Improving Efficiency of Micro Excavator With Decentralized Hydraulics

Author(s):  
Shuzhong Zhang ◽  
Tatiana Minav ◽  
Matti Pietola

Government regulations incentivize investigation of the potential for hybridization of non-road mobile machinery (NRMM). Many approaches to energy saving in hydraulic systems have been established. One of the methods first introduced in the aerospace industry is “decentralized” or “zonal” hydraulics. The decentralized system is realized with pump-controlled actuators, which are distributed throughout the system. In this research, decentralized hydraulics are realized with a direct-driven hydraulics (DDH) drive and implemented on a 1-ton class JCB micro excavator. The original valve-controlled system for boom, stick, and bucket is replaced with three DDH units. In a DDH unit, a double fixed displacement pump/motors with a speed-controlled electric servomotor directly controls the amount of hydraulic oil pumped into and out of the system. The hydraulic pump/motors create flows dependant on the rotating speed of the servomotor. A hydraulic accumulator is used as a conventional tank replacement. The aim of this paper is to investigate the efficiency improvement of the excavator with decentralized hydraulics compared to an electrified conventional load sensing system, from an energy consumption point of view under a typical digging cycle. In order to acquire the energy consumption distributions of the DDH and load sensing (LS) system, a model of the micro excavator which comprises mechanics, hydraulics, electronics, and control systems is developed in Matlab/Simulink. Simulation results demonstrate that the total efficiency of the excavator with LS control is 18.3%, and with DDH (decentralized hydraulics) is 71.3 % for a selected typical working cycle.

Author(s):  
Sanjar Mirzaliev ◽  
Kungratbai Sharipov

Nowadays energy saving is a topical issue due to increasing fuel costs and this aspect is amplified by more stringent emissions regulations that impact on vehicle development. A recent study conducted by the U.S. Department of Energy shows that about five percent of the U.S. energy consumption is transmitted by fluid power equipment. Nevertheless, this study also shows that the efficiency of fluid power averages 21 percent. This offers a huge opportunity to improve the current state-of-the-art of fluid power machines, in particular to improve the energy consumption of current applications. These facts dictate a continuous strive toward improvements and more efficient solutions: to accomplish this objective a strong reduction of hydraulic losses and better control strategies of the hydraulic systems are needed. In fluid power, there exist many techniques to reduce/recover energy losses of the conventional layouts, e.g. load sensing, electrohydraulic flow matching, independent metering, etc. One of the most efficient ways to analyze these different layouts and identify the best hydraulic solution is done through virtual simulations instead of prototyping, since the latter involves higher investment costs to deliver the product into the market. However, to build a fluid power machine virtual model, some problems arise relative to different aspects, for instance: loads on actuators (both linear and rotational) are not constant and pumps are driven by a real engine whose speed depends on required torque. Furthermore, it is important to achieve higher level of detail to simulate each component in the circuit: the greater detail, the better the machine behavior is portrayed, but it obviously entails heavy impact on simulation time and computational resources. Therefore, there is a need to create mathematical model of components and systems with sufficient level of detail to easily acquire all those phenomena necessary to correctly evaluate machine performance and make modifications to the fluid power component design. In this context, a hydraulic proportional valve PVG 32 by Danfoss is taken as an object of study, its performance is analyzed with suitable mathematical model and simulation is done to observe closeness of a model to the laboratory experiment.


Author(s):  
Joshua D. Zimmerman ◽  
Matteo Pelosi ◽  
Christopher A. Williamson ◽  
Monika Ivantysynova

This paper presents the results of a simulation study regarding the energy consumption of a load-sensing excavator hydraulic system and discusses the possible energy savings by eliminating the directional control valves. The energy consumption of the excavator hydraulic system has been studied for typical working cycles. For this purpose a coupled multi-body dynamics and hydraulic system model was developed in the Matlab Simulink environment, including a precise measurement-based loss model of the variable displacement pump. Power transmission and dissipation was calculated for each component and subsystem, including pumps, motors, valves, cylinders, transmission lines, and others. The simulation results show the amount of dissipated energy, indicating the major loss sources during various operations. Furthermore, the potential recoverable energy in the cycle is calculated, highlighting the prospective advantages of equipping the existing machine with new pump-controlled actuator technology.


Author(s):  
Arnold Hießl ◽  
Rudolf Scheidl

A series of detailed measurements of various mechanical and hydraulic system states of different excavators was performed. Main purpose of this study was to obtain a reliable information basis for assessing the potentials of hybrid drives, in particular the amount of recoverable energy. Differences concerned the size (tonnage) of the excavators and the hydraulic systems, open center versus load sensing. All machines were tested at the same set of operation scenarios, which are typical for practice, and with different operators. To this end, all test machines have been equipped with pressure, flow rate, temperature, angular and position sensors. These signals (about sixty) and several available from the machines CAN bus were recorded with a standard data acquisition system and electronically stored for later analysis. These raw data were processed to obtain the interesting data, like speeds, power flows, energies. In addition, videos of each test were recorded to facilitate the correct interpretation of the measurements and their correlation with the actual working processes. Power flows from the combustion engine, different pumps, and at each actuator and energetic losses at the different loss sources were plotted for the different operation scenarios. Total efficiencies of the machines for different scenarios and the energy in and outflow at each actuator were computed. From the latter so called relative and absolute recovery degrees for each actuator and for the total machine in the different operation scenarios were derived. The relative recovery degree is the ratio of the total outflow energy (second and fourth quadrant) and the total inflow energy (first and third quadrant). The absolute recovery degree is the ratio of the total outflow energy of an actuator and the total energy delivered by all pumps in an operation scenario. In most operation scenarios the total efficiency of consumed mechanical output energy at the hydraulic actuators relative to delivered hydraulic energy is in the range 15% to 25%. Reasonable recovery potentials do have the swing and the boom drive. For small machines, however, the boom drive dominates.


