An adaptive configuration-space and work-space based criterion for view planning

We consider the view planning problem, also called, next best view (NBV) problem for sensor based exploration for general robot-sensor systems, where a range scanner is mounted on a robot with non-trivial kinematics, e.g., an eye-in-hand system. Earlier approaches to NBV had considered purely work-space (we also use the term physical-space) based criteria, such as select the view that maximizes the unknown physical-space volume. While this works well for mobile robots (often modeled as point or circle, thereby having trivial geometry and kinematics), it ignores a critical aspect, i.e., to give priority to exploring "manoeuvrable" space around the robot so that it can move to better viewing configurations. Proposed C-space based view planning criteria address this problem. However, C-space criteria (assuming the robot has enough manoeuvrable space) may sacrifice efficiency in work-space volume coverage. For inspection or environment modeling tasks, efficient workspace volume coverage is important. In this paper, we propose an adaptive algorithm that biases the search toward C-space or toward work-space, as needed. We call it adaptive viewpoint candidates entropy (VCE) criterion. Results with different simulated scenes show the effectiveness of this criterion in efficient (in that it needs less scans) exploration of the workspace.