Dani Martinez

Dr. Dani Martinez


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 June 2014 in Sensors
Verified
Journal Article
Open access
PDF file
DCDavinia Font Calafell
Davinia Font Calafell
TCTomàs Pallejà Cabré
Tomàs Pallejà Cabré
MTMarcel Tresanchez
Marcel Tresanchez
DRDavid Runcan
David Runcan
JMJavier Moreno
Javier Moreno
Jordi PalacinJordi Palacin
Jordi Palacin
This paper proposes the development of an automatic fruit harvesting system by combining a low cost stereovision camera and a robotic arm placed in the gripper tool. The stereovision camera is used to estimate the size, distance and position of the fruits whereas the robotic arm is used to mechanically pickup the fruits. The low cost stereovision system has been tested in laboratory conditions with a reference small object, an apple and a pear at 10 different intermediate distances from the camera. The average distance error was from 4% to 5%, and the average diameter error was up to 30% in the case of a small object and in a range from 2% to 6% in the case of a pear and an apple. The stereovision system has been attached to the gripper tool in order to obtain relative distance, orientation and size of the fruit. The harvesting stage requires the initial fruit location, the computation of the inverse kinematics of the robotic arm in order to place the gripper tool in front of the fruit, and a final pickup approach by iteratively adjusting the vertical and horizontal position of the gripper tool in a closed visual loop. The complete system has been tested in controlled laboratory conditions with uniform illumination applied to the fruits. As a future work, this system will be tested and improved in conventional outdoor farming conditions.

9 April 2015 in Sensors
Verified
Journal Article
Open access
PDF file
DCDavinia Font Calafell
Davinia Font Calafell
MTMarcel Tresanchez
Marcel Tresanchez
DMDani Martinez
Dani Martinez
JMJavier Moreno
Javier Moreno
ECEduard Clotet
Eduard Clotet
Jordi PalacinJordi Palacin
Jordi Palacin
This paper presents a method for vineyard yield estimation based on the analysis of high-resolution images obtained with artificial illumination at night. First, this paper assesses different pixel-based segmentation methods in order to detect reddish grapes: threshold based, Mahalanobis distance, Bayesian classifier, linear color model segmentation and histogram segmentation, in order to obtain the best estimation of the area of the clusters of grapes in this illumination conditions. The color spaces tested were the original RGB and the Hue-Saturation-Value (HSV). The best segmentation method in the case of a non-occluded reddish table-grape variety was the threshold segmentation applied to the H layer, with an estimation error in the area of 13.55%, improved up to 10.01% by morphological filtering. Secondly, after segmentation, two procedures for yield estimation based on a previous calibration procedure have been proposed: (1) the number of pixels corresponding to a cluster of grapes is computed and converted directly into a yield estimate; and (2) the area of a cluster of grapes is converted into a volume by means of a solid of revolution, and this volume is converted into a yield estimate; the yield errors obtained were 16% and −17%, respectively.

10 October 2016 in Sensors
Verified
Journal Article
Open access
PDF file
JMJavier Moreno
Javier Moreno
ECEduard Clotet
Eduard Clotet
RLRuben Lupiañez
Ruben Lupiañez
MTMarcel Tresanchez
Marcel Tresanchez
DMDani Martinez
Dani Martinez
Jordi PalacinJordi Palacin
Jordi Palacin
This paper presents the design, implementation and validation of the three-wheel holonomic motion system of a mobile robot designed to operate in homes. The holonomic motion system is described in terms of mechanical design and electronic control. The paper analyzes the kinematics of the motion system and validates the estimation of the trajectory comparing the displacement estimated with the internal odometry of the motors and the displacement estimated with a SLAM procedure based on LIDAR information. Results obtained in different experiments have shown a difference on less than 30 mm between the position estimated with the SLAM and odometry, and a difference in the angular orientation of the mobile robot lower than 5° in absolute displacements up to 1000 mm.

28 April 2016 in Sensors
Verified
Journal Article
Open access
PDF file
ECEduard Clotet
Eduard Clotet
DMDani Martinez
Dani Martinez
JMJavier Moreno
Javier Moreno
MTMarcel Tresanchez
Marcel Tresanchez
Jordi PalacinJordi Palacin
Jordi Palacin
This paper presents the technical description, mechanical design, electronic components, software implementation and possible applications of a tele-operated mobile robot designed as an assisted living tool. This robotic concept has been named Assistant Personal Robot (or APR for short) and has been designed as a remotely telecontrolled robotic platform built to provide social and assistive services to elderly people and those with impaired mobility. The APR features a fast high-mobility motion system adapted for tele-operation in plain indoor areas, which incorporates a high-priority collision avoidance procedure. This paper presents the mechanical architecture, electrical fundaments and software implementation required in order to develop the main functionalities of an assistive robot. The APR uses a tablet in order to implement the basic peer-to-peer videoconference and tele-operation control combined with a tactile graphic user interface. The paper also presents the development of some applications proposed in the framework of an assisted living robot.

10 April 2019 in Robotics
Verified
Journal Article
Open access
PDF file
Jordi PalacinJordi Palacin
Jordi Palacin
ECEduard Clotet
Eduard Clotet
DMDani Martinez
Dani Martinez
DPDavid Martínez Piqué
David Martínez Piqué
JMJavier Moreno
Javier Moreno
This paper presents the application of a mobile robot designed as an Assistant Personal Robot (APR) as a walk-helper tool. The hypothesis is that the height and weight of this mobile robot can be used also to provide a dynamic physical support and guidance to people while they walk. This functionality is presented as a soft walking aid at home but not as a substitute of an assistive cane or a walker device, which may withstand higher weights and provide better stability during a walking. The APR operates as a walk-helper tool by providing user interaction using the original arms of the mobile robot and by using the onboard sensors of the mobile robot in order to avoid obstacles and guide the walking through free areas. The results of the experiments conducted with the walk-helper have showed the automatic generation of smooth walking trajectories and a reduction in the number of manual trajectory corrections required to complete a walking displacement.

27 March 2014 in Sensors
Verified
Journal Article
Open access
PDF file
DMDani Martinez
Dani Martinez
MTMercè Teixidó
Mercè Teixidó
DCDavinia Font Calafell
Davinia Font Calafell
JMJavier Moreno
Javier Moreno
MTMarcel Tresanchez
Marcel Tresanchez
Jordi PalacinJordi Palacin
Jordi Palacin
This paper proposes the use of an autonomous assistant mobile robot in order to monitor the environmental conditions of a large indoor area and develop an ambient intelligence application. The mobile robot uses single high performance embedded sensors in order to collect and geo-reference environmental information such as ambient temperature, air velocity and orientation and gas concentration. The data collected with the assistant mobile robot is analyzed in order to detect unusual measurements or discrepancies and develop focused corrective ambient actions. This paper shows an example of the measurements performed in a research facility which have enabled the detection and location of an uncomfortable temperature profile inside an office of the research facility. The ambient intelligent application has been developed by performing some localized ambient measurements that have been analyzed in order to propose some ambient actuations to correct the uncomfortable temperature profile.