Vehicle ISG Control Method for Expanded Engine Stopping Scenarios
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Solution Overview
Problem
Current Idle Stop and Go (ISG) systems in vehicles are limited in fuel consumption reduction as they do not effectively engage the ISG state when the clutch pedal is pressed during vehicle deceleration, restricting the system's ability to improve fuel efficiency at lower vehicle speeds.
Innovation Solution
A control method that determines specific activation and deactivation conditions for the Start Stop Coasting (SSC) and ISG functions based on vehicle state information, including accelerator, brake, gear lever, and speed sensors, to expand engine stopping scenarios and optimize fuel injection and transmission control, allowing for improved fuel efficiency by activating the ISG function at lower vehicle speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the ISG system operates only at vehicle speeds of about 5 kph or less, then the system structure remains simple, but the fuel consumption effect is limited
Solution Approach 1:
The patent introduces two different reference vehicle speeds (first reference vehicle speed and second reference vehicle speed) to define different ISG operation conditions. This parameter change allows the ISG system to operate at higher vehicle speeds by distinguishing between different braking scenarios, thereby expanding the operating speed range while maintaining system simplicity
Solution Approach 2:
The patent segments the ISG operation conditions into two distinct modes: first ISG operation condition (with first reference vehicle speed) and second ISG operation condition (with second reference vehicle speed). This segmentation allows the system to adapt to different driving scenarios, enabling broader speed range operation without increasing overall system complexity
2Use of energy by moving object
If the ISG system expands engine stopping scenarios to lower vehicle speeds, then fuel efficiency improves, but the control system complexity increases
Solution Approach 1:
The patent uses parameter changes (different reference vehicle speeds) to expand engine stopping scenarios to higher vehicle speeds rather than lower speeds, achieving fuel efficiency improvement through intelligent parameter selection rather than system complexity increase
Solution Approach 2:
The controller continuously monitors vehicle running state information (vehicle speed, accelerator pedal position, brake pedal position, gear lever position) and uses this feedback to dynamically determine whether to activate ISG or SSC functions, enabling expanded operating conditions without proportionally increasing control complexity
3Use of energy by moving object
If the vehicle enters ISG state when clutch pedal is pressed during deceleration, then fuel consumption reduces, but the system reliability may be compromised
Solution Approach 1:
The patent applies local quality by creating distinct control strategies for different pedal combinations: the first ISG operation condition applies when both accelerator and brake pedals are not operated, while the second ISG operation condition applies when the brake pedal is operated. This localized control approach ensures reliable operation in each specific scenario while enabling fuel savings in appropriate conditions
Data Source
AI summary
A control method for an SSC function and an ISG function includes: determining, by a controller, whether a SSC activation condition is satisfied based on a vehicle running state information; stopping, by the controller, an engine and activating the SSC function by controlling a transmission to neutral when the SSC activation condition is satisfied; determining, by the controller, whether a first ISG operation condition including a first reference vehicle speed is satisfied based on the vehicle running state information in a state that the SSC function is activated; and deactivating, by the controller, the SSC function and activating the ISG function when it is determined that the first ISG operation condition is satisfied.