[0001] This invention belongs to the field of engine electronic control technology, specifically a single-rotor engine ignition control strategy. Background Technology

[0002] Single-rotor engines have advantages such as simple structure, small size, high power density, and stable operation, and have broad application prospects in fields such as aviation power, small power generation, and special vehicles. Their combustion chamber is usually long and crescent-shaped, and the flame propagation path is significantly longer than that of reciprocating engines. The combustion process is extremely sensitive to the accuracy of ignition timing and the synergistic control effect of dual spark plugs.

[0003] Existing ignition control technologies for single-rotor engines generally suffer from insufficient adaptability to operating conditions: for L-type (leading) spark plugs and T-type (trailing) spark plugs, fixed advance angle, fixed delay angle, or simple speed segment control strategies are mostly adopted, which cannot dynamically adjust according to the engine's real-time speed, load, intake air temperature, cooling status, and combustion feedback.

[0004] Specifically, this manifests as: insufficient ignition energy, high misfire rate, and long start-up time under cold start conditions; large speed fluctuations and poor combustion stability under idling conditions; poor coordination between the two spark plugs under medium and high load conditions, resulting in slow flame propagation speed and limited power output; and the tendency to cause knocking due to excessive ignition advance angle under high temperature and high load conditions, damaging engine components. Furthermore, it is difficult to balance fuel economy and emission performance, failing to meet increasingly stringent environmental protection requirements.

[0005] Therefore, there is an urgent need to develop a TL dual spark plug collaborative ignition control strategy based on full-condition adaptive ignition. Through precise ignition timing control and TL spark plug collaborative operation, this strategy can solve the technical problems of poor combustion stability, weak adaptability to operating conditions, and difficulty in balancing power and emissions in existing technologies. Summary of the Invention

[0006] To address the problems existing in the background art, the present invention provides an ignition control strategy for a single-rotor engine.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an ignition control strategy for a single-rotor engine, the strategy comprising the following steps:

[0008] S1: Real-time acquisition of engine speed N, load Q, eccentric shaft angle θe, rotor phase θr, and selective acquisition of at least one parameter among intake air temperature, cooling temperature, power supply voltage, knock signal and exhaust temperature;

[0009] S2: Identify the working chamber currently in the compression stroke based on the eccentric shaft angle θe and rotor phase θr, and determine the target ignition window corresponding to the working chamber;

[0010] S3: Call the pre-stored basic ignition MAP, and based on the current speed N and load Q, obtain the basic ignition advance angle αL0 of spark plug L and the basic delay angle ΔTL0 of spark plug T relative to spark plug L;

[0011] S4: Correct αL0 and ΔTL0 according to the operating condition parameters to obtain the target ignition advance angle αL and the target delay angle ΔTL of spark plug L;

[0012] S5: Select the corresponding TL spark plug coordination control mode based on the current engine operating conditions;

[0013] S6: Within the target ignition window, control the L spark plug to ignite at the eccentric shaft angle corresponding to αL, and control the T spark plug to ignite at the eccentric shaft angle corresponding to ΔTL after the L spark plug ignites.

[0014] S7: Based on the knock signal and combustion indicators, the ignition advance angle, delay angle and ignition mode of the next working cycle are updated adaptively in a closed loop.

[0015] The TL spark plug co-control mode in S5 includes start mode, idle mode, economy mode, power mode, anti-knock mode, and emission optimization mode.

[0016] In the aforementioned start-up mode, TL synchronous ignition or small-delay dual ignition is used, the T spark plug delay angle is 0°~5° eccentric shaft angle, and if necessary, the L spark plug is subjected to 2~4 multiple ignitions.

[0017] In the idle mode, a delay-level control is adopted with L main ignition and T auxiliary ignition, and the T spark plug delay angle is 3°~10° eccentric shaft angle; when the combustion stability of several consecutive working cycles meets the preset threshold, the T spark plug participation frequency is reduced or the mode is switched to L single ignition.

[0018] In the economic mode, the L-type single ignition mode is preferred, or the T-type spark plug participation frequency is reduced.

[0019] In the aforementioned power mode, a TL delayed staged ignition mode is adopted, with the T spark plug delay angle being 6°~18° eccentric shaft angle.

[0020] In the anti-knock mode, a three-stage anti-knock strategy is adopted: first, the advance angle of the L spark plug is reduced, then the delay angle of the T spark plug is increased, and finally, the ignition of the T spark plug is suspended. First, the advance angle of the L spark plug is reduced by 1°~8°, while the delay angle of the T spark plug is increased by 2°~10°. When knocking still exists, the mode is switched to L-only ignition mode or the ignition of the T spark plug is suspended for several working cycles.

