Ultrasonic pen inclination deviation compensation method based on Bluetooth and nine-axis gyroscope

Abstract

The invention discloses an ultrasonic pen inclination deviation compensation method based on Bluetooth and a nine-axis gyroscope, and the method comprises the following steps: A, Bluetooth transmission: transmitting collected acceleration, gyroscope and magnetometer data to a host end through a nine-axis gyroscope module on an ultrasonic pen; according to the ultrasonic pen inclination deviation compensation method based on the Bluetooth and the nine-axis gyroscope, errors caused by inclination of the ultrasonic pen are corrected; the precision of the ultrasonic pen and the writing experienceof a user are improved; moreover, the ultrasonic pen inclination deviation compensation method based on the Bluetooth and the nine-axis gyroscope is good enough for use, a Kalman filtering data fusionalgorithm is used, the current posture of the ultrasonic pen can be quickly and accurately estimated; noise caused by natural shaking of the ultrasonic pen in the writing process is eliminated, the cost is low, and the scheme of inclination calibration can be achieved only by additionally arranging the Bluetooth and the nine-axis gyroscope hardware module and corresponding software programs without any change of an original ultrasonic pen positioning module.

Description

technical field [0001] The invention relates to the technical field of ultrasonic pens, in particular to an ultrasonic pen tilt deviation compensation method based on bluetooth and a nine-axis gyroscope. Background technique [0002] With the development of Internet technology and the influx of high-quality teachers and content, online education has also been accepted by more and more users. Through sound and video, the best way for students to express questions or solve problems is to speak while writing. Without this kind of whiteboard interaction, the teaching experience and learning quality will be greatly reduced. [0003] The products of desktop projection and smart pen also appear because of this. The desktop projector solves the problem of screen output, while the smart pen solves the problem of input. There are three mature smart pen solutions on the market, namely dot matrix pen and electromagnetic pen. And the ultrasonic pen, after analysis, finally chose the sol...

AI Technical Summary

Problems solved by technology

[0004] The traditional ultrasonic pen uses two-point ultrasonic positioning technology to locate the position of the pen, so as to obtain the user's writing information, but the defect of the ultrasonic pen is that the writing accuracy is very poor, because the position of the ultrasonic transmitter is far away from the tip of the pen. When the pen is tilted, there will be a deviation between the position received by the ultrasonic receiver and the actual writing position, resulting in inaccurate writing. If the ultrasonic pen is used as an input device for desktop projection, since the writing area and the display area completely overlap, so The deviation caused by the tilt of the ultrasonic pen will seriously affect the accuracy of user input and the experience of handwriting input. Therefore, we propose a compensation method for tilt deviation of the ultrasonic pen based on Bluetooth and nine-axis gyroscope

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