Multiple Pass Smoothing for MEMS Navigation Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Portable navigation devices equipped with MEMS sensors face challenges in maintaining navigation accuracy over time due to errors in heading and orientation, especially in indoor and urban environments where GNSS signals are weak and magnetometer readings are unreliable, leading to suboptimal performance in multi-sensor integrated navigation systems.
Innovation Solution
A method and system for multiple pass smoothing (MPS) that processes sensor data through forward and backward processing to derive interim navigation solutions, combines these to obtain enhanced smoothed navigation solutions, addressing the limitations of existing techniques by improving accuracy and reliability in constrained and unconstrained mobility scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If inertial sensors are used for navigation, then continuous navigation information can be provided, but navigation accuracy degrades over time due to heading and orientation errors
Solution Approach 1:
The patent applies preliminary action by performing forward processing to compute interim navigation solutions before final smoothing is applied. This allows the system to prepare navigation data in advance and then refine it through backward processing and smoothing operations, resolving the contradiction by enabling continuous navigation while improving accuracy through multi-pass processing
Solution Approach 2:
The patent implements feedback through the multiple pass smoothing process where backward processing uses future navigation information to correct past estimates. This feedback mechanism allows the system to continuously improve navigation accuracy while maintaining continuous operation, addressing both the duration and precision requirements
2Measurement precision
If GNSS signals are used for navigation, then absolute position information can be obtained, but signals are too weak to penetrate indoor environments
Solution Approach 1:
The patent uses an intermediary approach by introducing a smoothing algorithm that acts as a mediator between inertial sensor data and navigation solutions. This intermediary process combines forward and backward processing to enhance the reliability of navigation information in indoor environments where GNSS is unavailable, enabling the system to adapt to various environments
Solution Approach 2:
The patent achieves universality by creating a navigation system that can operate in both indoor and outdoor environments. The multiple pass smoothing technique enhances the inertial navigation system's ability to provide accurate navigation information regardless of environmental conditions, making the system universally applicable across different settings
3Measurement precision
If magnetometers are used for heading determination, then heading information can be obtained, but readings are unreliable due to magnetic field interferences
Solution Approach 1:
The patent applies feedback through backward processing that uses future heading information to correct past heading estimates. This feedback mechanism compensates for magnetometer errors caused by magnetic field interferences, improving both the accuracy and reliability of heading determination in complex electromagnetic environments
Solution Approach 2:
The patent substitutes the magnetometer-based magnetic field sensing with an inertial navigation approach enhanced by multiple pass smoothing. This replacement eliminates the system's vulnerability to magnetic field interferences while maintaining heading determination capability through sensor fusion and algorithmic processing
4Adaptability or versatility
If device orientation is allowed to change freely, then mobility flexibility is improved, but misalignment errors increase in navigation
Solution Approach 1:
The patent applies dynamics by implementing a flexible smoothing algorithm that adapts to changing device orientations and mobility conditions. The multiple pass processing dynamically adjusts to maintain navigation accuracy regardless of device orientation, allowing free mobility while preventing misalignment errors through iterative refinement
Data Source
AI summary
The navigation solution of a device may be enhanced by perforating multiple pass smoothing. Forward and backward processing of the input data may be performed to derive interim navigation solutions. One or more quantities of the interim navigation solutions may be combined to smooth the quantities. At least one additional pass of forward and backward processing may then be performed using quantities of the navigation solution that were combined to enhance the interim navigation solutions. Next, at least one uncombined quantity of the navigation solution from the enhanced interim navigation solution is combined to provide an enhanced smoothed navigation solution. Additional passes may be performed to combine other quantities of the navigation solution as desired.