This manuscript presents an implementation of the configurable indirect current-feedback instrumentation amplifier (CFIA) for sensor interface readout circuit. Configuration is achieved by designing digital weighted scalable arrays for some selected elements to serve as tuning knobs controlled by the evolutionary optimization algorithm. This scheme resulting in a programmable circuit for different aspects to support self-x functionality. The robustness and flexibility of the proposed circuit fit to the demands of measurement and sensory systems in industry 4.0 and other intelligent systems applications. The circuit is designed by Cadence tools using ams 0.35 μm CMOS technology.

Abstract. This paper aims to improve the traditional calibration method for reconfigurable self-X (self-calibration, self-healing, self-optimize, etc.) sensor interface readout circuit for industry 4.0. A cost-effective test stimulus is applied to the device under test, and the transient response of the system is analyzed to correlate the circuit's characteristics parameters. Due to complexity in the search and objective space of the smart sensory electronics, a novel experience replay particle swarm optimization (ERPSO) algorithm is being proposed and proved a better-searching capability than some currently well-known PSO algorithms. The newly proposed ERPSO expanded the selection producer of the classical PSO by introducing an experience replay buffer (ERB) intending to reduce the probability of trapping into the local minima. The ERB reflects the archive of previously visited global best particles, while its selection is based upon an adaptive epsilon greedy method in the velocity updating model. The performance of the proposed ERPSO algorithm is verified by using eight different popular benchmarking functions. Furthermore, an extrinsic evaluation of the ERPSO algorithm is also examined on a reconfigurable wide swing indirect current-feedback instrumentation amplifier (CFIA). For the later test, we proposed an efficient optimization procedure by using total harmonic distortion analyses of CFIA output to reduce the total number of measurements and save considerable optimization time and cost. The proposed optimization methodology is roughly 3 times faster than the classical optimization process. The circuit is implemented by using Cadence design tools and CMOS 0.35 µm technology from Austria Microsystems (AMS). The efficiency and robustness are the key features of the proposed methodology toward implementing reliable sensory electronic systems for industry 4.0 applications.

This paper aims to propose a new technique to extend the performance of the reconfigurable self-x sensory system for industry 4.0 to efficiently obtain robust solution even in the presence of uncertainty both in the input and output stage. Variance measure is employed to handle the uncertainty in the input stage or search space. As far as measurement or objective space, uncertainty is concerned archive-based method applied, and it does not demand any additional computational resources. The traditional evolutionary algorithm, i.e., particle swarm optimizer (PSO), has been modified by expanding its selection process with the proposed solutions. The performance of the extended algorithm is undertaken to study on three benchmarking functions in the presence of uncertainties. The extrinsic evaluation of the proposed algorithm is also performed on the Miller operational amplifier, which is a fundamental part of sensory systems for industry 4.0. Drift due to fabrication process tolerances and aging effects of the transistors is modeled as input uncertainty of the operational amplifier, and imperfect observer (sensor or analog to digital converter) is modeled as output uncertainty. The application confirms the worthiness of proposed uncertainty handling algorithm for industry 4.0.

The conventional method for testing the performance of reconfigurable sensory electronics of industry 4.0 relies on the direct measurement methods. This approach gives higher accuracy but at the price of extremely high testing cost and does not utilize the new degrees of freedom for measurement methods enabled by industry 4.0. In order to reduce the test cost and use available resources more efficiently, a primary approach, called indirect measurements or alternative testing has been proposed using a non-intrusive sensor. Its basic principle consists in using the indirect measurements, in order to estimate the sensory electronics performance parameters without measuring directly. The non-intrusive property of the proposed method offers better performance of the sensing electronics and virtually applicable to any sensing electronics. Efficiency is evaluated in terms of model accuracy by using six different classical metrics. It uses an indirect current-feedback instrumentation amplifier (InAmp) as a test vehicle to evaluate the performance parameters of the circuit. The device is implemented using CMOS 0.35 μm technology. The achieved maximum value of average expected error metrics is 0.24, and the lowest value of correlation performance metrics is 0.91, which represent an excellent efficiency of InAmp performance predictor.