Hybrid Vehicle Controller Deceleration Strategy for PM Filter Management
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Solution Overview
Problem
Existing hybrid electric vehicle controllers face challenges in managing particulate matter (PM) deposition on filters, leading to excessive temperature increases during deceleration, which can limit further reduction of the throttle valve opening and affect vehicle performance.
Innovation Solution
A controller for hybrid electric vehicles that executes a selection process between a first deceleration control process using fuel cutoff and a second deceleration control process, based on PM deposition amounts, to prevent excessive filter temperature increases, and adjusts regenerative power and engine speed according to the state of charge of the electric storage device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If fuel cutoff process is used during deceleration, then deceleration performance is improved, but filter temperature increases excessively when PM deposition amount is large
Solution Approach 1:
The controller changes the operational parameters of the internal combustion engine by switching between fuel cutoff process and non-fuel cutoff process based on PM deposition amount. When PM deposition exceeds the threshold, the system transitions from fuel cutoff (which causes excessive temperature rise) to non-fuel cutoff mode, thereby controlling filter temperature while maintaining deceleration capability
Solution Approach 2:
The system uses feedback from the PM deposition amount sensor to dynamically adjust the deceleration control strategy. The controller continuously monitors PM deposition and compares it against a threshold value, then automatically selects the appropriate deceleration process (fuel cutoff or non-fuel cutoff) to maintain filter temperature within acceptable ranges
2Force
If throttle valve opening degree is reduced to increase deceleration, then deceleration force is improved, but further reduction is limited when throttle valve opening is already small
Solution Approach 1:
The system changes the control parameter from throttle valve opening degree to fuel supply state (cutoff vs. non-cutoff). By switching to fuel cutoff process when PM deposition is low, the system can achieve strong deceleration force without further reducing throttle opening, effectively expanding the available control range beyond mechanical throttle limits
3Productivity
If fuel cutoff process is executed, then deceleration efficiency is improved, but PM oxidation increases when PM deposition amount is large
Solution Approach 1:
The controller uses real-time feedback from PM deposition amount measurements to dynamically adjust the fuel cutoff strategy. When PM deposition exceeds the threshold, the system automatically disables fuel cutoff to prevent excessive PM oxidation, while still maintaining deceleration capability through alternative means
Solution Approach 2:
The system changes the fuel supply parameter from cutoff state to non-cutoff state based on PM deposition levels. This parameter change directly controls the oxidation process by regulating oxygen availability to the filter, thereby managing harmful PM oxidation while preserving deceleration functionality
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 solution effectively manages deceleration without excessive filter temperature rises, stabilizes vehicle performance by limiting fluctuation in deceleration force, and notifies the user of potential deceleration restrictions, ensuring smooth operation.
Implementation Method 1
a filter arranged in an exhaust passage and configured to collect particulate matter from exhaust gas
Implementation Method 2
oxygen entering the filter tends to increase the oxidization amount of particulate matter
Implementation Method 3
an electric storage device, a crankshaft of the internal combustion engine may be configured to be mechanically coupled to a drive wheel by the gear ratio adjuster, the gear ratio adjuster may be configured to adjust a ratio of a rotation speed of the crankshaft to a rotation speed of the drive wheel, the electric storage device may be configured to be charged with regenerative power of the rotating electrical machine
Data Source
AI summary
A controller for a hybrid electric vehicle including an internal combustion engine is provided. The internal combustion engine includes a filter arranged in an exhaust passage collect particulate matter from exhaust gas. The controller executes a first deceleration control process, a second deceleration control process, and a selection process. The first deceleration control process uses a fuel cutoff process when deceleration of the hybrid electric vehicle is required. The second deceleration control process does not use the fuel cutoff process when deceleration of the hybrid electric vehicle is required. The selection process selects execution of the second deceleration control process when a PM deposition amount is greater than or equal to a threshold value and selects execution of the first deceleration control process when the PM deposition amount is less than the threshold value.