An internally-controlled memristor-based amplitude shift keying modulator

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chiemeka Loveth Maxwell ◽  
Dongsheng Yu ◽  
Yang Leng
Keyword(s):  
Control Signal ◽  
Current Conveyors ◽  
Pass Filter ◽  
Content Type ◽  
Amplitude Shift Keying ◽  
Additional Control ◽  
Binary Signal ◽  
Shift Keying ◽  
Control Circuits ◽  
Memristor Emulator

Purpose The purpose of this paper is to design and construct an amplitude shift keying (ASK) modulator, which, using the digital binary modulating signal, controls a floating memristor emulator (MR) internally without the need for additional control circuits to achieve the ASK modulated wave. Design/methodology/approach A binary digital unipolar signal to be modulated is converted by a pre-processor circuit into a suitable bipolar modulating direct current (DC) signal for the control of the MR state, using current conveyors the carrier signal’s amplitude is varied with the change in the memristance of the floating MR. A high pass filter is then used to remove the DC control signal (modulating signal) leaving only the modulated carrier signal. Findings The results from the experiment and simulation are in agreement showed that the MR can be switched between two states and that a change in the carrier signals amplitude can be achieved by using an MR. Thus, showing that the circuit behavior is in line with the proposed theory and validating the said theory. Originality/value In this paper, the binary signal to be modulated is modified into a suitable control signal for the MR, thus the MR relies on the internal operation of the modulator circuit for the control of its memristance. An ASK modulation can then be achieved using a floating memristor without the need for additional circuits or signals to control its memristance.

Robust active disturbance attenuation control of an uncertain quadrotor

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nigar Ahmed ◽  
Ajeet kumar Bhatia ◽  
Syed Awais Ali Shah
Keyword(s):  
Control Algorithm ◽  
Sliding Mode ◽  
The State ◽  
Disturbance Attenuation ◽  
State Variables ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Content Type ◽  
Highly Nonlinear ◽  
The Stability

PurposeThe aim of this research is to design a robust active disturbance attenuation control (RADAC) technique combined with an extended high gain observer (EHGO) and low pass filter (LPF).Design/methodology/approachFor designing a RADAC technique, the sliding mode control (SMC) method is used. Since the standard method of SMC exhibits a chattering phenomenon in the controller, a multilayer sliding mode surface is designed for avoiding the chattering. In addition, to attenuate the unwanted uncertainties and disturbances (UUDs), the techniques of EHGO and LPF are deployed. Besides acting as a patch for disturbance attenuation, the EHGO design estimates the state variables. To investigate the stability and effectiveness of the designed control algorithm, the stability analysis followed by the simulation study is presented.FindingsThe major findings include the design of a chattering-free RADAC controller based on the multilayer sliding mode surface. Furthermore, a criterion of integrating the LPF scheme within the EHGO scheme is also developed to attenuate matched and mismatched UUDs.Practical implicationsIn practice, the quadrotor flight is opposed by different kinds of the UUDs. And, the model of the quadrotor is a highly nonlinear underactuated model. Thus, the dynamics of the quadrotor model become more complex and uncertain due to the additional UUDs. Hence, it is necessary to design a robust disturbance attenuation technique with the ability to estimate the state variables and attenuate the UUDs and also achieve the desired control objectives.Originality/valueDesigning control methods to attenuate the disturbances while assuming that the state variables are known is a common practice. However, investigating the uncertain plants with unknown states along with the disturbances is rarely taken in consideration for the control design. Hence, this paper presents a control algorithm to address the issues of the UUDs as well as investigate a criterion to reduce the chattering incurred in the controller due to the standard SMC algorithm.

