A Novel Solution for the Elimination of Mode Switching in Pump-Controlled Single-Rod Cylinders

Gøytil, Petter H.; Padovani, Damiano; Hansen, Michael Rygaard

doi:10.3390/act9010020

Cited by 15 publications

(12 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If desired, it is expected that this load dependence can be mitigated to a large extent by a feed-forward compensator based on measured pressures. As identified by previous work [22,23], Figures 8 and 9 show a discontinuity in the velocity as the valve moves from one regime with P A < P B where the ideal velocity is based on Q s /A B , to the other valve position when P A > P B where the velocity is based on Q s /A A . This effect is small for the system presented here as the ratio A A /A B = 1.19 is close to unity, and also, due to the fact that the valve spool has no centering spring, the valve rarely exists in a centered position with either both orifices open or closed.…”

Section: Discussionsupporting

confidence: 69%

A Low-Cost Miniature Electrohydrostatic Actuator System

Wiens

Deibert

2020

Actuators

View full text Add to dashboard Cite

Hydraulic linear actuators dominate in high power applications but are much less common in low power (<100 W) systems. One reason for this is the cost: electric actuators in this power range generally exhibit lower performance but are also much less expensive than hydraulic systems. However, in recent years, some miniature hydraulic components have been mass produced, driving down prices. This paper presents the application of these low-cost components, together with a novel very low-cost 3D-printed valve to create an electrohydrostatic actuator. Capable of very high power and force density, this system is competitive on cost with lower-performing electric actuators. This paper presents models for the system’s performance, as well as experimental validation data.

show abstract

Section: Discussionsupporting

confidence: 69%

A Low-Cost Miniature Electrohydrostatic Actuator System

Wiens

Deibert

2020

Actuators

View full text Add to dashboard Cite

show abstract

“…In Rahmfeld and Ivantysynova (2001); Padovani et al (2019); Schneider et al (2014) this is achieved using pilot-operated check valves. To avoid oscillatory valve switchings -so-called mode oscillation -for certain load situations, Padovani et al (2020); Gøytil et al (2020) suggests using actively controlled on/off valves. A common disadvantage of valvecompensated architectures compared to conventional valve-control, is the fact that the pressure in the low pressure chamber is close to the low pressure reservoir.…”

Section: Introductionmentioning

confidence: 99%

A Self-Contained Cylinder Drive with Indirectly Controlled Hydraulic Lock

Ketelsen¹,

Andersen²,

Ebbesen³

et al. 2020

MIC

View full text Add to dashboard Cite

This paper presents a self-contained pump-controlled hydraulic linear drive including an innovative load holding sub-circuit. For safety critical applications such as crane manipulators, locking valves or load holding valves are enforced by legislation, but the load holding functionality may also be used actively to decrease the energy consumption for applications where the load is kept stationary for longer periods of time. The system proposed in this paper is based on a simple hydraulic architecture using two variablespeed electric motors each connected to a fixed-displacement pump. This architecture is well-known in academic literature, but in this paper a novel load holding sub-circuit has been included. To control this load holding functionality, the low chamber pressure needs to be controlled accurately, while still being able to control the motion of the cylinder piston as well. Due to strong cross-couplings between cylinder piston motion and chamber pressures this task is non-trivial. The control for opening the locking valves is indirect in the sense that it is controlled via the chamber pressures, which are actively controlled. The fundamental control strategy presented in this paper is based on transforming the highly coupled physical states to virtual states, significantly reducing cross-couplings. As a case study, a two link medium sized knuckle boom crane is selected as an application example. Simulation results confirm the applicability of the proposed system. Appropriate position tracking performance has been achieved for the considered motion trajectory, while the low chamber pressure is controlled in a satisfying manner. A smooth transition from motion operating mode to load holding mode is achieved, with the system not requiring any input energy to keep the load stationary when the hydraulic cylinder lock is engaged.

show abstract

“…The simple approach can find its additional application in leak-diagnostic systems in a network of pipes, in pipelines connected with turbines, in the appropriate use of actuators, in the estimation of the density of the pumped liquid, etc. [31][32][33][34][35][36][37][38].…”

Section: Discussionmentioning

confidence: 99%

Simplified Indirect Estimation of Pump Flow Discharge: An Example from Serbia

Rašić-Amon

Radić

Stajić

et al. 2021

Water

View full text Add to dashboard Cite

In the absence of a flowmeter or due to its inaccuracy, the flow rate at the discharge section of the pipeline following the observed pump can be roughly estimated if the pressure can be measured instead. To use the proposed procedure two main conditions should be achieved: (1) a manometer should be installed at the discharge pipeline between the pump and the flow regulation valve, and (2) the actual curve that relates pressure and flow for the observed pump unit should be known in advance. The described example is from Serbia, but it is of interest for any water pumping station with a submersible pump (installed in wells or tanks) where a limited number of adequate places for the measuring of flow are available (if any are available at all), but where the pressure at the discharge pipe of the observed pump can be measured. This simplified method can find applicability in installations in remote rural regions where limited resources are available. The results show that the calculated values of the flow obtained by the presented method deviate greatly in relation to the measured values provided by the portable ultrasonic flowmeter, up to 60% at one of the measuring points. However, in relation to the measured values provided by the permanently installed flowmeter the discrepancy is significantly lower (0.6–6.8%).

show abstract

A Novel Solution for the Elimination of Mode Switching in Pump-Controlled Single-Rod Cylinders

Cited by 15 publications

References 15 publications

A Low-Cost Miniature Electrohydrostatic Actuator System

A Low-Cost Miniature Electrohydrostatic Actuator System

A Self-Contained Cylinder Drive with Indirectly Controlled Hydraulic Lock

Simplified Indirect Estimation of Pump Flow Discharge: An Example from Serbia

Contact Info

Product

Resources

About