An Energy Efficient Method for Controlling Hydraulic Actuators Using Counterbalance Valves with Adjustable Pilot

2021 ◽  
Author(s):  
Annalisa Sciancalepore ◽  
Andrea Vacca ◽  
Steven T. Weber
Keyword(s):  
Control Strategies ◽  
Power Saving ◽  
External Pressure ◽  
Primary Control ◽  
Pressure Source ◽  
Smart System ◽  
System A ◽  
System Pressure ◽  
Hydraulic Machines ◽  
Hydraulic Crane

Abstract Counterbalance valves (CBVs) are widely used in hydraulic machines handling gravitational loads. They are usually adopted in hydraulic circuits that set the flow to the actuator with either metering control strategies or primary control strategies. In these circuits, the CBV does not determine the actuator velocity, but it establishes a proper counterpressure that balances the actuator during overrunning loads. A well-known problem of CBVs is the excessive power consumption introduced into the circuit, which is due to an excessive pressurization of the flow supply. This paper presents a solution for using CBVs to control the actuator velocity while also reducing energy consumption. The method consists in controlling the pilot port of the CBV through an external pressure source (adjustable pilot). The solution is first studied analytically, considering all the possible loading conditions at the actuator. Two different control strategies are presented: the "Smart CBV", where the CBV does not control the actuator velocity but it minimizes the system pressure; and the "Smart System" that uses the CBV to efficiently control the actuator velocity during overrunning load conditions. An experimental validation of the proposed solutions is also provided, taking as reference a truck-mounted hydraulic crane. The results of the proposed solutions are compared to those achieved by the traditional circuit of the reference hydraulic crane which uses standard CBVs. For both cases of "Smart CBV" and "Smart System", a remarkable power saving respectively up to 75% and up to 90% is observed.

A Review of Switched Inertance Hydraulic Converter Technology

2018 ◽  
Author(s):  
Chenggang Yuan ◽  
Min Pan ◽  
Andrew Plummer
Keyword(s):  
Power Management ◽  
Energy Efficient ◽  
Control Strategies ◽  
New Technology ◽  
High Energy ◽  
Management Systems ◽  
Hydraulic Power ◽  
Controlled Systems ◽  
Hydraulic Machines ◽  
And Control

Digital hydraulics is a new technology providing an alternative to conventional proportional or servovalve-controlled systems in the area of fluid power. Research is driven by the need for highly energy efficient hydraulic machines but is relatively immature compared to other energy-saving technologies. Digital hydraulic applications, such as digital pumps, digital valves and actuators, switched inertance hydraulic converters (SIHCs) and digital hydraulic power management systems, all promise high energy efficiency. This review introduces the development of SIHCs and evaluates the device configurations, performance and control strategies that are found in current SIHC research, particularly focusing on the work being undertaken in last 15 years. The designs for highspeed switching valves are evaluated, and their advantages and limitations are discussed. This article concludes with some suggestions for the future development of SIHCs.

scholarly journals Rotor Position Synchronization in Central-Converter Multi-Motor Electric Actuation Systems

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7485
Author(s):  
Cláudio de Andrade Lima ◽  
James Cale ◽  
Kamran Eftekhari Shahroudi
Keyword(s):  
Case Studies ◽  
Control Strategies ◽  
Induction Machines ◽  
Power Electronic ◽  
Primary Control ◽  
Rotor Position ◽  
Electromagnetic Transient Simulation ◽  
Electrical Motors ◽  
Drive Systems ◽  
Actuation Systems

