Method for restoring moving track of hand in air by using radio signal

Abstract

The invention discloses a method for restoring a moving track of a hand in the air by using a radio signal, which is free from a special sensor and is used for detecting and restoring a writing trackof a finger in the air by using the radio signal of existing communication equipment. One signal transmitting device Tx and two signal receiving devices Rx are placed, each receiving device is provided with at least two antennas, and no barrier exists between the Tx and the Rx. The hand does not need to wear any equipment. The moving area of the hand in air is interior of a square area defined byTx-Rx1 and Tx-Rx2. A radio signal is disturbed by using the movement of the hand, wireless channel changes on a plurality of receiving antennas are measured and extracted, and then the movement trackof the hand in the air is calculated. According to the method, the channel CSI value acquired by the existing wireless communication equipment is utilized, and extra hardware equipment or hardware change is not needed, so that the cost is saved. The application range is wide. Accurate tracking can be carried out, and the track restoration precision is high. Real-time continuous operation can be achieved, and convenience and practicability are achieved.

Description

technical field [0001] The invention belongs to radio communication and sensorless sensing technology, relates to sensing technology based on existing communication equipment without special sensors, and especially relates to a method of detecting and restoring hands (including hands or single fingers) using radio RF (Radio Frequency, radio frequency) signals. ) method of moving trajectory in the air, using the disturbance of the radio RF signal caused by the movement of the finger, by measuring and extracting the wireless channel changes on multiple receiving antennas, calculating the moving trajectory of the finger in the air, and realizing writing recognition and other types of applications . Background technique [0002] Finger writing in the air is an important information input method in human-computer interaction, and sensing the movement trajectory of fingers in the air can provide support for many applications. According to different technical principles, the exist...

AI Technical Summary

Problems solved by technology

Limited by the attenuation mechanism of sound waves propagating in the air, the perception range of finger tracking based on sound is relatively small. Currently, FingerIO with the farthest perception capability has a perception distance of less than 1 meter.

However, the basic operation of conjugate multiplication brings more noise on the amplitude, which limits the method to more fine-grained perception

Limited by the algorithm technology used in this method, this method cannot perceive Doppler shift within 1Hz

Therefore, this method can only perceive the overall movement of the human torso and arms, and the perception granularity is only at the decimeter level. It cannot perceive the centimeter-level movement of the fingers, and cannot be used to restore the trajectory of finger writing.

[0012] To sum up, the current sensor-based finger displacement sensing technology can achieve better accuracy under ideal conditions, but most of them require special equipment, the cost is high, and different technologies have their own application limitations

However, the existing sensorless sensing technology using WiFi signals has poor detection accuracy and can only roughly track the movement trajectory of the body's torso and arms.

At present, there is no technology that can accurately track the movement of small parts such as fingers without using sensors and only using the existing indoor communication facilities

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