Hybrid Vehicle Torque Coupling Control via Threshold Comparison

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Solution Overview

Problem

Hybrid vehicles face energy losses and potential damage due to unnecessary coupling of driving machines, especially when the second driving machine is capable of torque recovery, leading to inefficient fuel consumption and emissions.

Innovation Solution

A method that compares the required torque with thresholds based on the sum of the heat engine's loss torque and the second driving machine's maximum and minimum torque capabilities, delaying coupling requests and optimizing decoupling decisions to maintain the first driving machine decoupled unless necessary, thereby reducing energy losses and extending its longevity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the first drive machine is kept coupled to the transmission chain for extended periods to ensure torque availability, then vehicle performance is improved, but energy losses increase due to dissipation and potential damage occurs at maximum operating speed

Engineering Contradiction:
Improvetorque availabilityVSAvoidenergy dissipation
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent applies dynamic control of the first drive machine's coupling state by continuously monitoring torque requirements and comparing them against thresholds. The coupling state changes dynamically based on real-time operating conditions rather than remaining static, allowing the system to optimize between power availability and energy loss by coupling only when necessary and decoupling when torque can be supplied by other sources.

Inventive Principle:
Principle #15Dynamics

2Object-generated harmful factors

If coupling suggestions are rejected at low speeds to prioritize all-electric mode, then emissions are reduced, but the first drive machine remains coupled longer causing energy losses

Engineering Contradiction:
Improvepollutant emissionsVSAvoidenergy dissipation
Core Design Contradiction:
Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

The patent changes the decision parameter from a simple speed-based threshold rejection rule to a torque-based threshold comparison that applies across all speed ranges. Instead of rejecting coupling suggestions below a certain speed to prioritize electric mode, the system evaluates whether the required torque exceeds the sum of the heat engine's loss torque and the second drive machine's torque capabilities, making emissions and energy loss considerations secondary to actual torque requirements.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If the first drive machine is coupled immediately when torque is required to minimize fuel consumption, then fuel efficiency is improved, but the second drive machine's torque recovery potential is wasted

Engineering Contradiction:
Improvefuel consumptionVSAvoidtorque recovery potential
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent performs a preliminary evaluation before coupling the first drive machine by first assessing whether the second drive machine has available torque recovery potential. The system proactively checks if the required torque can be met by the combination of the heat engine's loss torque and the second drive machine's capabilities, and only couples the first drive machine if this preliminary assessment shows it is necessary, thereby preserving torque recovery opportunities.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3253605B1Method and device for assisting with decisions regarding coupling/uncoupling of a prime mover in a hybrid vehicle according to the torque recuperation potential of another prime mover
Publication Date: 2019.01.02 PSA AUTOMOBILES SA
  • EP3253605B1 patent drawingFigure 1
  • EP3253605B1 patent drawingFigure 2
  • EP3253605B1 patent drawing

AI summary

A device (DA) is intended to assist with the coupling/uncoupling of a first prime mover (MM1) to and from a drive train of a hybrid vehicle (V) further comprising a combustion engine (MT) and a second prime mover (MM2) that can be coupled to the combustion engine. The device (DA) is designed to compare a required torque with at least a first threshold s1 and a second threshold s2 when the combustion engine (MT) is in operation and a required torque is negative, and when the required torque drops below at least the first threshold s1, to order the coupling of the first prime mover (MM1), and when the required torque rises above at least the second threshold s2 to order the uncoupling of the first prime mover (MM1).