Tactile sensors are basically arrays of force that intended to emulate the skin in applications such as assistive robotics. Local electronics usually implemented reduce errors and interference caused by long wires. Realizations based on standard microcontrollers, Programmable Systems Chip (PSoCs) Field Gate Arrays (FPGAs) have been proposed authors for case piezoresistive tactile sensors. The solution employing FPGAs is especially relevant since their performance closer Application Specific...

Dexterity in robotic hands is not enough to cover the demands for more flexibility manufacturing process. Specifically, processes that involve cooperation or learning from humans, slippage detection and tactile feedback improve grasp stability when different objects are manipulated, object exploration classification, quality inspection, welding, etc. The sense of touch key capabilities human hands, so sensors must be incorporated into them. However, sensing technology yet mature an effective...

The typical layout in a piezoresistive tactile sensor arranges individual sensors to form an array with M rows and N columns. While this reduces the wiring involved, it does not allow values of resistors be measured individually due appearance crosstalk caused by nonidealities reading circuits. In paper, two methods that minimize errors resulting from phenomenon are assessed designing electronic system for reading, results compared those obtained using traditional method, obviating circuit....

Resistive sensor arrays are formed by a large number of individual sensors which distributed in different ways. This paper proposes direct connection between an FPGA and resistive array M rows N columns, without the need analog-to-digital converters to obtain resistance values where conditioning circuit is reduced use capacitor each columns matrix. The allows parallel measurements resistors form array, eliminating crosstalk typical these circuits. achieved addressing technique does not...

One of the most suitable ways distributing a resistive sensor array for reading is an with M rows and N columns. This allows reduced wiring certain degree parallelism in implementation, although it also introduces crosstalk effects. Several types circuits can carry out analogue-digital conversion this type sensors. article focuses on use operational amplifiers capacitive feedback FPGAs task. Specifically, modifications previously reported circuit are proposed to reduce errors due...

Tactile sensing is a serious issue in assistive robotics or prosthetics. It requires the hands and body of robot are equipped with many tactile arrays, large amount data has to be acquired transmitted central decision unit. Moreover, this done very short time improve dexterity performance service tasks Therefore, local electronics smart patch must powerful enough acquire pre-process real cope limited throughput communication buses. This paper presents an architecture based on FPGAs that...

Completely eliminating crosstalk effect is the most important challenge when reading a resistive sensor array with M rows and N columns. It may require complex electronics, ranging from large number of multiplexers switches to use AC voltage sources. More measurements than those considered strictly necessary, · N, also be required. Thus, an implementation uses 2 measurements, while this rises L in one that sources, where Fourier Transform length required obtain readings. This article...

Tactile sensors have been incorporated into robots to help in many tasks, such as preventing damage humans collaborative works or assistance dexterous manipulation. Proximity are also common robotics and proposed implement pretouch multimodal realizations. Many tactile based on off-the-shelf force-sensing resistors (FSRs). The parasitic capacitance associated with the electrodes of FSR can be exploited measure proximity. Moreover, it is possible both force proximity signal acquisition a...

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 work in parallel. They usually do not have converters, but many general purpose I/O pins. Therefore, direct sensor-FPGA connection is a good choice complex systems with sensors because several capture modules implemented perform parallel analog data acquisition. The...

This work presents examples of practice sessions to teach and learn digital electronics using an FPGA-based development platform, accessible either through the on-campus laboratory or online a remote developed by authors. The main tasks proposed in are design specific modules that will be included as block more complex projects. Each project is adapted ready once student implemented, debugged, and/or tested platform added aforementioned accessibility methods. proposal suggests use web-based...

Tactile sensors suffer from many types of interference and errors like crosstalk, non-linearity, drift or hysteresis, therefore calibration should be carried out to compensate for these deviations. However, this procedure is difficult in mounted on artificial hands robots prosthetics instance, where the sensor usually bends cover a curved surface. Moreover, repeated often because correction parameters are easily altered by time surrounding conditions. Furthermore, intensive complex could...

Developing and implementing a remote lab based on FPGA can improve the teaching of Digital Electronics, giving students web application to remotely test designs proposed in practical sessions real hardware. A server connected development system configures programmable digital device with allows user interact input output peripherals. The manage connections their time use order avoid congestion resources, also usage statistics be drafted.

