Project 1A2: Optimal Power Management for Mobile Fluid Power Machines
using Displacement-Controlled Actuators
1. Research Team
Project Leader:
Prof. Monika Ivantysynova, ABE/ME, Purdue
Other Faculty:
Prof. Kim Stelson, ME, UM
Prof. Andrew Alleyne, ME, UM
Prof. Perry Li, ME, UM
Post Doc(s):
Graduate Students:
Christopher Williamson (Purdue)
Joshua Zimmermann (Purdue)
Matteo Pelosi (Purdue, visiting researcher)
Undergraduate
Students:
TBD
Industrial Partner(s):
Bobcat, Parker Hannifin, Caterpillar?
2. Statement of Project Goals
The goal of this project is to develop system architectures and control methods for optimal power
management in multi-actuator mobile hydraulic machines using displacement-controlled linear
and rotary actuators. These concepts will reduce overall machine fuel consumption through use
of displacement controlled actuators by avoiding throttling losses and allowing energy recovery.
Additional fuel savings are expected due to end effecter control based on path optimization and
effective engine management.
3. Project Role in Support of Strategic Plan
The project primarily addresses the efficiency barrier by developing new system concepts and
control strategies for multi-actuator mobile machines. The project also addresses the
compactness barrier since displacement-controlled systems allow higher operating pressures and
a reduction of interfaces and components.
4. Overall Project Scope Summary
The primary desired result of this project is reduced fuel consumption by hydraulically-powered
mobile machines. This will be accomplished through three major innovations: (1) development
of system architectures that allow the use of potential and brake energy without adding an energy
storage system to the machine, (2) actively managing the generation and transmission of power
from an IC engine to multiple hydraulic actuators involving path optimization in order to
minimize power consumption while simultaneously satisfying machine performance
requirements, and (3) using pump-controlled linear and rotary actuator systems based on
previous work done by the research group of Ivantysynova.
The project specifically focuses on the class of mobile machines with redundant kinematics that
use multiple linear and rotary hydraulic actuators simultaneously. Many vehicles of this type are
currently in use, including excavators, cranes, telehandlers, and new types like large mobile
robots are under development. The project will be closely related to the development of systems
and controls for the excavator testbed. However, the project goal is to develop methods which
are generally applicable to many mobile machines and not one specific application or working
cycle. Actuator systems based on resistance control are outside of the project scope. The methods
developed in this project could be applied to teleoperated machines, however teleoperation is not
the focus of this project.
5. Description and explanation of research approach
One of the greatest strengths of fluid power technology is power density, the ability to exert large
forces and torques using actuators of relatively small mass. Because of this fact, fluid power
components are ubiquitous in applications such as agriculture, mining, construction, and
manufacturing. As a tradeoff, the efficiency of fluid power systems is relatively low when
compared to methods of transmitting power mechanically or electrically. This was not a
significant concern in the past, but has become increasingly important with rising fuel prices and
increasingly stringent emissions requirements.
Project 1A2 focuses on improving the overall efficiency of mobile machines with multiple linear
and rotary actuators. Advances in system efficiency will be obtained by:
1. Displacement-controlled actuator systems that eliminate throttling losses
2. Real-time engine and pump management in order to operate each component of the
powertrain as close to optimal efficiency as possible
3. Energy recovery without additional storage devices by sharing power between actuators
4. Optimizing machine motion in order to maximize energy recovery and minimize fuel
consumption
The state of the art will be summarized by topic, followed by a description of the main methods
proposed to accomplish the project objectives.
5A. State of the Art: Displacement-Controlled Actuators
In today’s mobile machines, working hydraulics are controlled almost exclusively by valves.
Valve control allows a simple realization of open loop motion control and load holding tasks, in
which the hydraulic actuators are usually supplied by a central pressure source. Displacementcontrolled hydrostatic transmissions are an exception to this rule, as they are often used as
propulsion drives for smaller mobile machines.
