scholarly journals Bioprocess Control: Current Progress and Future Perspectives

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 557
Author(s):  
Anurag S. Rathore ◽  
Somesh Mishra ◽  
Saxena Nikita ◽  
Priyanka Priyanka
Keyword(s):  
Best Practices ◽  
Control Strategies ◽  
Open Loop ◽  
Product Regulatory ◽  
Software Applications ◽  
Bioprocess Control ◽  
Unit Operations ◽  
Regulatory Constraints ◽  
Control Schemes ◽  
Modern Control

Typical bioprocess comprises of different unit operations wherein a near optimal environment is required for cells to grow, divide, and synthesize the desired product. However, bioprocess control caters to unique challenges that arise due to non-linearity, variability, and complexity of biotech processes. This article presents a review of modern control strategies employed in bioprocessing. Conventional control strategies (open loop, closed loop) along with modern control schemes such as fuzzy logic, model predictive control, adaptive control and neural network-based control are illustrated, and their effectiveness is highlighted. Furthermore, it is elucidated that bioprocess control is more than just automation, and includes aspects such as system architecture, software applications, hardware, and interfaces, all of which are optimized and compiled as per demand. This needs to be accomplished while keeping process requirement, production cost, market value of product, regulatory constraints, and data acquisition requirements in our purview. This article aims to offer an overview of the current best practices in bioprocess control, monitoring, and automation.

A Review of Classical and Modern Control Techniques Utilized in Modern Microgrids

2021 ◽  
Vol 14 ◽  
Author(s):  
Muhammad Hamza Shahbaz ◽  
Arslan Ahmed Amin
Keyword(s):  
Control Strategies ◽  
Optimal Solution ◽  
Energy Resources ◽  
Control Methods ◽  
Research Gaps ◽  
Control Techniques ◽  
Micro Grid ◽  
Exciting Development ◽  
Micro Grids ◽  
Modern Control

: Because of the consistently expanding energy request, the introduction of a decentralized micro-grid based on energy resources will soon be the most exciting development in the power system. Micro-grids, which are mainly based on inverters, are becoming more popular as they can handle different forms of renewable energy effectively. However, one of the most challenging areas of research is their control. In the last few years, many control strategies have been developed. In this review, different control methods have been discussed that apply to the micro-grid system. Furthermore, the comparative analysis of classical and modern control strategies is also considered. This survey guides the new researchers about all available control strategies and room for improvement towards the optimal solution of the micro-grid control techniques. It also identifies several research gaps and future trends therein as well as provides a solution to manage problems in MGs. The strategies are then compared based on their applicability to different control requirements.

A Survey on Brachiation Robots: An Energy-Based Review

Robotica ◽  
2021 ◽  
pp. 1-13
Author(s):  
Sibyla Andreuchetti ◽  
Vinícius M. Oliveira ◽  
Toshio Fukuda
Keyword(s):  
Special Class ◽  
Control Strategies ◽  
Underactuated Systems ◽  
Decision Variable ◽  
Robot Dynamics ◽  
Technical Literature ◽  
Control Schemes

SUMMARY Many different control schemes have been proposed in the technical literature to control the special class of underactuated systems, the- so-called brachiation robots. However, most of these schemes are limited with regard to the method by which the robot executes the brachiation movement. Moreover, many of these control strategies do not take into account the energy of the system as a decision variable. To observe the behavior of the system’s, energy is very important for a better understanding of the robot dynamics while performing the motion. This paper discusses a variety of energy-based strategies to better understand how the system’s energy may influence the type of motion (under-swing or overhand) the robot should perform.

scholarly journals An integrodifferential approach to modeling, control, state estimation and optimization for heat transfer systems

2016 ◽  
Vol 26 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Andreas Rauh ◽  
Luise Senkel ◽  
Harald Aschemann ◽  
Vasily V. Saurin ◽  
Georgy V. Kostin
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Control Strategies ◽  
Open Loop ◽  
Distributed Parameter ◽  
Dimensional System ◽  
State Equations ◽  
Large Space ◽  
Finite Dimensional ◽  
Spatially Distributed

Abstract In this paper, control-oriented modeling approaches are presented for distributed parameter systems. These systems, which are in the focus of this contribution, are assumed to be described by suitable partial differential equations. They arise naturally during the modeling of dynamic heat transfer processes. The presented approaches aim at developing finite-dimensional system descriptions for the design of various open-loop, closed-loop, and optimal control strategies as well as state, disturbance, and parameter estimation techniques. Here, the modeling is based on the method of integrodifferential relations, which can be employed to determine accurate, finite-dimensional sets of state equations by using projection techniques. These lead to a finite element representation of the distributed parameter system. Where applicable, these finite element models are combined with finite volume representations to describe storage variables that are—with good accuracy—homogeneous over sufficiently large space domains. The advantage of this combination is keeping the computational complexity as low as possible. Under these prerequisites, real-time applicable control algorithms are derived and validated via simulation and experiment for a laboratory-scale heat transfer system at the Chair of Mechatronics at the University of Rostock. This benchmark system consists of a metallic rod that is equipped with a finite number of Peltier elements which are used either as distributed control inputs, allowing active cooling and heating, or as spatially distributed disturbance inputs.

