Gil Lopes

Autonomous golf ball picking robot design and development

Purpose – The purpose of this paper is to present the methodology and the results on the design and development of an autonomous, golf ball picking robot, for driving ranges.Design/methodology/approach – The strategy followed to develop a commercial product is presented, based on prior identification requirements, which consist of picking up golf balls on a driving range in a safe and efficient way.Findings – A fully working prototype robot has been developed. It uses two driving wheels and a third cast wheel, and pushes a standard gang which collects the balls from the ground. A hybrid information system was implemented in order to provide a statistically relevant prediction of golf balls location, to optimize the path the robot has to follow in order to reduce time and cost. Autonomous navigation was developed and tested on a simulation environment.Research limitations/implications – Preliminary results showed that the new path planning algorithm Twin‐RRT* is able to form closed loop trajectories and im...

Development of a serious game for Portuguese Sign Language

Human-computer interaction by gesture recognition has been a technology increasingly powerful and with a wide range of applications. The aim of this research is to take advantage of these resources and tools, developing an application for gesture recognition in Portuguese Sign Language (PSL) focused in helping disabled deaf and/or mute and hearing children to learn PSL. The PSL involves the use of hands and facial expressions to interact, where the output of the communication (“talk”) comes from the hands and/or body and the input comes from the eyes observation (“hear”). This paper presents a serious game for children in the 1st cycle (primary Portuguese school) between the ages of 6 to 10 years. The game is based on a story, in order to promote the motivation of the students in the learning of the Portuguese Sign Language.

Robot orientation with histograms on MSL

One of the most important tasks on robot soccer is localization. The team robots should self-localize on the 18 × 12 meters soccer field. Since a few years ago the soccer field has increased and the corner posts were removed and that increased the localization task complexity. One important aspect to take care for a proper localization is to find out the robot orientation. This paper proposes a new technique to calculate the robot orientation. The proposed method consists of using a histogram of white-green transitions (to detect the lines on the field) to know the robot orientation. This technique does not take much computational time and proves to be very reliable.

Catadioptric system optimisation for omnidirectional RoboCup MSL robots

Omnidirectional RoboCup MSL robots often use catadioptric vision systems in order to enable 360° of field view. It comprises an upright camera facing a convex mirror, commonly spherical, parabolic or hyperbolic, that reflects the entire space around the robot. This technique is being used for more than a decade and in a similar way by most teams. Teams upgrade their cameras in order to obtain more and better information of the captured area in pixel quantity and quality, but a large image area outside the convex mirror is black and unusable. The same happens on the image centre where the robot shows itself. Some efficiency though, can be improved in this technique by the methods presented in this paper such as developing a new convex mirror and by repositioning the camera viewpoint. Using 3D modelling CAD/CAM software for the simulation and CNC lathe mirror construction, some results are presented and discussed.

Tracking sound source localization for a home robot application

The future of robotics is now trending for home servicing. Nursing homes and assistance to elder people are areas where robots can provide valuable help in order to improve the quality of life of those who need it most. Calling a robot, for a person of age, can be a daunting task if the voice is failing and any resort to battery operated devices fails to comply. Using a simple mechanical apparatus, such as a Click trainer for dogs, a person can call a robot by pressing the button of a powerless device. The high pitch sound produced by this device can be captured and tracked down in order to estimate the person’s location within a room. This paper describes a method that provides good accuracy and uses simple and low cost technology, in order to provide an efficient positional value for an assistance robot to attend its caller. The robot does not need to search for the person in a room as it can directly travel towards the Click’s sound source. Keywords-localization; sound source; interaural sound difference; time difference of arrival

Development of a prototype robot for transportation within industrial environments

This paper describes the design and development of an autonomous robot for the Robot@Factory league at “Festival Nacional de Robótica 2016”, held in Bragança, Portugal. This paper describes all the hardware and software components developed for a localization and performance of the robot according to the rules. The challenge consists of a table setup that recreates an industrial environment where a robot has to successfully transport boxes from an initial warehouse to the final warehouse. The destination to which the robot has to carry each box, depends on the state of the box, i.e., depending on the box LED color, even though in some cases the robot has to leave the box temporarily in the called processing machines (which are intermediate stations). The most significant innovation feature of this robot prototype consists of the possibility of carrying up to three boxes simultaneously while being able to select which box to drop. This project was developed with great success, since the team managed to reach the 3rd place in the competition.