Replacing of valve-controlled systems with displacement control was the subject of diverse
research works at universities in the 1990s [4,5,8,27-29,52,53] and of development projects in
industry [1,2,3]. These projects sought to transfer the previously known concept of a closed
hydraulic circuit drive from special stationary applications to applications in a higher power
range. The achievable dynamic performance and the development of control concepts were of
principle interest [7,8,52]. With new circuit solutions, design, and control techniques it has been
demonstrated that displacement controlled actuator are able to achieve a dynamic behavior
comparable to valve controlled servo drives [8-10]. The first real implementations can be found
in stationary hydraulics: e.g. press industry, injection molding machines, etc. For mobile
machines, load-sensing systems (working in an open control loop) are mainly used currently. In
spite of some research work dealing with electrohydraulic load-sensing [12,13,17,30,50,51] this
drive technology is not used in practice at the moment due to an extended signal control and
sensor effort. Feedback control, which will be required more and more in mobile machines in
the future, load-sensing technology leads to additional complicated control and stability
problems. In this case multi-variable control concepts have to be applied, which are able to
adapt the system pressure online during wide changes in the particular control plants. As
mentioned earlier, displacement-controlled linear drives represent an alternative.
Mainly because of space reasons, single rod cylinders are used almost exclusively as linear
actuators for the working boom structures of today’s mobile machines. To operate a single rod
cylinder in a closed hydraulic circuit with a servo pump as the final control element, appropriate
circuit solutions are necessary in order to balance the unequal flow rates entering and leaving the
cylinder volumes. Several concepts can be found in the literature [14,15,28,29,40,41] that were
developed mainly for stationary applications. Due to the relatively high number of components,
and in some cases very complicated multi-variable control concepts, these circuit concepts are
not suitable for mobile machines. Replacing valve-controlled actuators with displacementcontrolled actuators that require two or more displacement units and perhaps even more
components is too extensive for mobile machines and therefore not acceptable.
For example, Berbuer [8] in 1988 introduced a hydraulic transformer for the volume flow
compensation of the single rod cylinder. Continued implementation of a hydraulic transformer
with an additional variable displacement pump was developed by Lodewyks in 1993 and 1994
[28,29] . In this case, the transformer ratio had to be designed to the single rod cylinder area
ratio. Lodewyks further noted that by adding a variable displacement pump with a sum pressure
control valve (pressurized low pressure) the actuator eigenfrequency can be increased.
Lodewyks also researched the use of two servo pumps for the single rod cylinder in a multivariable control concept and in a single variable control concept. The single variable control
concept was realized with a sum pressure control valve and an additional pressure source. Next
to the development of suitable control concepts, Lodewyks proved some of his results on
stationary test rigs.
The use of two servo pumps [14,15] in a multi-variable control concept, in which one pump
works in position and the other pump in a pressure control, was also introduced by Feuser et al.
However, a four-quadrant operation of multiple actuators according to this concept leads to a
high installation cost for the pressure controlled units to realize parallel actuator movements.
An innovative hydraulic transformer, which is based on the bent axis principle, was developed
by INNAS [1-3]. It contains three ports, where the control of volume flow to the individual ports
is achieved by controlling the valve plate. This transformer can only be used for the single rod
cylinder in four quadrant operation together with an additional high pressure source. However, it
must be noted that this additional high pressure source has to be sufficient in size for all single
rod cylinders. And for each actuator one bent axis transformer needs to be implemented in the
overall machine system. A fork lift machine with two-quadrant cylinders was equipped with this
hydraulic drive technology as a prototype [2].
Another concept [6,40,41] consists mainly of a fixed displacement pump working together with a
control valve, a switch valve and a check valve. Here the rod-side chamber of the single rod
cylinder is only connected to an accumulator, so that a four quadrant operation cannot be realized
in all operating points. This concept was also successfully implemented and tested in a
stationary industry application.
Many authors have investigated displacement-controlled actuators with double-rod cylinders or
rotary motors. For instance, Hahmann in 1973 [19] and Kreth in 1979 [26] analyzed the
dynamic behavior of displacement controlled drives generally. They found out that these drives
are well-suited for control tasks. Sprockhoff mainly focused his work on control concepts on
displacement-controlled actuators with double rod cylinders [46,47]. Roth in 1983 [42]
developed control concepts for actuators with rotational motors in position control. Both
researchers concluded that the best dynamic behavior can be realized with acceleration or
pressure feedback as a partial state feedback.
