In-Motion Gyroscope Bias Calibration via Linear Fitting

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Solution Overview

Problem

Conventional methods for calibrating gyroscope sensors are inadequate when the device is in motion, as they rely on stationary data, which is often unavailable, and fail to account for time constraints, necessitating a more sophisticated method for estimating bias during dynamic conditions.

Innovation Solution

A system and method that utilize a computing device with gyro sensors, a GPS receiver, and a magnetometer to calibrate gyroscope sensors in motion by identifying a time period with a predetermined pattern, computing the orientation, and estimating bias through linear fitting of angular representations, allowing for continuous calibration during motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If simple averaging methods are used to estimate gyroscope bias, then calibration is easy to implement, but the method fails when stationary data is unavailable

Engineering Contradiction:
Improveease of calibrationVSAvoidapplicability to moving devices
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent transitions from static calibration methods to dynamic calibration methods that work during device motion. The system identifies time periods with predetermined motion patterns (e.g., linear motion, constant velocity) and performs bias estimation during these dynamic states, enabling calibration without requiring the device to be stationary.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the calibration approach by using linear fitting of angular representations instead of simple averaging. This involves computing orientation from gyroscope signals, identifying time periods with specific motion characteristics, and using linear regression on angular data to estimate bias, which is more sophisticated than simple averaging but works during motion.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If sophisticated methods like linear fitting are used to estimate bias during motion, then calibration accuracy improves, but computational complexity increases

Engineering Contradiction:
Improvebias estimation accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the time period into specific intervals with predetermined motion patterns. By identifying and isolating time periods where the device exhibits known motion characteristics (e.g., constant velocity, linear acceleration), the system can apply linear fitting only to these segmented portions, reducing the overall computational burden while maintaining accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies calibration only during specific time periods when predetermined motion patterns are detected, rather than continuously. This partial action approach reduces computational complexity by performing sophisticated bias estimation only when necessary, while using simpler methods or previously computed values during other periods.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If calibration is performed continuously to remove bias, then orientation accuracy is maintained, but time constraints are violated

Engineering Contradiction:
Improveorientation accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements periodic calibration by continuously monitoring for time periods with predetermined motion patterns and performing bias estimation only when such patterns are detected. This periodic approach maintains orientation accuracy by regularly updating bias estimates during suitable intervals without requiring continuous calibration computation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system performs preliminary identification of suitable time periods with predetermined motion patterns before executing the bias estimation. By pre-identifying intervals where calibration can be effectively performed based on motion characteristics, the system prepares in advance and executes calibration only when conditions are favorable, optimizing the use of time.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS10451438B2Systems and methods for in-motion gyroscope calibration
Publication Date: 2019.10.22 ALPINEREPLAY INC
  • US10451438B2 patent drawing
  • US10451438B2 patent drawing
  • US10451438B2 patent drawing

AI summary

Systems and methods to calibrate a gyroscope based on a motion of a predetermined characteristic. Data representing gyro sensor signals during a period of time is stored. A portion of the time period is identified, during which portion the gyroscope is subjected to a motion of the predetermined characteristic. Using the stored data the gyro signals are integrated with respect to time to calculate orientation of the gyroscope as a function of time. Deviation of a characteristic of the orientation of the gyroscope as the function of time during the portion of time period for the motion of the predetermined characteristic is determined to identify a component of bias in the gyro signals. The bias component is removed from the data to re-calculate the gyroscope orientation, and possible to further calculate the deviation in the re-calculated orientation and to identify a further bias component in the gyro signals.