Electronic Throttle Torque Limiting via Fault Counter Threshold
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Solution Overview
Problem
Existing methods for monitoring a control unit in internal combustion engines that generate torque are slow to detect malfunctions, leading to delayed limitation of undesirably high torque values and resulting in steep torque amplitudes.
Innovation Solution
A method that determines a maximum acceptable torque value and compares it to the actual torque value, using a fault counter to trigger air supply limitation when the actual value exceeds the threshold, with adjustments for interventions by usual functions like traction control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a fault counter with threshold comparison is implemented to detect torque deviations, then the detection speed of malfunctions is improved, but the system complexity increases
Solution Approach 1:
The patent implements preliminary action by pre-setting a fault counter and threshold value before operation. The monitoring system continuously compares actual torque against maximum acceptable torque and increments the fault counter when deviations occur. This pre-prepared detection mechanism enables rapid response (reducing waiting time from potentially a minute to 500-800 ms) without requiring complex real-time analysis during fault occurrence.
Solution Approach 2:
The patent employs feedback by continuously monitoring the torque actual value and comparing it with the maximum acceptable torque value. The fault counter receives feedback from each comparison cycle and adjusts accordingly (incrementing when torque exceeds maximum, decrementing when it returns to acceptable levels). This closed-loop feedback mechanism provides reliable malfunction detection while maintaining manageable system complexity through algorithmic rather than hardware complexity.
2Reliability
If the air supply is limited immediately when torque exceeds maximum value, then the safety response time is improved, but false activations due to usual functions (traction control, rotational speed limiting) increase
Solution Approach 1:
The patent prepares a fault counter in advance that accumulates evidence of torque deviations over time rather than triggering immediately on the first deviation. This preliminary accumulation mechanism distinguishes between temporary deviations caused by usual functions (traction control, rotational speed limiting) and persistent malfunctions, enabling reliable safety response while reducing false activations.
Solution Approach 2:
The patent applies partial action by using a threshold-based fault counter that requires multiple torque deviations before triggering air supply limitation. Instead of immediate full limitation on any single torque exceedance, the system accumulates fault instances and only activates limitation when the fault counter exceeds the threshold, indicating a genuine malfunction rather than temporary operational variations.
3Measurement precision
If a fault counter threshold mechanism is used to distinguish malfunctions from temporary deviations, then the measurement precision of fault detection is improved, but the device complexity increases
Solution Approach 1:
The patent uses feedback mechanisms to continuously update the fault counter based on torque comparisons. The threshold value acts as a precision filter that distinguishes between normal operational variations and genuine malfunctions. This algorithmic approach achieves high measurement precision for fault detection while maintaining relatively simple control unit implementation through software-based monitoring rather than complex hardware circuits.
Solution Approach 2:
The patent achieves precise fault detection by monitoring changes in the fault counter parameter over time rather than relying on single-point torque measurements. The threshold value and increment/decrement logic transform continuous torque data into discrete fault states, improving detection precision while keeping the control unit complexity manageable through parameter-based decision making rather than complex computational algorithms.
Data Source
AI summary
In a method for monitoring a function computer in a control unit which controls the generation of torque by an internal combustion engine, a maximum acceptable torque value is determined from a driver request. A torque actual value is determined from operational characteristic variables of the internal combustion engine and is compared with the maximum acceptable value. The air supply is limited when there is an unacceptably large actual value. The method is distinguished by the fact that the limitation takes place when a fault counter reading exceeds a threshold value. The fault counter reading is increased if the torque actual value is higher than the maximum acceptable torque value and is reduced by a predetermined value if the torque actual value is lower than the maximum acceptable value. In addition, a control unit which is configured to carry out the method is presented.