Engine Torque Estimation via Crankshaft Acceleration
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Solution Overview
Problem
The existing continuous torque monitoring methods for engine safety require significant calibration work and high ECU processing, making them inefficient and resource-intensive.
Innovation Solution
A method that estimates actual engine torque by differentiating crankshaft speed signals to determine maximum and minimum acceleration values, calculating their difference, and correlating this difference with torque values using a lookup table, reducing the need for extensive calibration and processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous torque monitoring uses a simplified model with different table lookups and input variables to calculate a redundant actual torque value, then safety monitoring capability is improved, but calibration work and ECU processing requirements increase
Solution Approach 1:
The patent extracts only the essential information needed for torque estimation by using a single torque model instead of multiple models. It takes out the redundant complexity of different table lookups and input variables while retaining the core functionality of torque calculation, thereby reducing calibration work and processing requirements while maintaining safety monitoring capability
Solution Approach 2:
Instead of calculating torque through multiple different models and comparing them, the patent inverts the approach by using a single model to calculate expected torque and comparing it with actual torque derived from crankshaft acceleration. This inversion simplifies the system by eliminating the need for multiple redundant calculation paths
2Measurement precision
If a second redundant torque value is calculated using different table lookups and input variables, then torque monitoring accuracy is improved, but ROM and RAM usage increases
Solution Approach 1:
The patent extracts only the necessary data elements needed for accurate torque monitoring, storing them in a compact structure with specific data types. This extraction approach reduces memory usage by eliminating redundant storage while maintaining the precision needed for comparing expected and actual torque values
Solution Approach 2:
The patent changes the parameters of the torque estimation by using crankshaft acceleration data and a single torque model with optimized input variables. This parameter change reduces the memory footprint by avoiding the storage requirements of multiple complex models while maintaining measurement precision through the use of acceleration-based torque calculation
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 significantly reduces calibration effort and microprocessor load, providing a precise actual torque estimate for safety monitoring with minimal ROM/RAM usage, enhancing the efficiency of continuous torque monitoring.
Implementation Method 1
differentiating said plot or signal indicative of instantaneous crankshaft speed with respect to time to determine acceleration values
Data Source
AI summary
A method of controlling a vehicle engine comprising estimating a value for the actual engine torque, comparing this with a further calculated (expected) torque value, and controlling the engine consequent to said comparing, the value for the actual engine torque being determined from the following steps: ⋅a) from a crankshaft signal, providing a plot or signal indicative of instantaneous crankshaft speed; ⋅b) differentiating said plot or signal indicative of instantaneous crankshaft speed with respect to time to determine acceleration values; ⋅c) within a crankshaft/time interval, determining a maximum and a minimum acceleration value from step b); ⋅d) determining the difference between said maximum and minimum acceleration values; ⋅e) determining a torque value dependent on said difference from step d).