Cylinder Deactivation Control for Engine Load Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dynamic skip fire technology for engine cylinder deactivation faces issues such as unbalanced cylinder loads, unstable working state, poor noise, vibration, and harshness (NVH) due to unequal ignition times and cycles, and complex control strategies, which affect engine reliability and specific model configurations.
Innovation Solution
A cylinder deactivation control method that determines the crankshaft rotation angle and speed to identify trigger moments, adjusts working condition regions, and calculates fuel injection quantities based on cylinder pressure forms and deactivation modes, using a processor and memory to implement a calibrated control strategy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If dynamic skip fire technology is used for cylinder deactivation, then oil consumption and exhaust temperature are reduced in low-load conditions, but cylinder loads become unbalanced and engine reliability deteriorates
Solution Approach 1:
The patent segments the engine operation into different working condition regions (low-load, medium-load, high-load) and applies different cylinder deactivation strategies to each region. This allows optimization for oil consumption in low-load conditions while maintaining reliability in higher-load conditions through appropriate ignition patterns and cylinder activation sequences.
Solution Approach 2:
The patent implements periodic cylinder deactivation patterns where cylinders are activated and deactivated in a cyclic manner based on the working condition region. This periodic action ensures that no single cylinder is continuously deactivated, thereby balancing loads over time and maintaining engine reliability while achieving fuel economy benefits during low-load operation.
2Temperature
If dynamic skip fire technology is used for cylinder deactivation, then exhaust temperature is reduced in low-load conditions, but working state stability deteriorates
Solution Approach 1:
The patent dynamically adjusts the cylinder deactivation strategy based on the current working condition region. The control system continuously monitors engine parameters and transitions between different deactivation modes (e.g., 1-2-1 pattern, 1-3-1 pattern, or all cylinders active) to maintain stable operation while controlling exhaust temperature in low-load conditions.
Solution Approach 2:
The patent employs feedback control where the actual engine performance parameters (including exhaust temperature and vibration levels) are monitored and used to adjust the cylinder deactivation pattern. This feedback mechanism ensures that the working state remains stable by preventing excessive temperature reduction that could lead to combustion instability or increased vibrations.
3Use of energy by moving object
If unequal ignition times are applied to cylinders, then fuel economy is improved in low-load conditions, but load balance between cylinders deteriorates
Solution Approach 1:
The patent uses periodic ignition patterns such as 1-2-1 or 1-3-1 sequences where cylinders are ignited in a repeating cycle rather than continuously. This periodic action allows certain cylinders to skip ignition in specific cycles, reducing overall fuel consumption in low-load conditions while ensuring that each cylinder receives periodic ignition to maintain balanced loads over time.
Solution Approach 2:
The patent applies local quality by allowing different cylinders to have different ignition frequencies based on their position and current operational state. Instead of uniform ignition across all cylinders, the system selectively activates specific cylinders in specific cycles, optimizing fuel economy locally while maintaining overall system balance through the periodic repetition of these patterns.
4Productivity
If dynamic cylinder deactivation is implemented, then productivity is improved through optimized performance, but control strategy complexity increases
Solution Approach 1:
The patent segments the control strategy into distinct working condition regions (low-load, medium-load, high-load) with predefined deactivation patterns for each region. This segmentation simplifies the control logic by avoiding the need for complex real-time optimization algorithms, as the control system only needs to identify the current region and apply the corresponding pre-determined strategy.
Solution Approach 2:
The patent changes control parameters (such as ignition timing, injection timing, and cylinder activation state) based on the identified working condition region. By using parameter changes rather than complex control algorithms, the system achieves optimized performance across different operating conditions while keeping the control strategy relatively simple and easier to implement.
Data Source
AI summary
In a cylinder deactivation control method of an engine, a cylinder deactivation trigger moment of a to-be-controlled engine is determined; a second cycle and a cylinder deactivation mode corresponding to the next first cycle are determined according to the crankshaft rotation speed at the cylinder deactivation trigger moment, the target torque at the cylinder deactivation trigger moment, and a second cycle and a cylinder deactivation mode corresponding to the current first cycle at the cylinder deactivation trigger moment; the cylinder pressure type of each cylinder in the current first cycle is determined in conjunction with the cylinder deactivation modes of three adjacent first cycles; the fuel injection quantity of each ignition cylinder in the current first cycle is determined based on the calibrated preset fuel injection quantity chart of the first cycle.