NxtAR: A generic software architecture for Augmented Reality based mobile robot control.

Android backend module

Abstract

NxtAR is a generic software architecture for the development of Augmented Reality games and applications centered around mobile robot control. This is a reference implementation with support for LEGO Mindstorms NXT mobile robots.

Module description

The Android backend module is a concrete LibGDX application that implements the operating system dependent parts of the NxtAR reference implementation. It is based around the OpenCV Computer Vision and Machine Learning library. Currently this module supports Android (>= 3.1) devices though it has been tested only on Android (>= 4.0). The module includes direct support for the OUYA gaming console and other devices using OUYA gamepads.

Module installation and usage.

Install the NxtAR-core_XXXXXX.apk file on your device. To use you need additionally an Android (>= 3.0) phone and a LEGO Mindstorms NXT robot with the LejOS firmware installed. The NxtAR-cam module must be installed on the device and the NxtAR-bot module must be installed on the robot. Then, to start the compiled scenario follow these steps:

• Start the NxtAR-core application.
• Start the NxtAR-bot program on the robot.
• Calibrate the robot's light sensor following the on-screen instructions.
• When the robot displays "Waiting for connection" start the NxtAR-cam application and connect it with the robot.
• Press the "Start video streaming" button on the NxtAR-cam application.
• Press the "Calibrate camera" button on the NxtAR-core application and point the camera of the device running NxtAR-cam to an OpenCV checkerboard camera calibration pattern.

The camera calibration step can be repeated if needed.