www.siemens.com/plm
White Paper
Mechatronic solutions enable all types of manufacturers to develop cutting-edge products that are more intelligent and complex. But how do you develop a successful mechatronic solution that optimizes the mechanics, electronics and software simultaneously as an integrated system?
Controls engineering is a discipline that deals with designing and implementing control systems to achieve a desired overall system behavior. It is the backbone of “smart” products. In its basic form, a control system lets you measure a performance factor in the product using sensors.
Based on this measurement data, you can adjust the behavior of a product to regulate the perfor- mance toward a desired objective.
This white paper describes how to get the mechanical design aligned to the electronic control systems and software to meet a variety of performance targets with the help of control experts from LMS™ Engineering services.
Using customized controls engineering to enhance
system design
1 A white paper issued by: Siemens PLM Software.
Executive summary
As products grow more complex, manufacturers in industries such as automotive and transportation, aerospace and de- fense, medical and mechanical, are faced with an ever in- creasing array of challenges that include developing high-quality controls in less time, reducing experimental testing costs, managing system complexity and increasing productivity when working with global teams on multiple product programs.
The key to meeting these challenges is possessing unique development experience, engineering skills and application know-how; adopting an integrated test and simulation approach; transferring technology and enabling parallel development.
By adopting these practices, the manufacturer can achieve:
• High-quality controls through structured customer-specific development processes
• Reduced cost by frontloading controller testing, such as virtual testing and virtual verification and validation
• Support for controls development for vehicle energy management, chassis and powertrain by using virtual test platforms and design processes
• Effective management of distributed collaborative design simulation models
• The efficient management, sharing, synchronizing and merging of virtual vehicle prototype models across the global team
A white paper issued by: Siemens PLM Software. 3 How to design a control system?
The first step is to understand the requirements. You can design a control system that can meet multiple objectives, but it is important to understand the different objectives and interactions. How fast should a part product react to change in the system? What about a change in external conditions?
You need to view the big picture. Some of the requirements could set performance goals, which have to be optimized, while others serve as constraints to be satisfied. Some of these requirements compete against each other, and the design should carefully manage the tradeoff between com- peting requirements.
Second, experts draw a boundary diagram of the system architecture: what are the system components that can be measured by sensors, and which system properties can be changed by actuation to satisfy the requirements? At this point, a requirement feasibility analysis is required to deter- mine if the existing sensors and actuators can meet the sys- tem objectives. Such analysis is mostly conducted using system simulation with computer models. After examining the analysis results, we can determine if the conceptual sys- tem architecture is really possible.
If the proposed system architecture is possible, you start a detailed design by dividing the controller into units accord- ing to the required functions. When designing an engine control system, for example, you must be sure to deliver the required torque. To do this, you design a management func- tion that measures the torque demand through the driver accelerator pedal input. Then this data is translated into the appropriate airflow and spark-timing actuations to deliver the required torque at the engine crank shaft.
In parallel, you look at the fuel management function, which should minimize fuel consumption, while delivering the required fuel to generate torque. The emission control and thermal management functions also impose constraints on how the airflow, spark timing and fuel system are actuated to ensure that exhaust emissions are minimized and the engine operates in an efficient temperature range. This chal- lenge is a bit like completing a 10,000-piece jigsaw puzzle.
To realize the control system within the overall architecture, you must define the interfaces and populate the various sys- tem functions to fulfill requirements. Today, computer mod- els of the controller units are built to virtualize the functions.
The units and their interfaces are rendered graphically to assist the engineers in rapidly evolving design processes.
In parallel, you design and implement test cases to assure that the control system works and meets requirements. This is called validation and verification (V&V).
Testing early in the process
Early V&V is critical to a product’s overall success. LMS experts from Siemens PLM Software design and test in stages, and testing at this stage can be done in various ways.
The classical method was to use hardware. Years ago, it was common to make some changes to the control software and then take it to the product and test it, but this methodology was very expensive and time consuming. Today, we are mov- ing toward model-based systems engineering and real-world virtual prototypes.
Today, you virtualize the physical system you are trying to control and the control system. Subsequently, you apply the virtual control system on the system prototype. This is all performed on the computer using models, then you run the test cases on the virtual product to verify if the requirements are being satisfied. Engineering such virtual products with sophisticated control systems and then testing them in the virtual world without creating physical design prototypes will become common in the future.
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The future of controls engineering
Controls engineering is a growing technological discipline with increasing applications in mechatronic solutions. Today, many applications are devoted to a single subsystem or a single machine. In the near future, controls engineering will enable smart machines to collaborate to achieve higher per- formance and productivity in a community of machines. You will have supervisory aspects incorporated in this intercon- nected environment as well as the ability to control and opti- mize your machines across locations according to production needs. Such growth will further increase the complexity of machines. In addition to the usual mechanical components, the electronic components and the software configurations must be carefully tracked and channeled to the manufactur- ing world so that the community of machines being deployed is compatible for the mission requirements and performance goals. This will accelerate the adoption of prod- uct lifecycle management (PLM) in product development organizations to manage the increasing data and informa- tion complexities of the software-enhanced hardware prod- ucts within the next three to five years.
By using smart mechatronic systems, you will be able to monitor not only machine performance according to the sys- tem goals, but also wear-and-tear. Where is the machine in its maintenance lifecycle? Having a community of electronics that interact will enable you to build a database of status reports. A supervisor no longer needs to be on the floor daily to check individual machines. He or she just needs to super- vise the collected data. Similarly, appliances and devices used at homes will be coordinated and monitored by smart supervisors advising and alerting humans of critical events in their homes.
Taking it a step further, it might be a virtual supervisor that will view the data and adjust the maintenance schedule to minimize downtime. With electronics and software becom- ing so prevalent in products, this can become a reality in the near future.
LMS Engineering industry solutions
The beauty of controls engineering is that the principal steps and methodology remain the same across all endeavors, such as biomedical, robotic surgery and aerospace. The con- cepts can be applied across the board. Many ideas that LMS software engineers pioneered and innovated in the automo- tive segment can be easily transferred to other sectors, such as industrial machinery, off-road or ground vehicles and con- sumer electronics.
Consider the trend in remotely piloted vehicles. LMS controls engineering experience in automotive active safety can eas- ily be applied to controls engineering projects for remotely piloted agricultural equipment or a robotic lawn mower.
Working beyond the automotive industry, LMS Engineering experts know how to set up the right controls engineering infrastructure and methodology to efficiently solve engi- neering design challenges. Together with Siemens PLM Software products, LMS Engineering helps solve these critical challenges, bringing controls engineering to a higher level.
A white paper issued by: Siemens PLM Software. 5 www.siemens.com/plm
© 2014 Siemens Product Lifecycle Management Software Inc.
Siemens and the Siemens logo are registered trademarks of Siemens AG. LMS, LMS Imagine.Lab, LMS Imagine.Lab Amesim, LMS Virtual.Lab, LMS Samtech, LMS Samtech Caesam, LMS Samtech Samcef, LMS Test.Lab, LMS
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About Siemens PLM Software
Siemens PLM Software, a business unit of the Siemens Industry Automation Division, is a world-leading provider of product lifecycle management (PLM) software, systems and services with nine million licensed seats and 77,000 customers worldwide. Headquartered in Plano, Texas, Siemens PLM Software helps thousands of companies make great products by optimizing their lifecycle processes, from planning and development through manufacturing and support. Our HD-PLM vision is to give everyone involved in making a product the information they need, when they need it, to make the smartest decisions. For more information on Siemens PLM Software products and services, visit www.siemens.com/plm.
