scholarly journals Force control on direct driven servo hydraulic actuator

2021 ◽  
Author(s):  
Aleks Petrovič ◽  
Mihael Janežič ◽  
Vito Tič
Keyword(s):  
Force Control ◽  
Energy Efficient ◽  
Experimental Testing ◽  
Hydraulic Cylinder ◽  
Modern Concept ◽  
Experimental Setup ◽  
Hydraulic Systems ◽  
Hydraulic Actuator ◽  
Electric Drives

Direct Driven Servo Hydraulic Actuator also known as Pump Direct Driven Cylinder (PDDC) represents a decentralized modern concept of energy efficient cylinder control without damping loses of direction valves. Such systems have many advantages over conventional hydraulic systems and combine benefits of hydraulic and electric drives. PDDC system developed in Laboratory for Oil Hydraulics at University of Maribor consists of hydro motor, which is used as a reversible pump that is directly driven by servomotor and is designed for experimental testing with differential hydraulic cylinder. In this paper, the aforementioned system runs experimental setup for force control of hydraulic cylinder, with load produced by pneumatic bellow.

Simulacija i odstranjivanje stick-slip efekta servosistema sprovodnog aparata hidraulične turbine

2021 ◽  
Vol 23 (1) ◽  
pp. 37-41
Author(s):  
Darko Babunski ◽  
◽  
Emil Zaev ◽  
Atanasko Tuneski ◽  
Laze Trajkovski ◽  
...  
Keyword(s):  
Hydraulic Cylinder ◽  
Friction Model ◽  
Slip Effect ◽  
Hydraulic Systems ◽  
Hydraulic Actuator ◽  
Stick Slip ◽  
Hydro Turbine ◽  
Servo Mechanism ◽  
The Mathematical Model ◽  
Slip Phenomenon

Friction is a repeatable and undesirable problem in hydraulic systems where always has to be a tendency for its removal. In this paper, the friction model is presented through which the most accurate results are achieved and the way of friction compensation, approached trough technique presented with the mathematical model of a hydraulic cylinder of a hydro turbine wicket gate controlled by a servomechanism. Mathematical modelling of a servo mechanism and hydraulic actuator, and also the simulation of hydraulic cylinder as a part of a hydro turbine wicket gate hydraulic system where the stick-slip phenomenon is present between the system components that are in contact is presented. Applied results in this paper and the theory behind them precisely demonstrate under what circumstances the stick-slip phenomenon appears in such a system. The stick-slip effect is simulated using Simulink and Hopsan software and the analysis of the results are given in this paper. Removal of the stick-slip effect is presented with the design of a cascade control implemented to control the behaviour of the system and remove the appearance of a jerking motion.

Development of digital stroke sensing cylinder and its performance evaluation

Robotica ◽  
1996 ◽  
Vol 14 (6) ◽  
pp. 687-694 ◽  
Author(s):  
S.Y. Yang ◽  
M.C. Lee ◽  
M.H. Lee ◽  
S. Arimoto
Keyword(s):  
Signal Processing ◽  
Performance Evaluation ◽  
Digital Signal ◽  
Hydraulic Cylinder ◽  
Experimental Setup ◽  
Hydraulic Systems ◽  
Construction Machinery ◽  
Sensor Device ◽  
Hall Sensors ◽  
Heavy Construction

Automation of heavy construction machinery needs sensors that can detect each position under severe construction fields. Motivated by this need a hydraulic cylinder equipped with Hall sensors of Ga-As type has been developed. However, this sensor device has some problems associated with incorrect detection of positions owing to the existence of some magnetic slope and electric noises. To solve these problems, this paper proposes a digital stroke sensing cylinder enhanced by digital signal processing. An apparatus of two hydraulic systems coupled with each other is installed in an experimental setup to evaluate the performance of the developed digital stroke sensing cylinder. In order to control the position of a cylinder rod, a PWM method is used. Evaluation of the performance is carried out under artificial disturbances such as an impulse, addition of some magnetic slope, and additional noises.

scholarly journals Classification and Review of Pump-Controlled Differential Cylinder Drives

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1293 ◽  
Author(s):  
Søren Ketelsen ◽  
Damiano Padovani ◽  
Torben Andersen ◽  
Morten Ebbesen ◽  
Lasse Schmidt
Keyword(s):  
Small Volume ◽  
Hydraulic Cylinder ◽  
Future Research ◽  
Hydraulic Systems ◽  
Hydraulic Circuit ◽  
Variable Speed ◽  
Electric Drives ◽  
Variable Displacement ◽  
Oil Tank ◽  
Pump Controlled Cylinder

