Position Control of an Over‐Actuated Direct Hydraulic Cylinder Drive

Schmidt, Lasse; Groenkjaer, Morten; Pedersen, Henrik C.; Andersen, Torben Ole

doi:10.1016/j.conengprac.2017.04.003

Cited by 34 publications

(33 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To avoid low-pressure operation, which is an inherent feature of the double pump configuration [77,78] added a third pump which is only active in the forward direction, see Figure 6c. Using advanced control functionality, it is possible to control the pressure level (i.e., the minimum chamber pressure) and thus the drive stiffness during motion.…”

Section: Class B-variable-speed Single Prime Mover With Multiple Pumpsmentioning

confidence: 99%

“…So far, this problem has not been solved without including an additional charge source. The authors in [78] succeeded in controlling the drive stiffness for a single variable-speed prime mover architecture, but only during motion of the cylinder piston. If two prime movers are used (class C), multiple researchers used this additional degree-of-freedom to control a pressure state as well as the cylinder motion to attain a reasonable drive stiffness.…”

Section: Ability To Control Drive Stiffnessmentioning

confidence: 99%

See 1 more Smart Citation

Classification and Review of Pump-Controlled Differential Cylinder Drives

et al. 2019

Self Cite

View full text Add to dashboard Cite

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. IntroductionWith an increased industrial focus on energy efficiency, plug-and-play installation, and compactness, conventional valve-controlled hydraulic cylinder drives are increasingly being replaced by electro-mechanical alternatives, such as roller or ball screws [1], especially for small power classes. This happens despite the well-known advantages of hydraulic linear actuation such as large force/power densities, reliability, and robustness. Hydraulic actuation is, however, still the preferred solution for many applications such as industrial presses, large mobile machinery, crane manipulators, primary aircraft control etc. [2][3][4]. Among other reasons this is due to certain limitations for the electro-mechanical alternatives, such as limited reliability (e.g., shock loads damage), the difficulties of implementing overload/failure protection and/or limited force capabilities [5][6][7]. To strengthen the position regarding these applications and to make hydraulic cylinder drives competitive with electro-mechanical drives for low power applications, there is a need to enhance both the energy efficiency and the overall flexibility of hydraulic cylinder drives.The flexibility of a hydraulic system may be related to how power is being distributed between the prime mover and the actuator(s). As illustrated in Figure 1, at least three different power distribution topologies exist: hydraulic, mechanical, and electrical distribution.

show abstract

Section: Class B-variable-speed Single Prime Mover With Multiple Pumpsmentioning

confidence: 99%

Section: Ability To Control Drive Stiffnessmentioning

confidence: 99%

Classification and Review of Pump-Controlled Differential Cylinder Drives

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Direct cylinder drives based on variable displacement units, rectifying bridges, hydraulic accumulator and/or other energy recovering solutions have been proposed (Heybroek et al, 2008(Heybroek et al, , 2006Ivantysynova and Rahmfeld, 1998;Zimmerman and Ivantysynova, 2011;Mingdong and Dingxuan, 2011). Alternatively, low cost solution direct pump control concept has been investigated (Schmidt et al, 2017(Schmidt et al, , 2015Ketelsen et al, 2018). However, all of these concepts require multiple pump units for each cylinder to achieve the desired redundancy, why the solutions become both expensive and complex.…”

Section: Introductionmentioning

confidence: 99%

Control of an Energy Efficient Hydraulic Cylinder Drive with Multiple Pressure Lines

Pedersen¹,

Jensen

Hansen³

et al. 2018

MIC

View full text Add to dashboard Cite

This paper concerns a novel energy efficient hydraulic cylinder drive concept, consisting of three pressure lines used to supply a hydraulic cylinder(s). The proposed concept allows for reduced throttling losses compared to conventional solutions, while maintaining accurately cylinder control. One application where the concept shows great potential is as the actuation system for life tests of large mechanical structures, where structure deflections is made through cylinder force control. This work contributes to the development and control of this hydraulic concept, where the purpose is to obtain a high energy efficiency and an accurate cylinder force control. The final concept design is implemented in simulation models, where the performance of the developed control system is investigated to verify that the control performance is satisfactory. Furthermore, the energy efficiency is compared to a conventional hydraulic concept to verify the feasibility. Through simulation models, control performance similar to a conventional hydraulic concept has been obtained with the proposed control structure, while reducing the hydraulic energy consumption by up to 50 %. Based on the findings in this paper it is assessed that the concept is ready for experimental validation.

show abstract

“…It is based on multiple fixed-displacement pumps/motors driven by a common variable-speed prime mover. Alternatives with two hydraulic units [6,[16][17][18] or with three hydraulic units [19][20][21] exist.…”

mentioning

confidence: 99%

“…Table 1 provides a synthesis of these options. [6,[16][17][18][19][20][21]46] Additionally, limited researches addressed passive load-holding capabilities for SCCs. This feature serves the purpose of maintaining a given actuator position without supplying any power to the system.…”

mentioning

confidence: 99%

A Self-Contained Electro-Hydraulic Cylinder with Passive Load-Holding Capability

et al. 2019

Self Cite

View full text Add to dashboard Cite

Self-contained electro-hydraulic cylinders have the potential to replace both conventional hydraulic systems and the electro-mechanical counterparts enhancing energy efficiency, plug-and-play installation, and reduced maintenance. Current commercial solutions of this technology are limited and typically tailor-made, whereas the research emphasis is primarily on cost efficiency and power applications below five [kW]. Therefore, there is the need of developing more flexible systems adaptable to multiple applications. This research paper offers a contribution in this regard. It presents an electro-hydraulic self-contained single-rod cylinder with passive load-holding capability, sealed tank, capable of recovering energy, and scalable up to about eighty [kW]. The system implementation on a single-boom crane confirms its feasibility: The position tracking error remains well within ±2 [mm], oscillations are limited, and the overall energy efficiency is about 60 [%] during actuation. Concerning the passive load-holding devices, it is shown that both vented and non-vented pilot-operated check valves achieve the desired functioning and can hold the actuator position without consuming energy. Additional observations about the size and the arrangement of the load-holding valves are also provided. In conclusion, this paper demonstrates that the proposed self-contained cylinder can be successfully extended to several practical applications, especially to those characterized by overrunning external loads and the need of securing the actuator position.

show abstract

Position Control of an Over‐Actuated Direct Hydraulic Cylinder Drive

Cited by 34 publications

References 12 publications

Classification and Review of Pump-Controlled Differential Cylinder Drives

Classification and Review of Pump-Controlled Differential Cylinder Drives

Control of an Energy Efficient Hydraulic Cylinder Drive with Multiple Pressure Lines

A Self-Contained Electro-Hydraulic Cylinder with Passive Load-Holding Capability

Contact Info

Product

Resources

About