Abstract
The precise localization of mobile robots is of utmost importance for
many industrial applications, especially when the mobile robot is part
of a more complex kinematic chain, such as in a mobile manipulator.
Furthermore, precise localization hugely affects the outcome of tasks
that rely on an open-loop kinematic computation, such as work-station
docking procedures. To achieve a repeatable and precise localization and
positioning, mobile robots generally rely on onboard sensors, most
commonly 2D laser scanners, whose readings are subjected to noise and
numerous disturbing factors ( e.g., materials reluctance). In
this work, we propose a recurrent neural network (RNN) based
registration system, which uses a pair of consecutive LiDAR readings and
estimates a fixed transformation. The capability of RNNs to process
contiguous inputs will help neglect errors embedded in punctual laser
scanner reading and output a more precise registration estimation. In
such a way, the RNN can estimate a displacement error based on multiple
consecutive readings and act as a sensor to be employed in a closed-loop
control scheme. After a model architecture and optimization of
hyperparameters, the devised model is tested in different scenarios,
comparing the AMR precise positioning capability with a classical
registration algorithm. The results suggest that an RNN model can
greatly improve the registration precision of laser scanner signals and,
consequently, the precise positioning efficiency of AMRs.