Regenerative Braking Control Using Pitch Motion Limits

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing wheel slip control methods in vehicles, particularly in electrified vehicles, fail to effectively manage wheel slip due to limitations in controlling regenerative braking force, leading to repeated occurrences of wheel slip and deterioration of slip control performance, primarily because they do not account for pitch motion characteristics and longitudinal load movement in real time.

Innovation Solution

A method is introduced to control regenerative braking force by using a filter simulation map to simulate vehicle suspension pitch motion, determining a required braking force command, and applying a limit value to prevent excitation of natural frequency components, thereby adjusting the braking force to match vehicle dynamics and prevent wheel slip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If regenerative braking force is increased to improve braking performance, then braking efficiency is improved, but wheel slip occurs due to longitudinal load movement and pitch motion

Engineering Contradiction:

Improvebraking efficiencyVSAvoidwheel slip control

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The control method performs preliminary action by predicting future pitch angle and vertical load changes based on current vehicle state and driver input, then proactively adjusting regenerative braking force before wheel slip occurs. This anticipatory control prevents the repeated wheel slip phenomenon by preparing the braking force adjustment in advance rather than reacting after slip detection.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention implements feedback control by continuously monitoring vehicle pitch angle, vertical load, and wheel slip conditions, then using this information to dynamically adjust regenerative braking force. The control system compares actual vehicle state with target state and modifies braking force to minimize deviations, ensuring stable wheel slip control while maintaining braking efficiency.

Inventive Principle:

Principle #23Feedback

2Speed

If feedback control is used to manage wheel slip, then control responsiveness is improved, but repeated wheel slip occurs due to pitch motion dynamics not being accounted for

Engineering Contradiction:

Improvecontrol responsivenessVSAvoidwheel slip control performance

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention changes control parameters by incorporating pitch angle prediction and vertical load estimation into the braking force control algorithm. Instead of using only current wheel speed and slip ratio, the system uses predicted pitch dynamics to adjust braking force commands, transforming the control approach from reactive to predictive and eliminating repeated slip events.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If regenerative braking force is adjusted in real-time based on pitch motion, then wheel slip control is improved, but control system complexity increases

Engineering Contradiction:

Improvewheel slip control performanceVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces complex mechanical sensing and adjustment systems with computational models. Instead of using additional physical sensors and mechanical feedback mechanisms to detect pitch motion and adjust braking, the system uses software-based pitch angle prediction and vertical load estimation algorithms that process existing sensor data to achieve the same control objective with simpler hardware.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The control system achieves multi-functionality by using a single integrated controller that simultaneously manages regenerative braking force, predicts pitch motion, estimates vertical load, and prevents wheel slip. This universal control unit performs multiple functions that could otherwise require separate systems, reducing overall complexity while maintaining improved wheel slip control performance.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12479305B2Method for controlling regenerative braking of vehicle

Publication Date: 2025.11.25 HYUNDAI MOTOR CO LTD

AI summary

A method for controlling regenerative braking includes setting a filter simulation map for simulating a filter of removing or passing a natural frequency component of vehicle suspension pitch motion according to suspension device characteristics of the vehicle and providing the filter simulation map to a controller of the vehicle, determining, by the controller, a required regenerative braking force command based on vehicle driving information collected during driving of the vehicle, determining a final front wheel regenerative braking force command and a final rear wheel regenerative braking force command from the determined required regenerative braking force command through a limit value application process using a limit value determined in the filter simulation map, and controlling a regenerative braking force applied to front and rear wheels as a force for decelerating the vehicle by a driving device for driving the vehicle according to the determined final front and rear wheel regenerative braking force commands.