Sensor Thermal Control via Periodic Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sensors in portable devices are sensitive to ambient temperature, leading to inaccuracies and errors due to temperature-dependent offset and sensitivity changes, which existing thermal stabilization methods are inefficient and power-intensive, especially in mobile applications.
Innovation Solution
A method involving a sensor assembly with a temperature element and controller that selectively activates to maintain a desired operating temperature, applying compensations based on the difference between the selected and ambient temperatures, using a duty cycle and energy quantification to minimize power consumption and hardware complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a feedback controlled integrated heating or cooling element is used to maintain the sensor at a desired temperature, then sensor accuracy is improved, but energy consumption increases and power resources are depleted faster
Solution Approach 1:
The patent implements periodic thermal calibration by alternating between calibration mode (heating/cooling the sensor to compensate for temperature drift) and normal operation mode. The system periodically determines the operating temperature and applies appropriate corrections, rather than continuously maintaining a fixed temperature. This periodic approach significantly reduces energy consumption compared to continuous thermal control, while still maintaining sensor accuracy through temperature compensation.
2Measurement precision
If a feedback controlled integrated heating or cooling element is used to maintain the sensor at a desired temperature, then sensor accuracy is improved, but the thermal control system becomes more complex
Solution Approach 1:
The patent extracts the thermal control functionality from a complex feedback-controlled system and implements it as a simplified periodic calibration approach. Instead of using integrated heating/cooling elements with feedback control circuits, the system uses a simpler temperature sensing mechanism combined with periodic calibration routines that determine operating temperature and apply corrections. This extraction of the essential temperature compensation function while removing complex thermal control hardware resolves the contradiction between accuracy and system complexity.
3Measurement precision
If individual calibration is performed by placing the sensor in an oven or refrigerator at high volume productions, then sensor performance characteristics are accurately determined, but production time and cost increase significantly
Solution Approach 1:
The patent implements self-calibration capability where the sensor system automatically determines its own operating temperature and applies appropriate compensation without requiring external calibration equipment. The system performs temperature characterization in-situ during normal operation by monitoring temperature drift and applying corrections based on pre-determined calibration data. This self-service approach eliminates the need for time-consuming external oven or refrigerator calibration processes, dramatically increasing production throughput while maintaining accurate temperature compensation.
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 improves sensor accuracy by maintaining a constant operating temperature, reducing energy usage, and extending the operational range of sensors in varying ambient conditions, while simplifying thermal control systems.
Implementation Method 1
selectively activating the temperature element to drive temperature within the thermal envelope towards the selected operating temperature
Implementation Method 2
estimating current ambient temperature based at least in part on quantifying energy supplied to the temperature element
Data Source
AI summary
A sensor is compensated by selectively activating a temperature element to drive temperature within the thermal envelope encompassing the sensor towards an operating temperature and applying a compensation to output of the sensor based at least in part on the operating temperature. The initial ambient temperature is estimated and the operating temperature is selected from a set of predetermined temperatures based on the estimate. The current ambient temperature is estimated and a new operating temperature selected when the current ambient temperature is within a threshold of the operating temperature. Correspondingly, the temperature element is selectively activated to drive temperature within the thermal envelope towards the new operating temperature and an appropriate compensation is applied to the sensor output.