Crankshaft Torque Sensing With Magnetic Angular Offset Measurement
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Solution Overview
Problem
Current methods for determining crankshaft torque in internal combustion engines are unreliable, particularly for cylinder-specific torques, leading to compromised engine control and lack of effective defect detection, as they rely on theoretical models rather than actual measured values.
Innovation Solution
The use of magnetosensitive rotary angle sensors, such as magnetoresistive and magnetoelastic sensors, spaced apart along the crankshaft to measure angular offsets caused by torsion, allowing for accurate determination of cylinder-associated torques and continuous status monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If theoretical models are used to determine crankshaft torque, then device complexity is reduced, but measurement precision and reliability deteriorate
Solution Approach 1:
The patent replaces mechanical strain gauge systems with a magnetic field-based measurement system using magnetosensitive sensors. This substitution eliminates the need for complex mechanical coupling while achieving accurate torque measurement through detection of magnetic field changes caused by crankshaft torsion.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the crankshaft and the sensors. The magnetosensitive sensors detect changes in the magnetic field caused by torsion of the crankshaft, providing an indirect but accurate measurement method that avoids direct mechanical contact and its associated complexity.
2Measurement precision
If strain gauges are used to measure crankshaft torque, then measurement precision improves, but device complexity and susceptibility to environmental factors increase
Solution Approach 1:
The patent replaces mechanical strain gauges with magnetosensitive sensors that operate based on magnetic field detection. This eliminates the mechanical coupling requirements and reduces sensitivity to environmental factors such as temperature and vibration while maintaining measurement precision.
Solution Approach 2:
The patent changes the measurement parameter from mechanical strain (detected by strain gauges) to magnetic field changes (detected by magnetosensitive sensors). This parameter change allows for non-contact or minimal-contact measurement, reducing device complexity and environmental susceptibility.
3Ease of operation
If theoretical torque values are used for engine control, then ease of operation is maintained, but reliability of engine control deteriorates
Solution Approach 1:
The patent implements a feedback system where magnetosensitive sensors continuously measure actual crankshaft torque and provide this information to the engine control unit. The ECU uses this real-time feedback to adjust fuel injection and other control parameters, ensuring reliable engine control based on actual operating conditions rather than theoretical values.
Solution Approach 2:
The measurement system is integrated directly into the crankshaft structure, with the crankshaft itself serving as part of the measurement apparatus through its interaction with the magnetic field. This self-service approach provides automatic, continuous measurement without requiring external complex measurement equipment.
4Measurement precision
If multiple sensors are spaced apart along the crankshaft to measure angular offsets, then measurement precision and defect detection capability improve, but device complexity increases
Solution Approach 1:
The patent divides the measurement function into multiple magnetosensitive sensors spaced at different locations along the crankshaft. Each sensor measures the angular position at its specific location, and by comparing these measurements, the system determines angular offsets and torsion with high precision while enabling defect detection.
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 enables reliable engine control based on actual torques, improves defect detection, and reduces pollutant emissions by optimizing fuel injection, facilitating predictive maintenance and real-time monitoring of engine performance.
Implementation Method 1
The first and the second rotary angle sensors are magnetosensitive, in particular magnetoresistive and/or magnetoelastic
Implementation Method 2
The first and the second rotary angle sensors are magnetosensitive, in particular magnetoresistive and/or magnetoelastic
Data Source
AI summary
A method for operating an internal combustion engine. The method includes providing a piston engine. The piston engine includes a crankshaft and a torque sensor system. The torque sensor system includes at least one first rotary angle sensor and at least one second rotary angle sensor. The method further includes measuring a first and a second rotary angle in a spacing region and determining an angular offset between the first and the second rotary angle. The angular offset results from the torsion of the loaded crankshaft wherein the spacing region is limited along the crankshaft to an actual partial region of the spacing between the bearing journals. The partial region includes an actual subgroup of at least one of the number of offsets and the number of shaft journals, so that the angular offset is assigned to the actual subgroup.