Exhaust Gas Purification Control Method for Torque Shock Prevention
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Solution Overview
Problem
Existing exhaust gas purification systems face challenges in simplifying data for fuel pressure control and preventing torque shock during forced regeneration control, particularly in high-load operation states where switching between multi-injection and normal injection modes can cause significant torque fluctuations.
Innovation Solution
A control method that divides the operation state into multi-injection, transition, and normal-injection regions based on engine speed and load, using interpolation to smoothly change fuel pressure settings, allowing for the elimination of multi-injection control in high-load states and reducing the number of data maps required.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multi-injection control is used to raise exhaust temperature in forced regeneration, then exhaust gas purification capability is improved, but control data complexity and torque shock risk increase
Solution Approach 1:
The engine operation map is segmented into three distinct regions: multi-injection control region, transition region, and normal injection control region. This segmentation allows the system to apply different injection strategies based on operating conditions, simplifying control logic while maintaining purification effectiveness.
Solution Approach 2:
The system changes the injection pressure parameter dynamically by transitioning from multi-injection control (lower pressure) to normal injection control (higher pressure) as the engine operates in high-load states. This parameter change eliminates the need for complex multi-injection data maps while maintaining exhaust temperature above catalyst activation temperature.
2Temperature
If fuel pressure is reduced to slow combustion and increase post-burning period, then exhaust temperature is raised, but torque shock occurs during mode switching
Solution Approach 1:
A transition region is established between the multi-injection control region and normal injection control region to cushion the switching process. In this transition region, injection pressure is gradually increased from multi-injection levels to normal injection levels, preventing abrupt torque changes and shock during mode transitions.
Solution Approach 2:
The injection pressure is made dynamic rather than fixed, allowing continuous adjustment between multi-injection and normal injection modes. The transition region enables smooth dynamic transition of fuel pressure settings, eliminating abrupt changes that cause torque shock while maintaining the temperature-raising effect throughout the process.
3Device complexity
If normal injection control is used in high-load operation state, then data map complexity is reduced, but exhaust temperature management becomes challenging
Solution Approach 1:
Different injection control qualities are applied to different regions of the engine operation map. In the multi-injection control region, lower injection pressure with extended post-burning is used to raise exhaust temperature. In the normal injection control region, higher injection pressure is used for efficient combustion. The transition region provides gradual transition between these qualities, maintaining temperature management while simplifying overall data structure.
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
This approach reduces the complexity of control data and prevents torque shock by allowing seamless transitions in fuel pressure, enabling efficient exhaust gas temperature management without the need for multi-injection in high-load conditions, thereby enhancing control controllability and reducing data map complexity.
Implementation Method 1
HC supplied into the exhaust gas by post injection (post-injection) in a cylinder (in-cylinder) and the like is burned by the oxidation catalyst arranged on the upstream side of the filter or the oxidation catalyst carried by the filter
Implementation Method 2
the PM is trapped by a filter called a diesel particulate filter (DPF: Diesel Particulate Filter: Hereinafter referred to as DPF)
Implementation Method 3
the temperature of the filter is raised above a temperature at which the PM accumulated at the filter is burned, and the PM is burned and removed
Data Source
AI summary
In forced regeneration control of an exhaust gas purification device 12, data for control such as the number of meshes of a data map and the number of data maps for forced regeneration control is reduced and occurrence of torque shock is avoided by smoothly changing a fuel pressure. In the forced regeneration control of the exhaust gas purification device, when an operation state of an internal combustion engine is in a high-load operation state, normal injection control by stopping multi injection is carried out and according to a rotation speed and a load of the internal combustion engine, a region for control is divided into a multi-injection control region, a transition region, and a normal injection control region, and in the transition region, data for fuel pressure control obtained by interpolation of data for fuel pressure control on the multi-injection control region side and data for fuel pressure control on the normal injection control region side is used.