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On Learning Navigation Behaviors for Small Mobile Robots with Reservoir Computing Architectures

on Wed, 12/16/2015 - 14:56

This work proposes a general Reservoir Computing (RC) learning framework which can be used to learn navigation behaviors for mobile robots in simple and complex unknown, partially observable environments. RC provides an efficient way to train recurrent neural networks by letting the recurrent part of the network (called reservoir) fixed while only a linear readout output layer is trained.
The proposed RC framework builds upon the notion of navigation attractor or behavior which can be embedded in the high-dimensional space of the reservoir after learning. 
The learning of multiple behaviors is possible because the dynamic robot behavior, consisting of a sensory-motor sequence, can be linearly discriminated in the high-dimensional nonlinear space of the dynamic reservoir. 
Three learning approaches for navigation behaviors are shown in this paper. The first approach learns multiple behaviors based on examples of navigation behaviors generated by a supervisor, while the second approach learns goal-directed navigation behaviors based only on rewards. The third approach learns complex goal-directed behaviors, in a supervised way, using an hierarchical architecture whose internal predictions of contextual switches guide the sequence of basic navigation behaviors towards the goal.






Robot learning through dynamical systems (PhD thesis)

on Wed, 12/09/2015 - 14:12

During my PhD, I've worked mainly on Reservoir Computing (RC) architectures with application to modeling cognitive capabilities for mobile robots from sensor data and sometimes through interaction with the environment.

Reservoir Computing (RC) is an efficient method for trainning recurrent neural networks, which can handle spatio-temporal processing tasks, such as speech recognition. These networks are also biological plausible, as recently argued in the literature.

In my case, I used these RC networks for modeling a wide range of capabilities for mobile robots, such as:

These tasks were modeled basically using regression for learning behaviors or classification for discrete localization.

My PhD thesis can be download here. It is entitled: "Reservoir Computing Architectures for Modeling Robot Navigation Systems".

My publications are listed and can be downloaded in Google Scholar or here.

Some simulated and real robots employed in the experiments:


Environment used for localization experiments using the real e-puck robot:


After using unsupervised learning methods for self-localization, the plots below show the mean activation of place cells as a function of the robot position in the environment.
Red denotes a high response whereas blue denotes a low response.

It is possible to perform map generation through sensory prediction given the robot position as input. Black points represent the sensory readings whereas gray points are the robot trajectory.


UTEMA (Unbiased Temporal Machine for General-purpose Times series-based Fraud detection)

on Thu, 05/03/2018 - 11:10

In the context of energy distribution networks, frauds are non-technical losses (NTL) that may account for up to 40% of the total distributed energy in some developing countries. The fraudster alters the eletricity meter in order to pay less than the right amount. In this context, the discovery or detection of frauds is necessary in order to decrease the non-technical losses of the energy distribution networks, consequently enhancing the stability and reliability of the network.

This project proposes the use of Recurrent Neural Networks (RNNs) for projecting a times series into a spatial dimension such that it can be used as a universal temporal feature for fraud detection predictive models. The particular problem tackled here jointly with the partner company is to predict whether a given time series of monthly energy consumption data is likely to indicate a fraud (NTL) or not.

Two main approaches are planned to be used with RNNs: supervised learning with bias correction techniques, and self-organized models for unsupervised learning of new fraud (anomaly) patterns.Finally, a last step is to integrate both of the previously developed models into an unified architecture that learns the responsibilities of each model in an online way by feedback from the environment using the results of the inspections of the fraudsters - the ground truth for some of the predictions.

This project has potential not only for generating significant technological and commercial value for the industrial partner, but also outstanding scientific output, being applicable in the long-term to other fields such as monitoring, prognosis/diagnostics in robotics, medical systems and security applications.

Funding: AFR-PPP / FNR, Luxembourg.


State-of-the-art Artificial Intelligence method for detecting that you is really you and not some intruder entering the code on your mobile phone.

Technologies used:
Python (backend & custom Neural network model);
Java (Android app frontend);

Developed in 2016/2017.


More information:  TigerAI_info.pdf



NatVim Marketplace is a marketplace for online stores of the segment of natural products in Brazil.

For more information, visit:

  • Technologies used: Ruby, Ruby on Rails, Apache Solr, JavascriptTwitter Boostrap and various ruby gems. 
  • Started Development in 2017.
  • Mobile ready.

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