ECAD-MCAD cooperation for mechatronics “in time, in budget, in quality”

Updates and innovations in mechatronic products should come onto the market faster, and of course with ever more power and being more energy-efficient, lighter and more compact. The dynamic markets for mechatronic systems are exacting. The same is true for the product development process (PDP).

The best chance of optimising the PDP and thereby shortening it lies in the development domains cooperating interconnectedly from the start. If they work out a cross-domain product concept together, this will highlight any incompatibilities before development begins. The teams create various solutions with differently organised features, evaluate them, and then make a decision.

Since all the domains involved, from mechanics, electronics, electrics and fluidics to software, know the goal, they can parallelise their development processes to a large extent and usually include downstream processes such as production and procurement at an early stage. The advantage of concurrent engineering lies in the frequent alignment of the development results. This early integration of potential solutions can reveal possible conflicts. These can be rectified immediately so that the functional system can go into production more quickly. This can be done without time-consuming reworking because production has long since started evaluating production alternatives.

Product Lifecycle Management (PLM) supports this PDP method by its transparent management of the overall product and its intelligent support for cross-domain processes. This is done without individual engineering teams having to give up the optimal data model for them or having to adjust their workflows. The following example shows what this kind of interdisciplinary cooperation could look like.

Not only is the format of the native design data different, but the work-in-process data (WIP) of electronics and mechanics are also different. For example:

• The mechanics manage their models, and the electronics technicians manage their projects
• The mechanics select the manufacturer's parts for the finished design, the electronics technicians take charge of the project planning process

However, an early compatibility check of the circuit board and housing requires a mechanical 3D model of the housing, which the ECAD tool can import, because the coordination process basically runs as follows:

• Mechanics create the circuit board geometry with mounting holes and recesses for interfaces, display elements, etc., store them in the PLM system at the defined location and convert the file into a neutral format such as IDF or STEP.
• Electronics technicians import the IDF or STEP file from PLM, create a layout of the circuit board, store it again in PLM and convert the PCBA geometry to IDF or STEP.
• Mechanics insert the PCB geometry into the housing and adjust it if necessary.
• Electronics technicians import the updated PCB geometry and provide an updated PCBA file.

During the entire coordination process, the EDA system is the main tool for the circuit board layout as well as for the electronic parts list.

A collision check requires a 3D representation of the mechatronic assembly with its components. Therefore, the more detailed the modelling of the components, the easier it is to identify and correct possible errors, such as an incorrectly placed connector.

Intelligent CAD direct integrations support this bidirectional data exchange by automatically storing the native data with an explicit name at the designated location in the common data model, converting it into the neutral format agreed upon and generating a parts list. It depends on the definition whether this process automatically triggers the message to the other domain or whether the designer sends it from the PLM system.

The PLM not only manages all versions in a common environment. Via the integrated change management, it also logs every single step in the design process, links compatible versions and controls their release.

According to the defined rules, the CAD connectors generate a cross-domain product parts list when a new version is stored. Users can choose their preferred structure:

• Flat: A range of item numbers is reserved for each domain
• Consolidated: Electronic components, as well as those from other domains, are assigned to the corresponding mechanical assemblies
• Interconnected individual parts lists

The “parts list comparison” feature included with the CAD connectors ensures that the parts lists are updated in accordance with every change.