Mechatronics efficiency achieved by designing for functional excellence
Looking at machine design from the functional rather than hardware capability point of view has a specific benefit: better machine efficiency. The efficiency comes from blended functionality of the subsystems combined with system sizing versus component sizing. System sizing has the advantage of multiple components designed to work together in maximum efficiency for the system in a predefined operation data. No more component oversizing for the "safety margin," and no more partial utilization of components is needed. The pre-engineered subsystems are already simplified and designed for an optimum application output based on the specific application input data.
Subsystems are designed to benefit from shared synergies and become as efficient as possible. Redundancies and component inefficiencies are eliminated by a simplified structural design, which creates a more efficient machine. Energy consumption is reduced as a result, which improves the machine operating cost. Machine cost is also reduced due to shorter design time and simplified functional control scheme. Overall, total efficiency is increased.
Teamwork, management, efficiency
Mechatronics design looks at complexity of interdisciplinary technologies including electrical, mechanical, computer science, pneumatics, and thermodynamics engineering as the main sections. The design process differs from the traditional design because it considers the concurrent technologic functionality rather than sequential hardware design stages.
In typical machine design, mechanical engineers develop the concept layout, pass it to the electrical engineers to add the electrical components, and they give the design to the controls engineers to link all the elements into a control system. However, this design style creates inefficiencies due to the lack of synergy in blended electromechanical concepts. As a result, functionality is missing and the machine can become too complex when it doesn’t need to be. As a consequence, bits and pieces of technologies are integrated fragmentally into the machine, with implications on machine cost, performance, and efficiency.
In mechatronics design, a group of electrical, mechanical, and controls engineers headed by the project manager works as a project team. They develop the design concept based on product management or customer specifications. Multiple team design sessions avoid design conflicts by proactively identifying cross-functional issues. Design concepts are developed as functional subsystems with an optimum blend of cross technologies, including from the start, the electrical, mechanical, and controls content.
Pre-engineered subsystems are used as functional components with defined input/output (I/O) data pertaining to machine process not individual hardware characteristics. The project manager has a very important role in organizing the team communication, mitigating cross-functional team conflicts, and managing the design schedule.
Product management is always involved to ensure optimal balance between cost, performance, and specifications. Functionality is examined for the optimum electric and mechanic solution with priority given to the most effective machine design integration.
A simplified machine provides benefits such as a smaller machine, less weight, and less mechanical wear. The impact on the machine design can now be measured as smaller footprint, less cost, less maintenance, greater functionality (cam profile function can change to different profiles for different machine output), higher machine speed, and greater mean time between failure (MTBF).
All those advantages are designed to make the machine more competitive in the market and help define the success or failure of the original equipment manufacturer (OEM). Mechatronics design teams use the electrical, mechanical, and controls engineering as a simultaneous voice in the design of the machine. Working as a project team, the machine is divided into subassemblies based on functionality rather than component capabilities. Multiple functions are gathered into integrated modular controls, eliminating the need for physical devices with limited capabilities.
Another example is the human-machine interface (HMI) with an industrial PC (IPC) built in as a programmable automation controller (PAC) capable of motion control, logic, and running comprehensive software. This design choice eliminates the need for individual counters, programmable logic controllers (PLCs), and motion controllers. Hardware wiring is now reduced. Physical mapping is replaced with software mapping. The logic and motion can be combined in one control software without need to wait for I/O scanning and logic to initiate the motion, resulting in faster machine response and better performance. Fewer components equal better MTBF for the system.
Functional subassemblies, less overhead
The effective mechatronic team looks at hardware design based on subassembly functionality as pre-engineered components, such as complete actuators with integrated servo motors and a gearbox. The servo actuator is being used as an electromechanical element that includes the proper sizing of the actuator with coupling, gearbox, servomotor, and servo drive, using bus communication for motion control. Control setup parameters for the subassembly can be downloaded from a cloud database provided by the manufacturer.
What are some of the benefits? The design team only looks at subsystem capabilities, eliminating the need for sizing for each and every component. Most of the time, the sizing for the subsystem is done using software tools from the subsystem manufacturer that only considers subsystem I/O data, simplifying the design, increasing design efficiency, and speeding time to market. Different subassembly capabilities can be compared based on mechanical, electrical, pneumatics, and controls capabilities and analyzed from the safety, production speed, and MTBF data for the optimum functional blend of characteristics for the predefined cost.
Using pre-engineered subsystems increases design efficiency and avoids hardware/software conflicts. Many manufacturers offer software-sizing tools for typical system configurations as gantry systems with multiple axes, accepting a large variation of input data for optimum performance.
Controls design, functionality
The controls software design also examines the entire machine based on functionality, integrating complex structures into reusable function blocks. Most of the up-to-date PAC software allows for logic and motion integration into a software package. Some actually extend the capabilities to control pneumatics logic.
The advantage of using function blocks in software is that canned engineering functionality is predefined and standardized. Reusing function blocks shortens the design time and increases design efficiency. Portability of function blocks increases design flexibility and allows for design changes as needed by customer application. Function blocks are available in function block libraries as pre-engineered tools, simplifying the design process. It is typical for OEMs to develop custom function blocks for their typical machine; this allows them to reuse blocks (with light deviations) in the structure of the new machines, increasing design efficiency.
All the current major suppliers of industrial automation products have included function blocks in their offerings, pushing the industry towards standardization. Machine connectivity allows for remote access with flexibility in customer requests for operational changes and troubleshooting.
Today’s advanced PAC controls software is built with the capability of the "Internet of Things," and "Industrie 4.0," addressing the need for connectivity and digitization of information. Ethernet-based protocols allow fast data transmission across the network with the capability of blending multiple protocols into one connected data output as highlighted by OPC Unified Architecture, integrating the IT with industrial automation. This way future system integrations into data management and reporting are supported from the lower level controls, ensuring operational capabilities needed for "Big Data" and cloud applications.
Mechatronic design principles, the supplier base excelling in functional subassemblies, and intelligence driven ever farther down into components create enormous competitive opportunities for OEMs and their customers. This is an exciting time for control and design engineers.
Paul Plavicheanu, electric automation product manager, Region Americas, Festo. Edited by Chris Vavra, production editor, Control Engineering, CFE Media, firstname.lastname@example.org.
Good teamwork and collaboration are essential for mechatronics design teams.
Better design efficiency provide a simplified machine, which offers benefits such as a smaller machine, less weight, and less mechanical wear.
Recent mechatronic developments offer new possibilities for control and design engineers and competitive opportunities for OEMs and their customers.
What developments would you like to see in future mechatronics designs?
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