[0021] In the emission optimization mode, the ignition timing of the T spark plug is fine-tuned; when an incomplete combustion trend is detected in the later stage of combustion, ΔTL is reduced; when the exhaust temperature is detected to be too high, αL is reduced and ΔTL is fine-tuned.

[0022] The correction parameters in S4 include intake air temperature, cooling temperature, power supply voltage, transient load changes, and combustion feedback signals.

[0023] The combustion parameters in S7 include exhaust temperature, combustion duration, and engine speed fluctuation.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. In response to the characteristic of single-rotor engines with multiple working chambers working alternately, based on the accurate identification of working chambers and the adaptive correction of multiple parameters under working conditions, combined with the combustion feedback closed-loop update mechanism, the shortcomings of existing technologies that cannot adapt to dynamic combustion states due to fixed ignition parameters are solved. It can achieve precise control of ignition timing and fully adapt to different engine speeds, loads and air-fuel mixture states.

[0026] 2. To address the inherent problem of long flame propagation paths in the narrow combustion chambers of single-rotor engines, the use of condition-adaptive L / T spark plug staged coordinated ignition control, instead of the existing fixed synchronous or fixed delayed ignition technology, can effectively shorten the flame propagation distance, improve flame propagation efficiency, accelerate the in-cylinder pressure build-up rate, and improve combustion completeness.

[0027] 3. By relying on the automatic switching of six operating modes—start, idle, economy, power, anti-knock, and emission optimization—it specifically solves the problem of existing single control strategies that fail to address all aspects. It can simultaneously take into account cold start success rate, idle stability, power output performance, fuel economy, and exhaust emission performance, achieving the overall optimal performance of the engine.

[0028] 4. Through real-time detection of knock signals and a three-stage progressive anti-knock adjustment strategy (retracting the advance angle → increasing the delay angle → pausing T-spark plug ignition), knocking under high load conditions can be quickly suppressed, while effectively reducing engine misfire rate and idle speed fluctuations across the entire operating range, significantly improving the safety and reliability of engine operation.

[0029] 5. This control strategy has clear logic, strong parameter calibrability, and good portability, and can be directly applied to the engineering development and mass production of electronic control systems for various single-rotor engines.

[0030] In summary, this invention effectively solves the inherent defects of existing single-rotor engines, such as insufficient adaptability of ignition control, poor combustion stability, and difficulty in balancing power and emissions, through the all-condition adaptive TL dual-spark plug graded coordinated ignition control. It comprehensively optimizes the overall performance of the engine while ensuring operational reliability, and has good practical value and broad engineering application prospects. Attached Figure Description

[0031] Figure 1 This is a flowchart of the single-rotor engine ignition control method of the present invention;

[0032] Figure 2 This is a schematic diagram of the TL spark plug ignition timing of the present invention;

[0033] Figure 3 This is a block diagram of the full-condition TL spark plug collaborative control mode of the present invention. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0035] This embodiment describes an ignition control strategy for a single-rotor engine. This strategy is applied to a single-rotor engine with a long and narrow combustion chamber, a long flame propagation path, and equipped with L-type and T-type spark plugs. The strategy includes the following steps:

[0036] S1: Real-time acquisition of engine speed N, load Q, eccentric shaft angle θe, rotor phase θr, and selective acquisition of at least one parameter among intake air temperature, cooling temperature, power supply voltage, knock signal and exhaust temperature;

[0037] S2: Identify the working chamber currently in the compression stroke based on the eccentric shaft angle θe and rotor phase θr, and determine the target ignition window corresponding to the working chamber;

[0038] S3: Call the pre-stored basic ignition MAP, and based on the current speed N and load Q, obtain the basic ignition advance angle αL0 of spark plug L and the basic delay angle ΔTL0 of spark plug T relative to spark plug L;

[0039] S4: Correct αL0 and ΔTL0 according to the operating condition parameters to obtain the target ignition advance angle αL and the target delay angle ΔTL of spark plug L;

[0040] S5: Select the corresponding TL spark plug coordination control mode based on the current engine operating conditions;

[0041] S6: Within the target ignition window, control the L spark plug to ignite at the eccentric shaft angle corresponding to αL, and control the T spark plug to ignite at the eccentric shaft angle corresponding to ΔTL after the L spark plug ignites.

[0042] S7: Based on the knock signal and combustion indicators, the ignition advance angle, delay angle and ignition mode of the next working cycle are updated adaptively in a closed loop.

