Virtual Accelerometer Using Kalman Filter for Vehicle Control

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Solution Overview

Problem

The installation, calibration, and maintenance of traditional longitudinal accelerometers in vehicles are costly and time-consuming, and complicate pre-production testing and in-vehicle diagnostics, especially when used for vehicle stability enhancement systems.

Innovation Solution

A vehicle control system that uses a third-order Kalman filter to process output shaft signals to determine vehicle acceleration, eliminating the need for a physical accelerometer by calculating longitudinal acceleration based on wheel radius and vehicle mass, and adjusting transmission shifts for smooth operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a physical longitudinal accelerometer is installed in the vehicle, then vehicle acceleration can be directly measured, but installation cost, calibration time, and maintenance complexity increase

Engineering Contradiction:

Improveacceleration measurementVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual accelerometer that copies the measurement function of a physical accelerometer by using mathematical algorithms (Kalman filter) to process data from existing sensors (output shaft position sensor, wheel speed sensors). This virtual copy provides acceleration measurements without requiring physical accelerometer hardware, thereby reducing device complexity while maintaining measurement capability

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/physical accelerometer system with an electronic/software-based calculation system. Instead of using a physical sensor that measures acceleration directly, the system uses computational algorithms to derive acceleration from positional and speed data, substituting a mechanical measurement system with an electronic computation system

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a physical longitudinal accelerometer is installed for pre-production testing, then acceleration data can be collected, but testing time and calibration costs increase

Engineering Contradiction:

Improveacceleration data collectionVSAvoidpre-production testing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The virtual accelerometer system uses data from existing vehicle sensors (output shaft position, wheel speed) that are already part of the vehicle's standard equipment. The system serves itself by utilizing already-collected data and existing infrastructure, eliminating the need for separate accelerometer installation and calibration processes during pre-production testing

Inventive Principle:

Principle #25Self-service

3Reliability

If a permanent longitudinal accelerometer is implemented for vehicle stability control, then stability enhancement can be achieved, but component costs and maintenance requirements increase

Engineering Contradiction:

Improvevehicle stability controlVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The virtual accelerometer serves multiple functions using the same computational approach: it provides acceleration data for both transmission shift control and vehicle stability enhancement systems. By making the acceleration calculation universal and reusable across different control functions, the system eliminates the need for dedicated physical accelerometers in each application, reducing overall component costs

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

This solution reduces costs and testing time by accurately simulating longitudinal acceleration without a physical accelerometer, enabling real-time calibration and improved vehicle stability control.

Implementation Method 1

A first module in the control module processes an output shaft signal, which is based on rotation of an output shaft of the transmission, through a third order Kalman filter to determine an acceleration of the output shaft

Methodology Applied

Scientific EffectKalman filter:

Implementation Method 2

A second module in the control module calculates the acceleration of the vehicle based on the acceleration of the output shaft

Methodology Applied

Scientific EffectKinematic calculation:

Data Source

PatentUS7885748B2Virtual accelerometer

Publication Date: 2011.02.08 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A vehicle control system for regulating operation of a vehicle having a transmission includes a first module that processes an output shaft signal which is based on rotation of an output shaft of the transmission through a third order Kalman filter to determine an acceleration of the output shaft A second module calculates the acceleration of the vehicle based on the acceleration of said output shaft. A third module regulates operation of the vehicle based on the acceleration of the vehicle.