Roth and Berbuer, mainly motivated by possible energy savings and achievable high dynamics,
presented the parallel use of servo pumps and servo valves [8,42]. Berbuer decoupled the
electrical signals so that the servo valve was only used for high frequency outputs. Next to these
concepts, according to research on displacement controlled actuators with single rod cylinders
the works dealing with the use of a variable speed servo pump can be mentioned here [18,43].
But for the implementation in mobile machines with an open loop controlled Diesel engine as
drive speed source these concepts clearly drop out of consideration. Concepts for mobile
manipulators and robots based on a control of the single rod cylinder by two control valves
[10,49] combined with advanced control theory, on the one hand not improve energy efficiency
significantly compared to throttling control and on the other hand require extended control,
signal and sensor expenditure.
Although not well known in the academic literature, a concept for closed circuit displacement
control was patented in 1994 based on a variable displacement pump and a low pressure charge
line for compensating the difference in volumetric flow through the cylinder [20]. A 2-position
3-way valve is used to connect the charge line to the low pressure side of the cylinder. This
circuit was successfully implemented on a mobile forestry machine [27].
A similar concept was developed independently by Ivantysynova and Rahmfeld [22,23,32-35,38]
which uses a variable displacement pump with differential flow compensation via a low pressure
charge line and two pilot operated check valves, as shown in Figure 1. Several advantages make
this concept attractive:
 Throttling losses are eliminated
 Relief and check valves can be integrated into the pump case, thereby reducing the
number of discrete components and fluid connectors


Multiple cylinders can share a single low pressure line
Recovery of potential and kinetic energy is possible since the pump automatically runs in
motoring mode when the cylinder is driven by an aiding load
xcom
Controller
adjustment
CE
Figure 1: Closed circuit displacement-controlled single rod cylinder
Fuel savings of 15% over a load-sensing system was demonstrated by experiment using
prototype wheel loaders [32]. The closed-circuit displacement control concept was also shown
to be robust and have sufficient bandwidth for controlling hydraulic cylinders in working
machines. Another advantage of this control concept is that it reduces some of the nonlinearities
that make feedback control of hydraulic systems problematic. Flow through control valves is
determined by pressure, which in turn is a function of the load on the cylinder. Traditional
circuits also use actuators arranged in parallel, so the motion of all of the cylinders is coupled.
The displacement-controlled circuit decouples the actuators by controlling each cylinder with a
separate pump. Further, the pump flow rate (and thus the cylinder velocity) is essentially
independent of pressure.
Of course, this concept is not without limitations. One pump is required for each actuator, and
the maximum speed at which the cylinder can be retracted is limited by the size and speed of the
pump. A recent development (2006) by Heybroek and Palmberg [19] addresses the latter by
using an open hydraulic circuit and 2-way switching valves. This is a promising concept that
will be evaluated more fully in future development and testing.
Another benefit of displacement control that has been investigated by Ivantysynova et al. is
active vibration damping. Active damping for valve-controlled excavators and similar hydraulic
manipulators has been researched by many authors (refer to review paper [39]), but has not been
put into commercial production because of the high cost of additional hardware and energy
consumption. Displacement-controlled systems offer an economical alternative because a
hydraulic servo pump (of sufficient control bandwidth) can be used for powering the cylinder as
well as actively cancelling oscillations. The only additional component required is an
accelerometer for acceleration feedback. This concept has been explored in some detail by
Rahmfeld and Ivantysynova [36,38]. Eggers compared active damping with load-sensing and
displacement-controlled systems based on energy consumption [11]. His simulations showed
that the displacement-controlled cylinders require 40-60% less power for active damping due to
reduced losses and energy recovery.
5B. State of the Art: Power Management
Diesel IC engines are the most common power source for mobile hydraulic machinery. The
efficiency of IC engines varies with torque and speed. Since the same power requirement can be
satisfied with multiple combinations for engine torque and speed, engine fuel consumption can
be minimized by controlling the engine so that it operates along its peak efficiency curve. This
topic has seen a great deal of development for vehicles with mechanical CVTs [55,58,6264,69,70]. Significant research has also been done on power management for vehicle drivetrains
based on hydrostatic transmissions and power-split drives [54,56-57,59-61,65-668,71-75]. For
example, Ossyra [65-68] presented a control method for hydrostatic transmissions involving two
real-time optimization loops: one feedback loop for the engine based on steady-state efficiency
characteristics and the other for the hydrostatic transmission based on detailed steady-state loss
models of the hydraulic pump/motor units.
