Development Environment for Fluid-Power-Mechatronic … · Development Environment for Fluid-Power-Mechatronic Systems Frank Engler EPLAN Software & Service GmbH & Co. KG, An der

Development Environment for Fluid-Power-Mechatronic Systems

Frank Engler

EPLAN Software & Service GmbH & Co. KG, An der alten Ziegelei 2, 40789 Monheim

Heiko Baum

FLUIDON GmbH, Jülicher Straße 336, 52070 Aachen

René von Dombrowski

FLUIDON GmbH, Jülicher Straße 336, 52070 Aachen

ABSTRACT

Fluid-power-mechatronic systems are characterized by close networking among all the

participating technical disciplines and through complex interactions between the subsystems

required to attain the overall functionality. In view of this close interconnectedness of the

development disciplines and the variety of companies involved as well as the resulting complex

process structures, the development process for fluid-power-mechatronic systems is becoming

increasingly difficult and the elimination of inadequacies in the product reliability is often realized

using iterative problem solutions at a much later moment in the development process.

Within the "Fluidtronic" joint project, which is funded by the German Federal Ministry of

Education and Research, work is therefore being carried out by a consortium consisting of nine

industrial companies and two research institutes on the creation of an adapted development

environment in the form of a PLM solution. The handling of data and information as well as the

integration of simulation tools within this PLM concept form the core of this article.

The EPLAN documentation tool functions as the information bearer, for both technical and

commercial data in the presented concept. Here the planning and documentation of the fluid-

power-mechatronic system is carried out on the basis of schematics for the overall system as

well as for any subsystems. All the component specifications are stored with the items. Thus, not

only the technical data, such as the geometric dimensions or the performance characteristics,

but also the commercial information, such as the part numbers or order information, is

7th International Fluid Power Conference Aachen 2010

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contained. Thanks to a direct link to the manufacturer databases, the current item information is

always available on this level.

From the schematics, in turn, all the relevant documents for a complete system design are

generated automatically. In addition to order lists and bills of materials, these are documents

such as maintenance schedules, lubrication lists or piping diagrams. All the schematics, item

formation and designing documents are interconnected dynamically, so that inconsistencies in

the database are avoided and changes within the plant planning are implemented consistently in

the complete documentation structure without the user having to lift a finger.

The simulation level is located under the level of the product information. This level contains

simulation tools that allow the designing engineer to carry out simulation-supported calculations

and to analyze the effects of different system configurations. Thus allowing simulations in any

detail desired to be derived from the system schematics, from simple logical interconnection

tests up to complex dynamic examinations of the system behavior. Simply by marking the

relevant system or partial system both the model structure and the current item parameters are

transferred directly into a simulation model. In turn, calculation results from the simulation flow

back into the documentation in the form of dimensioning and design proofs. Linking between the

simulation level and the product information level is also carried out dynamically so that changes

in the system structure or in the components used are implemented directly within the simulation

environment. Since building up the structure and the parameterization as a rule represent about

50% of the work required for simulation projects, a huge reduction in time can be achieved here

in addition to advantage of a consistent database.

All the companies involved in the development process use the same database. The entire

development process is thus optimized by means of an intelligent access rights management

and orientation to reference processes.


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1 INTRODUCTION

The development of increasingly powerful technical systems results in a constantly

increasing product complexity and and increasing functional scope. Modern fluid-power-

mechatronic systems unify partial systems from various specialized disciplines such as

hydraulics, pneumatics, electrical engineering, mechanical engineering, informatics or

control technology. These very heterogeneous systems have to cooperate increasingly

closely and communicate more effectively than ever with each other in order to ensure

the functionality of the overall system.