[0043] The TL spark plug co-control mode in S5 includes start mode, idle mode, economy mode, power mode, anti-knock mode, and emission optimization mode.

[0044] In the aforementioned start-up mode, TL synchronous ignition or small-delay dual ignition is used, the T spark plug delay angle is 0°~5° eccentric shaft angle, and if necessary, the L spark plug is subjected to 2~4 multiple ignitions.

[0045] In the idle mode, a delay-level control is adopted with L main ignition and T auxiliary ignition, and the T spark plug delay angle is 3°~10° eccentric shaft angle; when the combustion stability of several consecutive working cycles meets the preset threshold, the T spark plug participation frequency is reduced or the mode is switched to L single ignition.

[0046] In the economic mode, the L-type single ignition mode is preferred, or the T-type spark plug participation frequency is reduced.

[0047] In the aforementioned power mode, a TL delayed staged ignition mode is adopted, with the T spark plug delay angle being 6°~18° eccentric shaft angle.

[0048] In the anti-knock mode, a three-stage anti-knock strategy is adopted: first, the advance angle of the L spark plug is reduced, then the delay angle of the T spark plug is increased, and finally, the ignition of the T spark plug is suspended. First, the advance angle of the L spark plug is reduced by 1°~8°, while the delay angle of the T spark plug is increased by 2°~10°. When knocking still exists, the mode is switched to L-only ignition mode or the ignition of the T spark plug is suspended for several working cycles.

[0049] In the emission optimization mode, the ignition timing of the T spark plug is fine-tuned; when an incomplete combustion trend is detected in the later stage of combustion, ΔTL is reduced; when the exhaust temperature is detected to be too high, αL is reduced and ΔTL is fine-tuned.

[0050] The correction parameters in S4 include intake air temperature, cooling temperature, power supply voltage, transient load changes, and combustion feedback signals.

[0051] The combustion parameters in S7 include exhaust temperature, combustion duration, and engine speed fluctuation.

[0052] This invention targets single-rotor engines with a long and narrow combustion chamber and a long flame propagation path. It constructs a dual-ignition-source synergistic ignition system using L-type and T-type spark plugs. The L-type spark plug is positioned on the intake side of the combustion chamber, and the T-type spark plug is positioned on the exhaust side, distributed at both ends of the long and narrow combustion chamber along the rotor rotation direction. Its working principle is as follows: The controller collects operating parameters in real time, including engine speed, load, eccentric shaft angle, rotor phase, intake temperature, cooling temperature, power supply voltage, knock signal, and exhaust temperature. Based on the eccentric shaft angle and rotor phase signals, it accurately identifies the working chamber currently in the compression stroke and determines the target ignition window corresponding to that working chamber. The target ignition window is a preset angle range at the end of the current working chamber's compression stroke. Then, it calls a pre-stored basic ignition map, which is obtained through engine bench testing (calibration must consider combustion efficiency, emission performance, and knock boundaries) and covers the entire engine speed and load range. The parameter data table obtains the basic ignition advance angle of the L spark plug and the basic delay angle of the T spark plug relative to the L spark plug based on the current speed and load. Then, it combines the intake air temperature, cooling temperature, power supply voltage, transient load changes and combustion feedback signals to correct the basic ignition parameters, thereby obtaining the target ignition advance angle of the L spark plug and the target delay angle of the T spark plug adapted to the current operating conditions. At the same time, it automatically selects the corresponding TL spark plug cooperative control mode according to the engine's starting, idling, economy, power, anti-knock, and emission optimization conditions. Within the target ignition window, it controls the L spark plug to ignite at the target ignition advance angle, and the T spark plug ignites at a time corresponding to the eccentric shaft angle after the L spark plug ignites.

[0053] The starting mode employs TL synchronous ignition or small-delay dual ignition and can perform multiple ignitions on the L spark plug to enhance starting capability, shorten starting time, and reduce misfire rate; the idle mode uses delayed staged control of L main ignition and T auxiliary ignition to improve idle stability and reduce speed fluctuations; the economy mode prioritizes L single ignition or reduces the T spark plug participation frequency to reduce ignition energy consumption and improve fuel economy; the power mode uses TL delayed staged ignition to increase combustion propagation speed and pressure build-up rate, thereby improving power output; the anti-knock mode suppresses knock by retracting the L spark plug ignition advance angle, increasing the T spark plug delay angle, or suspending T spark plug ignition to improve operational safety and reliability under high load conditions; and the emission optimization mode improves HC and CO emissions by fine-tuning the T spark plug ignition timing.

