Predictive Stop Duration Control for Vehicle Auto Start-Stop

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Solution Overview

Problem

Existing methods for controlling automatic shutdown and start-up of a drive unit in motor vehicles with air conditioning systems are inflexible, leading to either very short or excessively long stop periods due to fixed evaporator temperature thresholds, and do not consider other climate parameters, resulting in unpredictable engine re-starts.

Innovation Solution

A method that predicts the stop duration before initiating shutdown, using a mathematical model considering various operating and state variables, including air conditioning system parameters, to ensure a sufficient standstill period meets system-dependent start requests, allowing or inhibiting shutdown based on a predetermined limit value.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed evaporator temperature threshold is used to determine shutdown inhibition, then the control logic is simple, but the stop duration becomes unpredictable and may be either too short or too long

Engineering Contradiction:

Improvecontrol logic complexityVSAvoidstop duration predictability

Core Design Contradiction:

Device complexityVSDuration of action of moving object

Solution Approach 1:

The system performs preliminary calculation of the predicted stop duration before executing the shutdown decision. The control unit calculates how long the drive unit would remain stopped based on current evaporator temperature and threshold, and uses this prediction to determine whether to inhibit shutdown, ensuring predictable minimum stop durations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the calculated predicted stop duration to adjust the shutdown decision. The control unit continuously monitors evaporator temperature, calculates the predicted stop duration, and uses this feedback information to make intelligent shutdown decisions that ensure minimum stop duration requirements are met.

Inventive Principle:

Principle #23Feedback

2Loss of energy

If the drive unit is shut down to reduce fuel consumption, then fuel efficiency improves, but driver uncertainty increases due to unpredictable engine re-starts

Engineering Contradiction:

Improvefuel consumptionVSAvoiddriver awareness of stop duration

Core Design Contradiction:

Loss of energyVSLoss of information

Solution Approach 1:

The control unit acts as an intermediary that calculates and determines the predicted stop duration before shutdown. This intermediary calculation provides the driver with predictable information about when the engine will restart, reducing uncertainty while still achieving fuel savings through automatic shutdown.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary calculation of stop duration information before the actual shutdown occurs. This advance calculation allows the driver to know the predicted stop duration in advance, maintaining awareness and reducing uncertainty while still enabling fuel-saving shutdowns.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If evaporator temperature threshold is used to prevent moisture and odor, then climate control effectiveness improves, but other climate parameters such as accumulator state of charge are not considered

Engineering Contradiction:

Improvemoisture and odor controlVSAvoidclimate parameter consideration

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The control unit is designed to handle multiple climate parameters and shutdown conditions universally. It can evaluate evaporator temperature, accumulator state of charge, and other climate parameters through a unified control logic that calculates predicted stop duration, making the system adaptable to various climate control scenarios.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically adjusts shutdown decisions based on multiple changing climate parameters. The control unit continuously monitors various climate conditions including evaporator temperature, accumulator state, and other parameters, adapting the shutdown decision in real-time based on the calculated predicted stop duration and current system state.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8346457B2Method for controlling an automatic shutdown and start-up process of a drive unit in a motor vehicle

Publication Date: 2013.01.01 BAYERISCHE MOTOREN WERKE AG

AI summary

A method controls an automatic shutdown and start-up process of a drive unit in a motor vehicle by way of a start and stop device, by which the drive unit is automatically shut down when the motor vehicle comes to a halt if predefined shutdown conditions are met, and by which a drive unit, which has been automatically shut down, is automatically started up if at least one start request is made. Before the initiation of an automatic shutdown process of the drive unit, a possible stop duration of the drive unit is predicted, taking into consideration the present operating variables of the vehicle, the state variables, and/or other parameters. Depending on the predicted stop duration, an automatic shutdown process is initiated when all other shutdown conditions are met.