Fluid-power-mechatronic applications are nowadays used by all fields of industry, with

these often being highly specialized individual developments that are manufactured on

the basis of specific customer requirements and in small batch sizes. Not only is the

correct coordination and synchronization of all the components as well as their

properties required in order for these plants to run reliably, but also efficient cooperation

of the participating companies is also indispensable. However these requirements were

not included sufficiently in the development processes in the past. Due to a lack of

networking and synchronization during the development, for example, functional

problems that are only discovered at a late point in the development process arise when

different partial systems are combined. In addition, unstructured information flows mean

that the derivation of requirements for individual components on the basis of the

specified constraints of the overall system is only possible through using experience

from previous projects. This applies in particular to incompatibilities regarding material

and system that are not recognized at an early stage in the development process and

whose late discovery requires a cost-intensive, iterative procedure in order to eliminate

the problem. /Mue08/

A large optimization potential lies in the support through simulation software that has not

been exploited sufficiently in the past. Fluid-power-mechatronic simulation programs are

often not during during the development process, but are only used in those cases in

which designing based on experience is insufficient or when malfunctions occur when

the plant is in operation. Insufficient integration of fluid-power simulation tools in the

development process complicates understanding of the overall system in the early


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development phases and makes later commissioning of the plants increasingly tedious.

/Mur09/

2 PRESENTATION OF THE FLUIDTRONIC JOINT PROJECT

In the course of the research project a hydraulic forging press was used as a reference

application of a fluid-power-mechatronic system. In its complex structure it unites a wide

variety of partial systems from the technical disciplines of hydraulics, mechanical

engineering and electronics as well as control technology. Its large dimensions in

particular mean that all the partial systems do not liaison until the actual plant

commissioning. Since the plant dimensions mean that this has to be carried out at the

customer, the customer notices all these inaccuracies and malfunctions in the

interactions of the partial systems during commissioning. In addition, finding faults at this

late moment in the development involves a large amount of time and high costs.

The aim of the "Fluidtronic" joint project is therefore the early identification of inherent

system risks and the ensuring of reliable commissioning and plant functioning for the

duration of the entire product lifecycle. This is only possible if the cooperation between

the concerned specialist disciplines and companies is synchronized and integrated

better with the aim of efficient product development.

For this reason the development of a fluid-power-mechatronic system requires a cross-

company platform that is called the development environment. Figure 1 shows the

operative coupling between the elements considered in the project in an integrated

development environment for fluid-power-mechatronic systems.


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Figure 1: Integrated fluid-power-mechatronic development environment

The development environment encompasses all the disciplines and activities within the

product development process as well as the methods, tools and IT systems used in it. In

addition, it contains both the associated product and process information from the

system concept through to the commissioning as well as the feedback of the operating

data during the product lifecycle.

3 CONTINUOUS ENGINEERING

An important point for optimizing the development processes is used by the continuous

usage of software support. The development and implementation of new software

models and methods transforms the conventional development process into a computer-

aided product development that makes it possible to carry out virtual plant design and

virtual commissioning at a very early stage.


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In the course of the Fluidtronic project concepts were implemented – using the two

development tools "EPLAN" and "DSHplus" (Figure 2) – that link the project designing

and documentation with the dimensioning of new systems and thus exploiting synergies.

Figure 2: Coupling principle DSHplus – EPLAN

Modern documentation programs such as EPLAN can already replace the still prevalent

purely drawing programs for creating schematics and offer integrated possibilities for

designing new plants. The user places and dimensions the components of his system

symbol-based and ISO-conform on the schematic by dragging-and-dropping. The

connections of the items between each other can in turn have specific properties

assigned to them and be evaluated.

At the same time as the drawing is created, the bills of materials and order lists are

created automatically with all the item identifiers, item sizes and part numbers. However,

report pages, such as maintenance lists, lubrication lists or pipe connection lists, are

also determined immediately from the created schematics. All the documents required


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for designing and documentation are interlinked dynamically so that a uniform database

is provided and errors as well as inconsistencies can be avoided.

At this point, however, the continuity of the development chain was at an end. For was

there any possibility of examining the designed system for plausibility or even optimizing

them with regard to increasing the performance or inefficiency?

In the classical development process, static system design by hand or dimensioning of

the items on the basis of experience was carried out – if at all. Only if extreme pressure

pulsations or vibration problems occurred during running plant operation and this

resulted in a functional impairment or even standstill of the plant, was dynamic

simulation brought into play in order to master the problem and conceive suitable

remedies. The consistent use of simulations on the one hand allows future weak points

of the system to already be recognized and eliminated at a very early point in the

development process while on the other hand the consistent use of software allows

further optimization potentials, such as reductions in costs and time, but also increases

in efficiency and performance, to be tapped.

Coupling of the documentation and simulation represents the link missing up to now.

The hydraulic schemes are transferred at the click of a button from EPLAN to the

DSHplus system simulation. In addition to the system schematic or the desired sub-

system structure, the simulation program automatically imports all the parameters of the

designed components from the engineering structure through the link to the component

database — and when changes take place in the documentation these are also imported

immediately into the simulation model by the dynamic linking of the two development

tools without the user having to do anything. The interconnection of the documentation

and simulation thus ensures a uniform database, and the latest component information

is always available to the simulation models as parameter inputs. The results of the

dynamic system simulation as well as important system and environment parameters of

the system and the constraints of the system are made available as an HTML report.

This report can in turn be linked dynamically with the original design schematic and thus

completes the documentation of the plant with design and dimensioning reports as

certitude for the customer. /Bau07/


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The range of possible applications of the new networking is almost unlimited and ranges

from simple logical circuiting checks of the hydraulic or pneumatic drives through the

item dimensioning, to the design of fluid-power-mechatronic systems and up to system

optimization with regard to performance, reliability or efficiency of the plant by means of

dynamic simulation.

Through the use of the interfaces available in DSHplus for the coupled PLC simulation

or hardware-in-the-loop simulation, this consistent engineering concept can additionally

be extended by the virtual commissioning of the reference system with a real control

device in the further course.

4 PROCESS STEPS OF THE DEVELOPMENT

Figure 3 shows the various phases of the development process of a fluid-power-

mechatronic system.

Figure 3: Phase structure of the development process

Starting from the initial sales-supporting feasibility analysis in the offer phase, the

system structure is planned in ever increasing detail trough rough concepting in Phase 2

to the final product structure in Phase 3. In Phase 4 commissioning of the plant is then

carried out, which can optionally be analyzed and optimized using condition monitoring

strategies in Phase 5 across the entire product lifecycle.


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Optimization of the various phases using a software-aided development environment is

shown in Figure 4 and explained in more detail below.

Figure 4: Support of the development processes by means of software tools

The emphasis of the explanations lies on the cooperation between the OEM and the

supplier in Phase 3. A noted acceleration of and increase in the quality of the

development process can be achieved through a PLM-aided process of exchanging the

design documents.

4.1 Phase 1: Information acquisition in Sales

In initial meetings with the customer, Sales records the required data, for example on

the basis of an Excel template. The parameters required for a feasibility study are

entered in this template on the basis of the customer requirements. An example of the

structure of such a template is shown in Figure 5. The parameters to be recorded are

divided roughly into basic components of the plant to be designed.

On the basis of individual parameters to be specified by the customer it is then possible

to derive further parameters required to design a press. An initial feasibility study of the

customer requirements for the press can be carried out by Sales in the background on

the basis of these data. In the process a comparison with the parameters of projects that


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have already been realized is used to identify commonalities of the requirements and to

point out such realized projects. The listing of these projects allows Sales to make a

rapid statement on the feasibility to the customer.

Figure 5: Template for parameters of the key point plan

If there is no similar project, a standard template is suggested to Sales, consisting

respectively of two documentation and simulation projects attuned to each other, that

can then be elaborated in detail by the developers in the back office. It may be possible

to already present existing simulation results or ones generated by the back office at this

stage. The feasibility study is used as the basis for the contract negotiations with the

customer.

4.2 Phase 2: Rough designing by the OEM

After the conclusion of the contract negotiations, the used template consisting of the

design template and simulation model is detailed further. The task of the experts is now

to optimize the interaction of the components further so that the performance assured in

the specifications are fulfilled. With the exception of individual specified parameters

which the OEM may not modify according to the contract, the experts have the option to


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modify the parameters of the components, if necessary also without consideration of any

availability of real components, and thus to improve the interaction continuously.

During the constant optimization of the interaction of the items within the system

structure, a continuous exchange takes place between the mechanical and hydraulic

sections of the company. In the process the mechanical and hydraulic constraints of the

press are localized ever further and help to form the image of the press continuously

(Figure 6).

