Autonomous mobile robots navigating through human crowds are required to foresee the future trajectories of surrounding pedestrians and accordingly plan safe paths to avoid any possible collision. This paper presents a novel approach for pedestrian trajectory prediction. In particular, we developed a new method based on an encoder–decoder framework using bidirectional recurrent neural networks (BiRNN). The difficulty of incorporating social interactions into the model has been addressed thanks to the special structure of BiRNN enhanced by the attention mechanism, a proximity-independent model of the relative importance of each pedestrian. The main difference between our and the previous approaches is that BiRNN allows us to employs information on the future state of the pedestrians. We tested the performance of our method on several public datasets. The proposed model outperforms the current state-of-the-art approaches on most of these datasets. Furthermore, we analyze the resulting predicted trajectories and the learned attention scores to prove the advantages of BiRRNs on recognizing social interactions.
Jiaxu Wu, Yusuke Tamura, Yusheng Wang, Hanwool Woo, Alessandro Moro, Atsushi Yamashita, and Hajime Asama: Smartphone Zombie Detection from LiDAR Point Cloud for Mobile Robot Safety, IEEE Robotics and Automation Letters, Vol.5, No.2, pp.2256-2263, 2020. doi:10.1109/LRA.2020.2970570abstract
Awareness of surrounding and prediction of dangerous situations is essential for autonomous mobile robots, especially during navigation in a human-populated environment. To cope with safety issues, state-of-the-art works have focused on pedestrian detection, tracking, and trajectory prediction. However, only a few studies have been conducted on recognizing some specific types of dangerous behaviors exhibited by pedestrians. Here, we propose a tracking enhanced detection method to recognize people using their smartphones while walking, referred to as smartphone zombie. Features used for pedestrian detection usually involve the rotation variance problem, and in this paper, the drawback is handled by employing motion information from multi-object tracking. The proposed solution has been validated through experiments performed on a newly collected dataset. Results showed that our detector can learn a distinct pattern of the appearance of smartphone zombies. Thus, it can successfully detect them outperforming the existed detection method.
In order for mobile robots to coexist with humans, both safety and efficiency should be satisfied. We propose a method to predict pedestrian movement for collision avoidance of mobile robots and pedestrians. In the proposed method, the pedestrian trajectories are measured and a database of human movement tendencies is generated. The database is applied to the prediction of future pedestrian movement. To decrease the initial time cost for database generation, environmental geometric configuration is considered in the form of virtual forces. To verify the usefulness of the proposed method, we generated the database based on five-hour observation and conducted three types of experiments based on the generated database. The first experiment showed the prediction performance of the proposed method and proved the method guaranteed the safety. The second experiment showed that the proposed method satisfied both the safety and efficiency through the comparative simulations. The third experiment showed the method could apply to the real mobile robot.
Shunsuke Hamasaki, Yusuke Tamura, Atsushi Yamashita and Hajime Asama: Prediction of Human’s Movement for Collision Avoidance of Mobile Robot, Proceedings of the 2011 IEEE International Conference on Robotics and Biomimetics, pp.1633-1638, Phuket, Thailand, December 2011. doi:10.1109/ROBIO.2011.6181523
人間は、周囲に存在する他者や環境の状況から、周辺他者を回避するか、追従するか、など意図を切り替えながら歩行していると考えられます。我々は、Social Force Model1 を拡張し、このような歩行意図の切り替えに応じたサブゴールを生成しながら動作生成を行うモデルを提案しています。
Yusuke Tamura, Phuoc Dai Le, Kentarou Hitomi, Naiwala P. Chandrasiri, Takashi Bando, Atsushi Yamashita and Hajime Asama: Development of Pedestrian Behavior Model Taking Account of Intention, Proceedings of the 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems, pp.382-387, Vilamoura, Portugal, October 2012. doi:10.1109/IROS.2012.6385599abstract
In order for robots to safely move in human-robot coexisting environment, they must be able to predict their surrounding people's behavior. In this study, a pedestrian behavior model that produces humanlike behavior was developed. The model takes into account the pedestrian's intention. Based on the intention, the model pedestrian sets its subgoal and moves toward the subgoal according to virtual forces affected by other pedestrian and environment. The proposed model was verified through pedestrian observation experiments.