Indoor Navigation System For Human Based On Multi-site Vibrotactile Feedback

In recent year,the technology about mobile robot has a great development.The mobile robot with autonomous navigation has been widely used in the inspection,security,cleaning and other fields.In this paper,the mobile robot with autonomous navigation is applied into the navigation aid to improve the traditional navigation methods based on the canes and guide dogs and offer the visually impaired and those who need the help of guidance better navigation service than the common guide aids.A navigation system for human based on multi-site vibrotactile feedback is designed in this paper.The system includes a small mobile robot and a multi-site vibrotactile device.The mobile robot consists of drive module,system-control module,detecting module and a Kinect sensor used to track the location of the user.The detecting module comprises a laser range radar,a gyroscope,a fall prevention sensor and encoders.This module detects environmental information and transmits this information to the system-control module.The system-control module uses environmental information to construct two-dimensional map of the environment by Gmapping algorithm and use navigation stack to plan the optimal path to target as well as provide real-time control speed.To make the user freely decide his/her own speed,the human-robot cooperative navigation algorithm and improved dynamic window algorithm handle real-time control speed and generate the drive speed which conveyed to the drive module.The drive module drives robot accurately according to the drive speed.The Kinect can capture the skeleton of the user to achieve the reference position of the user.The multisite vibrotactile device conveys corresponding navigation vibration prompts to the user according to the user's reference position relative to the robot and vibrotactile feedback strategy.The user apperceives vibration prompts and makes corresponding position adjustment.In this way,the relative distance and relative bearing between the robot and the user can be maintained.Finally,the user will be guided to the destination safely.In order to design a multi-site vibrotactile device as the human-robot interface of the system,the ability for vibrotactile perception of body parts is researched.According to the accuracy and response speed of recognizing vibrotactile signals with each body part and the subjective evaluation of the user about sensitivity and comfort of each body part,the finger and wrist are selected as the perception part of the vibrotactile signals.In this paper,Gmapping algorithm is implemented with the system built.And the map of experimental environment is created using this algorithm.Based on the map and the humanrobot cooperative navigation algorithm,the verification experiment about the system's navigation performance is performed.The experimental results show that the navigation system based on the multi-site vibrotactile feedback has better performance than the navigation system based on the kinaesthetic feedback and the one based on the single-site vibrotactile feedback.All testers' formation errors are less than 0.28 m,and the mean of the formation error is 0.23 m.The navigation speed is 0.13m/s.The results of the user acceptance tests show the rather high evaluation of the convenience,effectiveness and reliability of the multi-site vibrotactile human-robot interface and the navigation system.Finally,the antijamming capability of the system in indoor environment is verified via some experiments.