The previously calculated or recorded item parameters are entered by clicking the

symbols. Since the customer does not know all the parameters at this stage, individual

parameters have to be assumed and stored at the components.

Figure 6: Design-oriented component of the development template

After all the calculated and recorded parameters have been entered, the system

structure as well as the component data of the design schematic are passed on to the

simulation model matching the template (see Figure 7) so that an initial simulation of the


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interaction of the individual parameters is carried out. In the process several result

diagrams are created from which the feasibility of the requirements can be read.

The recorded parameters are not always sufficient in order to make a definitive

statement on the feasibility. Often the requirements also run in a threshold region so that

robust conclusions on the feasibility are not possible on the basis of the existing

information. In this case iterative loops between Sales and the experts of the company

are used to improve the information situation further. It is now possible for the expert to

adapt and set the constraints more precisely and in more detail.

The simulation environment allows a report to be created and the calculation results to

be stored after the simulation of the interaction. The report and its conclusion on the

feasibility make it possible for Sales to avoid making promises to the customer that can

result in enormous additional efforts in the further course of the press design. The

simulation results furthermore serve as a reference for the subsequent detailed planning

at the suppliers and form the basis for the beginning of detailed planning in Phase 3.

Figure 7: Simulation component of the development template


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4.3 Phase 3: Planning of plant details by the suppliers

During Phase 2 the OEM determined the required dynamic properties of the modules of

the hydraulic press using simulations in DSHplus. The interaction of the component

requirements that were defined in increasing detail was improved constantly in the

process. However, not only "standard components" as they can be obtained from

various suppliers have been used in the template. Instead the hydraulically optimal

parameters are determined and defined.

In order to pass from this "rough designing" to the real system design, the schematic,

which still highly simplified, now has to be planned in detail with regard to its real

feasibility. Individual systems, such as the pump, still stand as a summarization for

complete subsystems whose exact structure still have to be defined. Figure 8 illustrates

this schematically using geometric figures.

Figure 8: Interaction between DSHplus and EPLAN

Within the EPLAN design level it is now possible to store design information at the

individual symbols. However the suppliers first have to carry out detailing of the modules

into subsystems that can really be realized. To this purpose the design document is

made available to all the suppliers within the development environment by using the

PLM system.

In order to ensure know-how protection during exchanging of the design data, the

modules that do not have to be detailed by a specific supplier can be transferred

combined in a type of "overall blackbox" (Figure 9). Only the module that is to be

detailed by the supplier is left editable.


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Figure 9: "Black-box logic" for passing on to suppliers

The EPLAN document as well as the modified DSHplus schematic including the

reference result is transferred to the supplier in a suitable form. The supplier now has all

the relevant constraints of the overall system and requirements placed on the module to

be detailed.

The supplier forms and details the initially simply conceived subsystem that he wants to

offer to the OEM in EPLAN. In the process he builds up the interconnecting logic of the

individual components into a subsystem in the engineering software, as sketched in

Figure 10.

Figure 10: Detailing of subsystems by suppliers


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In the process the supplier can use his company-specific database in which the

components including their engineering and simulation data are stored.

The supplier subsequently transfers the engineering schematic into a simulation model.

The simulation parameters are in turn imported automatically from the documentation.

The supplier can now directly test the effects of the use of various components within

the plant engineering in the DSHplus simulation, compare them with the reference result

and thus find the optimal solution.

As soon as an optimal solution has been found, the design information is added to the

documentation and returned to the OEM via the PLM system (Figure 11). This process

is repeated in the interaction between the OEM and all the (system) suppliers.

Figure 11: Combining of the supplier information by the OEM

The OEM subsequently combines the detailed partial engineering schematic into an

overall document that automatically also contains all the parameters relevant for the

simulation.

The OEM in turn now transfers the overall schematic with all the detailed work into the

simulation model in order to validate the components and modules now available in real.

Unforeseeable interactions between supplier modules can be recognized in the detail

simulation of the overall system at an early stage of the development process and

remedial measures taken. If the OEM has recognized potential weak points or causes of

faults, he contacts the individual suppliers with this knowledge and requires

modifications of the corresponding subsystems.


