Drivetrain Model for Wheel Speed Estimation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing wheel speed detection systems in vehicles face challenges in accurately determining the speed of driven wheels in near real-time due to delays and differences in update intervals of wheel speed and drive shaft speed sensors, which can lead to errors in electronic stability control systems.

Innovation Solution

A controller-based system that receives speed data from wheel speed and drive shaft sensors, compensates for delays and differences in detection times, and uses models such as acceleration, Taylor Series, and drivetrain modeling to estimate wheel speed accurately, allowing for improved timing and accuracy in wheel speed determination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If wheel speed sensors are used on each wheel for accurate real-time speed detection, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvewheel speed detection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of the wheel speed sensor by using a drivetrain model that calculates the speed of unsensed wheels based on data from sensed wheels and drive shaft speed. This mathematical model replicates the function of physical sensors without requiring additional hardware, thereby reducing device complexity while maintaining measurement precision for all wheels.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The drivetrain model serves multiple functions: it estimates speeds of unsensed wheels, compensates for timing delays between sensors, and provides a unified framework for processing speed data from different sources. This multi-functional approach replaces what would otherwise require separate dedicated sensors and processing systems for each wheel.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If wheel speed sensors are installed on each wheel for accurate speed data, then measurement precision is improved, but the cost of the system increases

Engineering Contradiction:
Improvewheel speed detection accuracyVSAvoidnumber of sensors
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts the speed estimation function from physical sensors and implements it through a computational drivetrain model. By taking out the speed sensing function from hardware and relocating it to software-based calculations, the system reduces the quantity of physical sensors needed while maintaining the precision required for accurate wheel speed detection.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If drive shaft speed sensor update intervals are reduced for more frequent data, then measurement precision is improved, but use of energy increases

Engineering Contradiction:
Improvespeed data timelinessVSAvoidsensor energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The drivetrain model performs preliminary calculations using previously collected speed data and mathematical relationships to estimate current wheel speeds. This preliminary action allows the system to maintain accurate, timely speed information without requiring continuous high-frequency sensor updates, thereby reducing energy consumption while preserving measurement precision.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2681087B1Wheel speed estimation using a drivetrain model
Publication Date: 2016.07.13 ROBERT BOSCH GMBH
  • EP2681087B1 patent drawingFigure 1
  • EP2681087B1 patent drawingFigure 2
  • EP2681087B1 patent drawingFigure 3

AI summary

A controller. The controller includes a processor and a non-transitory computer readable medium. The processor is configured to receive the speed of a first driven wheel from a wheel speed sensor and the speed of a drive shaft from a drive shaft sensor. The non-transistory computer readable medium includes program instructions executed by the processor for determining a speed of a second driven wheel based on a plurality of detected speeds of the first driven wheel and detected speeds of the drive shaft over time.