Transmission Control Torque Offloading

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Solution Overview

Problem

Motor vehicles with internal combustion engines experience reduced dynamism and torque issues in high environmental stress conditions such as high altitude or extreme temperatures, leading to inadequate power delivery at low engine speeds.

Innovation Solution

A method that offloads torque from accessories like air conditioning and alternators during high stress conditions and dynamically shifts gear ratio change laws to higher speed regimes, ensuring torque delivery while minimizing energy expenditure and maintaining passenger comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the transmission downshifts to increase rpm and maximum torque potential in high environmental stress conditions, then the torque available for traction is improved, but the power consumed by accessories (air conditioning, alternator) increases drastically

Engineering Contradiction:
Improvetorque available for tractionVSAvoidpower consumed by accessories
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the gear ratio change laws adaptive rather than fixed. The control system dynamically adjusts the shift curves based on detected environmental stress conditions (high altitude, extreme temperatures, battery state of charge). This allows the transmission to operate in higher rpm ranges only when necessary for torque delivery, while returning to lower rpm operation under normal conditions to reduce accessory power consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of the gear ratio change laws by shifting the curves towards higher speeds under high environmental stress conditions. This parameter modification allows the system to access higher torque regimes when needed while maintaining awareness of the trade-off with accessory power consumption, enabling optimized control strategies to manage the balance between traction torque and accessory power requirements.

Inventive Principle:
Principle #35Parameter changes

2Power

If the transmission operates at higher rpm to satisfy driver torque requests in high environmental stress conditions, then the torque delivery is improved, but the fuel consumption increases

Engineering Contradiction:
Improvetorque deliveryVSAvoidfuel consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The system dynamically adapts the gear ratio change laws based on real-time detection of environmental stress conditions. By making the transmission control adaptive rather than fixed, the system can optimize the balance between torque delivery and fuel consumption, operating at higher rpm only when necessary to satisfy driver torque requests under stress conditions while minimizing fuel waste during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system incorporates feedback mechanisms by continuously monitoring environmental conditions (altitude, temperature, battery state of charge) and adjusting the gear ratio change laws accordingly. This feedback loop enables the system to detect when high environmental stress conditions exist and modify transmission behavior to maintain torque delivery while managing fuel consumption through appropriate shift point adjustments.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3277985B1Method for controlling a motor vehicle transmission
Publication Date: 2021.03.17 PSA AUTOMOBILES SA
  • EP3277985B1 patent drawingFigure 1~3
  • EP3277985B1 patent drawingFigure 4a~5b
  • EP3277985B1 patent drawingFigure 6

AI summary

The invention primarily relates to a method for controlling the transmission of a motor vehicle (10) comprising: - a heat engine (11) driving the wheels (12) of said vehicle (10) via a controlled drive-train (13), and - accessories (14, 15) taking a torque from said heat engine (11), characterised in that said method comprises: - a step in which at least some of the torque taken by said accessories (14, 15) is off-loaded during operation in a real situation with strong environmental constraints, and - a step in which the gearshift ratio distribution curves are shifted towards engine speeds higher than the engine speeds for the gearshift ratio distribution curves applied in a normal situation of operation of the motor vehicle (10).