2001 ◽  
Author(s):  
Timo J. Käppi

Abstract In this paper modeling of variable displacement pump system is discussed. The system described is typically used in mobile hydraulic applications. An easy-to-parameterize loss model is presented which is based on the Dorey’s model. The model identification is done semi-empirically with a reduced number of parameters. Two parameters are required to identify the volumetric losses and four to determine the hydromechanical efficiency. The accuracy of the loss model is proven by comparing calculated values between the measured values of a commercial axial piston pump. The relative error in total efficiency is less than 4% over the whole range of variables and thus acceptable. The pump system model presented includes the operation of load sensing regulator and power restrictor. The pump system model also includes the dynamic effect of a load sensing line from the mobile valve to the pump regulator and the first order dynamics of the pump itself. The suggested model is usable in carrying out the system level simulation of mobile hydraulic machine systems. Simple examples demonstrate the application.


2019 ◽  
Vol 942 (12) ◽  
pp. 22-28
Author(s):  
A.V. Materuhin ◽  
V.V. Shakhov ◽  
O.D. Sokolova

Optimization of energy consumption in geosensor networks is a very important factor in ensuring stability, since geosensors used for environmental monitoring have limited possibilities for recharging batteries. The article is a concise presentation of the research results in the area of increasing the energy consumption efficiency for the process of collecting spatio-temporal data with wireless geosensor networks. It is shown that in the currently used configurations of geosensor networks there is a predominant direction of the transmitted traffic, which leads to the fact that through the routing nodes that are close to the sinks, a much more traffic passes than through other network nodes. Thus, an imbalance of energy consumption arises in the network, which leads to a decrease in the autonomous operation time of the entire wireless geosensor networks. It is proposed to use the possible mobility of sinks as an optimization resource. A mathematical model for the analysis of the lifetime of a wireless geosensor network using mobile sinks is proposed. The model is analyzed from the point of view of optimization energy consumption by sensors. The proposed approach allows increasing the lifetime of wireless geosensor networks by optimizing the relocation of mobile sinks.


10.14311/1622 ◽  
2012 ◽  
Vol 52 (5) ◽  
Author(s):  
Juraj Beniak ◽  
Juraj Ondruška ◽  
Viliam Čačko

The shredding process has not been sufficiently investigated for the design of better, energy and material saving shredding machines. In connection with present-day concern about the environment, ecology, energy saving, recycling, and finding new sources of energy, we need to look at the design of shredding machinery, the efficiency of the machines that we using, and ways of improving them to save electric energy for their operation. This paper deals with sizing and designing shredding machines from the point of view of energy consumption and optimization for specific types of processed material.


2020 ◽  
Vol 11 (3) ◽  
pp. 11054-11065

The article is devoted to the study of the forms of moisture bond in mature cheeses. The kinetics of mass transfer processes depend on the mobility and binding energy of water with solid and dissolved substances. Therefore, the removal of bound water is accompanied by deterioration in kinetics and increased energy consumption. In this regard, information on the state of bound water in substances during dehydration is very important from a scientific point of view and from a practical one. Based on the studies carried out, the forms of moisture bond in various types of cheese were determined by strain-gauge and thermographic methods. Based on this, it has been established that the forms of moisture bond in cheeses can be determined by strain-gauge and thermographic methods.


Author(s):  
Kjeld Thomsen ◽  
Christian Riis Petersen

<p>The present paper describes developments in the design of the most common types of movable bridges – Bascule bridges and Swing Bridges. The selection of design concepts is influenced by span, foundation conditions as well as environmental issues. Application of modern hydraulic systems and innovative bearing types for swing bridges facilitate the creation of outstanding designs. Recently built moveable bridges in Denmark exemplifies the trend and how application of modern technology and creativity can lead to outstanding solutions. There are many governing parameters such as the span, free opening height and loading conditions. Equally important issues such as surroundings, landscape, foundation conditions, requirement to low weight, achievable tolerances and from a mechanical point of view, the operation time. Risk assessment, mechanical- and electrical systems and the requirement to operation time and maintenance cost, will have influence on the selection of machinery and the architectural and structural design. For each of the moveable bridges described, it is shown how innovative application of modern bearing concepts and hydraulic systems can lead to elegant and cost-effective solutions.</p>


2015 ◽  
Vol 811 ◽  
pp. 45-49
Author(s):  
Dan Prodan ◽  
Anca Bucuresteanu ◽  
Adrian Motomancea ◽  
Emilia Balan

This paper shows several issues related to decrease in electric power consumption for hydraulic systems of modern machine tools, especially CNCs. A core element in the structure of such systems is the pneumo-hydraulic accumulator. Here, examples are shown for hydraulic systems destined to locking and unlocking of skids and to opening of tool holders. This paper shows mathematical models, diagrams, simulations and certain experimental executions.


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