The influence of global trends like electric mobility and the rising demand for consumer goods in emerging nations has made a lasting impact on technological developments by changing requirements for machines and systems, thereby necessitating new design and manufacturing approaches. One promising approach to which engineers and their automation partners are increasingly turning is mechatronics, which has been aptly described as a synergistic collaboration between mechanical engineering, electrical engineering, and information technology in the design and production of industrial products and the design of processes. Mechatronics can help ensure design and project success on a number of levels including improved product performance, space savings and cost savings.
Mechatronics requires synergistic ways of looking at design tools and drive systems. From transistors with discrete circuitry to field programmable gate array (FPGAs), electronics began with standardized units. Standardization is a prerequisite of greater integration. Integration enabled new developments and continues to fuel innovation in the electronics industry. The well known Moore’s Law of Mechatronics, formulated in 1965 by Gordon Moore, states that the number of transistors on a chip nearly doubles every 18 months. That also means that performance nearly doubles with no change in cost. This continuous increase in performance is the basis for explosive development in the electronics industry, which finds applications in more and more areas.
Mechatronic robotics and handling systems are critical components for factory automation, enabling motion sequences that would otherwise require extensive manual labor, such as automatic equipment assembly, loading and unloading, picking and palletizing. In modern automotive factories, up to 95% of body-in-white processes—where a car takes shape—are automated, saving labor and materials costs. In a typical welding application, for example, a robot might place 30 welding spots every 60 seconds, achieving short cycle times and an extremely high level of repeat accuracy.
Originally developed primarily for automotive applications, robot-enabled and other automation technologies have made significant headway into other manufacturing sectors, including electronics, pharmaceuticals, solar energy and textiles. A recent analyst report from Global Industry Analysts, 2011 projected the global industrial robotics market will reach 143 thousand units by 2015. The research cites numerous drivers—integrated products, rising value proposition, labor shortages and technological developments—spurring the rapid proliferation of industrial robotics.
Given the conditions for mechatronics, it would be extremely difficult to match the rapid development seen in semiconductor technology. There are considerable incompatibilities and challenges when combining electrical engineering, mechanical engineering and IT to develop integrated systems. Similar to the early trajectory of the burgeoning electronics markets, however, the mechatronics field is at the start of several important technological trends.
Material handling operations require drive systems which offer maximum productivity together with the highest order picking quality and reliability. Whether the need is for space-saving drive solutions in electro mobility or flexible automation systems for packaging machinery which can rapidly adjust to short cycles of the consumer goods industry, the best response to these new challenges is to leverage the power of interdisciplinary collaboration.
Common designs of robots and handling systems include articulated robots, parallel kinematics systems, gantry systems and linear axis systems. For example, a six-axis vertical articulated robot has six degrees of freedom and can therefore be used universally for mounting and handling of product parts in the automotive and plastics industries (see fig. 1). Other robot types, such as gantry robots, are commonly used in larger working areas for bigger machines or palletizing and de-palletizing. Depending on design, articulated robots can move a range of load sizes with a repeat accuracy in the range of one-tenth of a millimeter. A central robot controller coordinates control of the servo inverters, which together with servo motors or geared servo motors, enable dynamic and precise motion sequences.
Transmissions, motors, and frequency or servo inverters can essentially be viewed as mechatronic units. Precisely designed, they fulfill requirements for speed, torque, motion sequence, dynamics and positioning accuracy. Drive selection depends on numerous factors—the application, mass to be moved and the dynamic performance required. Elements used for the connection of the drives and mechanical components typically include shafts, spindles and toothed belts. Gearboxes are sometimes connected directly with the mechanical joints.
Designs that demand space-optimization or machine modularity need a toolbox of standardized drive modules. A standardized mechanical drive package consisting of a 20-Hz motor, gearbox, and decentralized frequency inverter, for example, adheres to the integration principle to achieve a more efficient and space-saving solution that can be visualized and incorporated into designs as a module. Standardized drive modules can then be refined for performance and scaled down for even greater space savings—and this is where the analogy to electronics becomes clearer. The trend toward greater integration and modularization is not restricted to drive and automation technology products. Integration of modules is increasingly being used to build machinery as well.
