Jorge Lino

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...

Additive manufacturing of polyethylene terephthalate glycol /carbon fiber composites: An experimental study from filament to printed parts

This research focuses on the definition and application of a characterization methodology to determine the characteristics of fused deposition modeling 3D printing materials. Commercial short fiber reinforced and unreinforced polyethylene terephthalate glycol parts were tested achieving comparison terms. The presented methodology is composed of three classes: thermal analysis, mechanical testing, and material morphology. Filament was tensile tested with specially developed setup for determining the mechanical properties of raw materials. Standardized flexural and tensile samples were printed 100% dense in both materials and tested. Differential scanning calorimetry results showed that the thermal properties of both materials do not change with successive heating cycles. Thermogravimetric analysis allowed to understand the thermal stability of materials and quantify the amount of fiber in the matrix. Tensile tests indicated that the addition of fibers increases the Young’s modulus by 70.10% but there is lesser withstanding of stress by 28.21%. Flexural tests exhibited an increase in flexural modulus of 191.38% and 5.14% in flexural strength for the reinforced polyethylene terephthalate glycol, due to the presence of fiber. Microscopic analysis revealed a 12% of void spots and fiber alignment accordingly to the deposition path.

Path planning towards non-compulsory multiple targets using TWIN-RRT*

Purpose The purpose of this paper is to characterise the TWIN-RRT* algorithm which solves a motion planning problem in which an agent has multiple possible targets where none of them is compulsory and retrieves feasible, “low cost”, asymptotically optimal and probabilistically complete paths. The TWIN-RRT* algorithm solves path planning problems for both holonomic and non-holonomic robots with or without kinematic constraints in a 2D environment. Design/methodology/approach It was designed to work equally well with higher degree of freedom agents in different applications. It provides a practical implementation of feasible and fast planning, namely where a closed loop is required. Initial and final configurations are allowed to be exactly the same. Findings The TWIN-RRT* algorithm computes an efficient path for a single agent towards multiple targets where none of them is mandatory. It inherits the low computational cost, probabilistic completeness and asymptotical optimality from RRT*. Research limitations/implications It uses efficiency as cost function, which can be adjusted to the requirements of any given application. TWIN-RRT also shows compliance with kinematic constraints. Practical implications The practical application where this work has been used consists of an autonomous mobile robot that picks up golf balls in a driving range. The multiple targets are the golf balls and the optimum path is a requirement to reduce the time and energy to refill as quickly as possible the balls dispensing machine. Originality/value The new random sampling algorithm – TWIN-RRT* – is able to generate feasible efficient paths towards multiple targets retrieving closed-loop paths starting and finishing at the same configuration.