However, there has been little work on engine power management for mobile hydraulic
machinery in which the primary energy consumers are working functions rather than the
propulsion drive. Two papers from Asian industrial research groups in 1988 and 1993 describe
efficiency improvements by controlling engine speed on an excavator [76,79]. Lawrence and
Sepehri et al. [27] measured significant energy savings with a pump-controlled excavator that
was developed for demonstrating operator control concepts. Reducing fuel consumption was not
a main objective of their project, however, and power management was not considered. More
recently, Alleyne et al. have developed control methods for optimizing the powertrains of
earthmoving vehicles with respect to energy consumption [77,80,82]. No previous research
exists on power management for excavators or similar machines using pump-controlled
actuators. One advantage of displacement control for power management is that each actuator is
powered by an independently controllable pump. This arrangement offers more degrees of
freedom than valve-controlled systems in which the actuators are arranged in parallel and
powered by a single pump.
It should be noted that excavators and similar hydraulic manipulators, unlike trucks and
passenger vehicles, often demand maximum engine power during typical working cycles.
Therefore, the efficiency improvements that can be expected by engine power management alone
will likely be modest compared to vehicles with continuously variable transmissions (either
mechanical or hydraulic) that rarely operate at maximum load and speed.
Displacement-controlled systems are also well-suited for power management because of the
potential for energy recovery. Power can be recovered from actuators with aiding loads and
simultaneously applied to actuators with resistive loads. Power sharing between actuators is
particularly attractive for machines with multi-link manipulators such as excavators and cranes,
since aiding and resistive loads are frequently encountered simultaneously during typical
working cycles. Previous research has been done by several authors [78,81 for example]
regarding energy recovery for excavators using high pressure accumulators as storage devices.
The obvious disadvantages of this approach are the cost, space, and maintenance requirements
associated with adding accumulators as well as the energy losses inherent to storage and
retrieval. Recovering energy without storage using displacement-controlled actuators was
researched to some extent in the early 1990s by Lawrence et al. [27], but there appears to have
been no subsequent work on this topic in the last ten years.
A logical progression of research involving power sharing is controlling the actuator motion in
order to maximize recovered energy. This topic will be discussed in more detail in the next State
of the Art topic.
5C. State of the Art: Machine Motion Control and Automation
A great deal of research has been done to develop automated motion controls for hydraulic
manipulators. Dozens, perhaps hundreds, of papers could be cited. (See refs [83-114]) Singh
attempted to summarize the state of the art in 1997 and again in 2002 [104,105]. He classifies
most of the research into four levels of automated earthmoving, in order of increasing
automation:
1. Tele-operation. The operator controls the machine joints just as he would for manual
operation, except he is physically removed from the machine.
2. Trajectory Control. The system assists a human operator by controlling the digging
motion within a narrow range of parameters. Trajectory control could take many forms,
including maintaining a certain bucket angle while moving the boom, keeping the bottom
of a trench level while digging, adjusting the digging motion according to measured soil
conditions, or controlling the implement to avoid hitting a buried object such as a pipe or
unexploded ordnance.
3. Tactical Planning. The system senses the current state of the environment and decides
where to dig and in some cases a nominal plan of how to dig.
4. Strategic or Site Planning. The system is able to accomplish an entire excavation, such
as digging a foundation, by dividing the task into subtasks and effectively executing them
based on an overall strategy and sensor information regarding the initial and
instantaneous state of the job site.
Many hydraulic robots have been successfully developed, including a few that function at the
highest levels of automation [102,103,107]. However, designing a hydraulic robot with sensor
systems and artificial intelligence is far outside the scope of Project 1A2. Instead, we intend to
develop a system along the lines of Level 2 that controls the implement trajectory in order to
satisfy the required machine function (e.g. digging a trench, moving an object) while optimizing
the motion for energy consumption. Many hydraulic manipulators employ redundant
kinematics, i.e. the machine has more degrees of freedom than the minimum necessary to
position an end effecter in space at a particular orientation. This fact can be exploited to choose
the optimal manipulator trajectory for minimizing the consumption of primary energy and
maximizing energy recovery.
