Freezing Degrees of Freedom During Motor Learning: A Systematic Review

Motor Control ◽  
2020 ◽  
Vol 24 (3) ◽  
pp. 457-471 ◽  
Author(s):  
Anderson Nascimento Guimarães ◽  
Herbert Ugrinowitsch ◽  
Juliana Bayeux Dascal ◽  
Alessandra Beggiato Porto ◽  
Victor Hugo Alves Okazaki
Keyword(s):  
Motor Learning ◽  
Control Strategy ◽  
Degrees Of Freedom ◽  
Control Strategies ◽  
System Solution ◽  
Dart Throwing ◽  
The Central Nervous System ◽  
Enormous Variation ◽  
And Control ◽  
Selection Of

According to Bernstein, the central nervous system solution to the human body’s enormous variation in movement choice and control when directing movement—the problem of degrees of freedom (DF)—is to freeze the number of possibilities at the beginning of motor learning. However, different strategies of freezing DF are observed in literature, and the means of selection of the control strategy during learning is not totally clear. This review investigated the possible effects of the class and objectives of the skill practiced on DF control strategies. The results of this review suggest that freezing or releasing the DF at the beginning of learning does not depend on the class (e.g., discrete skill class: football kick, dart throwing; continuous skill class: athletic march, handwriting) or objective of the skill (e.g., balance, velocity, and accuracy), in isolation. However, an interaction between these two skill elements seems to exist and influences the selection of the DF control strategy.

Control Proxy Functions for Sequential Design and Control Optimization

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Diane L. Peters ◽  
P. Y. Papalambros ◽  
A. G. Ulsoy
Keyword(s):  
Simultaneous Optimization ◽  
Sequential Optimization ◽  
Control Optimization ◽  
Smart Products ◽  
System Solution ◽  
Optimal System Design ◽  
Problem Formulations ◽  
And Control ◽  
Sequential Strategy ◽  
Selection Of

Optimal system design of “smart” products requires optimization of both the artifact and its controller. When the artifact and the controller designs are independent, the system solution is straightforward through sequential optimization. When the designs are coupled, combined simultaneous optimization can produce system-optimal results, but presents significant computational and organizational complexity. This paper presents a method that produces results comparable with those found with a simultaneous solution strategy, but with the simplicity of the sequential strategy. The artifact objective function is augmented by a control proxy function (CPF), representing the artifact’s ease of control. The key to successful use of this method is the selection of an appropriate CPF. Four theorems that govern the choice and evaluation of a CPF are given. Each theorem is illustrated using a simple mathematical example. Specific CPFs are then presented for particular problem formulations, and the method is applied to the optimal design and control of a micro-electrical mechanical system actuator.

Study and Simulation on the Energy Efficiency Management Control Strategy of Ship Based on Clean Propulsion System

2015 ◽  
Author(s):  
Kai Wang ◽  
Xinping Yan ◽  
Yupeng Yuan
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Control Strategy ◽  
Control Strategies ◽  
Management Control ◽  
Propulsion System ◽  
Power Requirement ◽  
Doubly Fed ◽  
System Configurations ◽  
And Control

Nowadays, with the higher voice of ship energy saving and emission reduction, the research on energy efficiency management is particularly necessary. Energy efficiency management and control of ships is an effective way to improve the ship energy efficiency. In this paper, according to the new clean propulsion system configurations of 5000 tons of bulk carrier, the energy efficiency management control strategy of the clean propulsion system is designed based on the model of advanced brushless doubly-fed shaft generator, propulsion system using LNG/diesel dual fuel engine and energy consumption of the main engine for reducing energy consumption. The simulation model of the entire propulsion system and the designed control strategy were designed. The influence of the engine speed on the ship energy efficiency was analyzed, and the feasibility of the energy efficiency management control strategies was verified by simulation using Matlab/Simulink. The results show that the designed strategies can ensure the power requirement of the whole ship under different conditions and improve the ship energy efficiency and reduce CO2 emissions.

