Engine Torque Setpoint Control for Adaptive Economy Mode

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Solution Overview

Problem

Existing methods for reducing energy consumption in motor vehicles through economical driving modes often result in driving inconveniences, such as difficulty climbing steep hills, due to non-contextual torque limitations and require complex calculations or driver behavior changes, which are not easily adopted by drivers.

Innovation Solution

A method that determines a torque setpoint for a motor vehicle engine in energy-saving mode by calculating the current longitudinal acceleration and applying a torque correction using a proportional-integral regulator, allowing the vehicle to adapt to traffic conditions without requiring significant driver skill or calculation resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a non-contextual torque limitation strategy is imposed in economy mode, then energy consumption is reduced, but driving performance deteriorates (inability to climb steep hills)

Engineering Contradiction:
Improveenergy consumptionVSAvoiddriving performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies dynamics by making the torque limitation adaptive rather than static. The control device dynamically adjusts the torque setpoint based on real-time vehicle acceleration feedback. When the vehicle is on a slope or under high load, the system detects increased acceleration demand and automatically relaxes the torque limitation, allowing the engine to deliver higher torque when needed while maintaining energy-saving operation during normal conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by continuously monitoring actual vehicle acceleration and comparing it with desired acceleration profiles. The control device uses this feedback information to adjust the torque setpoint in real-time, ensuring that the torque limitation adapts to changing driving conditions such as slopes or varying vehicle loads, thereby maintaining both energy efficiency and driving performance.

Inventive Principle:
Principle #23Feedback

2Use of energy by moving object

If pedal progressiveness is reduced in economy mode, then energy consumption is reduced, but ease of operation deteriorates (driver must press pedal further for same acceleration)

Engineering Contradiction:
Improveenergy consumptionVSAvoidpedal progressiveness
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The system dynamically adjusts the relationship between accelerator pedal position and torque output based on actual vehicle acceleration. When the vehicle is on a slope or under high load, the control device increases the torque setpoint beyond what the pedal position alone would suggest, effectively restoring pedal progressiveness when needed while maintaining reduced progressiveness during normal energy-saving operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of torque setpoint based on acceleration feedback. Instead of using a fixed progressiveness curve, the system adjusts the torque output parameter dynamically according to actual vehicle acceleration, allowing the effective progressiveness to vary with driving conditions while maintaining energy-saving operation during normal conditions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If complex calculations are used to maintain acceleration insensitivity to load and slope, then driving performance is maintained, but device complexity increases

Engineering Contradiction:
Improveacceleration consistencyVSAvoidcalculation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses feedback control to maintain acceleration consistency without requiring complex predictive calculations. The control device monitors actual vehicle acceleration and adjusts the torque setpoint accordingly, allowing the system to automatically compensate for changes in vehicle load and slope through real-time feedback rather than through complex advance calculations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment based on acceleration feedback without requiring external input about vehicle load or slope. The control device automatically compensates for changing conditions by monitoring acceleration and adjusting torque accordingly, eliminating the need for separate sensors or complex calculations to determine vehicle state.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4371837A1Method for determining a torque setpoint of a motor vehicle engine operating in an energy-saving mode, and corresponding vehicle
Publication Date: 2024.05.22 RENAULT SA
  • EP4371837A1 patent drawingFigure 1~2
  • EP4371837A1 patent drawingFigure 3~4
  • EP4371837A1 patent drawingFigure 5

AI summary

This method for determining a torque setpoint for a motor vehicle (1) engine (2) operating in an energy-saving mode includes the following steps: - determining the current longitudinal acceleration of the vehicle (1); - determining a target value for the maximum longitudinal acceleration not to be exceeded; - determining an acceleration gap from the difference between the value of the current longitudinal acceleration of the vehicle (1) and the target value for the maximum acceleration not to be exceeded; and - determining a motor torque setpoint by subtracting a torque correction from a motor torque value obtained as a function of the depressment of an accelerator pedal (5) representative of the driver's intention to accelerate, said torque correction being derived from a proportional-integral type regulator based on the acceleration gap.