Turbo Speed Sensor Diagnostic Using Engine Control Signals

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Solution Overview

Problem

Traditional sensor diagnostic systems for turbocharged engines require intensive initial calibration and additional hardware, increasing costs and time, and do not effectively determine sensor accuracy across the entire operating range.

Innovation Solution

A method for diagnosing the operation of a turbo speed sensor that involves determining the engine's operating range, comparing actual turbo speed values to threshold values, and generating diagnostic signals based on these comparisons, with optional considerations for engine temperature and the use of a compressor map to estimate turbo speed values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional sensor diagnostic systems are implemented, then sensor monitoring capability is provided, but intensive initial calibration effort and additional hardware are required, increasing cost and development time

Engineering Contradiction:

Improvesensor monitoring capabilityVSAvoidcalibration effort and hardware requirements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The diagnostic system uses existing engine sensors (MAF sensor, manifold pressure sensor, throttle position sensor, engine speed sensor) to self-diagnose turbo speed sensor accuracy without requiring external calibration equipment or additional hardware. The system leverages readily available data from these sensors to compute expected turbo speed and compare it with actual sensor readings, enabling the system to monitor itself using resources already present in the engine control system.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The existing sensor network in the engine system serves multiple functions: it provides data for both normal engine operation control and for turbo speed sensor diagnostics. The MAF sensor, manifold pressure sensor, throttle position sensor, and engine speed sensor are used for both primary engine management functions and for generating expected turbo speed values to validate the turbo speed sensor, eliminating the need for dedicated diagnostic hardware.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If traditional sensor diagnostic systems are implemented, then sensor monitoring is available, but the time required to develop and manufacture the engine system increases

Engineering Contradiction:

Improvesensor monitoring capabilityVSAvoiddevelopment and manufacture time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The diagnostic algorithm is pre-programmed into the engine control system, allowing the turbo speed sensor to be validated throughout its entire operating range during normal engine operation. By continuously comparing expected turbo speed (calculated from other sensors) with actual sensor readings across all operating conditions, the system performs comprehensive validation without requiring separate calibration sessions or extended testing procedures during development or manufacturing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The diagnostic comparison occurs continuously during normal engine operation across the entire operating range, rather than requiring intermittent calibration sessions or separate testing phases. This continuous validation approach ensures the turbo speed sensor is monitored throughout all operating conditions without interrupting engine operation or requiring additional development time for calibration procedures.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If traditional sensor diagnostic systems are implemented, then sensor diagnostics are provided, but the sensor accuracy across the entire operating range is not determined

Engineering Contradiction:

Improvesensor diagnostic capabilityVSAvoidsensor accuracy across operating range

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The diagnostic system dynamically adapts to varying engine operating conditions by continuously calculating expected turbo speed based on real-time readings from the MAF sensor, manifold pressure sensor, throttle position sensor, and engine speed sensor. As engine operating conditions change, the expected turbo speed calculation automatically adjusts, enabling validation of the turbo speed sensor across the entire operating range rather than at fixed calibration points.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system validates sensor accuracy by comparing readings under varying operating parameters including different mass air flow rates, manifold pressures, throttle positions, and engine speeds. By changing these operating parameters throughout the engine's full operating range, the system determines whether the turbo speed sensor provides accurate readings under all conditions, not just at a single calibration point.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7937996B2Turbo speed sensor diagnostic for turbocharged engines

Publication Date: 2011.05.10 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method of diagnosing operation of a turbo speed sensor that monitors a turbocharger in an internal combustion engine system includes determining whether the engine system is operating in one of a high speed and a low speed range and determining a threshold turbo speed value based on whether engine system is operating in one of the high speed and the low speed range. An actual turbo speed value of the turbocharger is monitored based on a signal generated by the turbo speed sensor. The actual turbo speed value is compared to the threshold turbo speed value and a diagnostic signal is generated based on the step of comparing.