Pump-controlled hydraulic cylinder drives may offer improved energy efficiency, compactness, and plug-and-play installation compared to conventional valve-controlled hydraulic systems and thus have the potential of replacing conventional hydraulic systems as well as electro-mechanical alternatives. Since the late 1980s, research into how to configure the hydraulic circuit of pump-controlled cylinder drives has been ongoing, especially in terms of compensating the uneven flow requirements required by a differential cylinder. Recently, research has also focused on other aspects such as replacing a vented oil tank with a small-volume pressurized accumulator including the consequences of this in terms of thermal behavior. Numerous references describe the advantages and shortcomings of pump-controlled cylinder drives compared to conventional hydraulic systems or electro-mechanical drives. This paper presents a throughout literature review starting from the earliest concepts based on variable-displacement hydraulic pumps and vented reservoirs to newer concepts based on variable-speed electric drives and sealed reservoirs. By classifying these drives into several proposed classes it is found that the architectures considered in the literature reduce to a few basic layouts. Finally, the paper compares the advantages and shortcomings of each drive class and seek to predict future research tasks related to pump-controlled cylinder drives.

Development of lightweight hydraulic cylinder for humanoid robots applications

2017 ◽  
Vol 232 (18) ◽  
pp. 3351-3364 ◽  
Author(s):  
M Elasswad ◽  
A Tayba ◽  
A Abdellatif ◽  
S Alfayad ◽  
K Khalil
Keyword(s):  
Humanoid Robot ◽  
Mechanical Design ◽  
Experimental Testing ◽  
Fiber Composite ◽  
Humanoid Robots ◽  
Hydraulic Cylinder ◽  
Hydraulic Actuator ◽  
Carbon Fiber Composite ◽  
Robotic Applications ◽  
Actuator Performance

This paper presents a lightly weighted hydraulic actuator that is designed mainly for robotic applications. This hydraulic cylinder will be used as the main actuator for the hydraulic humanoid robot HYDROïD. For implementation, the knee joint is taken as an example in order to execute the necessary steps to build the actuator from carbon fiber composite material. An optimization process is used to minimize the total weight of the actuator and satisfy its constraints. Meanwhile, the mechanical design with the integrated sensors is shown. In addition, results are discussed on the spot of the weight minimization and actuator performance. Finally, experimental testing is carried out to monitor the pressure and the position readings of the hydraulic cylinder.

On/Off Valve Based Position Control of a Hydraulic Cylinder

2007 ◽  
Author(s):  
Michael B. Rannow ◽  
Perry Y. Li
Keyword(s):  
Position Control ◽  
Hydraulic Cylinder ◽  
Conventional Technique ◽  
Hydraulic Systems ◽  
Hydraulic Actuator ◽  
Nonlinear Controller ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Averaged Model ◽  
Valve Control

A method of precisely controlling the position of a hydraulic actuator using an on/off valve is developed. Since valves exhibit little power loss when they are fully open or fully closed, the proposed system is more efficient than throttling valve control and can achieve flow variation without the expense or bulk of a variable displacement pump. Mating a pulse-width-modulated (PWMed) on/off valve with a fixed displacement pump and a smoothing accumulator creates a software enabled variable displacement pump. A drawback of using digital valve control for hydraulic systems is that the relatively low speed of the currently available switching valves results in a significant ripple in the pressure and flow rate. We propose a solution to this problem by using a throttling valve to shield the actuator from the ripple in the output. This creates an effective load sensing system with the throttling valve used only to provide a small known pressure drop between the supply and the load. This approach is significantly more efficient than the conventional technique of using throttling to vary the full flow. This paper presents an averaged model of the system, a nonlinear controller to achieve position control of an actuator and a simulation based study of the effectiveness of the controller.

Force Control of a Hydraulic Actuator With a Neural Network Inverse Model

2021 ◽  
Vol 6 (2) ◽  
pp. 2814-2821
Author(s):  
Sung-Woo Kim ◽  
Buyoun Cho ◽  
Seunghoon Shin ◽  
Jun-Ho Oh ◽  
Jemin Hwangbo ◽  
...  
Keyword(s):  
Neural Network ◽  
Force Control ◽  
Inverse Model ◽  
Hydraulic Actuator

Modeling and Pressure-Based Force Control of a Hydraulic Actuator

1997 ◽  
Author(s):  
Scott M. Lyon ◽  
Mark S. Evans
Keyword(s):  
Dynamic Model ◽  
Force Control ◽  
Feedback Linearization ◽  
External Surface ◽  
Bond Graph ◽  
Hydraulic Pressure ◽  
Velocity Control ◽  
Hydraulic Actuator ◽  
Spool Valve ◽  
Piston Position

Abstract A dynamic model of a hydraulic actuator/spool valve combination is developed using the bond graph method. Feedback linearization is used to develop a force controller for the system using hydraulic pressure in each chamber of the actuator along with piston position and velocity as feedback. The use of a feedforward term to compensate for the seal friction within the actuator provides for a stable and accurate controller. Velocity control is achieved through calculation of the reference force required to overcome the seal friction and produce the acceleration required to reach the desired velocity. It is shown that the use of such a force controller allows for an acceptable transition from velocity to force control when the piston comes in contact with an external surface.

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