Navigation Device GNSS Data Editing for Speed and Attitude

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing navigation systems face challenges in calculating speed and displacement with high precision while minimizing the amount of processing data, as using both GPS and INS measurements increases data processing requirements and accuracy is compromised when reducing data volume.

Innovation Solution

A navigation device configuration that includes a GNSS data editing part to generate attitude angle and speed estimation data using dual GNSS signals from antennas with different cycles, and an attitude angle calculating part that estimates integrated attitude angles using IMU angular velocity and GNSS data, allowing for longer data cycles and reduced processing data without compromising accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If both GPS and INS measurement results are used to calculate position, then calculation accuracy of position is improved, but amount of processing data increases

Engineering Contradiction:

Improveposition calculation accuracyVSAvoidamount of processing data

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the calculation process into two distinct parts: (1) position calculation using only GPS data at long cycles, and (2) attitude angle calculation using both GPS and INS data. This segmentation allows the system to maintain high position accuracy while reducing overall data processing requirements, as the computationally intensive INS data is only processed for attitude angles rather than full position calculations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using INS data selectively and partially - only for attitude angle estimation rather than complete position calculation. The INS measurement results are integrated with GPS data specifically for the attitude angle component, which then serves as a correction term in the position calculation, rather than processing all INS data for full position determination.

Inventive Principle:

Principle #16Partial or excessive action

2Productivity

If amount of processing data is reduced to decrease processing load, then processing load is reduced, but calculation accuracy of speed and displacement cannot be maintained

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidspeed and displacement calculation accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary calculation of attitude angles using both GPS and INS data before the main speed and displacement calculations. By pre-computing the attitude angle integration using complementary filtering, the system prepares accurate orientation data in advance, which then enables accurate speed and displacement calculations to be performed with reduced subsequent data processing loads.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the processing parameters by using different data cycles for different calculation purposes: long cycles for GPS position data, short cycles for INS data, and selectively combining them. The system transforms the raw high-frequency INS data into lower-frequency attitude angle estimates through filtering, changing the temporal parameters to match the requirements of position-based speed and displacement calculations.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If GNSS data cycle is lengthened to reduce data amount, then amount of processing data is reduced, but accuracy of attitude angle may deteriorate

Engineering Contradiction:

Improveamount of GNSS dataVSAvoidattitude angle accuracy

Core Design Contradiction:

Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent merges GPS attitude angle data with INS angular velocity data through complementary filtering to create integrated attitude angle estimates. By combining these two different measurement systems with complementary characteristics (GPS provides absolute orientation at long cycles, INS provides relative orientation at short cycles), the system achieves accurate attitude angles even when using lengthened GNSS data cycles.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces complementary filtering as an intermediary process that mediates between the low-frequency GPS attitude data and high-frequency INS angular velocity data. This filtering mechanism acts as a bridge, combining the reliable long-term GPS orientation information with the responsive short-term INS data to produce accurate attitude angles without requiring high-frequency GPS data.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11333501B2Navigation device, method of generating navigation support information, and navigation support information generating program

Publication Date: 2022.05.17 FURUNO ELECTRIC CO LTD

AI summary

A navigation device may include a GNSS data editing part, an attitude angle calculating part, and a speed calculating part. The GNSS data editing part may generate GNSS attitude angle estimation data and GNSS speed estimation data by using first GNSS data based on a GNSS signal received by a first antenna, and second GNSS data obtained at a shorter cycle than the first GNSS data based on a GNSS signal received by a second antenna. The attitude angle calculating part may estimate an integrated attitude angle based on the IMU angular velocity outputted from an Inertial Measurement Unit (IMU) and the GNSS attitude angle estimation data. The speed calculating part may estimate an integrated speed based on an IMU acceleration outputted from the IMU, the GNSS speed estimation data, and the integrated attitude angle.