Solenoid Valve Temperature Compensation Using Current Sweep Metrics
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Solution Overview
Problem
Solenoid fluid control valves exhibit variations in response to command currents due to temperature changes, leading to errors in output pressure, especially in extreme temperatures, and existing methods rely on averaged data that fail to accurately correct for temperature variations.
Innovation Solution
A method involving a current sweep to determine characterization pressures and assigning metrics to solenoid fluid control valves, allowing for the creation of a temperature code that enables precise optimization of command currents for specific temperatures, reducing errors and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If averaged data from multiple solenoids is used for temperature compensation, then manufacturing complexity is reduced, but measurement precision and reliability deteriorate due to individual solenoid variations
Solution Approach 1:
The patent performs a current sweep and determines characterization metrics during the manufacturing process, before the solenoid is deployed. This preliminary characterization captures individual solenoid behavior at multiple temperatures, creating a customized compensation profile for each unit. The metrics are stored and later used to optimize command currents for specific temperature conditions, eliminating the need for complex real-time measurements while maintaining high precision.
Solution Approach 2:
The patent changes the operating temperature parameter during manufacturing to characterize solenoid behavior at different temperatures. By measuring the solenoid response at multiple predetermined temperatures and calculating metrics that represent the relationship between command current and control pressure at each temperature, the system captures temperature-dependent variations. These metrics are then used to adjust command currents for optimal performance across the temperature range.
2Measurement precision
If individual solenoid characterization is performed at multiple temperatures, then solenoid response accuracy is improved, but manufacturing time and productivity decrease
Solution Approach 1:
The patent performs measurements at a limited number of predetermined temperatures (e.g., 5-10 temperatures) rather than continuously across the entire operating range. This partial action approach captures the essential temperature-dependent behavior without requiring exhaustive measurement. The characterization metrics derived from these discrete temperature points are sufficient to enable accurate command current optimization across the full temperature range, balancing measurement effort with performance improvement.
3Reliability
If command current is optimized for specific temperatures using characterization metrics, then solenoid performance reliability is improved, but device complexity increases due to additional calibration data storage and processing
Solution Approach 1:
The patent creates a simplified digital representation (copy) of the solenoid's temperature-dependent behavior through characterization metrics. Instead of storing complete current-pressure curves at multiple temperatures, the system calculates and stores compact metrics that capture the essential relationship between command current and control pressure at each temperature. These metric copies are sufficient to enable command current optimization without requiring access to the full measurement datasets, reducing storage and processing requirements.
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
The method significantly reduces errors in solenoid performance, achieving nearly half the pressure delta error of previous methods, resulting in more reliable products and higher shift quality by providing tailored temperature calibration without additional testing.
Implementation Method 1
an electromagnetic solenoid actuator having an armature mechanism that drives a fluid control element
Data Source
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AI summary
A method is disclosed for determining off-temperature behavior of a solenoid fluid control valve. The method comprises performing a current sweep at a first temperature. The method further comprises choosing a first and second characterization control pressure for characterizing the solenoid fluid control valve. A first current may be determined that corresponds to the first characterization control pressure based on the current sweep, and a first metric may be assigned to the solenoid fluid control valve based on the first current. A second current corresponding to the second characterization control pressure may be determined based on the current sweep, and a second metric may be assigned to the solenoid fluid control valve based on the second current. Information regarding the behavior of the solenoid fluid control valve at a second temperature may be determined based on the first and second metrics.