Study on a global control strategy for rotation speed with different work states in variable-speed constant-frequency wind turbines

2011 ◽  
Vol 225 (7) ◽  
pp. 968-976 ◽  
Author(s):  
G Zheng ◽  
H Xu ◽  
X Wang ◽  
J Zou
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Control Strategy ◽  
Control Strategies ◽  
Stable Operation ◽  
Constant Frequency ◽  
Global Control ◽  
Control Rules ◽  
The Individual ◽  
And Control

This paper studies the operation of wind turbines in terms of three phases: start-up phase, power-generation phase, and shutdown phase. Relationships between the operational phase and control rules for the speed of rotation are derived for each of these phases. Taking into account the characteristics of the control strategies in the different operational phases, a global control strategy is designed to ensure the stable operation of the wind turbine in all phases. The results of simulations are presented that indicate that the proposed algorithm can control the individual phases when considered in isolation and also when they are considered in combination. Thus, a global control strategy for a wind turbine that is based on a single algorithm is presented which could have significant implications on the control and use of wind turbines.

Rule based control of a periodic activated sludge process

1998 ◽  
Vol 38 (3) ◽  
pp. 281-289 ◽  
Author(s):  
S. Isaacs ◽  
D. Thornberg
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Control Strategy ◽  
Periodic Operation ◽  
Rule Based ◽  
Criterion Functions ◽  
Strategy Performance ◽  
Working Region ◽  
And Control ◽  
Selection Of

A rule based control strategy for automatically adjusting phase lengths and aeration intensity for an activated sludge nutrient removal process based on a periodic operation is examined using simulations based on the Activated Sludge Model No. 1. The strategy is based on four criterion functions, two which determine the switching of the roles of two nitrifying/denitrifying reactors and two which adjust the dissolved oxygen setpoint levels in the two reactors as functions of ammonia and nitrate concentrations. Trajectory plots of reactor concentrations in the ammonia-nitrate plane are shown to be a useful means of visualizing process and control performance. Together, the trajectories from a working region in the ammonia-nitrate plane, the size and location of which can to some extent be predetermined by selection of the criterion functions. The presented results include the influence of one of the criterion functions on control strategy performance, how an incompatibility between two criterion functions can lead to unsymmetric reactor loading, and the effect of allowing simultaneous nitrification and denitrification during nitrifying periods by reducing the dissolved oxygen level as ammonia is consumed.

Downshifting Control Strategy for Dual Clutch Transmission With Single Clutch Slippage

2016 ◽  
Author(s):  
Jikai Liu ◽  
Biao Ma ◽  
Heyan Li ◽  
Man Chen ◽  
Jianwen Chen
Keyword(s):  
Control Strategy ◽  
Control Strategies ◽  
Bench Test ◽  
Dual Clutch Transmission ◽  
Pressure Profiles ◽  
Simulation Results ◽  
And Control ◽  
Engagement And Disengagement ◽  
External Loads ◽  
Good Agreement

The cooperation mode between the engagement and disengagement clutches for vehicles equipped with Dual Clutch Transmission (DCT) is of vital importance to achieve a smooth gearshift, in particular for the downshift process as its unavoidable power interruption during the inertia phase. Hence, to elevate the performance of DCT downshifting process, an analytical model and experimental validation for the analysis, simulation and control strategy are presented. Optimized pressure profiles applied on two clutches are obtained based on the detailed analysis of downshifting process. Then, according to the analysis results, a novel control strategy that can achieve downshift task with only one clutch slippage is proposed. The system model is established on Matlab/Simulink platform and used to study the variation of output torque and speed in response to different charging pressure profiles and various external loads during downshifting process. Simulation results show that, compared with conventional control strategies, the proposed one can not only avoid the torque hole and power circulation, but shorten the shift time and reduce the friction work. Furthermore, to validate the effectiveness of the control strategy, the bench test equipped with DCT is conducted and the experiment results show a good agreement with the simulation results.

Control Strategy of Soluble Boron-Free Operation for a Small PWR

2017 ◽  
Author(s):  
Guangwen Bi ◽  
Chuntao Tang ◽  
Bo Yang
Keyword(s):  
Control Strategy ◽  
Power Distribution ◽  
Short Term ◽  
Control Rod ◽  
Burnable Poison ◽  
Power Operation ◽  
And Control ◽  
Power Distribution Control ◽  
Selection Of

Elimination of soluble boron will be a challenge to reactor operation for PWR. This paper is to promote a control strategy of soluble boron-free operation for a small PWR, through selection of burnable poison (BP), BP loading and control rod loading, based on the reactivity balance and manage requirement. The analysis for on-power operation and shutdown condition indicated that this strategy could be suitable for long-term and short-term reactivity and power distribution control for soluble boron-free operation.

