Blended Vehicle Braking Control for Electric-Mechanical Torque Handover

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Solution Overview

Problem

Current vehicle braking systems face challenges in achieving precise control over braking torque, particularly in transitioning between electric and mechanical braking, which affects safety and riding comfort.

Innovation Solution

A method and device that calculate and control the vehicle's braking torque by obtaining state information, including mass and deceleration, to determine when to apply or release electric and mechanical braking torque based on current speed and delay times, ensuring synchronized and precise braking control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If electric braking is used to maximize braking efficiency, then energy recovery is improved, but mechanical wear increases due to delayed mechanical braking application

Engineering Contradiction:

Improveenergy recoveryVSAvoidmechanical wear

Core Design Contradiction:

Use of energy by moving objectVSLoss of substance

Solution Approach 1:

The system performs preliminary calculation of the mechanical braking application speed based on the electric braking exit speed and mechanical braking application delay time. This allows the mechanical braking to be applied at the precise moment needed, ensuring timely intervention while maximizing electric braking utilization, thereby reducing mechanical wear from unnecessary early application.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the current vehicle speed and compares it with the calculated mechanical braking application speed. This feedback mechanism ensures that mechanical braking is applied only when the vehicle speed reaches the predetermined threshold, optimizing the balance between energy recovery and mechanical wear reduction.

Inventive Principle:

Principle #23Feedback

2Reliability

If mechanical braking is applied early to ensure safety, then braking reliability is improved, but energy recovery decreases due to reduced electric braking utilization

Engineering Contradiction:

Improvebraking reliabilityVSAvoidenergy recovery

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system calculates the mechanical braking application speed in advance by considering the electric braking exit speed and the mechanical braking application delay time. This preliminary action ensures that mechanical braking is applied at the optimal moment, maintaining braking reliability while maximizing electric braking utilization for energy recovery.

Inventive Principle:

Principle #10Preliminary action

3Use of energy by moving object

If the transition between electric and mechanical braking is delayed, then energy recovery is improved, but braking precision deteriorates

Engineering Contradiction:

Improveenergy recoveryVSAvoidbraking precision

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The system performs preliminary calculation of the mechanical braking application speed based on the electric braking exit speed and mechanical braking application delay time. This advance calculation ensures that the transition from electric to mechanical braking occurs at the precise moment needed, maintaining both energy recovery efficiency and braking precision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the current vehicle speed and compares it with the calculated mechanical braking application speed. This real-time feedback ensures that the transition between electric and mechanical braking occurs at the precise moment needed, maintaining braking precision while maximizing energy recovery.

Inventive Principle:

Principle #23Feedback

4Manufacturing precision

If the transition between electric and mechanical braking is accelerated, then braking precision is improved, but energy recovery decreases

Engineering Contradiction:

Improvebraking precisionVSAvoidenergy recovery

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The system calculates the mechanical braking application speed in advance by considering the electric braking exit speed and the mechanical braking application delay time. This preliminary calculation allows for an optimized transition timing that balances braking precision requirements with energy recovery maximization, avoiding unnecessarily early mechanical braking application.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12172549B2Vehicle and braking method and device therefor

Publication Date: 2024.12.24 BYD CO LTD

AI summary

A braking method includes: obtaining a first state information of the vehicle, which includes a vehicle mass and a deceleration required by braking; calculating a braking torque according to the first state information, and controlling the vehicle to output an electric braking torque according to the braking torque; obtaining a current vehicle speed and a mechanical braking application delay time; calculating an electric braking exit speed according to the braking torque required by the vehicle and the deceleration required by braking; calculating a mechanical braking application speed according to the mechanical braking application delay time, the deceleration required by braking, and the electric braking exit speed; and determining whether to control the vehicle to unload the electric braking torque, and whether to control the vehicle to apply a mechanical braking torque according to the current vehicle speed, the electric braking exit speed, and the mechanical braking application speed.