An active headrest device based on infrared positioning

Abstract

The invention discloses an active headrest device based on infrared positioning, which includes: a secondary sound source, a reference microphone and a control system; the device also includes: an infrared range finder and a positioning system, and the controller includes the most Optimal control coefficient database; the number of the infrared range finder is at least 3; the positioning system determines the position of the head of the person in the activity area according to the distance information provided by the infrared range finder, and sends it to the control system, According to the position of the head of the person, the optimal controller coefficient is obtained from the optimal controller coefficient database, and the reference signal collected by the reference microphone is filtered according to the coefficient and then sent to the secondary sound source to make the secondary sound source emit sound. Thereby noise control is achieved. The device of the present invention selects the optimal controller coefficient pre-designed at the current position after obtaining the control target position, thereby ensuring that a stable and consistent noise control effect can be obtained even when the human head is moving.

Description

technical field [0001] The invention relates to the field of active noise control, in particular to an active headrest device based on infrared positioning. Background technique [0002] In the field of traditional noise control, sound insulation and sound absorption materials are usually used to reduce the noise in the space. This method has a good control effect on high-frequency noise, but if the same control effect is also required on low-frequency noise, a larger volume is required. , weight, such a method increases the cost and is not practical in actual situations. Therefore, for low-frequency noise, the method of active noise control is usually used to reduce low-frequency noise, that is, the speaker emits reverse sound waves to offset the original noise at the current position to achieve noise reduction. These speakers are called secondary sound sources. Active noise control is also called "active noise control" (Active noise control, ANC) in some literatures. [...

AI Technical Summary

Problems solved by technology

[0005] U.S. Patent No. 8,325,934 and U.S. Patent No. 9,640,167, etc. have all mentioned the method of using the method of active headrest system to control the noise at the ears of the head in the prone position, but considering that in the real environment, the position of the head will change. , the position of the human ears (target point) will change, and the secondary pathway will also change accordingly. At this time, the control effect of the system will decrease

The University of Southampton in the UK proposed to use some commercial kits for VR systems to accurately locate the head position, but the system volume and space occupied are large, the cost is high, and the system complexity increases accordingly.

[0006] To sum up, the current active headrest system using active noise control has a general control effect when the position of the head changes, while the use of third-party commercial software makes the system larger and less flexible

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