Paste Dispensing for Utility-Scale Wind Turbine Blades

Introduction: TPI Composites is a company that designs composite materials primarily for use in the transportation and energy sectors.  One of the products developed by this company is utility-scale wind turbine blades, which are highly engineered aerodynamic devices designed for the production of clean wind power. 

The process of constructing these blades requires the manufacturing of two distinct halves, which are then glued together.  The gluing process involves the application of a special composite epoxy (bond paste) to one half of the blade.  Then, the other half is lifted, inverted, and installed on top of the bond paste, gluing the halves together.  The bond paste is then allowed to dry.  Once glued, the blade is complete and is transported to the wind turbine.  

TPI Composites has identified the need for a device that moderates the movement of the paste shoe in conjunction with a worker to apply an even bead of bond paste to the blade.  The worker would apply pressure to the device, and the device would be responsible for navigating the paste shoe at an even, constant rate, while providing a signal to the paste-dispensing machine that the device is in motion.  This signal will initiate and stop the flow of paste as necessary.  

The robotic system is designed using a Raspberry Pi as the primary control system, which also drives a touchscreen user interface for the TPI Composite operator. The system will be running off Python that allows the software and hardware components to communicate with one another. The touchscreen monitor will be attached to the back of the device chassis. This will allow the operator to fully configure the robot using onboard controls.  

A force loading cell is attached to the end of the handle to measure consistent downward pressure on the paste shoe. This paste shoe is 3D printed with ABS+ plastic and is be attached in between the flanges of the chassis. The robot width is adjustable in order to fit versatile paste shoe sizes.  The system will follow a colored line projected onto a flat surface, mimicking an actual manufacturing scenario with a real turbine blade shell. 

Notable Design Elements:

  • Agent 390 robot chassis with motors
  • RaspberryPi 4B 8GB RAM
  • 12V 5V Dual 12A Power Supply
  • Custom handle-press component

Manufacturing Overview:

  • Order Parts
  • Create manufacturable items
  • Assemble hardware and electronics
  • Install device user interface
  • Test for functionality

A summary of the construction process is shown in the photos above.  All parts were assembled and machined as necessary to produce a working prototype.  This prototype underwent tests to verify it met the criteria provided by TPI Composites.  

A demonstration video of the prototype can be seen below: