Multichannel Control Research Articles

Wireless programmable patterns of electro-hydraulic haptic electronic skins able to create surface morphology

Haptic feedback technology represents a frontier with revolutionary potential, particularly in virtual and augmented reality. Skin, as an underexplored sensory interface, holds tremendous potential to significantly enrich our perceptual experiences while directly impacting the fields of communication, entertainment, and medicine. This article presents a programmable, ultra-lightweight, and ultra-thin wireless wearable haptic electronic skin that achieves rapid response and large mechanical feedback force and deformation displacement output. The electronic skin comprises a series of haptic electro-hydraulic actuators, each with the weight of 0.023 g and the thickness of 199 μm. Each actuator can be independently regulated and produce a maximum normal force of 150 mN and a normal displacement of 0.58 mm, simultaneously achieving the haptic presentation of textures. Relying on a portable multi-channel control circuit system designed, each electro-hydraulic actuator of the haptic electronic skin can be precisely control to achieve various haptic patterns. Showcasing its potentials, the haptic technology aids visual-impaired individuals in reading books, provides ground navigation instructions, and enhances gaming experiences, contributing to a more immersive and authentic artificial intelligence environment.

Microscale Flow Control and Droplet Generation Using Arduino-Based Pneumatically-Controlled Microfluidic Device.

Microfluidics are crucial for managing small-volume analytical solutions for various applications, such as disease diagnostics, drug efficacy testing, chemical analysis, and water quality monitoring. The precise control of flow control devices can generate diverse flow patterns using pneumatic control with solenoid valves and a microcontroller. This system enables the active modulation of the pneumatic pressure through Arduino programming of the solenoid valves connected to the pressure source. Additionally, the incorporation of solenoid valve sets allows for multichannel control, enabling simultaneous creation and manipulation of various microflows at a low cost. The proposed microfluidic flow controller facilitates accurate flow regulation, especially through periodic flow modulation beneficial for droplet generation and continuous production of microdroplets of different sizes. Overall, we expect the proposed microfluidic flow controller to drive innovative advancements in technology and medicine owing to its engineering precision and versatility.

A low-complexity parallel local remote microphone technology for multichannel narrowband active noise control systems

Narrowband active noise control (NANC) systems can effectively eliminate periodic disturbances at its error sensors, but sometimes the error sensors are inconvenient to be placed at target locations for a long period. Remote microphone technology (RMT) can tackle this problem by moving quiet zones to the target areas. Nevertheless, the RMT-NANC system has significantly higher computational complexity than conventional NANC systems, particularly for multichannel systems. This hinders their implementation in real-time systems with limited computational resources. The additional computational burden stems from multiple convolutions involving the estimated global high-order secondary paths and observation filters when estimating the virtual error signals. To address this problem, a low-complexity parallel local RMT is proposed based on the narrowband filtered-x least mean square (PLRMT-NFxLMS) algorithm in this paper. Using a two-step local modeling approach, multiple local modeling low-order filters for both secondary paths and observation filters are constructed during the training stage. In the subsequent control stage, virtual error signals are estimated in parallel for different frequency components using these filters instead of global modeling filters, thereby alleviating the substantial computational cost arising from convolutions between lengthy vectors. Moreover, a filtered-error structure, termed the PLRMT-NFeLMS algorithm, is introduced in the proposed algorithm to further reduce the computational complexity. A comprehensive analysis of computational complexity is provided to demonstrate the superiority of the two proposed algorithms. Extensive simulations and real-time experiments were conducted to validate the feasibility and practicability of these proposed methods.

An online decoupling-whitening frequency domain filtered-error least mean square algorithm for active road noise control.

Active road noise control (ARNC) systems have been widely investigated for low-frequency road noise attenuation in vehicle cabins. Multiple reference and error sensors are usually required to ensure noticeable noise reduction. However, this tends to slow down the convergence speed of adaptive algorithms due to the coupling of secondary paths and the cross correlation of reference signals. Furthermore, the high computational burden of normally utilized multichannel control algorithms exacerbates the difficulty of practical implementations. In this paper, an online decoupling-whitening frequency domain filtered-error least mean square (ODW-FDFeLMS) algorithm is proposed to address the aforementioned problems. Secondary path decoupling through inner-outer product decomposition and online reference whitening through spectral factorization effectively accelerate the convergence rate. Additionally, the utilization of the filtered-error algorithm based on frequency domain processing mitigates the computational complexity. Simulations with measured road noise data confirm the superiority of the ODW-FDFeLMS algorithm over existing algorithms in terms of convergence speed and computational complexity. Real-time experiments in a vehicle cabin further confirm the effectiveness of the proposed algorithm.

