Towards long-distance inspection for in-pipe robots in water distribution systems with smart motion facilitated by particle filter and multi-phase motion controller

Incidents in water distribution systems cause water loss and water contamination that requires the utility managers to assess the condition of pipelines frequently. However, pipelines are long and access to all parts of it is a challenging task; current in-pipe robots have the limitation of short-distance inspection and inability to operate in-service networks. In this work, we improve the design of our previously developed in-pipe robot as reported by Kazeminasab et al. (IEEE 5th international conference on robotics and automation engineering (ICRAE), 2020) and a multi-phase motion controller is proposed that ensures reliable motion for the robot during operation. The controller provides stabilized configuration with zero velocity at junctions (i.e. phase 1), stabilized configuration with velocity tracking at straight paths (i.e. phase 2), and facilitates desired amount of rotation around two axes for the robot (i.e. phase 3). We propose a localization technique with a particle filter that receives information about the surrounding environment with a rangefinder sensor. The map of the operation that is needed for the particle filter is an array that comprises non-straight paths in the operation that the robot passes through. We also develop a method that facilitates smart navigation for the robot in different configurations of pipelines. In this method, the localizer (i.e. particle filter) is synchronized with the multi-phase motion controller, and the robot switches between different phases of the controller based on its location in the network. We validated the functionality of the controller in the three phases with simulations and also the localization and navigation methods with experimental results. The results show that the robot has smart navigation with the synchronized motion controller and the localizer inside pipelines.