Transmission Grade Sensor Calibration via Barometric Elevation

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Solution Overview

Problem

Commercial vehicle transmission grade sensors often provide inaccurate terrain information due to improper calibration, especially when hardware changes occur, leading to incorrect gear selection, and there is a lack of effective methods to verify their accuracy.

Innovation Solution

A system and method using a controller connected to barometric pressure and vehicle speed sensors to calculate elevation changes, compare them with transmission grade sensor data, and apply a grade correction factor to modify shift logic and adjust the transmission grade sensor for accurate terrain-based gear selection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual calibration of the transmission grade sensor is performed using a service tool, then the transmission grade sensor can be calibrated, but the calibration is inaccurate if not done on a level surface and requires external equipment

Engineering Contradiction:

Improvetransmission grade sensor accuracyVSAvoidcalibration convenience

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The transmission grade sensor performs self-calibration using the barometric pressure sensor and vehicle motion data. The system automatically detects elevation changes through barometric pressure variations and compares them with grade sensor readings during vehicle motion, eliminating the need for external service tools and manual level surface calibration.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical level surface requirement with a barometric pressure-based elevation measurement system. Instead of requiring the vehicle to be physically level during calibration, the system uses atmospheric pressure changes to determine elevation differences, substituting a mechanical constraint with a sensor-based measurement approach.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If the transmission grade sensor is manually calibrated, then calibration can be performed, but verification of accuracy is difficult without service tools

Engineering Contradiction:

Improvegrade sensor accuracy verificationVSAvoidverification system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system continuously verifies grade sensor accuracy by comparing its readings against elevation changes calculated from barometric pressure sensor data. This feedback mechanism allows the system to detect calibration drift and trigger re-calibration when discrepancies are detected, providing ongoing verification without requiring external service tools.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The barometric pressure sensor serves multiple functions: it provides elevation data for transmission shift control and simultaneously serves as a reference for verifying and calibrating the transmission grade sensor. This multi-functionality eliminates the need for separate verification equipment while enhancing system reliability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If hardware changes occur on the truck, then the transmission may be upgraded or modified, but the transmission grade sensor calibration becomes inaccurate and must be re-calibrated

Engineering Contradiction:

Improvehardware adaptabilityVSAvoidgrade sensor calibration accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system transitions from static manual calibration to dynamic continuous calibration. The calibration process occurs automatically during normal vehicle operation through comparison with barometric pressure data, allowing the system to adapt to hardware changes without requiring manual intervention or service tool connection.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system performs preliminary calibration actions automatically by continuously comparing grade sensor readings with barometric pressure-derived elevation data during vehicle motion. This preliminary calibration occurs before any transmission hardware changes take effect, ensuring accurate operation from the outset.

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

This approach ensures more accurate transmission gear selection by continuously verifying and calibrating the transmission grade sensor, reducing discrepancies and improving shift quality and consistency.

Implementation Method 1

calculate a first vehicle change in elevation over a time interval based on a change in barometric pressure determined from data reported by the at least one barometric pressure sensor

Methodology Applied

Scientific EffectBarometric pressure measurement: Pressure Gradient

Data Source

PatentUS11221068B2Transmission grade sensor rationality and trim algorithm

Publication Date: 2022.01.11 INT ENGINE INTPROP CO LLC

AI summary

A system for conducting a rationality check of a transmission grade sensor includes a controller configured to calculate a change in elevation over time based on a change in barometric pressure. The controller calculates another change in elevation based on an average grade determined from a transmission grade sensor. The controller compares the second change in elevation to the first change in elevation and, if there is a significant discrepancy between them, calculates a grade correction factor. The controller then modifies the shift logic and/or shift schedule of the transmission based on the average grade from the transmission grade sensor and on the grade correction factor.