Design of a Multi-Channel PID Temperature Control System Based on PLC and Internet of Things (IOT)

Design of a Multi-Channel PID Temperature Control System Based on PLC and Internet of Things (IOT)

Multichannel direct communication based on a programmable topological plasmonic metasurface

With the gradual improvement of the future wireless communication technology, the demand for high information capacity and reliable links in communication systems is also ever-increasing. Programmable topological plasmonic metasurfaces, consisting of artificially engineered structures with robust propagation pathways control, have emerged as a revolutionary technology for stable microwave and on-chip communication systems. Programmable topological plasmonic metasurfaces offer unprecedented flexibility and adaptability in managing multiple communication channels as the propagation paths can be easily reconfigured to meet specific communication requirements. Here, we have experimentally demonstrated the ability to dynamically manipulate electromagnetic waves along eight distinct topological pathways for a multichannel direct communication system. The simulation results of topological plasmonic metasurfaces with different coding schemes have showcased their excellent performance in multichannel wavefront control. Experimental results have consistently aligned with the simulation findings, validating the effectiveness of multichannel topological routes. Furthermore, an eight-channel direct communication system based on a programmable topological plasmonic metasurface is designed and implemented to transmit different information. The proposed multichannel communication system based on a programmable topological plasmonic metasurface opens up new possibilities for high-capacity, efficient, and adaptive communication systems, which hold great potential in transformative applications in areas such as 6G, Internet of Things, and beyond.

Space, Sound, and Acousmatic Music. The Heart of the Research

The acoustic and musical relationship with architectural space has a long history: ancient Greeks, the Romanesque Middle Ages, and the Renaissance, for example, utilized it in various ways. Electroacoustic composition on a support (acousmatic music), with its deliberate choice of “nothing to see,” and the acousmonium as an instrument for spatialized performance, serves as a laboratory for researching space as a musical element both during composition and as the principal agent of performance. Four categories of space emerge from this particular practice of interpreting and understanding the acousmatic repertoire: ambiophonic space immerses the listener in a sonic ‘bath’, source space localizes sounds, and geometric space structures a work in planes and volumes. These three categories most often pertain to multiphonic pieces. The fourth, illusion space, is consciously or unconsciously addressed in works in a stereophonic format, which create the illusion of depth of field through two loudspeakers. A few examples, diagrams, and explanations demonstrate how various spatialization systems are designed, particularly the acousmonium as designed by François Bayle in 1974. The performance of an acousmatic work tends to connect various spatial figures that reinforce the composition’s writing, highlight existing figures, or create new ones. Stereophonic works offer the performer greater freedom of choice. Sixteen figures are listed, along with their musical function. Depending on the character of each piece, a different spatial approach can emphasize one aspect of the composition over another: icons, movement, unmixing of polyphony, phrasing and variations, subjectivity, and matter. Thus, we can observe the significant role of the ‘spatializer’ and the necessity of their active presence in concerts. We witness the emergence of a new musical profession with numerous other applications. The spatial writing of multiphonic works also employs these figures in the studio. Some software is dedicated to this function, but multichannel control is essential in the studio. Lastly, figuralism, by playing with spatial figures, appears to be a key approach to giving meaning to and justifying space as an element that enhances the expressiveness of musical works. Annette Vande Gorne’s opera Yawar Fiesta is an exploration of this topic. The spatial projection of music for acousmatic listening – sound in space – opens up the future space to a fifth dimension of expressive music: the Space of Sound.

