Self-Compensated Driving Circuit for Reducing Drift and Hysteresis in Force Sensing Resistors

Paredes-Madrid, Leonel; Fonseca, Johanna; Matute, Arnaldo; Velásquez, Elkin I. Gutiérrez; Palácio, Carlos

doi:10.3390/electronics7080146

Cited by 17 publications

(16 citation statements)

References 35 publications

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“…For the purpose of the field test using the flexible pressure sensor, a completed electronic system using the sensor and a wireless DAQ was designed with the circuit diagram presented in Figure 9, where a NE555 based-oscillator [27,28] was utilized to convert the sensing capacitance to a pulse train and then digitized with a 10-bit-ADC (analog-to-digital converter). With the aim of constructing a DAQ with a small size and low-power, an IoT microprocessor of L106 32-bit RISC and IEEE 802.11 b/g/n integrated in the ESP8266 module were used.…”

Section: Resultsmentioning

confidence: 99%

A Low-Cost, Flexible Pressure Capacitor Sensor Using Polyurethane for Wireless Vehicle Detection

et al. 2019

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Detection of vehicles on the road can contribute to the establishment of an intelligent transportation management system to allow smooth transportation and the reduction of road accidents. Thus far, an efficient and low-cost polymer flexible pressure sensor for vehicle detection is lacking. This paper presents a flexible sensor for vehicle sensing and demonstrates a wireless system for monitoring vehicles on the road. A vehicle sensor was fabricated by sandwiching a polyurethane material between aluminum top/bottom electrodes. The sensing mechanism was based on changes in capacitance due to variation in the distance between the two electrodes at an applied external pressure. A clear response against a pressure load of 0.65 Mpa was observed, which is the same pressure as that of the car tire area in contact with the road. Significantly, the sensor was easy to embed on the road line due to its mechanical flexibility and large size. A field test was carried out by embedding the sensor on the road and crossing the sensor with a car. Moreover, the signal displayed on the tablet indicated that the sensing system can be used for wireless detection of the axle, speed, or weight of the vehicle on the road. The findings suggest that the flexible pressure sensor is a promising tool for use as a low-cost vehicle detector in future intelligent transportation management.

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Section: Resultsmentioning

confidence: 99%

A Low-Cost, Flexible Pressure Capacitor Sensor Using Polyurethane for Wireless Vehicle Detection

et al. 2019

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“…The first is the limited the operational range, given that setting a high gain for better resolution in the higher pressure range reduces the operating range of the system, which implies an increase in the complexity of the circuitry needed to measure different intervals. The second problem is hysteresis, which has been addressed in the literature [46]- [49]. These studies show that resistance to the frequency circuit reduces the effect of hysteresis.…”

Section: A Force-sensing Resistormentioning

confidence: 99%

Battery-Less NFC Bicycle Tire Pressure Sensor Based on a Force-Sensing Resistor

et al. 2021

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This paper describes a novel low-cost tire pressure monitoring system (TPMS) for bicycles. The system is based on a battery-less near field communication (NFC) tag that integrates a pressure sensor, which is placed between the tire and the inner tube. The system uses no battery since the energy is obtained from the magnetic field induced by the reader in order to establish the communication. The pressure can be read by any NFC-enabled reader such as a smartphone. The pressure sensor is a force-sensing resistor (FSR) that controls the oscillation frequency of a 555 timer-based oscillator. The frequency is read and computed by a microcontroller, and the result is written via I C bus to the memory of a near-field communication integrated circuit (IC), which is read by a commercial smartphone or NFC reader. A prototype is designed on an FR4 substrate which integrates a 12×16 mm antenna connected to the NFC IC (NT3H211 from NXP). The proposed prototype has a 3D-printed enclosure to protect the components mounted on the surface of the PCB and to protect the tire from puncture. A system for characterizing the read range is presented. The tag requires a minimum magnetic field of 2.9 A RM S /m to operate up to a distance of 8 mm between reader and the tire, providing enough power to supply energy to the whole circuitry and to receive the information stored at the NFC IC. The system has been tested with a 59 mm-width mountain bike tire. The sensor has been characterized using a simple polynomial fitting to obtain the pressure from the measurement of the oscillation frequency. An accuracy of 0.1 has been accomplished in the range of 0.5 to 2.2 bar. To test the system, several inflation cycles have been performed and showed that the system presents good repeatability.

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“…Dividing ( 16) by (15) gives the same equation as (6), from which can be obtained as in (7). Thus, the presence of has no impact on the determination of using the proposed scheme.…”

Section: A Input Offset Voltage Of Comparator and Threshold Voltagementioning

confidence: 99%

“…Resistive sensors are a popular choice to form touchpads [3], and tactile sensors [4]. Similarly, they are used to measure pressure [5], force [6], [7] and temperature [8]. Conventional resistive sensing methods require direct contact of the resistive element to the measurement circuit, thus limiting the reliability of the sensor and its versatility in the range of applications.…”

Section: Introductionmentioning

confidence: 99%

Analysis of a Direct Microcontroller Interface for Capacitively Coupled Resistive Sensors

Areekath

George

Reverter

2021

IEEE Trans. Instrum. Meas.

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A novel approach to directly interface a capacitivelycoupled resistive sensor to a microcontroller is presented in this paper. The existing measurement schemes for such sensors are complex. In addition, the coupling capacitance often also holds important data. The proposed simple measurement system, for such series RC sensors, is capable of measuring both the resistance and the coupling capacitance. A detailed analysis on the effect of the non-idealities on the resistance measurement showed that it is independent of the accuracy of the charging capacitor, supply voltage and preset threshold voltage. The performance of the proposed scheme has been evaluated by building suitable prototypes. Initially, a setup was designed such that the measurement was not limited by the non-idealities of the microcontroller. The test results from this showed a maximum error of 0.28% and 0.96% for the resistance and capacitance measurement, respectively. The subsequent study with the microcontroller interface exhibited a maximum error of 0.91% (resistance) and 2.94% (capacitance). Noise and resolution studies have also been conducted and the results presented. The accuracy of the prototype is promising, with a measurement time of 5 ms per parameter. This is a practical, low-power, low-cost measurement system as it provides digital data on the resistance and capacitance, in series, using only a microcontroller, and a couple of passive components.

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Self-Compensated Driving Circuit for Reducing Drift and Hysteresis in Force Sensing Resistors

Cited by 17 publications

References 35 publications

A Low-Cost, Flexible Pressure Capacitor Sensor Using Polyurethane for Wireless Vehicle Detection

A Low-Cost, Flexible Pressure Capacitor Sensor Using Polyurethane for Wireless Vehicle Detection

Battery-Less NFC Bicycle Tire Pressure Sensor Based on a Force-Sensing Resistor

Analysis of a Direct Microcontroller Interface for Capacitively Coupled Resistive Sensors

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