The aerospace industry is increasingly transitioning from hydraulic and pneumatic drives to power-electronic based drive systems for reduced weight and maintenance. Electromechanical thrust reverse actuation systems (EM-TRAS) are currently being considered as a replacement for mechanical based TRAS for future aircraft. An EM-TRAS consists of one or more power-electronic drives, electrical motors, and gear-trains that extend/retract mechanical members to produce a drag force that decelerates the aircraft upon landing. The use of a single (“central”) power electronic converter to simultaneously control a set of parallel induction machines is a potentially inexpensive and robust method for implementing EM-TRAS. However, because the electrical motors may experience different shaft torques—arising from differences in wind forces and a flexible nacelle—a method to implement rotor position synchronization in central-converter multi-motor (CCMM) architectures is needed. This paper introduces a novel method for achieving position synchronization within CCMM architecture by using closed-loop feedback of variable stator resistances in parallel induction machines. The feasibility of the method is demonstrated in several case studies using electromagnetic transient simulation on a set of parallel induction machines experiencing different load torque conditions, with the central converter implementing both voltage-based and current-based primary control strategies. The key result of the paper is that the CCMM architecture with proposed feedback control strategy is shown in these case studies to dynamically drive the position synchronization error to zero. The initial findings indicate that the CCMM architecture with induction motors may be a viable option for implementing EM-TRAS in future aircraft.

scholarly journals Comparative study of a small size wind generation system efficiency for battery charging

2013 ◽  
Vol 10 (2) ◽  
pp. 261-274 ◽  
Author(s):  
Messaoud Mayouf ◽  
Rachid Abdessemed
Keyword(s):  
Control Strategies ◽  
Power Converter ◽  
Maximum Power ◽  
Wind Generation ◽  
Direct Drive ◽  
Generation System ◽  
Battery Charging ◽  
Pulse Width Modulated ◽  
System A ◽  
Wind Generation System

This paper presents an energetic comparison between two control strategies of a small size wind generation system for battery charging. The output voltage of the direct drive PMSG is connected to the battery through a switch mode rectifier. A DC-DC boost converter is used to regulate the battery bank current in order to achieve maximum power from the wind. A maximum powertracking algorithm calculates the current command that corresponds to maximum power output of the turbine. The DC-DC converter uses this current to calculate the duty cycle witch is necessary to control the pulse width modulated (PWM) active switching device (IGPT). The system overview and modeling are presented including characteristics of wind turbine, generator, batteries, power converter, control system, and supervisory system. A simulation of the system is performed using MATLAB/SIMULINK.

scholarly journals Robustness Comparison of Synthetic Inertia Strategies for Doubly Fed Induction Generators under Different Operating Conditions

2020 ◽  
Author(s):  
Paulo Andrade Souza ◽  
Renan R. dos Santos ◽  
Manoelito C. N. Filho ◽  
Daniel Barbosa ◽  
Luciano Sales Barros
Keyword(s):  
Wind Energy ◽  
Large Scale ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Operating Conditions ◽  
Wind Condition ◽  
Primary Control ◽  
Parameter Uncertainties ◽  
Doubly Fed ◽  
Frequency Behavior

Due to the increasing penetration of Renewable Energy Sources (RES) such as wind energy in electrical grids, Wind Energy Conversion Systems (WECS) participation in primary control is becoming required including the Doubly Fed Induction Generator (DFIG)-based WECS. High integration of large scale DFIG-based WECS brings new challenges to their primary control support, and more strongly due to the wind condition and grid parameter uncertainties. One of the most used types of control strategy for DFIG-based WECS primary support is the synthetic inertia, however, robustness of these techniques have not been tested. In this work three synthetic inertia control strategies will be tested under different operating conditions of wind speed, frequency and voltage sag. For testing the DFIG-based WECS, it was modeled on ATP including its control systems and the results quantified the controllers robustness on the tested controllers with respect to transient frequency behavior.

Does Aging and Disease Increase the Importance of Cognitive Strategies? Social and Temporal Comparisons in Healthy Younger and Older Adults and in Younger and Older Cancer Patients

2017 ◽  
Vol 88 (1) ◽  
pp. 60-81
Author(s):  
Mimi Mehlsen ◽  
Mai Bjørnskov Mikkelsen ◽  
Christina Maar Andersen ◽  
Chaitali Ollars
Keyword(s):  
Older Adults ◽  
Cancer Patients ◽  
Control Strategies ◽  
Cognitive Strategies ◽  
Well Being ◽  
Primary Control ◽  
Physical Decline ◽  
Age Related ◽  
Older Cancer Patients ◽  
The Individual

Social and temporal comparisons may help the individual anchor his or her self-image in a social and temporal context. In the Life-Span Theory of Control, comparisons are included in the repertoire of secondary control strategies individuals may apply when primary control strategies are obstructed, for example, by age-related losses or physical decline. The aim of this study was to explore differences in prevalence and effects of social and temporal comparisons in younger and older adults and healthy and diseased individuals ( n = 34). Semistructured interviews were conducted and analyzed using a mixed-methods approach combining qualitative and quantitative data analysis. The results revealed that older adults engaged in more comparisons than younger adults and that the outcomes of comparisons were more positive for older adults, particularly older cancer patients. The results indicate that comparisons may be applied more often by older and diseased individuals in the service of maintaining well-being.

