Visual Inertial Unit Initialization Using Pre-Acquired Stable Parameters
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Solution Overview
Problem
The initialization of visual inertial units in mobile terminals is often inaccurate due to the units acquiring parameters in unstable states, leading to incorrect posture recognition.
Innovation Solution
An accompanying unit is introduced to acquire initialization parameters earlier than the visual inertial unit, ensuring these parameters are obtained when the mobile terminal is in a stable state, allowing the visual inertial unit to initialize accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the visual inertial unit acquires initialization parameters directly when initialization condition is met, then the initialization speed is fast, but the accuracy deteriorates because the mobile terminal may be in unstable state
Solution Approach 1:
The accompanying unit performs preliminary acquisition of initialization parameters before the visual inertial unit needs them. The accompanying unit continuously monitors and stores initialization parameters (such as acceleration, angular velocity, and posture data) in advance, so when the visual inertial unit requires initialization, it can directly acquire pre-acquired accurate parameters without waiting for the terminal to stabilize.
Solution Approach 2:
The accompanying unit acts as an intermediary between the sensor system and the visual inertial unit. It decouples the parameter acquisition process from the initialization trigger, allowing the visual inertial unit to obtain parameters from the accompanying unit's storage rather than acquiring them directly from sensors during initialization, thus avoiding the instability issue.
2Measurement precision
If the visual inertial unit waits for stable state to acquire parameters, then the accuracy improves, but the initialization speed deteriorates
Solution Approach 1:
The accompanying unit performs the parameter acquisition action in advance during normal operation when the terminal is likely in a more stable state. It continuously collects and stores initialization parameters (acceleration, angular velocity, posture) before they are needed, eliminating the need to wait for stability at initialization moment while ensuring high accuracy.
Solution Approach 2:
The parameter acquisition function is segmented into a separate accompanying unit that operates independently from the visual inertial unit. This segmentation allows the accompanying unit to continuously acquire and store parameters during normal operation, while the visual inertial unit can immediately use these pre-acquired parameters without waiting for stability conditions.
3Measurement precision
If the accompanying unit is started earlier than the visual inertial unit, then the parameter acquisition timing is improved, but the device complexity increases
Solution Approach 1:
The accompanying unit is designed with multi-functionality: it not only acquires initialization parameters but also continuously monitors terminal state, stores data in buffer, and provides data to the visual inertial unit when needed. This universal design consolidates multiple functions into one unit, reducing overall system complexity despite adding a component.
Solution Approach 2:
The accompanying unit autonomously performs parameter acquisition, storage, and provision without requiring direct control from the visual inertial unit. It independently monitors terminal state, automatically stores parameters when stabilization conditions are met, and makes them available when the visual inertial unit requests initialization, reducing inter-component complexity.
Data Source
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AI summary
A posture recognition method is applied to a mobile terminal, the mobile terminal includes a visual inertial unit (301) and an accompanying unit (302) different from the visual inertial unit, and the accompanying unit is started earlier than the visual inertial unit. The method includes: acquiring (102) by the accompanying unit initialization parameters used by the visual inertial unit for initialization when the mobile terminal is in a stable state; and acquiring (104) by the visual inertial unit the initialization parameters from the accompanying unit when an initialization condition is met, and initializing the visual inertial unit based on the acquired initialization parameters, to output posture data of the mobile terminal based on an initialization result.