Implementation of a Feedback I2-Controlled Constant Temperature Environment Temperature Meter

Abstract

Abstract:A feedback thermo-resistive sensor-based measurement scheme was proposed to estimate physical quantities like solar radiation (H), fluid velocity (U) and environment temperature (T a ). It was implemented as an environment temperature meter, using PI controller. Controller implementation was done digitally using FPGA. Practical results are presented.

Sensors Characterization and Control of Measurement Systems Based on Thermoresistive Sensors via Feedback Linearization

“…However, in the non-linearized system overshoot occurs for all temperature steps, as well as for the designed operation point. Similar behaviour is observed in (Palma et al, 2003). Considering the linearized system, by adjusting the system response curves using the least squares method, for each temperature step (Fig.…”

“…Then, the value of the measurand is obtained from the variation of the control signal. This method inherits the advantages of feedback control systems such as low sensitivity to changes in the system parameters (Palma et al, 2003).…”

Sigma-Delta Modulator with Thermoresistive Sensor Frequency Response

“…The analog output may be treated with analog filter, which demands complex circuitry. Even in the architectures that produce digital output, they need to use ADC at Nyquist rate sampling to convert reference value [2]- [3]. In this case the resolution depends on ADC at Nyquist rate sampling bit number, which also demands complex circuitry when we think about microsensors.…”

CMOS sigma-delta thermal modulator

“…For the controlled system, a variation of one of the input quantities (ambient temperature, thermal radiation or fluid velocity) corresponds to a variation, of equal value and opposite signal, of the electric power dissipated by the sensor. Hence, it is possible to estimate the value of the variation of the input quantity from equations (1), (2) and (3), by measuring the value of the electric power variation [2][3][4][5][6][7]. This method is called electric equivalence principle.…”