A Review of Switched Inertance Hydraulic Converter Technology1

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Chenggang Yuan ◽  
Min Pan ◽  
Andrew Plummer
Keyword(s):  
Energy Efficient ◽  
High Speed ◽  
Control Strategies ◽  
New Technology ◽  
High Energy ◽  
Hydraulic Power ◽  
Controlled Systems ◽  
Hydraulic Machines ◽  
And Control ◽  
High Speed Switching

Abstract Digital hydraulics is a new technology providing an alternative to conventional proportional or servovalve-controlled systems in the area of fluid power. Digital hydraulic applications, such as digital pumps, digital valves and actuators, switched inertance hydraulic converters (SIHCs), and digital hydraulic power management systems, promise high-energy efficiency and less contamination sensitivity. Research on digital hydraulics is driven by the need for highly energy efficient hydraulic machines but is relatively immature compared to other energy-saving technologies. This review introduces the development of SIHCs particularly focusing on the work being undertaken in the last 15 years and evaluates the device configurations, performance, and control strategies that are found in the current SIHC research. Various designs for high-speed switching valves are presented, and their advantages and limitations are compared and discussed. The current limitations of SIHCs are discussed and suggestions for the future development of SIHCs are made.

A Virtual Environment for the Simulation and Programming of Excavation Trajectories

2001 ◽  
Vol 10 (5) ◽  
pp. 465-476 ◽  
Author(s):  
Simon P. DiMaio ◽  
Septimiu E. Salcudean ◽  
Claude Reboulet
Keyword(s):  
Virtual Environment ◽  
Force Feedback ◽  
Control Strategies ◽  
Haptic Interface ◽  
Visual Environment ◽  
Heavy Duty ◽  
Interaction Forces ◽  
Impedance Model ◽  
Hydraulic Machines ◽  
Human Operators

An excavator simulator has been developed to facilitate the training of human operators and to evaluate control strategies for heavy-duty hydraulic machines. The operator controls a virtual excavator by means of a joystick while experiencing visual and force feedback generated by environment and machine models. The simulator comprises an impedance model of the excavator arm, a model for the bucket-ground interaction forces, a graphically rendered visual environment, and a haptic interface. This paper describes the simulator components and their integration.

scholarly journals Control Strategies and Daily Affect

GeroPsych ◽  
2020 ◽  
Vol 33 (3) ◽  
pp. 155-169
Author(s):  
Nina Knoll ◽  
Jan Keller ◽  
Aleksandra Luszczynska ◽  
Urte Scholz ◽  
Christina Röcke ◽  
...  
Keyword(s):  
Negative Affect ◽  
Control Strategies ◽  
Functional Limitations ◽  
Goal Pursuit ◽  
Personal Resources ◽  
Primary Control ◽  
Heterosexual Couples ◽  
Diary Data ◽  
Technical Aids ◽  
Daily Affect

Abstract. Adjusting strategies to manage daily goal pursuit with new functional limitations may impact not only the affect of patients, but also that of their partners. Associations between patients’ control strategies and both partners’ affect were examined at the onset of patients’ incontinence following prostatectomy. Eight-day diary data from 180 heterosexual couples were used to fit two-level models. In patients, investing personal resources to keep up goal pursuit despite incontinence (selective primary control) was associated with better affect, particularly when incontinence was pronounced. Yet, partners’ decreased negative affect coincided with patients’ asking for help and using technical aids (compensatory primary control) when the incontinence was severe. Patients and partners may benefit from different control strategies used by patients, especially when their functional limitations are pronounced.

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