Modeling the System and Component Performance Interactions of a SOFC Based APU for Changes in Application Load: Transient Response and Control Strategy

2004 ◽  
Author(s):  
D. F. Rancruel ◽  
M. R. von Spakovsky
Keyword(s):  
Transient Response ◽  
Control Strategy ◽  
Control Strategies ◽  
Control Variable ◽  
System Level ◽  
System Component ◽  
System Response ◽  
Optimal Control Strategy ◽  
Synthesis Design ◽  
And Control

Solid-Oxide-Fuel-Cell (SOFC) stacks respond in seconds to changes in load while the balance of plant subsystem (BOPS) responds in times several orders of magnitude higher. This dichotomy diminishes the reliability and performance of SOFC electrodes with changes in load. In the same manner current and voltage ripples which result from particular power electronic subsystem (PES) topologies and operation produce a negative effect on the SOFC stack subsystem (SS) performance. The difference in transient response among the sub-systems must be approached in a way which makes operation of the entire system not only feasible but ensures that efficiency and power density, fuel utilization, fuel conversion, and system response are optimal at all load conditions. Thus, a need exists for the development of transient component- and system-level models of SOFC based auxiliary power units (APUs), i.e. coupled BOPS, SS, and PES, and the development of methodologies for optimizing subsystem responses and for investigating system-interaction issues. In fact the transient process occurring in a SOFC based APU should be systematically treated during the entire creative process of synthesis, design, and operational control, leading in its most general sense to a dynamic optimization problem. This entails finding an optimal system/component synthesis/design, taking into account on- and off-design operation, which in turn entails finding an optimal control strategy and control profile for each sub-system/component and control variable. Such an optimization minimizes an appropriate objective function while satisfying all system constraints. A preliminary set of chemical, thermal, electrochemical, electrical, and mechanical models based on first principles and validated with experimental data have been developed and implemented using a number of different platforms. These models have been integrated in order to be able to perform component, subsystem, and system analyses as well as develop optimal syntheses/designs and control strategies for transportation and stationary SOFC based APUs. Some pertinent results of these efforts are presented here.

scholarly journals Guidance Navigation and Control for Autonomous Multiple Spacecraft Assembly: Analysis and Experimentation

2011 ◽  
Vol 2011 ◽  
pp. 1-18 ◽  
Author(s):  
Riccardo Bevilacqua ◽  
Marcello Romano ◽  
Fabio Curti ◽  
Andrew P. Caprari ◽  
Veronica Pellegrini
Keyword(s):  
Degrees Of Freedom ◽  
Control Strategies ◽  
Guidance And Control ◽  
Navigation And Control ◽  
Rotational Degrees Of Freedom ◽  
Multiple Spacecraft ◽  
Three Degree Of Freedom ◽  
Extra State ◽  
And Control ◽  
Spacecraft Assembly

This work introduces theoretical developments and experimental verification for Guidance, Navigation, and Control of autonomous multiple spacecraft assembly. We here address the in-plane orbital assembly case, where two translational and one rotational degrees of freedom are considered. Each spacecraft involved in the assembly is both chaser and target at the same time. The guidance and control strategies are LQR-based, designed to take into account the evolving shape and mass properties of the assembling spacecraft. Each spacecraft runs symmetric algorithms. The relative navigation is based on augmenting the target's state vector by introducing, as extra state components, the target's control inputs. By using the proposed navigation method, a chaser spacecraft can estimate the relative position, the attitude and the control inputs of a target spacecraft, flying in its proximity. The proposed approaches are successfully validated via hardware-in-the-loop experimentation, using four autonomous three-degree-of-freedom robotic spacecraft simulators, floating on a flat floor.

Analysis of Control Strategy for Extended-Range Electric Vehicle

2011 ◽  
Vol 135-136 ◽  
pp. 261-267
Author(s):  
Hai Tao Min ◽  
Dong Jin Ye ◽  
Yuan Bin Yu
Keyword(s):  
Electric Vehicles ◽  
Control Strategy ◽  
Optimal Strategy ◽  
Control Strategies ◽  
Power Train ◽  
Operating Modes ◽  
Load Following ◽  
Extended Range ◽  
Main Components ◽  
And Control

This paper introduced the structure of Extended-Range Electric Vehicles as well as its characteristics. Principle researches have been offered on the parameters matching of the power-train and main components. Operating modes and control strategies were discussed, especially the two control strategies of charge sustaining mode which is shown as load following strategy and engine optimal strategy, and the effects of both control strategies are simulated and analyzed. The results indicate that the load following strategy can obviously extend battery’s lifespan, but the engine optimal strategy can reduce fuel consumption and emission effectively.

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