Direct interface circuits (DICs) avoid the need for signal conditioning and analog-to-digital converters (ADCs) to obtain digital measurements of resistive sensors using only a few passive elements. However, such simple hardware can lead quantization errors when measuring small resistance values as well high measurement times uncertainties resistances. Different solutions some these problems have been presented in literature over recent years, although increased uncertainty at higher is...

A simple method to measure the resistance of a sensor and convert it into digital information in programmable device is by using direct interface circuit. This type circuit deduces value resistor based on discharge time through for capacitor known value. Moreover, times this should be measured one or two resistors with values order ensure that estimate not dependent certain parameters change time, temperature, aging. can slow down conversion speed, especially high values. To overcome...

Traditional calibration methods for measuring resistance values using a direct interface circuit, comprising capacitor and some resistors, offer straightforward, economical option. However, such show greater inaccuracies as decrease. This article presents modification of the method that ensures more accurate measurements extends range can be measured. Unlike linear equation used in traditional method, proposed obtains power functions related to value measured discharge time. Since these...

Reading resistive sensors and converting their information to digital values is a matter of great interest in practical applications. Direct Interface Circuits (DICs) perform this task efficiently through resistance-to-time-to-digital conversion. The main benefit type circuit the simplicity its design accuracy results. However, one drawbacks that quantization errors measurements seriously compromise if not converted using high-frequency clock or with high capacitor values. To avoid...

A novel approach to interface resistive sensors directly a Field Programmable Gate Array (FPGA) is presented in this paper. The circuit based on Direct Interface Circuits (DICs), which make the sensor reading through magnitude-to-time-to-digital conversion using just few passive elements and programmable digital device. Specifically, system uses two calibration resistors of known value, capacitors, new equation estimate resistance order obtain an improved estimation both high low parts...

This paper presents a novel method to compensate for hysteresis nonlinearities observed in the response of tactile sensor. The External Loop Adaptation Method (ELAM) performs piecewise linear mapping experimentally measured external curves loop obtain all possible internal cycles. optimal division input interval where curve is approximated provided by error minimization algorithm. process carried out off line and provides parameters compute split point real time. A different transformation...

Direct interface circuits are a simple, inexpensive alternative for the digital conversion of sensor reading, and in some these only passive calibration elements required order to carry out this conversion. In case resistive sensors, most accurate methods calibration, namely two-point method (TPCM) fast I II (FCMs II), require two resistors estimate value sensor. However, although FCMs considerably reduce time necessary sensor, may still be excessive certain applications, such as when making...

A feature extraction algorithm for texture detection oriented to its implementation on embedded electronics based a Field-Programmable Gate Array (FPGA) is proposed in this paper. Local pre-processing with smart tactile sensors can help improve dexterity artificial hands. Simplicity the goal order achieve hardware-friendly strategy that be replicated and integrated another circuitry. This interesting, considering are arrays FPGAs capable of parallel execution. The proposal was tested custom...

Many artificial skins for robotics are based on piezoresistive films that cover an array of electrodes. Local preprocessing is a must in these systems to reduce errors and interferences cope with the large amount data provided by sensor. This paper presents circuitry FPGA implement interface skin. The approach consists direct connection. analog digital conversion procedure simple. It measuring discharging time capacitor through resistance we want read. first proposed needs isolated tactels,...

Tactile sensors are applied to different areas like robotics, medicine or virtual reality. Many of these based on piezoresistive films that cover an array electrodes. This approach is simple and cheap seems be able fit the requirements applications manipulation with robotic hands grippers. Local preprocessing a must in systems reduce errors interferences cope large amount data from sensor. paper presents circuitry FPGA implement interface tactile The consists direct connection can save area...

Tactile sensors are a sort of artificial skin. Therefore, they should be able to detect static pressure patterns but also dynamic events such as those involved in slippage detection or texture recognition. A suitable shaping the cover sensor can improve response this stimulus. This paper addresses goal for raw piezo-resistive with structured made 3D printer, and laser-isolated tactels reduce crosstalk effects. Simulations experimental results show design aspects performance so obtained sensor.

Direct Interface Circuits (DICs) carry out resistive sensor readings using a resistance-to-time-to-digital conversion without the need for analog-to-digital converters. The main advantage of this approach is simplicity involved in designing DIC, which only requires some additional resistors and capacitor order to perform conversion. drawback time needed conversion, given by sum up three charge times their associated discharge times. This article presents modification most widely used...