Dynamic Rail Pressure Filter for Transient Response
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rail pressure regulation systems in internal combustion engines face challenges in managing steady state and transient operational states, leading to delayed target high pressure responses during transient operations, which result in higher emissions and poorer engine performance.
Innovation Solution
A dynamic target high pressure filter with variable filter parameters, such as time constant or filter angle, is used to differentiate between steady state and transient operational conditions, allowing for steep gradients in target high pressure performance characteristics without compromising steady state stability. This filter is calculated based on the transient air mass ratio, enabling a PT1-filter or mean value filter to adjust its settings dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a PT1-filter with a constant time constant is used to regulate rail pressure, then steady state performance is improved, but transient response is delayed
Solution Approach 1:
The patent applies the dynamics principle by transitioning from a static time constant to a dynamic time constant that varies with engine operating conditions. The time constant is calculated based on the transient air mass ratio, allowing the filter to adapt its characteristics in real-time. This enables the system to maintain optimal steady-state filtering while achieving faster transient response when needed.
Solution Approach 2:
The patent implements parameter changes by making the time constant a variable parameter rather than a fixed value. The time constant is dynamically adjusted based on the transient air mass ratio, which reflects the current engine operating state. This parameter change allows the filter to optimize its performance characteristics according to whether the engine is in steady-state or transient operation.
2Stability of the object's composition
If a long dwell time filter is used, then steady state fluctuations are reduced, but transient pressure changes are delayed
Solution Approach 1:
The patent resolves this contradiction by making the filter's dwell time dynamic rather than static. The dwell time is continuously adjusted based on the transient air mass ratio, allowing the system to use longer dwell times for steady-state stability and shorter dwell times for rapid transient response. This dynamic adaptation eliminates the need to choose between the two opposing requirements.
Solution Approach 2:
The patent changes the parameter of dwell time from a constant value to a variable parameter that responds to engine operating conditions. By calculating the dwell time based on the transient air mass ratio, the system can optimize the filtering characteristics to match the current operational state, thereby reducing the time loss during transient operations while maintaining steady-state stability.
3Object-generated harmful factors
If high rail pressure is maintained during transient operation, then emissions are reduced, but steady state filter performance is compromised
Solution Approach 1:
The patent applies dynamics by making the filter characteristics adaptive to transient conditions. During transient operations, the dynamic time constant allows the filter to respond more quickly to pressure changes, enabling the system to maintain optimal rail pressure for emission control. During steady-state operation, the filter returns to its normal filtering performance, thus resolving the contradiction between emission reduction and filter performance.
Solution Approach 2:
The patent changes the filter parameters dynamically based on the transient air mass ratio. When the engine is in transient operation, the parameter adjustment allows for faster response and better emission control. When the engine returns to steady-state, the parameters are adjusted to restore optimal filter performance. This parameter adaptation resolves the conflict between the two operational requirements.
Data Source
AI summary
The invention describes a method and an arrangement for the regulation of the rail pressure in an internal combustion engine. In the method, the rail pressure is regulated, with a target high pressure being predefined. Said target high pressure is filtered, before being input, by way of a target high pressure filter which is configured as a dynamic target high pressure filter.