Start-Stop Control Logic for Engine Restart Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing start-stop systems for internal combustion engines in vehicles do not adequately consider various influencing variables, leading to unplausible system states and discomfort for drivers, such as inability to restart the engine due to low fuel levels or incorrect detection of driver presence.

Innovation Solution

Incorporating additional influencing variables like fuel tank level, driver identification, tank ventilation system state, diesel particulate filter regeneration, ambient temperature, seat occupancy, and other vehicle modes into the evaluation of switch-off and switch-on conditions to ensure the engine is only automatically switched off or on when safe and feasible, preventing issues like low fuel shutdowns and incorrect key detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the engine is automatically switched off to reduce fuel consumption and emissions, then fuel efficiency improves, but the risk of being unable to restart the engine increases when critical parameters like fuel level are low

Engineering Contradiction:
Improvefuel consumptionVSAvoidengine restart capability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The control device evaluates the fuel level in advance before allowing automatic engine shutdown. If the fuel level is below a predetermined threshold, the device prevents shutdown before it occurs, ensuring the engine can always be restarted when needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors fuel level and uses this feedback to dynamically adjust shutdown eligibility. The control device receives real-time fuel level information and adjusts the automatic shutdown decision based on whether the level remains above the threshold.

Inventive Principle:
Principle #23Feedback

2Reliability

If multiple influencing variables are evaluated to prevent implausible shutdown states, then system reliability improves, but the complexity of the control system increases

Engineering Contradiction:
Improvesystem state plausibilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control device integrates multiple evaluation functions into a single multi-functional unit. It simultaneously assesses fuel level, battery state, climate control status, and other parameters through one centralized control mechanism rather than separate systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines multiple control functions (fuel level monitoring, battery management, climate control coordination) into a unified control device that handles all shutdown eligibility decisions in one integrated system.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2126338B1Method for controlling an automatic shut-down process and/or start-up process of an internal combustion engine in a motor vehicle
Publication Date: 2011.05.11 BAYERISCHE MOTOREN WERKE AG

AI summary

The invention relates to a method for controlling an automatic shut-down process of an internal combustion engine by means of a start-stop-device when predetermined shut-down conditions are met by corresponding influencing variables and/or a start-up process when predetermined start-up conditions are met by corresponding influencing variables. At least one of the following influencing variables for an evaluation of the shut-down conditions and/or start-up conditions are taken into account: the presence and/or absence of a vehicle key, the current state of the tank ventilation system present in the vehicle, the current fill level of the fuel tank, the current state of the diesel particle filter present in the vehicle, the activity state of a workshop mode and/or works mode and/or service mode and/or production mode, the current ambient temperature outside the vehicle, an evaluation of the detection device for the occupation of the driver's seat and optionally the detection device for the occupation of the passenger seat, the detection of cylinder equalisation, the activity state of a vehicle speed control system, the activity state of an auto-hold function in motor vehicles with an automatic gear-box, the activity state of an electric parking brake, and/or the activity state of a hill hold function.