Multimodal Control Research Articles

Improvement of vibration isolation performance of multi-mode control seat suspension system through road recognition using wavelet-LSTM approach

Improvement of vibration isolation performance of multi-mode control seat suspension system through road recognition using wavelet-LSTM approach

Dual-redundancy multi-mode control of high safety reliability steering wheel system

Dual-redundancy multi-mode control of high safety reliability steering wheel system

Multimodal Control of Bacterial Gene Expression by Red and Blue Light.

By applying sensory photoreceptors, optogenetics realizes the light-dependent control of cellular events and state. Given reversibility, noninvasiveness, and exquisite spatiotemporal precision, optogenetic approaches enable innovative use cases in cell biology, synthetic biology, and biotechnology. In this chapter, we detail the implementation of the pREDusk, pREDawn, pCrepusculo, and pAurora optogenetic circuits for controlling bacterial gene expression by red and blue light, respectively. The protocols provided here guide the practical use and multiplexing of these circuits, thereby enabling graded protein production in bacteria at analytical and semi-preparative scales.

Fast Flight of the Flying Robot With Fuzzy Decision and Multimodal Control Tackling Uncertainties

Fast Flight of the Flying Robot With Fuzzy Decision and Multimodal Control Tackling Uncertainties

Dual-redundancy multi-mode control of high safety reliability steering wheel system

Dual-redundancy multi-mode control of high safety reliability steering wheel system

Analysis of damping multi-mode switching control of semi-active suspension based on digital controlled hydraulic cylinders group

In order to improve the ride comfort of vehicle suspension, this article proposes a damping multi-mode semi-active suspension system and its control method. The semi-active suspension takes a hydraulic electromagnetic shock absorber based on a digital controlled hydraulic cylinders group as the core, and realizes the switching of multiple damping modes by controlling the on-off statuses of three groups of switch solenoid valves, thus making the semi-active suspension have the characteristics of damping multi-mode adjustable. The damping characteristics corresponding to the single damping mode are verified through the prototype bench test of the shock absorber principle. On this basis, the semi-active suspension model of the vehicle is established, and a multi-mode switching control strategy of suspension damping using fuzzy control is designed. The filtered Gaussian white noise is used as the random road excitation for simulation. The simulation results show that compared with the traditional passive suspension and the semi-active suspension based on skyhook control, the damping multi-mode semi-active suspension based on the digital controlled hydraulic cylinders group can realize the switching of multiple damping modes, have good damping performance, and help to improve the vehicle ride comfortable capability.

Mechanism design and dynamic switching modal control of the wheel-legged separation quadruped robot

AbstractCurrently, most wheel-legged robots need to complete the switching of the wheel-and-leg modal in a stationary state, and the existing algorithms of statically switching the wheel-leg modal cannot meet the control requirements of multimodal switching dynamically for robots. In this paper, to achieve efficient switching of the wheel-and-leg modal for a quadruped robot, the novel transformable mechanism is designed. Then, a multimodal coordination operation control framework based on multiple algorithms is presented, incorporating the minimum foot force distribution method (algorithm No.1), the minimum joint torque distribution method (algorithm No.2), and the method of combining the single rigid body dynamic model with quadratic programming (algorithm No.3). In the process of switching wheel-leg modal dynamically, the existing algorithm No.3 is prone to produce the wrong optimal force due to the change of the whole-body rotational inertia. Therefore, an improved algorithm No.1 and algorithm No.2 are proposed, which do not consider the change in the body’s inertia. The control effects of the three algorithms are compared and analyzed by simulation. The results show that algorithm No.3 can maintain a small error in attitude angle and speed tracking regardless of whether the robot is under multilegged support or omnidirectional walking compared to the other two algorithms. However, proposed algorithms No.1 and No.2 can more accurately track the target speed when the robot is walking with wheels raising and falling. Finally, a multi-algorithm combination control scheme formulated based on the above control effects has been demonstrated to be effective for the dynamic switching of the wheel-and-leg modal.