A blockchain-based privacy protecting framework with multi-channel access control model for asset trading

A blockchain-based privacy protecting framework with multi-channel access control model for asset trading

Driver circuit design based on NI-6363 data acquisition card for the magnetic fluid deformable mirror

Abstract Commonly used methods for generating diffraction-free beams are prone to signal loss or coding errors. Therefore, a method of generating a diffraction-free beam based on a magnetic fluid deformation mirror (MFDM) with dual-layer actuators is proposed. It can produce the desired wavefront in real-time and has the advantages of a large magnitude of mirror deformation, low manufacturing cost, continuous and smooth surface, and easy expansion of the actuator. In this paper, a driver circuit is designed based on Simulink and NI-6363 data acquisition card for the MFDM with its multi-channel control ability. The experiment result shows that the driver circuit can accurately produce the signal for each channel, and has the advantages of stable output, simple operation, and strong expandability.

Multi-channel decentralized decoupling FxLMS algorithm and active vibration control experiment

When vibrations generated by marine machinery propagate through a ship’s hull into the ocean, they produce low-frequency radiated noise with distinct “acoustic fingerprint” characteristics. This noise, characterized by stable and concentrated energy, long transmission distances, and difficulty in elimination, becomes the primary target for enemy sonar detection. Active vibration isolation serves as a critical method for reducing low-frequency vibrations in ships and enhancing their acoustic stealth performance. However, control challenges persist, including multi-frequency excitation, frequency fluctuation, multi-channel coupling, and slow convergence speed. To address these issues, this paper introduced an innovative multi-channel decentralized decoupling filtered-x least mean square (DMFxLMS) algorithm. Firstly, a recursive least squares identification algorithm with a forgetting factor was proposed, taking into account the characteristics of single-input, multi-output and multi-input, and multi-output control systems, effectively enhancing the algorithm’s convergence speed and control accuracy. Secondly, based on the decentralized decoupling control concept, the multi-channel control system was simplified into parallel single-channel control loops. The control weight coefficient updates were only related to adjacent error signals, significantly reducing the algorithm’s computational complexity. Thirdly, an anti-impact link was designed to improve the algorithm’s robustness, considering the interference caused by other mechanical equipment during the control process. The influence of abnormal error signals in the control weight coefficient correction term was suppressed, and a percentage function was introduced to limit the output signal. Finally, the feasibility and effectiveness of the DMFxLMS algorithm were verified through simulations and experiments. The results demonstrated that the DMFxLMS algorithm achieved significant control effects for both constant frequency line spectrum excitation and frequency fluctuating line spectrum excitation, fulfilling the objective of reducing base vibration. The DMFxLMS algorithm exhibited fast convergence and excellent robustness, making it suitable for practical engineering applications.

Enhanced selective delayless subband algorithm independent of primary disturbance configuration for multi-channel active noise control system in vehicles

The selective delayless subband structure stands out as a promising algorithmic choice for the multi-channel active control of vehicle interior noise, particularly in the context of road noise. This type of algorithm reduces the eigenvalue spread of the autocorrelation matrix of the signal by decomposing the signal into subbands, and the desired subbands are activated selectively, thus achieving a significant performance improvement while consuming less computational resources compared with the traditional fullband algorithms. Nevertheless, the effectiveness of the subband algorithm appears to be closely tied to the configuration of the primary disturbance signal. In cases where the primary disturbance signal encompasses both broadband and tonal components, the performance advantage of the subband algorithm becomes constrained. In this paper, we conduct a thorough comparative analysis of two extensively employed subband algorithms, namely the Morgan and the Milani methods, through simulations employing data obtained from a multi-channel active noise control (ANC) headrest system. The results indicate that the Morgan method outperforms the Milani method when configured optimally. Subsequently, we propose an enhanced version of the subband algorithm based on the Morgan method. The enhanced algorithm incorporates an additional sinusoidal noise canceller (SNC) subsystem and a narrowband active noise control (NANC) subsystem based on local secondary path modeling to address tonal components, while the selective subband structure is employed for controlling broadband components. In addition, the computational complexity of the algorithm is analyzed. The effectiveness of the proposed algorithm is validated through numerous simulations and the ANC tests conducted on an actual vehicle utilizing the multi-channel ANC headrest system. The performance of the proposed algorithm surpasses that of traditional selective subband and fullband algorithms, and balanced binaural noise reduction is achieved.