Physical limits and challenges in drive technology share certain similarities, but are naturally different from those in electronics. Things like cooling and electromagnetic compatibility are very much design issues. Even for companies with IT and engineering resources, synchronizing complex processing tasks and control systems with sufficient speed and accuracy can be extremely difficult or impossible. The advantages offered by automation solutions are diluted or lost if the handling and robotic components of the control application must be programmed independently. Troubleshooting and engineering is more challenging because of differences in programming methods and tools. In this regard standardization is also necessary, just as software becomes more important. Software brings flexibility to mechatronics and simplifies the relationship between automation partners and engineers by providing a common language and platform.
Software and other design tools can also drive a more agile and rapid design response. Such advantages are readily seen in the market for packaging equipment, for example. Given the rapidly diminishing sales cycles in the consumer goods industry, short time-to-market periods for packaging equipment bring an entirely new dynamic into the market. Once a branded goods manufacturer has developed a new kind of packaging and, after costly market research, wants to put it into production, the clock starts ticking for the engineer.
In addition to modern equipment concepts, the use of tried and tested modules is absolutely necessary so engineers can react more quickly and reduce delivery times. They need well-tested solutions for machinery sub-processes, such as material handling and the separation of products. For example, Lenze has developed mechatronic modules for in-feed and dual belt applications, composed of an L-force controller 3200 C, inverters and motors. To enable optimal software control, the module incorporates functional components for the dual-belt and in-feed systems whose structures are not dependent on the mechanical details (see fig. 2). This alleviates programming issues for users, who can simply choose the configuration best suited to their equipment.
Engineering expertise, collaboration and powerful design tools are all essential elements to the design of effective mechatronic solutions. One such tool is Drive Solution Designer (DSD), which can rapidly perform in-depth analysis to easily size and choose between L-force drives. Combined with the simplification of proven electronic and mechatronic modules, universal engineering tools ensure peak drive and automation performance. This is also the rationale for creating modified component models to determine energy efficiency, accuracy, and drive optimization. Mechatronic models can analyze the impact of uncertain factors, like friction and elasticity. Model-based parameter identification also allows calculation of important variables in the real system and the visualization of parameters which cannot be directly measured. This simplifies the process of setting control parameters and shortens the time needed to put machinery into operation.
Components models that analyze equipment or operations may pass in-depth analysis, but fail from the start when combined for holistic analysis. In an electric drive train including mechanical load, the mechanical loads carried between individual components may vary by up to six orders of magnitude, with the fastest found in the power electronics and the slowest in the mechanics. Effective mechatronic design systems eliminate the single-discipline approach to complex design engineering by providing compatible analysis tools and integrated simulations that give a perspective of the overall system.
Trends in mechatronics are moving toward maximum availability through modularization, an intelligent reduction in the number of assemblies, and elimination of proprietary hardware. Future technical consolidation will continue to yield increases in performance and availability. Flexible software enables a user to integrate standard kinematics, in addition to custom-designed mechanics on a hardware platform. The advantage is that PLC, motion and robot functions can run in real-time from a single controller. Compared to conventional approaches using separate robot controllers, this latest concept means fewer components and less engineering expertise is required.
Modularization and the standardization of drive systems and other machine components, in addition to greater collaboration and design tools, are all essential to the continued proliferation of automation and robotic applications for industry. A more profound understanding of the interaction between individual components allows better founded assumptions with regard to the system features needed—and, ultimately, better designs. The numerous advantages are evident across the product lifecycle, which can be a crucial competitive advantage in bringing mechatronic solutions to industry.
ABOUT THE AUTHOR
Brian Comparini joined Lenze Americas in January 2011 as a regional sales manager, where he is responsible for the Midwest region. He has served in the industrial automation and motion control industry for over 20 years. Brian holds a bachelor of science degree in mechanical engineering from the University of Illinois, Urbana.
LENZE AMERICAS CORP.