Adaptive multi-mode control system for stability and tracking control of distributed drive automated electric vehicle

Conventional tracking control algorithms of Distributed Drive Automated Electric Vehicles (DDAEVs) are typically designed for a unique control mode, which may lead to poor lateral stability under various driving conditions. Aimed this problem, an Adaptive Multi-mode Control System (AMCS) is proposed. Firstly, according to the adhesion utilization between tires and road surface, the driving condition is classified into three categories, and three control modes corresponding to them are proposed. Secondly, an Adaptive Neuro-fuzzy Inference-based Mode Matching Control System (ANFI-MMCS) is constructed to calculate the matching degree between vehicle states and control modes. Then, in order to achieve the ideal distribution of road wheel angle and yaw moment while avoiding approaching the limit speed corresponding to the reference trajectory, a model predictive control trajectory tracking controller and a speed controller with limitations were built. Finally, to achieve smooth switching between control modes, the outputs of AMCS are weighted according to the matching degree. In the experimental section, AMCS is evaluated on Carsim-Simulink co-simulation platform, and the results under different tests reveal that the proposed controller is more adaptable.

Model based optimal magnetic feedback control of multiple resistive wall modes with discrete coil and sensor arrays

A model-based optimal control method for multiple resistive wall mode (RWM) feedback stabilization has been developed and tested in plasma experiments at the EXTRAP T2R reversed field pinch (RFP) device. The controller is designed to target issues that arise in connection with RWM magnetic feedback stabilization systems based on discrete control coil and sensor arrays in tokamak and reversed field pinch devices. Multi-mode control capabilities in these systems is limited due to coupling of modes induced by the control system. The coupling originates from the generation of side-band control field harmonics and from aliasing of multiple harmonics in the sensor measurements. These couplings naturally leads to a multiple-input, multiple-output (MIMO) control problem. A model based state space controller has been designed based on a relatively simple physics model of the RWM plasma response. The physics model, which is applicable for the high aspect ratio RFP, is the basis for Fourier decoupling of the MIMO control problem into a set of single-input, multiple-output (SIMO) systems using the discrete Fourier transform (DFT). The linear, time-invariant physics model allows for the design of a state space model with states representing physical quantities; in this case the Fourier harmonics of the radial field at the resistive wall. Since the states cannot be directly measured, a Kalman filter is used for estimation of the states from the aliased sensor array measurements. A linear–quadratic (LQ) optimal state controller has been implemented. Design parameters, such as the LQ control cost function state weights and the Kalman filter input error covariances have been used to optimize the control operation in various ways. The controller has enhanced multi-mode control capabilities compared to earlier designs. For example it allows the prioritizing of suppression of one of the multiple magnetic field Fourier harmonics produced by a given control current DFT component. The controller has been tested in plasma experiments at EXTRAP T2R device, utilizing a newly installed extended sensor array, and the enhanced capabilities for multiple RWM feedback stabilization has been demonstrated.

Fabric electromagnetic actuators

Soft electromagnetic actuators have important applications in fields, such as soft robots, human–machine interaction, and biomedicine, owing to their fast response speed, high driving efficiency, and large driving force. However, there are persistent challenges in the development of high-performance soft electromagnetic actuators that are light, thin, low-cost, controllable, and efficient. In this study, we propose a fabric electromagnetic actuator (FEMA) based on copper-mesh hot-pressing technology, which exhibits the advantages of simple processing, fast preparation speed, low cost, thinness and flexibility, and strong reliability and repeatability. This process is suitable for the preparation of electromagnetic actuators for various fabrics, such as cotton, nylon, terylene, and silk. Furthermore, the static and dynamic control characteristics of one and two actuators were tested and analyzed. The FEMA exhibits excellent flexibility, shape controllability, and high-speed driving ability. The results of the correlation analysis provide theoretical support for the controlling of FEMAs. Finally, we developed a 3 × 1 array actuator and 2 × 2 array actuators based on a modular combination of FEMA units and achieved multi-mode motion control. Furthermore, a large-area FEMA was developed, demonstrating excellent shape adaptability and gripping ability. Our findings have significant implications for the advancement of lightweight electromagnetic actuators, and further studies on design concepts and multi-mode control could unveil even more potential applications.

Spanwise layout optimization of aerodynamic countermeasures for multi-mode vortex-induced vibration control on long-span bridges

Aerodynamic countermeasures are widely used to control vortex-induced vibration (VIV) on long-span bridges. However, due to the lack of appropriate three-dimensional (3-D) VIV analysis approach, these countermeasures are usually installed along the entire span of the bridge deck, leading to excessive costs. This study proposes an optimization method for the spanwise layout of aerodynamic countermeasures, aiming to achieve an economical control scheme for multi-mode VIV. An improved mode-by-mode 3-D VIV analysis approach is developed based on the generalized polynomial model to predict the VIV responses of the bridge with different spanwise layouts of aerodynamic countermeasures. The genetic algorithm (GA) is then employed to search for the most economical layout scheme with constraints of limited multi-mode VIV responses. Two alternative types of search spaces for the optimization are presented. The effectiveness of this optimization method is demonstrated on a long-span suspension bridge in conjunction with finite element simulation and wind tunnel tests. The results show a noteworthy reduction in the use of aerodynamic countermeasures, thus highlighting the necessity of countermeasure layout optimization.

