In recent years, the complexity of devices and systems in all industrial areas increased significantly. From vehicles using up to eight electrical motors and multiple motor controllers in one car seat alone, to industrial machines using high-efficiency synchronized DC motors instead of mechanical gears and cams, these systems are highly integrated and require a system-level approach to design.
Mechatronics is a design approach that engineers can use to collaborate on mechanical, electrical, and control design. By using digital models that incorporate information from different disciplines, engineering teams can quickly realize a virtual prototype of the complete system for design evaluation and optimization. With this seamless path to embedded deployment hardware, you can reuse algorithms developed during the design and prototyping phase, and development teams can rapidly implement a functional prototype of their systems by using commercial-off-the-shelf (COTS) embedded hardware. Measurement technology allows them to validate the functionality of the complete system before moving the design to the final deployment platform. Growing investment in such industries as medical, life science, and renewable energy are fueling this trend, in addition to the development seen in the area of industrial machines.
1. Virtual Prototyping Tools Facilitate a Mechatronics Design Approach
Historically, teams of engineers from different disciplines worked in silos and in sequential development. Engineers made design decisions independently, resulting in longer development times and higher costs. With a mechatronics approach, they now streamline development with teams that work in parallel and collaborate on designing, prototyping, and deploying their systems. They use measurement and simulation data to base their design decisions on additional information, and they combine software design tools to create a digital model (virtual prototype) of the complete system. Creating virtual prototypes is a critical aspect of the mechatronics approach because it helps engineers and scientists explore the system performance of the complete design before building a physical prototype.
The seamless integration of the NI LabVIEW NI SoftMotion Module and DS SolidWorks software delivers a design environment that is ideal for virtual prototyping. Engineers can easily connect existing SolidWorks CAD models to LabVIEW software, which automatically links the motor actuators and position sensors defined in the model to LabVIEW NI SoftMotion resources. Using the high-level motion functions provided by the LabVIEW NI SoftMotion Module, engineers and scientists can develop sophisticated motion control applications that include logic based on sensor feedback. Design teams, customers, and sales engineers can then use the virtual prototype to visualize realistic machine operations and analyze cycle time performance. By using LabVIEW and SolidWorks, engineers can simulate the mechanical dynamics of a machine, including mass and friction effects, as well as motor and mechanical actuator torque requirements, before specifying parts. With the seamless deployment path to embedded control platforms, engineers can use LabVIEW to easily transfer their motion control application, which was designed and validated using a SolidWorks 3D CAD model, to an embedded motion control system such as the NI CompactRIO programmable automation controller (PAC).
2. Developing a Six-Axis Precision Positioning System Using Virtual Prototyping Tools
Square One Systems Design, a multidisciplinary engineering company that specializes in the design and development of innovative automated workcells, robots, and precision positioning devices, used a mechatronics design approach and virtual prototyping tools to optimize the development of a six-axis precision positioning system. The unique mechanical design and the complex kinematic control algorithms required a system-level representation of the complete system to test the equations, validate the control algorithms, and optimize the mechanical design.
For several years, Square One used SolidWorks as its platform for mechanical CAD development, which they used to detect construction interferences and ensure alignment of mechanical fastening features early in the design process. By using the simulation features of SolidWorks and combining it with the LabVIEW NI SoftMotion Module, Square One smoothly integrated the development of control systems into the early stages of the design process.
“By combining the software and mechanical efforts, our goal was to reduce the number of iterations and modifications involved in bringing the system to realization,” said Lisa Mosier, a lead engineer at Square One Systems Design.
Figure 1. Virtual prototyping technology helped Square One engineers reduce the number of physical prototypes they needed to create.
After creating a 3D model in SolidWorks, Square One constructed a physical representation of the system. With the goal of designing a modular control architecture that could easily be adapted for different mechanical systems in the future, the controls team started to implement the software application in parallel to building the physical prototype. Using LabVIEW and the NI SoftMotion Module, the team implemented the motion equations and motor controls as a modular set of VIs. Because of the seamless integration of LabVIEW and SolidWorks, the Square One team applied the motion application to a 3D CAD model for design validation before deploying it to the CompactRIO embedded motion system.
By importing the CAD model into the LabVIEW project, the team controlled the assembly with the VIs it developed for the control system. The assembly behaved as a fully functional system with moving mechanicals in SolidWorks simulation. SolidWorks provided the features the Square One engineering team needed to track the motion of the system and run a full analysis of force distribution and velocity profiles of the assembly, including friction loads and safety factors of parts. All of these results helped in motor sizing and component design.
“One of the biggest advantages of the virtual prototyping tools was that it allowed us to test our control application on different mechanical systems without the need to build all of those different options. This will help us in the future to customize our mechanical systems quicker and with fewer test iterations,” said Mosier.
Figure 2. Square One engineers used virtual prototyping in the process of building CARMA, their six-axis precision positioning system controlled by NI CompactRIO.
Mechatronics-oriented design tools improve system development by simulating the interaction between mechanical, electrical, and control subsystems throughout the design process. They can help companies lower the cost and risk of mechatronics systems and help engineering teams collaborate on system-level design.
Christian Fritz is the product manager for motion control and mechatronics at National Instruments. He focuses on advanced motion control and helps machine and device builders improve their design process. Christian has a degree in electrical engineering from the University of Applied Sciences in Munich.