Multi-Channel Phase-Compensated Active Disturbance Rejection Control with an Improved Backstepping Strategy for Electro-Optical Tracking Systems

A multi-channel phase-compensated active disturbance rejection control (MPADRC) incorporating an improved backstepping strategy is proposed in this paper to handle the phase lag in the extended state observer (ESO) and the residual uncertainty in the system. Firstly, a multi-channel phase-compensated ESO (MPESO) is constructed by adding phase-advanced networks to all output channels of the ESO, which allows disturbances and system states to be compensated and feedback in a more timely manner, respectively. Then, to estimate and offset the residual uncertainty in the system, an improved backstepping control method is employed and a Lyapunov function is designed to verify the convergence of the error between the estimated and actual values of the residual uncertainty. After that, the improved backstepping control is combined with MPADRC, and comparisons with the conventional linear active disturbance rejection control (LADRC) are conducted for a range of cases. Finally, on an inertial stabilization platform in the electro-optical tracking system (ETS), simulation and experimental results verified the effectiveness of the proposed method.

A scalable hybrid analog-digital architecture for multi-channel feedforward active noise control

This paper proposes a hybrid analog-digital architecture, aimed at reducing hardware resource consumption and improving the scalability of a multi-channel feedforward active noise control system to accommodate a large number of error microphones. This hybrid architecture employs a partial-update filtered-x least mean squares algorithm that is lightweight and suitable for real-time execution, as it updates the control filters in each iteration using only two selected error signals. The selection of these two error signals is achieved through a dedicated analog circuit comprising analog comparators and multiplexers. Thus, the hybrid architecture requires only two analog-to-digital converters for error signals, regardless of the number of error microphones. Experiments were conducted on two active noise control casings, demonstrating that, with a specific computational capacity, the proposed hybrid architecture can accommodate significantly longer control filters, resulting in higher steady-state noise reduction. Moreover, additional error microphones were introduced to demonstrate the scalability. The hybrid architecture simplifies the implementation of the multi-channel feedforward active noise control system when additional error microphones are needed for more evenly distributed residual noise levels or a larger zone of quiet.

Grouping Neural Network-Based Smith PID Temperature Controller for Multi-Channel Interaction System

The thermal vacuum test (TVT) is an important verification process in the development of spacecraft and load. There are often multiple temperature points on the device under test (DUT) that require control. The interaction among multiple channels poses a challenge for temperature control in the TVT. To solve this problem, a multi-channel Smith proportional–integral–derivative (PID) controller based on a grouping neural network (Grouping-NN) is proposed. Firstly, the mathematical derivation for a typical multi-channel temperature control model of the TVT is carried out. Then, the multi-channel interaction system is identified using a Grouping-NN to predict the output temperature of each channel by grouping the hidden layer neurons according to the number of channels. Finally, two Grouping-NNs are utilized to update the Smith predictor, and the time-delay error is fed back to the PID controller, which is used to optimize the control effect of the multi-channel interaction system under high time delay. The proposal is compared with the traditional PID controller and Smith predictor-based PID controller through simulation. The simulation results show that the proposed method has better suppression of overshooting. In addition, the algorithm is verified by controlling the temperature of six channels in a practical thermal vacuum test.

Multi-channel gas-diesel engine control system based on jet-convective sensors

Accurate measurement of the dynamic flow rate of the components of the gas-fuel mixture is required in electronic automatic control systems of the internal combustion engine. The paper substantiates the structural construction of the measurement channels of the multi-channel gas-diesel engine control system. In the implementation of the measurement channels, special attention is paid to the structure of the jet-convective channel for obtaining an informative signal on the gas fuel flow rate and the structure of the ion-labeled channel for measuring the air flow rate. Application of jet-convective transducers is supplemented by the original structural scheme of primary signals processing, which will allow expanding the measurement range towards low flow rate values, increasing the speed and reducing the random component of the error.

