Air-Conditioning User Positioning With Distributed Ultrasonic Sensors
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Solution Overview
Problem
Existing air-conditioning control systems face challenges in accurately estimating the position of a user due to significant errors in ultrasonic wave arrival time differences, especially when the user is distant from the air-conditioning indoor unit.
Innovation Solution
The system incorporates a second ultrasonic sensor positioned differently, such as in a remote operation device or a fluorescent light, in conjunction with a look-up table for accurate position estimation of the user's terminal based on arrival time differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If ultrasonic waves are detected using only first ultrasonic sensors in the air-conditioning indoor unit, then the device complexity is reduced, but the position estimation accuracy deteriorates when the user is distant from the unit
Solution Approach 1:
The patent introduces a second ultrasonic sensor positioned at a different location (in another air-conditioning indoor unit, fluorescent light, or remote operation device) to create a spatially distributed sensor network. This dimensional expansion from a single-location sensor to multi-location sensors enables accurate position estimation even when users are distant from any single air-conditioning indoor unit, resolving the contradiction between device simplicity and measurement accuracy.
2Measurement precision
If multiple ultrasonic sensors are distributed at different positions, then the position estimation accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent makes existing devices multi-functional by integrating second ultrasonic sensors into devices that already serve other purposes - air-conditioning indoor units for cooling/heating, fluorescent lights for illumination, and remote operation devices for control. This allows the same physical device to perform both its original function and ultrasonic detection, reducing overall system complexity while improving position estimation accuracy through distributed sensing.
Solution Approach 2:
The patent uses existing infrastructure devices (fluorescent lights, remote operation devices, other air-conditioning units) as intermediaries to host ultrasonic sensors. These intermediary devices provide convenient mounting locations and power sources, avoiding the need to install dedicated sensor infrastructure while achieving distributed position estimation coverage.
3Ease of manufacture
If ultrasonic sensors are installed in existing devices like remote operation devices or fluorescent lights, then the installation cost is reduced, but the reliability of sensor positioning may deteriorate
Solution Approach 1:
The patent incorporates position information about the second ultrasonic sensor into the position estimation calculation process. The control device receives detection results from both first and second ultrasonic sensors along with their known positions, and uses this feedback information to accurately calculate the terminal's position. This ensures that even though sensors are installed in existing devices, the system maintains reliability by compensating for the fixed known positions of these sensors in the mathematical estimation algorithm.
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
This configuration allows for a wider permissible range of detection error and improved accuracy in estimating the user's position, reducing installation costs and processing load while enabling efficient air-conditioning control.
Implementation Method 1
ultrasonic waves are radiated from a terminal such as a smartphone held by a specific user, and the ultrasonic waves are detected by ultrasonic sensors such as a plurality of microphones provided at different positions on an air-conditioning indoor unit
Implementation Method 2
estimate the position of the user on the basis of differences in arrival times of ultrasonic waves at the different positions of the ultrasonic sensors
Data Source
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AI summary
An air-conditioning control device that is configured to control an air-conditioning indoor unit in accordance with terminal position of a terminal held by a user includes an ultrasonic detection processing unit which is configured to detect ultrasonic waves emitted from the terminal through a first ultrasonic sensor provided in the air-conditioning indoor unit and a second ultrasonic sensor provided at a position different from the position of the air-conditioning indoor unit, an arrival time difference calculation unit which is configured to calculate an arrival time difference which is a difference between a time when the ultrasonic wave is detected by the first ultrasonic sensor and a time when the ultrasonic wave is detected by the second ultrasonic sensor, a position estimation unit which is configured to estimate the terminal position of the terminal on the basis of the arrival time difference, and an indoor unit control unit which is configured to control the air-conditioning indoor unit on the basis of the terminal position.