IEEE Trans Haptics. 2021 Oct-Dec;14(4):914-921. doi: 10.1109/TOH.2021.3076489. Epub 2021 Dec 16.
Non-contact tactile presentation using ultrasound phased arrays is becoming a powerful method for providing haptic feedback on bare skin without restricting the user's movement. In such ultrasonic mid-air haptics, it is often necessary to generate multiple ultrasonic foci simultaneously, which requires solving the inverse problem of amplitudes and phases of the transducers in a phased array. Conventionally, matrix calculation methods have been used to solve this inverse problem. However, a matrix calculation requires a non-negligible amount of time when the number of control points and the number of transducers in the array are large. In this article, we propose a simple method based on a greedy algorithm and brute-force search to solve the field reconstruction problem. The proposed method directly optimizes the desired field without matrix calculation or target field phase optimization. The empirical results indicate that the proposed method can reproduce the target sound with an accuracy of more than 80%.
基于超声相控阵的非接触式触觉呈现技术正在成为一种在不限制用户运动的情况下为裸露皮肤提供触觉反馈的强大方法。在这种超声空中触觉技术中，通常需要同时生成多个超声焦点，这需要解决相控阵中换能器的幅度和相位的逆问题。传统上，已经使用矩阵计算方法来解决这个逆问题。然而，当控制点的数量和阵列中的换能器的数量较大时，矩阵计算需要花费相当多的时间。在本文中，我们提出了一种基于贪婪算法和穷举搜索的简单方法来解决声场重建问题。所提出的方法直接优化所需的声场，而无需矩阵计算或目标声场相位优化。经验结果表明，所提出的方法可以以超过 80%的精度再现目标声音。
