Neumann's team put that approach into action with the design of the Festo Bionic Handling Assistant, a mechatronic robot arm designed to work closely and safely with humans. Unlike most industrial robot arms, which are stiff and thus could be dangerous if they come into direct contact with humans, the Bionic Handling Assistant is made of lightweight polymer components, so it's safe to the touch. A complex system of 12 pneumatic chambers, 13 actuators, and 12 position sensors work in concert to control the motion of the arm, and a control system manages the pneumatics, so that the arm will yield immediately in the event of a collision.
The controller models for the pneumatic chambers were designed and optimized in The MathWorks' Simulink, and Simulink Coder was used to generate C code from the model to be put to work in the prototype hardware.
Neumann says that even though the model-based design approach definitely saves time and ensures a more streamlined engineering workflow, there are hurdles, including getting engineers comfortable with a front-loaded design process that doesn't necessarily yield results until later in the project. It also takes some work getting engineers trained on the tools and acclimated to the mathematical background necessary for building models.
Nevertheless, heavy lifting aside, Neumann and Beltman say the transition to model-based design practices is well worth the effort. "It depends on the level of mechatronics," Beltman says. "If the specifications are very tight, model-based design is a must."