Active Control of Combustion Instability Using Symmetric and Asymmetric Premix Fuel Modulation

2007 ◽  
Author(s):  
Daniel Guyot ◽  
Christian Oliver Paschereit
Keyword(s):  
Heat Release ◽  
Closed Loop ◽  
Modulation Frequency ◽  
Combustion Instability ◽  
Open Loop ◽  
Closed Loop Control ◽  
Nox Emissions ◽  
Loop Control ◽  
Asymmetric Modulation ◽  
Control Schemes

Active instability control was applied to an atmospheric swirl-stabilized premixed combustor using open loop and closed loop control schemes. Actuation was realised by two on-off valves allowing for symmetric and asymmetric modulation of the premix fuel flow while maintaining constant time averaged overall fuel mass flow. Pressure and heat release fluctuations in the combustor as well as NOx, CO and CO2 emissions in the exhaust were recorded. In the open loop circuit the heat release response of the flame was first investigated during stable combustion. For symmetric fuel modulation the dominant frequency in the heat release response was the modulation frequency, while for asymmetric modulation it was its first harmonic. In stable open loop control a reduction of NOx emissions due to fuel modulation of up to 19% was recorded. In the closed loop mode phase-shift control was applied while triggering the valves at the dominant oscillation frequency as well as at its second subharmonic. Both, open and closed loop control schemes were able to successfully control a low-frequency combustion instability, while showing only a small increase in NOx emissions compared to, for example, secondary fuel modulation. Using premixed open loop fuel modulation, attenuation was best when modulating the fuel at frequencies different from the dominant instability frequency and its subharmonic. The performance of asymmetric fuel modulation was generally slightly better than for symmetric modulation in terms of suppression levels as well as emissions. Suppression of the instability’s pressure rms level of up to 15.7 dB was recorded.

Control Systems for Automotive Vehicle Fuel Economy: A Literature Review

1981 ◽  
Vol 103 (3) ◽  
pp. 173-180 ◽  
Author(s):  
L. M. Sweet
Keyword(s):  
Control Systems ◽  
Combustion Engine ◽  
Control Strategies ◽  
Engine Performance ◽  
Type Systems ◽  
Open Loop ◽  
Feedback Systems ◽  
Fuel Flow ◽  
Loop Feedback ◽  
Hybrid Vehicle Control

This paper is a review of current research on applications of control systems and theory to achieve energy conservation in automotive vehicles. The development of internal combustion engine control systems that modulate fuel flow, air flow, ignition timing and duration, and exhaust gas recirculation is discussed. The relative advantages of physical and empirical models for engine performance are reviewed. Control strategies presented include optimized open-loop schedule type systems, closed-loop feedback systems, and adaptive controllers. The development of power train and hybrid vehicle control systems is presented, including controllers for both conventional transmissions and those employing flywheel energy storage.

A Parametrically Amplified MEMS Gyroscope

2010 ◽  
Vol 2010 (DPC) ◽  
pp. 001322-001334
Author(s):  
Barry J. Gallacher ◽  
Z. X. Hu ◽  
J. S. Burdess ◽  
K. M. Harish
Keyword(s):  
Open Loop ◽  
Parametric Amplification ◽  
Vibration Modes ◽  
Q Factor ◽  
Amplitude Control ◽  
Mems Gyroscope ◽  
Primary Mode ◽  
Harmonic Forcing ◽  
Control Schemes ◽  
Order Of Magnitude

The applicability of parametric amplification of either the primary and secondary vibration modes of a MEMS gyroscope, shown in Fig.1 is investigated experimentally in this paper. All control schemes have been implemented digitally onto a SHARC DSP development board. Parametric gains in excess of 80, which correspond to multiplication of the Q-factor by a factor of 80, are demonstrated experimentally for open-loop operation of the primary mode and are shown in Fig. 2. For open-loop operation it is shown that amplitude limiting nonlinearities become important as the vibration amplitude increases (see Figs.3) and that parametric amplification in excess of 80 can be only be achieved by further reducing the harmonic forcing amplitude. In many applications it is desirable to have as high a Q-factor as possible. The rate gyroscope is one application were active control of the Q-factor is extremely pertinent. If applied to the primary mode then it permits reduced forcing levels and hence contamination from “feedthrough”. If applied to the sense mode then the Coriolis force is effectively amplified. Parametric amplification of the secondary mode of the gyroscope is a challenging problem but it has the potential to improve the performance of MEMS rate gyroscope but an order of magnitude. In operation as a rate gyroscope it is important to maintain the amplitude of the primary mode of vibration at a constant level. For the case of a parametrically amplified primary mode the amplitude control circuit automatically adjusts the parametric excitation parameters to ensure the required parametric gain is achieved whilst at the same time reducing the amplitude of the harmonic forcing. In closed loop parametric amplification of the primary mode by a factor 20 have been demonstrated. Experimental results obtained from the amplified primary mode are shown in Fig.4.

