Mechatronics and embedded software add complexity to smart device design

Anderl, Nattermann and Rollmann [1] have made a timely contribution with a concept based on the V-model. The V-model is widely seen as a central pillar of systems engineering [2]. By specifying a mid-project phase (which turns the V-model into a W-model), Anderl et al. specifically address the issue of dependencies between the multiple technologies involved in a project. This W-model concept has the consequence that data management systems must be able to analyze and synchronize discipline-specific data across disciplines.

Vendors of software tools for product development recognize this challenge. Engineering managers can choose any starting point – mechanical CAD, engineering analysis, software development, electronic design and even the PLM parts of ERP solutions, and vendors will offer some sort of capability or roadmap towards multi-domain development, modelling and data management.

For example, consider tools that support systems engineering and embedded software development. There's plenty to choose from in this $2.6B market [3], and some 'turbulence' as both technology and provider boundaries change. For example, PLM vendor PTC acquired embedded software tools provider MKS. Other global PLM vendors such as Dassault Systèmes and Siemens offer systems engineering tools, which integrate with their design systems, and cover multiple technologies.

Precise mechanisms to enable PLM applications to synchronize multiple technology streams of product information vary, but typically involve configuration and customization. Dassault bought Geensoft and extended its requirements management and automotive software capabilities. EDA companies such as Cadence, Mentor and Synopsys offer tools such as system-level design, virtual prototyping and requirements management in which embedded software is a usual component of, say, system-on-a-chip designs.

IBM Rational offers requirements management, systems engineering and software development tools. These IBM tools handle software systems with components not only embedded in a device, but also running on the computers at headquarters. They also offer a management environment that can monitor progress and performance indicators by direct tracking of activities across an extended team.

Business systems providers such as SAP and Oracle have design and manufacturing applications that are relevant to embedded software development because they cover parts libraries, bill of materials, version and status handling, data access management and workflows. Oracle also offers technical development tools for embedded systems including Java tools specific to TV, smartcard and general embedded use. National Instruments offers the LabView system, a way of creating embedded software (especially for test systems) directly from diagrams. IBM's 'Rhapsody' also builds code from diagrams, integrating with requirements and test handling.

This is a long yet still very partial list. Microcontroller manufacturers usually offer plug-ins to an open-source, free-of-charge, development environment (almost always Eclipse). The plugins enable the development environment to generate code and interface to the hardware provided by the microcontroller manufacturer. Many tools address multi-domain simulation by interfacing to Mathworks Simulink multi-domain simulation software.

Of course, many traditional engineering concepts apply to embedded software in mechatronics devices. An interesting example is make-or-buy. There is a large and growing market for software components for use in embedded systems. Components range from the underlying real-time operating systems and device interfaces to libraries that handle signal processing, or physics, or user interfaces.

For any hardware component that is seen as a mechatronics 'commodity,' designers and engineers prefer to specify components that come complete with a software stack. This means they can avoid the effort of writing software to interface to the component, and focus their software development efforts on making the component execute functions that represent added-value for their customers.

At one level, this use of bought components simplifies version and change management. However, software always has the power to surprise. Does the software stack for a network interface handle the security requirements of the product? If we change the speed of the memory on the controller, will the camera interface stack still work? Will all the bought-in software modules co-exist and function correctly in the single software address-space we are using? It is perhaps no surprise that with software integrated into the product, there are even more possible outcomes of a design review meeting!

Mechatronics had its origins in a specific technology area. But today's reality is software everywhere, and products in every sector that depend on the successful integration of mechanisms, sensors, actuators, interfaces and software. So the message to designers, engineers and their managers is loud and clear – skills in individual disciplines are essential, and so are the skills and tools that break down the walls between technologies in both directions. This means you have to care about skills and tools to partition problem solving across disciplines, as well as the skills and tools that bring together developments made in each and every discipline.

Teams that are comfortable moving functions between technologies as they develop a design proposal will search a less constrained solution space. This will give them a better chance of coming up with an optimum way of meeting requirements – or, at least, something better than the competition.

References:
1. http://www.plmportal.org/index.php/research-in-detail/items/the-w-model-a-systems-engineering-based-approach-for-active-systems-development.html
2. http://sdm.mit.edu/news/news_articles/sdm_keio/v_model.jpg
3. http://www.cambashi.com/embedded-software-development-tools

About the author
Peter Thorne is Managing Director at Cambashi (www.cambashi.com). Peter is responsible for consulting projects related to the new product introduction process, e-business, and other industrial applications of information and communication technologies. He works closely with IT vendors, providing them with independent expertise on matching their products and services to real industry needs. He has applied information technology to engineering and manufacturing enterprises for more than 20 years, holding development, marketing and management positions with both user and vendor organizations.

Immediately prior to joining Cambashi in 1996, he headed the UK arm of a major IT vendor's Engineering Systems Business Unit, which grew from a small R&D group to a multi-million dollar profit center under his leadership. Peter holds a Master of Arts degree in Natural Sciences and Computer Science from Cambridge University, is a Chartered Engineer, and a member of the British Computer Society.