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Oscar Oballe-Peinado   Mr.  University Lecturer 
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Oscar Oballe-Peinado published an article in December 2017.
Top co-authors
Fernando Vidal-Verdú

55 shared publications

Department of Electronics, Institute of Biomedical Research of Málaga (IBIMA), University of Málaga, 29071 Málaga, Spain;(J.C.-R.);(F.V.-V.)

José A. Hidalgo-López

15 shared publications

Departamento de Electrónica, Andalucía Tech, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain

Rafael Navas-González

6 shared publications

Universidad de Málaga; Málaga Spain

Julián Castellanos-Ramos

2 shared publications

Department of Electronics, University of Málaga, Málaga 29071, Spain; s:(M.J.B.);(J.C.-R.);(R.N.-G.);(J.A.S.)

Publication Record
Distribution of Articles published per year 
(2009 - 2017)
Total number of journals
published in
Publications See all
Article 2 Reads 3 Citations FPGA-Based Tactile Sensor Suite Electronics for Real-Time Embedded Processing Óscar Oballe-Peinado, Jose Antonio Hidalgo-Lopez, Julian Cas... Published: 01 December 2017
IEEE Transactions on Industrial Electronics, doi: 10.1109/tie.2017.2714137
DOI See at publisher website
Article 0 Reads 2 Citations High-Accuracy Readout Electronics for Piezoresistive Tactile Sensors José A. Hidalgo-López, Óscar Oballe-Peinado, Julián Castella... Published: 01 November 2017
Sensors, doi: 10.3390/s17112513
DOI See at publisher website PubMed View at PubMed ABS Show/hide abstract
The typical layout in a piezoresistive tactile sensor arranges individual sensors to form an array with M rows and N columns. While this layout reduces the wiring involved, it does not allow the values of the sensor resistors to be measured individually due to the appearance of crosstalk caused by the nonidealities of the array reading circuits. In this paper, two reading methods that minimize errors resulting from this phenomenon are assessed by designing an electronic system for array reading, and the results are compared to those obtained using the traditional method, obviating the nonidealities of the reading circuit. The different models were compared by testing the system with an array of discrete resistors. The system was later connected to a tactile sensor with 8 × 7 taxels.
Article 4 Reads 3 Citations Accuracy and Resolution Analysis of a Direct Resistive Sensor Array to FPGA Interface Óscar Oballe-Peinado, Fernando Vidal-Verdú, José A. Sánchez-... Published: 01 February 2016
Sensors, doi: 10.3390/s16020181
DOI See at publisher website PubMed View at PubMed ABS Show/hide abstract
Resistive sensor arrays are formed by a large number of individual sensors which are distributed in different ways. This paper proposes a direct connection between an FPGA and a resistive array distributed in M rows and N columns, without the need of analog-to-digital converters to obtain resistance values in the sensor and where the conditioning circuit is reduced to the use of a capacitor in each of the columns of the matrix. The circuit allows parallel measurements of the N resistors which form each of the rows of the array, eliminating the resistive crosstalk which is typical of these circuits. This is achieved by an addressing technique which does not require external elements to the FPGA. Although the typical resistive crosstalk between resistors which are measured simultaneously is eliminated, other elements that have an impact on the measurement of discharge times appear in the proposed architecture and, therefore, affect the uncertainty in resistance value measurements; these elements need to be studied. Finally, the performance of different calibration techniques is assessed experimentally on a discrete resistor array, obtaining for a new model of calibration, a maximum relative error of 0.066% in a range of resistor values which correspond to a tactile sensor.
Article 0 Reads 5 Citations Improved Circuits with Capacitive Feedback for Readout Resistive Sensor Arrays Óscar Oballe-Peinado, Fernando Vidal-Verdú, José A. Sánchez-... Published: 25 January 2016
Sensors, doi: 10.3390/s16020149
DOI See at publisher website PubMed View at PubMed ABS Show/hide abstract
One of the most suitable ways of distributing a resistive sensor array for reading is an array with M rows and N columns. This allows reduced wiring and a certain degree of parallelism in the implementation, although it also introduces crosstalk effects. Several types of circuits can carry out the analogue-digital conversion of this type of sensors. This article focuses on the use of operational amplifiers with capacitive feedback and FPGAs for this task. Specifically, modifications of a previously reported circuit are proposed to reduce the errors due to the non-idealities of the amplifiers and the I/O drivers of the FPGA. Moreover, calibration algorithms are derived from the analysis of the proposed circuitry to reduce the crosstalk error and improve the accuracy. Finally, the performances of the proposals is evaluated experimentally on an array of resistors and for different ranges.
Article 0 Reads 7 Citations Smart Capture Modules for Direct Sensor-to-FPGA Interfaces Óscar Oballe-Peinado, Fernando Vidal-Verdú, José A. Sánchez-... Published: 16 December 2015
Sensors, doi: 10.3390/s151229878
DOI See at publisher website PubMed View at PubMed ABS Show/hide abstract
Direct sensor–digital device interfaces measure time dependent variables of simple circuits to implement analog-to-digital conversion. Field Programmable Gate Arrays (FPGAs) are devices whose hardware can be reconfigured to work in parallel. They usually do not have analog-to-digital converters, but have many general purpose I/O pins. Therefore, direct sensor-FPGA connection is a good choice in complex systems with many sensors because several capture modules can be implemented to perform parallel analog data acquisition. The possibility to work in parallel and with high frequency clock signals improves the bandwidth compared to sequential devices such as conventional microcontrollers. The price to pay is usually the resolution of measurements. This paper proposes capture modules implemented in an FPGA which are able to perform smart acquisition that filter noise and achieve high precision. A calibration technique is also proposed to improve accuracy. Resolutions of 12 effective number of bits are obtained for the reading of resistors in the range of an example piezoresistive tactile sensor.
Article 3 Reads 1 Citation A New Model Based on Adaptation of the External Loop to Compensate the Hysteresis of Tactile Sensors José A. Sánchez-Durán, Fernando Vidal-Verdú, Óscar Oballe-Pe... Published: 15 October 2015
Sensors, doi: 10.3390/s151026170
DOI See at publisher website PubMed View at PubMed ABS Show/hide abstract
This paper presents a novel method to compensate for hysteresis nonlinearities observed in the response of a tactile sensor. The External Loop Adaptation Method (ELAM) performs a piecewise linear mapping of the experimentally measured external curves of the hysteresis loop to obtain all possible internal cycles. The optimal division of the input interval where the curve is approximated is provided by the error minimization algorithm. This process is carried out off line and provides parameters to compute the split point in real time. A different linear transformation is then performed at the left and right of this point and a more precise fitting is achieved. The models obtained with the ELAM method are compared with those obtained from three other approaches. The results show that the ELAM method achieves a more accurate fitting. Moreover, the involved mathematical operations are simpler and therefore easier to implement in devices such as Field Programmable Gate Array (FPGAs) for real time applications. Furthermore, the method needs to identify fewer parameters and requires no previous selection process of operators or functions. Finally, the method can be applied to other sensors or actuators with complex hysteresis loop shapes.