A Nonlinear Multimode Controller for Seamless off-Grid of Energy Storage Inverter Under Unintentional Islanding

A nonlinear multimode controller (NMC) is proposed to achieve the whole process seamless off-grid of energy storage inverter (ESI) from the grid-connected state of current control mode (CCM) to the islanded state of voltage control mode (VCM) under unintentional islanding. Based on the presented design idea of intelligent equivalent substitution, NMC is composed of multimode voltage controller (MVC), multimode power compensator (MPC) and multimode current controller (MCC). MVC can control load voltage in islanding and maintain manipulated variables of load current in other modes. MPC can compensate the power flowing into grid and help inner loop reference value achieve the smooth drop, and also compensate for load current variation during grid-connection. MCC can track the given current during grid-connection and make MPC quickly obtain the compensation of load power variation. The reference values of inner loop are logically split into the output of MVC, MPC and MCC, so that the manipulated variables can be combined nonlinearly to achieve seamless off-grid of ESI under unintentional islanding. This paper also analyzes the ESI stability with NMC during the off-grid process, and analyzes the relationship between manipulated variables by simulations. Finally, the correctness and effectiveness of proposed NMC are verified by experiments.

Dual-layer active equalization control for series-connected batteries based on hybrid Cuk-flyback topology

The inevitability of energy inconsistency among batteries within a battery pack poses operational challenges and potential safety hazards. It is imperative to swiftly harmonize the state of charge across all batteries to mitigate these issues. Addressing this concern, a dual-layer hybrid equalization topology is introduced, leveraging the Cuk circuit and flyback transformer. The battery pack is segmented into modules, with the Cuk circuit employed for intra-module equalization. Subsequently, the flyback transformer facilitates inter-module equalization. A multimodal equalization control strategy is devised, considering the status of individual modules to minimize repeated energy transfers between batteries. Simulation and experimental findings affirm that the proposed dual-layer active equalization control markedly mitigates the inconsistency among series-connected batteries, demonstrating rapid equalization and heightened efficiency.

Multimodal Human–Robot Interaction for Human‐Centric Smart Manufacturing: A Survey

Human–robot interaction (HRI) has escalated in notability in recent years, and multimodal communication and control strategies are necessitated to guarantee a secure, efficient, and intelligent HRI experience. In spite of the considerable focus on multimodal HRI, comprehensive disquisitions delineating various modalities and intricately analyzing their combinations remain elusive, consequently limiting holistic understanding and future advancements. This article aspires to bridge this inadequacy by conducting a profound exploration of multimodal HRI, predominantly concentrating on four principal modalities: vision, auditory and language, haptics, and physiological sensing. An extensive review encapsulating algorithmic dissection, interface devices, and applicative dimensions forms part of this discourse. This manuscript distinctively combines multimodal HRI with cognitive science, deeply probing into the three dimensions, perception, cognition, and action, thereby demystifying algorithms intrinsic to multimodal HRI. Finally, it accentuates the empirical challenges and contours preemptive trajectories for multimodal HRI in human‐centric smart manufacturing.

Multimodal Motion Control of Soft Ferrofluid Robot With Environment and Task Adaptability

Soft microrobotics has recently been an active field that advances new microrobot design, adaptive motion, and biomedical applications. In this work, we study the ferrofluid robot (FR), which has soft nature and exhibits paramagnetism. Currently, motion of the FR is usually realized by magnetic force, and the task execution requires relatively complex systems for simultaneous field and gradient control. To enable the FR with more motion modes for environment and task adaptability, we program three dynamic field forms and realize three corresponding torque-actuated motion modes: <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Rolling</i> , <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Wobbling</i> , and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Oscillating</i> . Together with the force-based <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Dragging</i> mode, we provide a complete motion control scheme for the FR. As this scheme only requires 3-D dynamic fields or gradients for actuation, the complexity of the magnetic actuation system is reduced. We formulate the motion and deformation actuation principles of the FR, and the four motion modes are demonstrated and characterized. With the implementation of automated tracking and control algorithms, controllability of the new torque-based modes is testified. We then fabricate different kinds of environments and cargoes to validate the environment and task adaptability of the FR by using the proposed scheme. Especially, we implement the scheme on a self-constructed system consisting of three mobile coils, and experiments realize the long-distance navigation of the FR via <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Rolling</i> or <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Dragging</i> modes. The ultrasound-guided navigation in a 3-D tissue-mimicking endovascular environment shows the potential for delivery applications.

