Intake Throttle Feedback in Engine Compression Braking Instability
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Solution Overview
Problem
Multi-cylinder reciprocating piston internal combustion engines experience abnormal vibration and noise during engine compression braking due to differences in cylinder-specific components, leading to undesirable levels that affect vehicle comfort and longevity.
Innovation Solution
An electronic control unit acquires operating data on in-cylinder pressure, engine speed, noise, and vibration, and adjusts the intake air throttle to prevent or alleviate abnormal engine compression braking operations by generating intake actuator commands based on feedback-loop control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If engine compression braking is implemented by controlling cylinder valves to allow compressed gases to exit at top dead center, then the braking effect is achieved, but abnormal vibration and noise occur due to differences in cylinder-specific components
Solution Approach 1:
The electronic control unit performs preliminary detection of abnormal engine compression braking operations by monitoring operating data before the abnormal conditions fully develop. The system detects deviations in in-cylinder pressure, engine speed, noise, or vibration patterns and takes preventive action by adjusting the intake air throttle to restore normal operation before severe vibration and noise occur.
Solution Approach 2:
The system implements a feedback control mechanism where the electronic control unit continuously monitors operating data from sensors and uses this information to dynamically adjust the intake air throttle position. The feedback loop compares actual operating parameters against expected ranges and automatically corrects deviations by modulating the intake air flow, thereby eliminating abnormal vibration and noise while maintaining effective braking.
2Adaptability or versatility
If cylinder-specific components have manufacturing tolerances or malfunctions, then individual cylinder operations differ, but this leads to abnormal engine compression braking operations with excessive vibration and noise
Solution Approach 1:
The electronic control unit dynamically changes operating parameters by adjusting the intake air throttle position to compensate for variations in cylinder-specific components. By modifying the intake air flow parameters, the system balances the operating conditions across all cylinders, ensuring that manufacturing tolerances and minor malfunctions do not lead to abnormal vibration and noise during compression braking operations.
3Object-affected harmful factors
If the intake air throttle is adjusted to correct abnormal operations, then vibration and noise are reduced, but additional control complexity is introduced
Solution Approach 1:
The electronic control unit performs multiple functions using a single integrated system: it monitors engine operation, detects abnormal compression braking conditions, and controls the intake air throttle to correct deviations. This multi-functional approach eliminates the need for separate dedicated vibration control systems, reducing overall control complexity while effectively reducing abnormal vibration and noise through intelligent throttle management.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method increases the reliability of the engine compression braking system, reduces nuisance to passersby, and ensures a prompt return to normal operation by stabilizing the control method and decoupling exhaust gas pressure from intake air filling.
Implementation Method 1
generating intake actuator setting commands for the intake actuator based on the operating data, wherein the adjusting of the degree of closing of the intake air throttle is performed according to the intake actuator setting commands
Data Source
AI summary
A method for controlling an engine compression braking mode of an engine arrangement, wherein the method comprises acquiring, during an engine compression braking mode, with one or more sensors, operating data representative of at least one engine operating parameter in the list of: in-cylinder pressure, at least one of engine rotation speed and acceleration, and at least one of noise and vibration generated by the engine arrangement in the engine compression braking mode, and wherein, upon determination of an occurrence of an abnormal engine compression braking operation by the electronic control unit, the method comprises adjusting the degree of closing of the intake air throttle by the intake actuator according to the intake actuator setting commands. The invention also relates to an electronic control unit, a computer program, at least one of an engine arrangement and a heavy-duty vehicle embodying and implementing such method.