A configuration is anticipated in which the operator specifies the desired position and orientation
of the end effecter, while the control system calculates the necessary actuator motions based on
the inverse kinematics of the joints and an energy cost function. Related research on this type of
“coordinated motion control” has been conducted by Lawrence et al. [88]. The goal of previous
research was to improve operator productivity, particularly for remotely operated machines. To
the best of our knowledge, coordinated actuator control in order to reduce fuel consumption has
not been previously considered.
Although developing autonomous mobile machines is not a goal of Project 1A2, the systems
developed in this project are likely to contribute to the development of mobile hydraulic robots
in general. One of the difficulties encountered by researchers in the past is the high degree of
nonlinearity of fluid power systems. In a valve-controlled excavator, for example, the pressure
and flow to each cylinder is dependent on the load it sees. Because the cylinders are arranged in
parallel, the equations describing the flow to each actuator and to tank are coupled. Variation of
fluid properties (such as viscosity) with temperature and the presence of pressure relief valves
add to the nonlinearity of the hydraulic system. These nonlinearities necessitate extensive effort
to design and implement effective control systems, as well as high computational requirements to
execute them in real time.
Displacement-controlled actuators reduce the system nonlinearity in two ways. First, the
actuator flow equations are decoupled since each actuator operates in a separate closed hydraulic
circuit. The low pressure charge lines remain coupled, but the pressure in these lines is only
allowed to vary within a narrow range. Second, the actuator motion is essentially loadindependent. (There is some pressure dependence due to volumetric pump losses.) The relative
simplicity of displacement-controlled actuator systems will facilitate the development of mobile
hydraulic robots with less cost and complexity compared to previous projects based on hydraulic
valve control.
5D. Research Approach and Methods
The basic research approach that will be employed for Project 1A2 involves detailed modeling
and simulation followed by experimental measurement. The emphasis on careful modeling will
ensure that methodologies are developed which can be employed in a more general way to the
development of related machines and applications.
The first step in this project is the analyzing the current state of the art. A dynamic model will be
created to simulate the hydraulic system and multi-body dynamics of a load-sensing excavator
(the machine to be used as test bed 1). Typical working cycles will be simulated and the model
will be used to quantify power losses and the possibility for efficiency improvements.
Measurements of fuel consumption on the actual machine will be made to validate the accuracy
of the model. Experimental measurements will also help to quantify expected variations in
working cycles and fuel consumption due to environmental conditions and different operators.
The second project step is the design and simulation of a displacement-controlled hydraulic
system for the excavator test bed. This will be an iterative process in which the system design
will be optimized for fuel efficiency while meeting performance requirements and other
constraints. Simulations using the dynamic model of the pump-controlled excavator will be
used to estimate the expected fuel savings compared to the load-sensing machine. The dynamic
model will also be used in the development of control systems as a nonlinear plant model.
The basic control structure developed in previous work for displacement-controlled cylinders
consists of cascaded feedback loops in which the inner loop consists of the pump displacement
control (typically with a simple proportional gain) and the outer loop consists of cylinder
position or velocity control. This concept is illustrated in Figure 2. This simple approach will be
used in the early stages of the project for implementing displacement-controlled actuators on the
test bed prototype.
Control methods for power management and path optimization will be developed and
demonstrated primarily by simulation. Hardware in the loop testing may be used to validate
results obtained through simulation. Complete implementation of these algorithms on the test
bed prototype is proposed for a second five years of project development.