Inverted pendulum controlled by an analog PID controller: a framework for a laboratorial experiment

This paper presents the design of a framework for a didactic kit for control studies based on a rotary inverted pendulum. One of the challenges was to involve students in the design of the platform. This first version of the kit was developed by students of the Integrated Master on Industrial Electronics and Computers Engineering at the University of Minho. It considers the design and implementation of the control of the angular position of an inverted pendulum through an analog Proportional, Integral and Derivative (PID) controller. This Single Input Single Output (SISO) control system allows retrieving the equilibrium position of the pendulum when it is subjected to disturbances.

Motion Control of Mobile Autonomous Robots Using Non-linear Dynamical Systems Approach

This paper presents a solution to the problem of motion control of an autonomous robot, moving in a dynamical and unstable environment. It is based on non-linear dynamical systems, modelling the state variables that define the motion of a robot under an omnidirectional platform, like its direction of navigation and velocity. The approach used, is based on a set of non-linear differential equations that model the evolution of state variables along time, based on the concept of attractors and repellers. In the official RoboCup Middle Size League field, a target is used to attract the robot to a certain position (could be the ball or a desired position to receive the ball), while a repeller could move the robot away from its original path (given by obstacles in the surrounding environment). The research was firstly carried out in a computational simulation environment and later on with robots in a real environment.

High Resolution Trichromatic Road Surface Scanning with a Line Scan Camera and Light Emitting Diode Lighting for Road-Kill Detection

This paper presents a road surface scanning system that operates with a trichromatic line scan camera with light emitting diode (LED) lighting achieving road surface resolution under a millimeter. It was part of a project named Roadkills—Intelligent systems for surveying mortality of amphibians in Portuguese roads, sponsored by the Portuguese Science and Technology Foundation. A trailer was developed in order to accommodate the complete system with standalone power generation, computer image capture and recording, controlled lighting to operate day or night without disturbance, incremental encoder with 5000 pulses per revolution attached to one of the trailer wheels, under a meter Global Positioning System (GPS) localization, easy to utilize with any vehicle with a trailer towing system and focused on a complete low cost solution. The paper describes the system architecture of the developed prototype, its calibration procedure, the performed experimentation and some obtained results, along with a discussion and comparison with existing systems. Sustained operating trailer speeds of up to 30 km/h are achievable without loss of quality at 4096 pixels’ image width (1 m width of road surface) with 250 µm/pixel resolution. Higher scanning speeds can be achieved by lowering the image resolution (120 km/h with 1 mm/pixel). Computer vision algorithms are under development to operate on the captured images in order to automatically detect road-kills of amphibians.

Learning Robotics for Youngsters - The RoboParty Experience

The involvement of children and adolescents in robotics is on demand by the many robotics events and competitions all over the world. This non-deterministic world is more attractive, fun, hands-on and with real results than computer virtual simulations and 3D worlds. It is important, by different reasons, to involve people of all ages in an area that some consider the future of mankind and an opportunity to increase the low rate of engineers globally. Robotics competitions at this level are essentially based on teaching motion and programming skills by using Lego™ based robots and a set of challenges to overcome. This paper presents a different approach that is being used by Minho University in order to attract STEM candidates into these fields, with visible success and excellent results. The event is called RoboParty® and teaches children, adolescents and adults, from any area, how to build a robot from scratch, using electronics, mechanics and programming during three non-stop days.