Dynamic sliding mode position control of induction motors based load torque compensation using adaptive state observer

2018 ◽  
Vol 37 (6) ◽  
pp. 2249-2262
Author(s):  
Ali Karami-Mollaee ◽  
Hamed Tirandaz ◽  
Oscar Barambones
Keyword(s):  
Position Control ◽  
Sliding Mode ◽  
State Observer ◽  
Practical Implementation ◽  
Load Torque ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Content Type ◽  
Adaptive State Observer ◽  
Dynamic Sliding Mode

Purpose The purpose of this paper is position control scheme for a servo induction motor (SIM) with uncertainty has been designed using a new observer issue and a dynamic sliding mode control (DSMC). Design/methodology/approach In DSMC, the chattering is removed due to the integrator (or a low-pass filter) which is placed before the input control of the plant. However, in DSMC, the augmented system has one dimension bigger than the actual system (if integrator is used) and then, the plant model should be completely known. To solve this problem in SIM, the use of a new adaptive state observer (ASO) is proposed. Findings The advantage of the proposed approach is to maintain the system controlled under the external load torque variations. Then, the load variations do not affect the motor positioning. Moreover, it is demonstrated that the observer error converges to zero based on the Lyapunov stability theory. Originality/value The knowledge of the upper bound for the system uncertainty is not necessary in an adaptive state observer, which is important in practical implementation. Simulation results are presented to demonstrate the performance of the proposed approach.

Self-aided SINS for spiral-diving human-occupied vehicle in midwater

2021 ◽  
Vol 41 (1) ◽  
pp. 106-115
Author(s):  
Xianjun Liu ◽  
Xixiang Liu ◽  
Hang Shen ◽  
Peijuan Li ◽  
Tongwei Zhang
Keyword(s):  
Error Propagation ◽  
Inertial Measurement Unit ◽  
Design Methodology ◽  
Horizontal Velocity ◽  
Measurement Unit ◽  
Positioning Error ◽  
Pass Filter ◽  
Content Type ◽  
High Pass ◽  
Delay Correction

Purpose Motivated by the problems that the positioning error of strap-down inertial navigation system (SINS) accumulates over time and few sensors are available for midwater navigation, this paper aims to propose a self-aided SINS scheme for the spiral-diving human-occupied vehicle (HOV) based on the characteristics of maneuvering pattern and SINS error propagation. Design/methodology/approach First, the navigation equations of SINS are simultaneously executed twice with the same inertial measurement unit (IMU) data as input to obtain two sets of SINS. Then, to deal with the horizontal velocity provided by one SINS, a delay-correction high-pass filter without phase shift and amplitude attenuation is designed. Finally, the horizontal velocity after processing is used to integrate with other SINS. Findings Simulation results indicate that the horizontal positioning error of the proposed scheme is less than 0.1 m when an HOV executes spiral diving to 7,000 meters under the sea and it is inherently able to estimate significant sensors biases. Originality/value The proposed scheme can provide a precise navigation solution without error growth for spiral-diving HOV on the condition that only IMU is required as a navigation sensor.

A Novel Floating/Grounded Meminductor Emulator

2020 ◽  
Vol 29 (15) ◽  
pp. 2050247 ◽  
Author(s):  
Hasan Sozen ◽  
Ugur Cam
Keyword(s):  
Hysteresis Loop ◽  
Operational Amplifier ◽  
Current Conveyors ◽  
Current Feedback ◽  
Transconductance Amplifier ◽  
Additional Control ◽  
Pinched Hysteresis Loop ◽  
Terminal Element ◽  
Current Feedback Operational Amplifier ◽  
Pinched Hysteresis

Meminductor is a nonlinear two-terminal element with storage energy and memory ability. To date, meminductor element is not available commercially as memristor and memcapacitor are. Therefore, it is of great significance to implement a meminductor emulator for breadboard experiment. In this paper, a flux-controlled floating/grounded meminductor emulator without a memristor is presented. It is built with commercially available off-the-shelf electronic devices. It consists of single operational transconductance amplifier (OTA), single multiplier, two second-generation current conveyors (CCIIs), single current-feedback operational amplifier (CFOA) and single operational amplifier. Using OTA device introduces an additional control parameter besides frequency and amplitude values of applied voltage to control the area of pinched hysteresis loop of meminductor. Mathematical model of proposed emulator circuit is given to describe the behavior of meminductor circuit. The breadboard experiment is performed using CA3080, AD844, AD633J and LM741 for OTA, CCII–CFOA, multiplier and operational amplifier, respectively. Simulation and experimental test results are given to verify the theoretical analyses. Frequency-dependent pinched hysteresis loop is maintained up to 5 kHz. The presented meminductor emulator tends to work as ordinary inductor for higher frequencies.

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