Accuracy and Resolution Analysis of a Direct Resistive Sensor Array to FPGA Interface.

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...

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Detalles Bibliográficos
Autores: Oballe-Peinado, Óscar, Vidal-Verdú, Fernando, Sánchez-Durán, José A, Castellanos-Ramos, Julián, Hidalgo-López, José A
Tipo de recurso: artículo
Fecha de publicación:2016
País:España
Institución:Instituto de Salud Carlos III (ISCIII)
Repositorio:Repisalud
Idioma:inglés
OAI Identifier:oai:repisalud.isciii.es:20.500.12105/17126
Acceso en línea:http://hdl.handle.net/20.500.12105/17126
Access Level:acceso abierto
Palabra clave:FPGAs
direct sensor-to-digital device interface
parallel analogue data acquisition
resistive sensor arrays
Descripción
Sumario: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.