Ultrasonic Position Detection Using Trigger Signal Timing
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Solution Overview
Problem
Existing position detection methods face challenges in accurately identifying and tracking multiple mobiles simultaneously due to clock synchronization deviations and increased power consumption, particularly when using ultrasonic waves and infrared signals, leading to rendering delays and inaccurate coordinate detection.
Innovation Solution
A position detection apparatus and method that employs a mobile with a trigger signal transmitting and receiving unit, and a receiver with multiple ultrasonic wave receiving units, allowing for precise ultrasonic wave propagation time calculation and position determination by controlling trigger signal timing and using band-divided trigger signals to prevent signal duplication among multiple mobiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple mobiles transmit ultrasonic waves simultaneously using time-division multiplexing with clock synchronization, then multiple mobiles can be identified and tracked, but clock deviation between mobile and stationary body causes coordinate detection accuracy to deteriorate
Solution Approach 1:
Instead of having the stationary body transmit timing signals to mobiles for synchronization, the invention inverts the approach by having each mobile transmit its own identification signal and have the stationary body independently determine timing based on receiving these signals. This eliminates clock synchronization issues between mobile and stationary body.
Solution Approach 2:
Each mobile device independently transmits its identification signal and operates autonomously without relying on timing signals from the stationary body. The stationary body independently processes these signals to determine positions, making the system self-sufficient and eliminating clock deviation problems.
2Measurement precision
If the stationary body transmits electromagnetic wave signals including ID information at regular intervals to enable multiple mobiles to transmit ultrasonic waves in time-division manner, then multiple mobiles can be identified, but the transmission interval must be longer than ultrasonic wave propagation time across maximum input range
Solution Approach 1:
The stationary body transmits electromagnetic wave signals including ID information at regular intervals, creating periodic time-division multiplexing slots. Each mobile transmits ultrasonic waves only during its assigned time slot, preventing signal overlap while enabling multiple mobiles to be tracked simultaneously.
Solution Approach 2:
The time domain is segmented into distinct intervals, with each mobile assigned a specific time slot for transmission. This segmentation prevents ultrasonic wave overlap from multiple mobiles and enables the stationary body to independently process signals from each mobile without interference.
3Productivity
If ultrasonic wave transmission interval is reduced to improve coordinate measurement speed, then responsiveness improves, but the maximum propagation distance is limited by the transmission interval
Solution Approach 1:
The system dynamically adjusts the ultrasonic wave transmission interval based on the mobile's position and movement speed. When the mobile is closer or moving slower, the interval is reduced to improve measurement speed. When the mobile is farther away or moving faster, the interval is increased to ensure the ultrasonic wave can propagate the full distance.
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
Enables stable and accurate position detection of multiple mobiles by preventing signal duplication and reducing power consumption, ensuring precise coordinate tracking without rendering delays, even in scenarios with multiple mobiles activated simultaneously.
Implementation Method 1
a mobile transmits and receives a trigger signal and transmits an ultrasonic wave; and a receiver that transmits and receives the trigger signal and receives the ultrasonic wave
Implementation Method 2
a trigger signal transmitting unit that transmits a trigger signal of requesting transmitting ultrasonic wave that is capable of identifying the mobile
Data Source
AI summary
To detect the positions of the respective mobiles correctly without being affected by the ultrasonic waves from other mobile(s) in a case where plural mobiles are used simultaneously.The mobile comprises a unit that transmits a trigger signal of requesting transmitting ultrasonic wave that is capable of identifying the mobile, a unit that receives a trigger signal of allowing transmitting ultrasonic wave from the receiver, and a unit that transmits an ultrasonic wave immediately upon receipt of the trigger signal of allowing transmitting ultrasonic wave. The receiver comprises a unit that receives a trigger signal of requesting transmitting ultrasonic wave from the mobile, a unit that transmits a trigger signal of allowing transmitting ultrasonic wave that can be identified at the mobile side, a control unit that controls a transmitting timing of the trigger signal of allowing transmitting ultrasonic wave, at least two ultrasonic wave receiving units provided at predetermined gaps, a unit that calculates an ultrasonic wave propagation time from the mobile based on a time of transmitting the trigger signal of allowing transmitting ultrasonic wave and an ultrasonic wave arrival time, and a position calculation unit that calculates a position of the mobile based on the ultrasonic wave propagation time calculated.