Figure 2: Basic displacement control structure
6. Brief research plan and a timeline of major milestones

Task 1: Analysis of state-of-the-art example machine (excavator) [Months 1-12]
o Development of a coupled hydraulic and multi-body dynamics simulation model
in Matlab/Simulink to simulate typical working cycles and predict energy
consumption for excavator with LS hydraulic system
o Estimate possible efficiency improvements from throttling losses and recoverable
energy based on simulation
o Measurements of fuel consumption on state of the art machine (Test bed 1)

Task 2: Hydraulic system design using pump-controlled actuation for entire machine
[Months 13-18]
o Actuator design for selected functions
o Dynamic model of the displacement-controlled actuator including detailed
empirical pump loss model (Polymod)
o Development of coupled hydraulic and multi-body dynamics simulation model in
Matlab/Simulink for displacement-controlled hydraulic system

Task 3: Development of actuator control methods [Months 6-18]
o Development of linearized plant model
o Control synthesis based on linear methods and cascaded feedback loops
o Simulation of controller performance using nonlinear continuous and discrete
time models

Task 4: Detailed design and implementation of one actuator on excavator test bed
[Months 18-24]
o Installation of prototype actuator based on available hardware in excavator test
bed
o Implementation of actuator control on CAN based microcontroller
o Performance demonstration
o Measurement of fuel consumption to demonstrate energy savings

Task 5: Development of power management control methods [Months 25-48]
o Development of steady-state efficiency maps and loss models
o Analysis of typical tasks and working cycles
o Control synthesis based on linear and nonlinear methods (exact approach TBD)
o Simulation of controller performance using nonlinear continuous and discrete
time models, various working cycles

Task 6: Detailed design and implementation of second actuator on excavator test bed
[Months 37-48]
o Installation of second prototype actuator in excavator test bed
o Performance measurements
o Demonstration of potential energy savings using a combination of simulation and
hardware in the loop

Task 7: Implementation of power management control methods [Months 49-60]
o Implementation of control algorithms on CAN-based microcontroller
Milestones:
[Month 12]:
 Model of state of the art load sensing system of example machine (excavator) Coupled
hydraulic and multi-body dynamics simulation model in MatLab to simulate typical
working cycles and predict energy consumption
 Fuel consumption for typical operating cycle of state of the art machine (test bed 1)
 Actuator design for one selected function
[Month 24]:
 System design for a complete displacement controlled machine to allow optimal use of
regenerative brake energy
 Dynamic model of the displacement controlled actuator including Polymod loss model
 Coupled hydraulic and multi-body dynamics simulation model in MatLab for the
combined actuator system (LS and displacement controlled actuators)
 Prototype Design and control concept for one function based on available hardware
[Month 26]:
 Prototype actuator installed and tested in excavator test bed including CAN bus
controller, performance demonstration , fuel consumption for test bed measured
[Month 48]:
 Second prototype actuator installed and tested, performance demonstration
[Month 60]:
 Demonstrated energy savings by machine power management strategy and control
2006
ID
Task Name
Start
Finish
2007
2008
2009
2010
2011
Duration
Q3
1
Task 1
7/3/2006
7/3/2007
52.4w
2
Task 2
7/2/2007
1/1/2008
26.4w
3
Task 3
1/1/2007
1/1/2008
52.4w
4
Task 4
1/1/2008
7/1/2008
26.2w
5
Task 5
8/1/2008
7/1/2010
100w
6
Task 6
7/1/2009
7/1/2010
52.4w
7
Task 7
7/1/2010
7/1/2011
52.4w
Q4
9/1/2008
Demonstration of one displacementcontrolled actuator on excavator testbed,
validating simulation results for complete
system energy savings using
displacement-controlled actuators
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
7/1/2010
Demonstration of second displacementcontrolled actuator. Demonstration of
effective actuator control methods.
Q1
Q2
Q3
Q4
Q2
7/1/2011
Demonstration of power
management control
methods and system
energy savings
7/3/2006 - 7/1/2011
Project 1A2
7. How will project results be integrated into test beds?
The prototype actuators and control methods will be implemented and tested on the excavator
test bed (TB1).
