Themes

Precision Mechatronics

  • High-speed intelligent linear motion systems: To achieve high-bandwidth motions with minimal perturbations / vibrations
  • Ultra-precision positioning: To develop actuators and drivers featuring large range (a few mm) and high-repeatability (nm scale)
  • Wide-format roll-to-roll web handling: To enable high-precision roll-to-roll processes using passive and active means for precise positional alignment and localized speed and tension control
  • Thermal effects in precision systems: To minimise thermal distortion in electromagnetic actuators and stages with thermal reduction design and compensation techniques
Research Relevance

In order to tackle the challenging issues in precision mechatronics, the PM team has made continuous research efforts to develop effective modelling, analysis, and design methods for both high-speed high-precision machines and nano-positioning systems. Apart from such design analysis issues, the PM team has also paid particular attention to develop critical control schemes and techniques so as to push the system performance (e.g., speed and accuracy) to its limits.

Contact PersonTeo Chek Sing(csteo@simtech.a-star.edu.sg)
Approach
  • High-speed intelligent linear motion systems: This research track is to primarily address the issues resulting from high-acceleration (up to 30g) and high-speed (up to 5m/s) motions in the high-precision stages (< 5 um tracking errors), particularly for applications in SMT, pick and place, and inkjet printing, whereby the process's precision requirements and its theoretical bandwidth implies that the throughput bottleneck lies on the motion system.  One of the major limitations in such systems is low bandwidth due to self-induced vibration and thermal factors. Approaches being considered to investigate and address the issues include noncontact bearings (e.g., air-bearing and magnetic levitation), active damping, coarse-fine motion mechanisms, and model-based feed forward control schemes. A new approach being considered in the coming year is Adaptronics, whereby topologically optimized sensor data are actively used to control and achieve the optimal performance under the varying self-induced vibration and thermal sources.
  • Ultra-precision positioning: The vision of this track is to develop a tool holder module for applications such as 3D additive manufacturing, laser marking, inkjet printing, and nanoimprint lithography, where very tight tolerance of alignment for both overlay and coplanarity are required. This requirement stretches into the nanometer scale as the tool's standoff distance from the substrate increases. Thus, the focus will be on the development of nano-accuracy actuators and flexure mechanisms to realize long travel range (a few mm) and high-repeatability (nm scale) motions. By combining mechanism synthesis and topological optimization holistically, high-performance flexure-based nanopositioning stages are developed. An integrated design approach will be investigated in order to advance this development. In addition, the design and control methodologies for flextronics-based nanopositioning systems (i.e., flexure stages with embedded sensors and actuators) will be investigated to further enhance the precision and bandwidth of these modules.
  • Wide-format roll-to-roll web handling: The approach of this track is to develop modular units which can be integrated seamlessly into any R2R machine. Two key issues have been identified for such systems, namely tension control and tool/web alignment.  Due to the varying forces acting of the web and process influences such as oven heating, web tension control is one of the most challenging problem to tackle systematically yet it is one of the most critical parameters to achieve quality output. Both passive and actively aligned process tools and web alignment modules will also be developed for precise positional alignment in the key processing stage.
  • Thermal effects in precision systems:  In high-speed motion stages and nanopositioning systems, the thermal effects generated by actuators (particularly electromagnetic actuators), moving elements and other thermal sources will significantly degrade the performance of the system such as energy efficiency and positioning accuracy. With the understanding of the thermal behaviour through modelling and simulation, accurate and efficient precision motion system will be realised from this research track.
Expertise
  • Long-travel, high-speed, and high-precision motion stages
  • High-bandwidth and  high-resolution drive-controllers
  • Model-based high-speed and high-precision motion control
  • Flexure-based nano-positioning stages
  • Electromagnetic nano-positioning actuators
  • System dynamics analysis and vibration control
  • Thermal effect modelling, prediction, and compensation
Research Showcases