Practical Fixed-Time Event-Triggered Time-Varying Formation Tracking Control for Disturbed Multi-Agent Systems with Continuous Communication Free

2020 ◽  
Vol 09 (01) ◽  
pp. 23-34
Author(s):  
Xiaofeng Chai ◽  
Jian Liu ◽  
Yao Yu ◽  
Jianxiang Xi ◽  
Changyin Sun
Keyword(s):  
Control Strategies ◽  
Fixed Time ◽  
Settling Time ◽  
Time Varying ◽  
Multi Agent Systems ◽  
Agent Systems ◽  
Formation Tracking ◽  
Control Schemes ◽  
Multi Agent ◽  
Event Triggered

In this paper, we study the practical fixed-time event-triggered time-varying formation tracking problem of leader-follower multi-agent systems with multi-dimensional dynamics. Fixed-time event-triggered control schemes with continuous communication and intermittent communication are developed, respectively. Continuous communication and measurement are avoided, and computation cost is reduced greatly in the latter scheme. And the settling time is to be specified regardless of initial states of agents. Meanwhile, tracking errors are adjustable as desired with expected settling time. It is demonstrated that time-varying formation tracking can be achieved under the two proposed control schemes and Zeno behavior can be excluded. Finally, numerical examples are provided to illustrate the effectiveness of the proposed control strategies.

Stability and Energy Efficiency Improvement of Hydraulic Excavator Arm Control System With a Novel Asymmetric Pump

2017 ◽  
Author(s):  
Long Quan ◽  
Lei Ge ◽  
Jing Yang ◽  
Bin Zhao ◽  
Zhen Lu ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Control Strategies ◽  
Open Loop ◽  
Load Force ◽  
Cooling Power ◽  
Operating Characteristics ◽  
Flow Rates ◽  
Energy Efficiency Improvement ◽  
Working Cycle ◽  
Efficient Alternative

Pump controlled hydraulic circuit is an energy efficient alternative to valve controlled system, as they eliminate the throttling loss and require less cooling power. In all pump controlled systems, the internal and external leakages of the pump and actuator, especially the unequal flow rates of the single rod cylinder must be compensated. In presently existing solutions, an additional pump or some valves are used to compensate the unequal flow rates, leakages and to pressurize the system. However, these approaches increase the system complexity and complex control strategies are required to improve the overall system dynamic performances. Also, some of them suffer from undesired and uncontrolled pressure and velocity oscillations when the load force is small or its direction changes. This paper addresses the unequal flow rates compensation problem and stability problem of pump controlled single rod cylinder system, and proposes a novel solution for it. The system under consideration utilizes a new designed asymmetric pump which can match the unequal flow rates of the single rod cylinder basically. The feasibility of the new circuit is validated by both mathematics and multi-body simulation model. The results show that the undesired velocity oscillations can be removed up. Furthermore, the operating characteristics and energy efficiency of the arm cylinder with the new scheme based on the designed open-loop and closed-loop strategies are studied on a real excavator. The results show that there is no obvious velocity fluctuation with the asymmetric pump and the position controlled precision is satisfied. Compared with the independent metering circuit, the energy-saving ratio reaches to 57% during a working cycle.

First Test Results of a Haptic Tele-Operation System to Enhance Stability of Telescopic Handlers

2010 ◽  
Author(s):  
Stefano Cenci ◽  
Giulio Rosati ◽  
Damiano Zanotto ◽  
Fabio Oscari ◽  
Aldo Rossi
Keyword(s):  
Degrees Of Freedom ◽  
Force Feedback ◽  
Control Strategies ◽  
Input Device ◽  
Test Results ◽  
Operation System ◽  
Work Related ◽  
Control Schemes ◽  
Working Capability ◽  
Stiff Joint

According to a recent report of ILO (International Labour Organization), more than two million people die or loose the working capability every year because of accidents or work-related diseases. A large portion of these accidents are related to the execution of motion and transportation tasks involving heavy duty machines. The insufficient degree of interaction between the human operator and the machine may be regarded as one of the major causes of this phenomenon. The main goal of the tele-operation system presented in this paper is to both preserving slave (machine) stability, by reducing the inputs of slave actuators when certain unsafe working conditions occur, and improving the level of interaction at master (operator) side. Different control schemes are proposed in the paper, including several combinations of master and slave control strategies. The effectiveness of the algorithms is analyzed by presenting some experimental results, based on the use of a two degrees-of-freedom force feedback input device (with one active actuator and one passive stiff joint) coupled with a simulator of a telescopic handler.

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