Brake Torque Profile for Hybrid Vehicle Transition

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Solution Overview

Problem

Existing brake control systems for hybrid electric vehicles fail to effectively manage the transition between regenerative and foundation braking, leading to inefficient energy recovery and inconsistent braking performance, especially during changes in vehicle speed and inclination.

Innovation Solution

A method that temporarily disables regenerative braking and applies foundation brakes to maintain a predetermined speed profile, using vehicle speed, inclination, and brake pressure data to determine a foundation brake torque profile, ensuring smooth blending of braking forces and accurate torque estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If regenerative braking is used continuously, then energy recovery is maximized, but braking performance becomes inconsistent during transitions between regenerative and foundation braking

Engineering Contradiction:

Improveenergy recovery efficiencyVSAvoidbraking performance consistency

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The system performs preliminary characterization of foundation brake torque by temporarily disabling regenerative braking and collecting data at various speeds and inclinations before normal operation. This pre-established torque profile enables smooth transitions and consistent braking performance when switching between regenerative and foundation braking modes.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The foundation brake torque profile acts as an intermediary reference that mediates between regenerative braking and foundation braking systems. By using this pre-characterized profile as a guide, the system achieves smooth blending of braking forces and consistent performance during transitions.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If foundation brake torque is estimated without calibration data, then system simplicity is maintained, but torque estimation accuracy deteriorates

Engineering Contradiction:

Improvecontrol system simplicityVSAvoidbrake torque estimation accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The brake control system performs self-calibration by automatically collecting and processing foundation brake torque data during temporary regenerative braking disablement events. This self-characterization eliminates the need for external calibration equipment or complex manual procedures.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If regenerative braking is temporarily disabled for calibration, then foundation brake torque profile accuracy is improved, but energy recovery efficiency decreases during calibration events

Engineering Contradiction:

Improvetorque profile accuracyVSAvoidenergy recovery during calibration

Core Design Contradiction:

Measurement precisionVSLoss of energy

Solution Approach 1:

The system temporarily disables regenerative braking only for brief calibration events rather than continuously, achieving sufficient torque profile accuracy with minimal disruption to overall energy recovery. The calibration events are limited in duration and frequency to maintain acceptable energy efficiency.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentEP2623380B1A method of controlling a brake system for a vehicle

Publication Date: 2016.11.16 ARVINMERITOR TECHNOLOGY LLC

Figure 1
Figure 2~3

AI summary

A method of controlling a brake system for a vehicle. A foundation brake may be applied to provide a foundation brake torque. Vehicle speed data, vehicle inclination data, and foundation brake pressure data may be obtained. A foundation brake torque profile may be determined that includes a set of vehicle speed values, a set of foundation brake pressure values, and a set of foundation brake torque values.