8. Describe upstream and downstream dependencies
With respect to the strategic goal of the ERC (compact, efficient and effective fluid power
systems) many dependencies appear. The displacement controlled actuator technology developed
in this project require more efficient pumps and motors (upstream dependency), which will be
developed in 1B. The displacement controlled actuators require advanced pump control systems
of high bandwidth. One of the possible solutions could be based on the fast switching valve
technology to be developed in 1E. The implementation of complete machine functions based on
displacement controlled actuators will involve new human machine interface systems to be
developed in 3A (Human Factors and Haptic Interfaces for Fluid Power Systems). Most of the
studied systems will involve relatively long transmission lines of actuators. The results of project
1D can contribute to more energy savings of the technology developed within this project. An
appropriate system design methodology is required for a successful implementation of a machine
power management strategy. The methods developed in 2F (Dynamically Scalable Fluid Power
Systems) could be potentially used to design entire systems more effective. The development of
displacement controlled machine functions will also require major changes in machine design.
Here the technologies developed in project 2E (Component Integration for Compact Fluid Power
Systems) could be key factor for introducing the new system architecture in complex machines.
New control methods developed in 1A1 (Integrated Algorithms for Optimal Energy Use) could
also be used as part of the control development for this project.
9. Expected resources required from the ERC in years 1, 2 and project completion
Q1
Monika Ivantysynova (PI) 0.5 month summer pay each year
Year 1: one graduate students ($45,000), one visiting researcher 0.5 ($10,000), Travel: $ 2,000
Year 2: Two graduate students ($90,000), 1 REU ($ 5,000), Travel: $ 5,000
Year 3: Two graduate students ($90,000), 1 REU ($ 5,000), Travel: $ 5,000
Year 4: Two graduate students ($90,000), 1 REU ($ 5,000), Travel: $ 5,000
Year 5: Two graduate students ($90,000), 1 REU ($ 5,000), Travel: $ 5,000
10. Requests from industry partner.
 Excavator
 Detailed model parameter information for excavator
 Test cycles
 Benchmark energy usage data for existing excavator
11. References
11A. References: Displacement Control of Hydraulic Actuators
[1] Achten, P.A.J. 1997. Transforming Future Hydraulics – A new design of a hydraulic
transfer. 8th Scandinavian International Conference on Fluid Power. Linkoping,
Sweden.
[2] Achten, P.A.J. 1999. Trennen statt stapeln – Die Nutzung des Centaur Freikolbenmotors bei
einem Gabelstapler. (Separation instead of stacking – the application of the Centaur free
piston engine in a fork-lift truck. VDI-MEG Tagung Landtechnik, pp. 353-358,
Braunschweig, Germany.
[3] Achten, P. A. J. and Palmberg, J.-O. 1999. What a Difference a Hole Makes – the
Commercial Value of the INNAS Hydraulic Transformer. 6th Scandinavian International
Conference on Fluid Power.
[4] Backé, W. 1994. Verlustarme hydrostatische Antriebe – Grundlagen und Anwendungen.
VDI Berichte No. 1132. Dusseldorf: VDI.
[5] Backé, W. 1995. Trends in Mobile Hydraulics. 4th International Conference on Fluid
Power. Tampere, Finland.
[6] Backé, W. 2000. Concerning: Research and Development in Fluid Power Technology. 1st
FPNI-PhD Symposium Hamburg 2000, pp. 9-21, Hamburg, Germany.
[7] Berbuer, J. 1985. Parallelschaltung von Servopumpe und Servoventil – ein Weg zu
energiesparenden hochdynamischen Antrieben. Olhydraulik und Pneumatik 29 (1985) No.
10, pp. 742-751.
[8] Berbuer, J. 1988. Neuartige Servoantriebe mit primärer Verdrängersteuerung. Dissertation,
RWTH Aachen, Germany.
[9] Berg, H. 1999. Robuste Regelung verstellbarer Hydromotoren am Konstantdrucknetz. PhD
dissertation. VDI Fortschritt-Berichte. Reihe 8 Nr. 764. Düsseldorf: VDI. ISBN: 3-18376408-3.
[10] Bindel, R. et al. 2000. Flachheitsbasierte Regelung eines hydraulischen Antriebs mit zwei
Ventilen fur einen Grossmanipulator. at Automatisierungstechnik, No. 3/2000, pp. 124131.
[11] Eggers, B. 2004. Extended Control Concepts and Energetic Aspects for Active Oscillation
Damping with Displacement Controlled Linear Actuators. Diploma Thesis, Purdue
University, December 20
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