[0054] After ignition is completed, the controller continuously collects combustion indicators such as knock signal, exhaust temperature, combustion duration and speed fluctuation, and performs adaptive closed-loop updates on the ignition advance angle, delay angle and ignition mode for the next working cycle. This enables dynamic adaptive optimization of ignition timing and dual spark plug coordination strategy across all operating conditions, including cold start, idling, medium-high load, and high-temperature high load. It effectively solves the problems of insufficient adaptability of ignition control, poor combustion stability and difficulty in balancing power and emissions in single-rotor engines, allowing the engine to maintain a high-efficiency, stable and reliable combustion state under different speeds, loads and air-fuel mixtures.

[0055] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalent features of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A single-rotor engine ignition control strategy, characterized by: The strategy includes the following steps: S1: Real-time acquisition of engine speed N, load Q, eccentric shaft angle θe, rotor phase θr, and selective acquisition of at least one parameter among intake air temperature, cooling temperature, power supply voltage, knock signal and exhaust temperature; S2: Identify the working chamber currently in the compression stroke based on the eccentric shaft angle θe and rotor phase θr, and determine the target ignition window corresponding to the working chamber; S3: Call the pre-stored basic ignition MAP, and based on the current speed N and load Q, obtain the basic ignition advance angle αL0 of spark plug L and the basic delay angle ΔTL0 of spark plug T relative to spark plug L; S4: Correct αL0 and ΔTL0 according to the operating condition parameters to obtain the target ignition advance angle αL and the target delay angle ΔTL of spark plug L; S5: Select the corresponding TL spark plug coordination control mode based on the current engine operating conditions; S6: Within the target ignition window, control the L spark plug to ignite at the eccentric shaft angle corresponding to αL, and control the T spark plug to ignite at the eccentric shaft angle corresponding to ΔTL after the L spark plug ignites. S7: Based on the knock signal and combustion indicators, the ignition advance angle, delay angle and ignition mode of the next working cycle are updated adaptively in a closed loop.

2. The single-rotor engine ignition control strategy of claim 1, wherein: The TL spark plug co-control mode in S5 includes start mode, idle mode, economy mode, power mode, anti-knock mode, and emission optimization mode.

3. The single-rotor engine ignition control strategy of claim 2, wherein: In the aforementioned start-up mode, TL synchronous ignition or small-delay dual ignition is used, the T spark plug delay angle is 0°~5° eccentric shaft angle, and if necessary, the L spark plug is subjected to 2~4 multiple ignitions.

4. The single-rotor engine ignition control strategy of claim 2, wherein: In the idle mode, a delay-level control is adopted with L main ignition and T auxiliary ignition, and the T spark plug delay angle is 3°~10° eccentric shaft angle; when the combustion stability of several consecutive working cycles meets the preset threshold, the T spark plug participation frequency is reduced or the mode is switched to L single ignition.

5. The single-rotor engine ignition control strategy of claim 2, wherein: In the economic mode, the L-type single ignition mode is preferred, or the T-type spark plug participation frequency is reduced.

6. The single-rotor engine ignition control strategy of claim 2, wherein: In the aforementioned power mode, a TL delayed staged ignition mode is adopted, with the T spark plug delay angle being 6°~18° eccentric shaft angle.

7. The ignition control strategy for a single-rotor engine according to claim 2, characterized in that: In the anti-knock mode, a three-stage anti-knock strategy is adopted: first, the advance angle of the L spark plug is reduced, then the delay angle of the T spark plug is increased, and finally, the ignition of the T spark plug is suspended. First, the advance angle of the L spark plug is reduced by 1°~8°, while the delay angle of the T spark plug is increased by 2°~10°. When knocking still exists, the mode is switched to L-only ignition mode or the ignition of the T spark plug is suspended for several working cycles.

8. The ignition control strategy for a single-rotor engine according to claim 2, characterized in that: In the emission optimization mode, the ignition timing of the T spark plug is fine-tuned; when an incomplete combustion trend is detected in the later stage of combustion, ΔTL is reduced; when the exhaust temperature is detected to be too high, αL is reduced and ΔTL is fine-tuned.

9. The ignition control strategy for a single-rotor engine according to claim 1, characterized in that: The correction parameters in S4 include intake air temperature, cooling temperature, power supply voltage, transient load changes, and combustion feedback signals.

10. The ignition control strategy for a single-rotor engine according to claim 1, characterized in that: The combustion parameters in S7 include exhaust temperature, combustion duration, and engine speed fluctuation.

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