Downhill EV Speed Control Using DOB Regenerative Braking

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Solution Overview

Problem

Electric vehicles experience unnecessary acceleration during downhill motion, requiring driver intervention to control speed, which can be unsafe and inconvenient.

Innovation Solution

A method and system for automatically controlling vehicle speed using regenerative braking, involving a processor to determine pedal states, set target velocities, and apply regenerative braking torque via a disturbance observer (DOB) and feedback controller to maintain desired speeds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If regenerative braking control is implemented during downhill motion, then vehicle speed control is improved and driver workload is reduced, but system complexity increases due to DOB and feedback controller integration

Engineering Contradiction:

Improvedriver workloadVSAvoidcontrol system complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The vehicle control system automatically detects downhill motion conditions and executes regenerative braking without driver intervention. The processor monitors pedal states, determines velocity deviations, and autonomously applies regenerative braking torque, allowing the system to serve itself and reduce driver workload.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system implements a feedback controller that continuously monitors actual vehicle velocity and compares it with target velocity. Based on the velocity deviation feedback, the processor adjusts regenerative braking torque in real-time to maintain desired speed, creating a closed-loop control system that improves speed regulation.

Inventive Principle:

Principle #23Feedback

2Use of energy by moving object

If regenerative braking is applied to control downhill speed, then energy recovery is improved, but braking precision may be affected by disturbance forces

Engineering Contradiction:

Improveenergy recoveryVSAvoidvelocity control precision

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The disturbance observer acts as an intermediary that estimates and compensates for gravitational disturbances before they affect velocity control. By introducing this intermediate estimation layer, the system can accurately determine the disturbance force and compensate for it, maintaining velocity precision while enabling energy recovery through regenerative braking.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system converts the harmful gravitational force causing unwanted acceleration into a beneficial regenerative braking opportunity. By detecting downhill motion and applying regenerative braking, the system recovers energy from the gravitational force that would otherwise cause speed increase, turning a problem into an energy recovery opportunity.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If automatic speed control is implemented during downhill motion, then safety is improved by reducing driver burden, but response time may increase due to processing requirements

Engineering Contradiction:

ImprovesafetyVSAvoidresponse time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary detection of downhill conditions by monitoring acceleration pedal state, braking pedal state, and velocity deviation before automatic control is needed. By pre-identifying the control scenario and preparing target velocity calculations, the system reduces response time when automatic regenerative braking activation is required.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Automatically regulates vehicle speed during downhill motion, reducing driver workload and improving safety by effectively utilizing regenerative braking to manage acceleration.

Implementation Method 1

performing regenerative braking on the vehicle using a disturbance observer (DOB) structure and a feedback controller

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Gravity plays a roll in the acceleration and deceleration of vehicles as they move on driving surfaces

Methodology Applied

Scientific EffectGravity: Gravitation

Data Source

PatentUS20240375519A1Disturbance observer-based electric vehicle control method during downhill motion

Publication Date: 2024.11.14 HYUNDAI MOTOR CO LTD

AI summary

Systems and methods for automatically applying braking during downhill motion and performing regenerative braking are provided. The method may comprise determining a state of an acceleration pedal and a braking pedal of a vehicle, when the state of the acceleration and braking pedals is off, setting a set velocity of the vehicle to be equal to a current velocity of the vehicle, determining whether a value of the current velocity minus the set velocity is greater than a threshold velocity of the vehicle, when the value of the current velocity minus the set velocity is greater than the threshold velocity, setting a target velocity of the vehicle equal to a sum of the set velocity and the threshold velocity, and performing, using a brake controller, regenerative braking on the vehicle using a disturbance observer (DOB) structure and a feedback controller to maintain the target velocity.