Navigation and control of a mobile manipulator for inspection

摘要

Oil and gas workers in the Middle East are frequently faced with environmental challenges when performing their daily tasks, as temperature could get as high as 50 degrees C with humidity level fluctuating between 80-90%. As common with other oil and gas environments, the workers are often faced with potential exposure to poisonous gases like H2S, Methane, etc., hence, making their job very risky. Developing a mobile robotic system will help remove these workers from harms way. However, integrating this robotic system into the environment demands that it can navigate through narrow spaces from one location to another location to execute a task successfully without colliding with obstacles. Also, it requires that humans are kept in the control loop to make critical decisions as there is zero tolerance to error in this environment. Using an oil refinery as the target deployment environment, we develop an inexpensive navigation system to enable a mobile manipulator to perform inspection tasks within this environment. This includes the fusion of several information from WiFi, GPS, IMU, encoders, laser range finder, compass, and artificial visual markers to determine the robot location within the facility. We also present a gap-finding obstacle avoidance algorithm, and address the problem of defining inspection poses for the robotic arm to inspect a gauge. Leveraging on these capabilities, we propose a shared control framework to achieve human collaboration in performing inspection tasks. The implementation results are promising; the robot accurately localizes, efficiently avoids obstacles, successfully executes inspection tasks, and collaborates with a human operator to achieve tasks.