**Recent Progress in Sensing and Computing Techniques for Human Activity Recognition and Motion Analysis**

### **Zhaozong Meng, Mingxing Zhang, Changxin Guo, Qirui Fan, Hao Zhang \*, Nan Gao and Zonghua Zhang**

School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, China; zhaozong.meng@hebut.edu.cn (Z.M.); mingxing.zhang123@outlook.com (M.Z.); changxinguo1@outlook.com (C.G.); qirui.fan@outlook.com (Q.F.); ngao@hebut.edu.cn (N.G.); zhzhang@hebut.edu.cn (Z.Z.)

**\*** Correspondence: zhanghao@hebut.edu.cn; Tel.: +86-1382-1425-017

Received: 28 July 2020; Accepted: 18 August 2020; Published: 21 August 2020

**Abstract:** The recent scientific and technical advances in Internet of Things (IoT) based pervasive sensing and computing have created opportunities for the continuous monitoring of human activities for different purposes. The topic of human activity recognition (HAR) and motion analysis, due to its potentiality in human–machine interaction (HMI), medical care, sports analysis, physical rehabilitation, assisted daily living (ADL), children and elderly care, has recently gained increasing attention. The emergence of some novel sensing devices featuring miniature size, a light weight, and wireless data transmission, the availability of wireless communication infrastructure, the progress of machine learning and deep learning algorithms, and the widespread IoT applications has promised new opportunities for a significant progress in this particular field. Motivated by a grea<sup>t</sup> demand for HAR-related applications and the lack of a timely report of the recent contributions to knowledge in this area, this investigation aims to provide a comprehensive survey and in-depth analysis of the recent advances in the diverse techniques and methods of human activity recognition and motion analysis. The focus of this investigation falls on the fundamental theories, the innovative applications with their underlying sensing techniques, data fusion and processing, and human activity classification methods. Based on the state-of-the-art, the technical challenges are identified, and future perspectives on the future rich, sensing, intelligent IoT world are given in order to provide a reference for the research and practices in the related fields.

**Keywords:** Internet of Things (IoT); human activity recognition (HAR); motion analysis; wearable sensors; machine learning