Multimode control strategy to improve the power quality and autonomy of PV-Wind-BESS based microgrid using harmonic frequency adaptive observer filter

Multimode control strategy to improve the power quality and autonomy of PV-Wind-BESS based microgrid using harmonic frequency adaptive observer filter

Multimode Control of WPT Systems for Efficiency Improvement in Wide Output Voltage Range Applications

Multimode Control of WPT Systems for Efficiency Improvement in Wide Output Voltage Range Applications

Discrete viscous dampers for multi-mode vortex-induced vibration control of long-span suspension bridges

Multi-mode vertical vortex-induced vibrations have been observed on several long-span suspension bridges, where several vertical modes of stiffening girder are excited in turn with increasing of wind velocity. This paper proposed a discrete viscous dampers solution and its optimization targeting multi-mode vortex-induced vibration control for long-span suspension bridges. The minimal modal damping ratio was used to evaluate the performance of the damper system. The wind tunnel test verified that the modal damping ratio is an alternative to the resonance response amplitude and can be obtained by complex modal analysis. The ternary search algorithm was adopted to find the optimal damper parameter for the Yingwuzhou Yangtze River Bridge, which is a suspension bridge that suffered excessive vortex-induced vibrations. Using linear damper elements to connect the bridge tower and the bridge girder directly turned out to be a feasible method of increasing multiple modal damping ratios. Four torsional eddy current dampers have been installed in the Yingwuzhou Yangtze River Bridge, based on the numerical optimization results calculated in this paper. Although the measured modal damping ratios were smaller than the numerical results, the structural damping increased by three times after dampers were installed, and the requirement of the current specification was satisfied.

Multi-Mode Switching Control Strategy for IWM-EV Active Energy-Regenerative Suspension Based on Pavement Level Recognition

Aiming at the problems of poor overall vibration reduction and high energy consumption of in-wheel motor-driven electric vehicle (IWM-EV) active suspension on mixed pavement, a multi-mode switching control strategy based on pavement identification and particle swarm optimization is proposed. First, the whole vehicle dynamic model containing active energy-regenerative suspension and the reference model was established, and the sliding mode controller and PID controller designed, respectively, to suppress the vertical vibration of the vehicle and the in-wheel motor. Second, a road grade recognition model based on the dynamic travel signal of the suspension and the road grade coefficient was established to identify the road grade, and then the dynamic performance and energy-feedback characteristics of suspension were optimized by particle swarm optimization. According to the results of pavement identification, the optimal solution of the suspension controller parameters under each working mode was divided and selected to realize the switch of the suspension working mode. The simulation results show that the control strategy can accurately identify the grade of road surface under the condition of mixed road surface, and the ride index of the optimized active energy-regenerative suspension is obviously improved, while some energy is recovered.

Early pain experiences in dairy calves on pain sensitivity later in life

In humans, early painful experiences can increase pain sensitivity later in life, but little is known regarding this phenomenon in cattle. This study assessed if a painful event early in life affects later pain sensitivity in 40-d-old calves. Holstein calves (n = 26) were randomly assigned to control or treatment conditions, blocked within sex and birth weight. At 9.5 ± 1.8 d old, treatment calves had 1 horn bud disbudded using caustic paste, whereas control calves had 1 horn sham disbudded; in both cases, multimodal pain control was provided. All calves had the contralateral horn bud disbudded using a hot iron 4 wk later, again with multimodal pain control. Mechanical nociceptive responses were assessed weekly using an algometer applied adjacent to both horn buds and on the rump, beginning 3 d before the first disbudding and ending 30 d after the second disbudding. Following the second disbudding, both groups of calves showed evidence of increased sensitivity (i.e., algometer pressure declined 3.69 ± 0.60 √N to 2.13 ± 0.70 √N) on the contralateral bud, but there was no difference between the control group and the treatment groups. An interaction between treatment and time, likely driven by treatment differences, was found on the rump when tested 5 h after the second disbudding event. These responses are not consistent with the hypothesis that an early pain experience results in increased sensitivity to later painful experiences.