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Thanks to this more direct and more efficient cooperation as well as the multiple iterative

loops between the customer, the OEM and the suppliers within the simulation

environment, it is possible to design more reliable and more robust machines in shorter

times. /Mue08/

4.4 Phase 4: Virtual commissioning

The detailed virtual plant model created in Phase 3 can be used in the further

development processes in order to already carry out virtual plant commissioning in the

run-up stage. Figure 12 shows the trial press with display panel realized in the course of

the Fluidtronic project to this purpose.

Figure 12: Display wall and trial press of the Fluidtronic project

Software-in-the-loop interfaces (SiL interfaces through OPC interfacing) can be used to

couple the real PLC software to the simulation model created beforehand. Thus the

machine control unit no longer communicates with the real plant but receives its input

variables from the virtual plant model and controls it with the calculated output variables.

The aim of this coupling is not only to test the PLC software in the simulation, but also, if

necessary, develop it further as well as to ensure transferability of the results to the

implemented drive. Adaptation strategies to possible system changes can already be

tried and, if necessary, be adapted long before the real commissioning of the fluid-power

system. This virtual design of the machine control system can furthermore be used to

develop and analyze new control and and regulation strategies with a minimum of time

and without danger of damage to the real plant.


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A further reduction of the development and commissioning time is provided by the

Hardware-in-the-Loop (HiL) simulation. By coupling the real PLC hardware to the system

simulation the real control hardware can already be conditioned optimally in advance.

Starting from a host PC on which the simulation model is calculated, connection is

carried out via a fieldbus card that has input and output modules (signal converters).

The signals from the model are converted in to real signals and are read in, processed

and subsequently returned as actuation and control signals to the simulation by the

controller hardware. A special software module carries out the data exchange between

the fieldbus coupler and the simulation model. Virtual commissioning of the real PLC

hardware thus allows cable errors within the enclosures to be discovered in advance,

limit queries to be calibrated and various operating and error scenarios to be run

through. /Ket08/

4.5 Phase 5: Condition monitoring

Further usage options for the virtual plant model lie in plant monitoring during ongoing

operation. By coupling the virtual model to real operating data the simulation model can

be used as a monitoring unit and interpret deviations between the simulation model and

the real plant using previously defined algorithms in order to predict, for example,

component wear.

CONCLUSION

In view of the high complexity during the conception, the development and the

commissioning of fluid-power-mechatronic plants the current conventional development

process manifest clear deficits. The presented development environment overcomes

these deficits through an optimization of the development processes as well as the

consistent use throughout the development of engineering and simulation software.

The structured interaction and cooperation of all the companies involved in the

development process and the supply to these of detailed system information and up-to-

date data results in the acceleration of the development processes under simultaneous

optimization of the overall system.

The presented results were elaborated in the course of the Fluidtronic research project

that is funded by the German Federal Ministry of Education and Research in the


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"Research for Future Production" framework concept and is managed by the PTKA in

Karlsruhe as the project manager.

REFERENCES

/Mue08/ G. Schuh, J. Müller, C. Nussbaum, Fluidtronic - Entwicklungsumgebung

für fluidtechnisch-mechatronische Systeme, Tagungsband 6.

Gemeinsames Kolloquium Konstruktionstechnik, Aachen 2008

/Mur09/ H. Murrenhoff, R. von Dombrowski, T. Verkoyen, Fluidtronic -

Entwicklungsumgebung für fluidtechnisch-mechatronische Systeme, wt

Werkstattstechnik online Jahrgang 01/2009

/Bau07/ H. Baum, R. von Dombrowski, G. Birmes, Durchgängiges Engineering

im Bereich der Fluidtechnik - Konstruktions-Workflow durch direkte

Kopplung von Dokumentation und Simulation, O+P Zeitschrift für

Fluidtechnik, 08/2007

/Ket08/ R. Kett, Virtuelle Inbetriebnahme von Reglern und Steuergeräten,

Tagungsband zum 5. Kolloquium Mobilhydraulik, Karlsruhe 2008


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Documents

Development Environment for Fluid-Power-Mechatronic … · Development Environment for Fluid-Power-Mechatronic Systems Frank Engler EPLAN Software & Service GmbH & Co. KG, An der