MCSG: A Morphology Configurable Soft Gripper With Self-Adaption Modular Composite Finger

Current soft grippers lack active variable stiffness composite fingers and flexible modular configuration, which limit their robust grasp abilities. We proposed a morphology configurable soft gripper (MCSG) assembled with self-adaption modular composite fingers (SAMCFs), whose grasping force can be up to 193N. The SAMCF with three actuator modules embedded arranged sponge and paperboard and one sensor module made with pre-inflated air chamber is developed to perform soft grasp with high load capacity and self-sensing ability. Through assembling corresponding SAMCFs to main frame, MCSGs with dual fingers (MCSG-DF), with three fingers (MSCG-TF), with four fingers (MSCG-FF) and with six fingers (MSCG-SF) are manufactured to adapt for grasping objects with different shapes, sizes, and weights. A pneumatic control system with hybrid valve combination is designed to output air pressure from negative to positive to perform contraction and elongation motion simultaneously, and output positive pressure to provide preset pressure for sensor modules. Finally, a multi-channel pneumatic control system is developed to control MCSGs to grasp a variety of objects, such as cherry tomato (10g), egg (170g), banana (155g), stool (3570g), etc. Furthermore, MCSGs can complete complicated tasks in daily life, such as water decanting, bottle cap unscrewing, mobile phone charging and water pumping.

Adaptive Multi-Channel Control for Anti-Aliasing in Fiber-Optic Fabry-Perot Vibration Systems

Adaptive Multi-Channel Control for Anti-Aliasing in Fiber-Optic Fabry-Perot Vibration Systems

Simulation Research on Active Noise Control in Turboprop Cabin with Complex Sound Field Environment

This article summarizes the research work on the complex sound field environment in the cabin of a certain turboprop aircraft, the construction of multi-channel noise active control system and the verification of noise reduction effect were carried out. On the basis of spectrum analysis and distribution characteristic analysis of the measured data in the cabin of this turboprop, taking the key peak frequency as the target frequency, a multi-channel noise active control system with 16 inputs and 16 outputs that meets the requirements of noise reduction indicators is built. And a comprehensive verification platform for the noise reduction effect of turboprop aircraft similar to the real environment was built in a semi-anechoic chamber to verify the real environment was built in a semi-anechoic chamber to verify the noise reduction effect of the system. The result show that the system can reduce the sound pressure level at key frequencies by 14.9 dB(A), the system noise reduction effect is significant and effective.

Frequency domain adaptation of multichannel active road-noise sound control system with virtual sensing

The convergence speed of multichannel adaptive active noise control algorithms can be improved by pre-whitening the reference signals and reducing their cross-correlations. When considering nonstationary processes, like road noise, it proves advantageous to use a short time-based cross-correlation estimation of the reference signal, which can be obtained as part of the bin-normalised frequency domain least-means-squares algorithm. However, the regularisation of such an algorithm is crucial to its success and can further improve the convergence rate. In addition, virtual sensors can be employed by using the additional filter method, which provides targets for the measured error signals to follow, generated from the reference signals. Still, the performance of this virtual sensing is known to be degraded if the properties of the reference signals change, so special consideration should be taken when the reference signals are nonstationary.

A novel parallel multi-harmonic global multi-channel control algorithm for helicopter active vibration control

The vibrations of the helicopter fuselage are mainly induced by the rotor with blade pass frequency and the high order harmonics. The conventional filtered-x least mean square (FxLMS) control algorithm usually used a uniform convergence factor for all the harmonics which leads poor effect in controlling multi-harmonic vibration. In this paper, a novel parallel multi-harmonic global multi-channel (MHGMC) control method is proposed to suppress the multi-harmonic vibration components transmitted from the main rotor to the fuselage. Bandpass filters are used to separate multiple frequency components of the error signals, the control channel models are identified for the corresponding frequency range to independently control each frequency component, and the reconstruction of the reference input signals can be obtained from the separated error signal, effectively improving the performance of tracking interference signals. In addition, the coupling of the control channels is considered, and the global vibration optimization is taken as the control objective to update the weight coefficient of the controller. An active vibration control system of the helicopter main gearbox eight-strut installation configuration has been established. The simulation and experiment results show that the proposed controller has faster control convergence speed and better control effect of multiple harmonics than the conventional filtered-x least mean square algorithm, and the attenuations of the disturbing frequency harmonic components at all measurement points in the experiment are over 38dB. The experimental results of variable excitation also verify that the proposed control algorithm has excellent adaptability and strong robustness.