Moving from Mechanical to Electromechanical Machine Design

As machine builders implement new technology and replace yesterday's coupled gears, cams, and line shafts with servo actuators for precision motion, sensors for diagnostics, and cameras for inspection, these machine builders are embedding more functionality in the controls of the machine as opposed to the mechanical components.

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Figure 1. Today’s engineers use servo-driven actuators for precision motion.

Previously, with the mechanical approach, an engineer implemented a simple push/pull mechanism using a rocker arm connected to a cam and a motor that only needed an on/off signal for actuation. The engineer could easily control this system with a programmable logic controller (PLC) and determine the travel distance of the push/pull mechanism by the design of the cam. Machines today need flexible travel lengths to accommodate the production of multiple product designs on the same machine. Today, engineers design these machines using servo actuators and servo controllers and determine travel lengths by software parameters.

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Figure 2. To achieve efficient machine design, engineers need to simulate the integrated mechanical and control design in software before moving to the prototype stage.

What used to be a purely mechanical design is now an electromechanical design, adding complexity to the design process. In the past, the mechanical engineer designed the complete system, and the controls engineer added simple on/off controls to actuate the machine. Now the mechanical engineer can design only part of the system, while the controls engineer designs the “brains” of the system without which the mechanical design is severely handicapped. To achieve efficient machine design, engineers need to simulate the integrated mechanical and control design in software before moving to the prototype stage. This helps them make trade-offs in the early stages of design, visualize the electromechanical system in action, and save money on creating prototypes after every design iteration.