Electrical and mechanical engineering are no longer islands and the two and are becoming closely intertwined. That’s affecting how products are being designed and manufactured, and engineers need to stay up to date.
The emergence of electric and autonomous cars provides a clue. Multiple high-voltage systems are tied to automation, navigation, and safety systems. Unlike previous car designs, the lighting system, the braking system, and the audio system, cannot be treated independently of one another.
“You now have to look at the design in a holistic manner. You can no longer assess the design of processes by looking at individual products,” said Martin O’Brien, vice president and general manager for integrated electrical systems at Mentor Graphics, a division of Siemens.
More electronics means more wires in cars and trucks, and there’s a realization that design
needs to be more efficient. The integration makes products more efficient, but also adds complexity to tasks like repair and maintenance.
“With ever increasing connectedness, almost all products are becoming electro-mechanical systems. Hence when designing and simulating a product, electrical engineers and mechanical engineers have an increasing need to understand the interactions between the various electrical and mechanical components,” said Robert Van Til, chair of the Industrial and Systems Engineering Department at Oakland University.
Historically, actuators were the interface between many mechanical and electrical components, with either open-loop control or a limited number of sensors. But the ever-increasing use of sensors are a key element in driving the need for ever closer interaction between the various engineering disciplines, Van Til said.
A proper set of requirements are key to successfully integrating the design of mechanical and electrical components. While this may sound relatively straightforward, in practice it can be difficult to implement for complex products. The aerospace industry is at the forefront of implementing systems engineering concepts due to the historically high-level of interactions between mechanical and electrical components. That’s changing rapidly in the auto industry with the advent of autonomous vehicles.
“I know of a recent case where an actuator on a prototype was controlled by two different subsystems. But due to incomplete requirements, the designers of each subsystem were not aware the other could also control the actuator. Under certain testing conditions, the actuator began to flutter as one subsystem tried to open it while the other simultaneously tried to close it,” Van Til said.
New software and design tools like Siemens’ Solid Edge 2019 make it possible to merge baseline electrical and mechanical technologies in a cohesive way when designing devices. Called convergent modeling, it involves creating the best possible digital twins that are easy to assemble or manufacture.
The systems-driven development process associates every part, the subsystems, the relationships, and the requirements to understand the impact of changes in design. For example, a change in the size of a fuel tank can affect the entire model and trigger a virtual redesign of a car from scratch as size and electrical requirements may vary. Instead of throwing more engineers to solve the problem, a convergent model assesses the impact on the electrical and mechanical systems in real time. The goal is to not throw more engineers to solve a problem, but to automate the integration of mechanical
components and electronics in cars.
Basic electrical engineering courses are offered to most mechanical engineering students, but some universities are doing a bit more.
Oakland University offers a comprehensive integrated systems program as part of the Master’s and Bachelor’s in System Engineering, which are multidisciplinary programs where students can opt to take a set of courses in mechanical and electrical engineering and computer science. For working engineers, the university’s M.S. in Systems Engineering program brings a perspective to the engineering process
, such as requirements definition, top-level functional designs, project management, product lifecycle management, which serves to organize and coordinate other engineering activities.
“The program educates engineers to serve as the primary interface between management, customers, suppliers, and specialty engineers in the systems development process in order to focus on the integration of all of aspects of the product–electronics, mechanics, ergonometric, software–as a coherent and effective system,” Van Til said.
Agam Shah is associate editor at Mechanical Engineering