A Three-Dimensional Ultrasonic Pen-Type Input Device With Millimeter-Level Accuracy for Human–Computer Interaction

Jian Chen,Fan Yu,Lin Lin,Jiaxin Yu

doi:10.1109/access.2020.3014169

Jian Chen, Fan Yu + Show 2 more

Open Access

https://doi.org/10.1109/access.2020.3014169

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Abstract

In this article, a pen-type device that enables three-dimensional (3D) human-computer interaction is presented. This device is based on a high-precision 3D ultrasonic (US) positioning method, which can achieve millimeter-level accurate 3D positioning and six degrees of freedom (6DoF) within a working range of 4 m × 1.5 m × 1.5 m. The 3D positioning of the electronic pen is realized by a highprecision time-of-flight (TOF) detection method based on dynamic thresholding and zero-crossing detection as well as a multigroup positioning coordinate averaging method. During the 3D positioning process, correlation filtering is adopted to process the received US signals and suppress any interference signals below 20 kHz and above 60 kHz. The positioning method can achieve a high positioning accuracy without any complex calculations. The attitude of the electronic pen is measured using an inertial measurement units (IMUs). To demonstrate the positioning accuracy of the proposed device, a total of 108 test positions are uniformly set in the workspace, and static and dynamic positioning accuracy experiments are carried out at all test positions. The experimental results show static and dynamic positioning errors of less than 0.35 mm and less than 1.0 mm, respectively, which indicate a high positioning accuracy. The proposed device can provide 6DoF and enable writing in 3D. Therefore, the device can meet the common requirements of a 3D human-computer interaction interface.

Highlights

In recent years, pen-type devices have emerged as input modules for tablet computers, handheld devices, and large interactive display systems [1], [2]
A high-precision TOF detection method based on dynamic thresholding and zero-crossing detection is proposed
A high-precision TOF detection method based on dynamic thresholding and zero-crossing detection is proposed, which can obtain a high detection accuracy without a high sampling rate

Summary

INTRODUCTION

Pen-type devices have emerged as input modules for tablet computers, handheld devices, and large interactive display systems [1], [2]. The IR pulse is used by the receiver as the synchronization signal to measure the TOF, which is used to calculate the distance from the electronic pen. 3D HIGH-PRECISION ULTRASONIC POSITIONING METHOD The proposed device uses 3D high-precision US positioning technology based on the measured distances to locate the electronic pen in real time. A. HIGH-PRECISION TOF MEASUREMENT METHOD To reduce the cost and improve the real-time performance, the total amount of data acquired by the device should be low, which means that the sampling frequency should be low. By using more than three receivers, the problem of ranging failure caused by the small beam angle of the electronic pen US transmitter can be mitigated, and the stability of positioning results can be improved through averaging

ATTITUDE MEASUREMENT

EXPERIMENTAL SETUP

CONCLUSION