Demonstrator 2: Advance Control Loop Demonstrator

In this project IK4-Ideko has built a two axis test bench in its prototype workshop with a LabVIEW control system to validate the advance control loop function. In this way it is possible to measure the status of the vibrating structure using an accelerometer, which is the simplest and most direct way to measure vibrations in mechanical structures, and introduce a force on the system directly proportional to the acceleration of the vibrating component. The immediate result that is obtained with the use of this technique is a significant increase on the damping coefficient of the vibrating mode, which means that after an excitation the vibration will disappear much faster. The force is introduced on the mechanical system using the ordinary motors of the machine. However, an important difficulty is that commercial CNCs do not provide the necessary customization options to introduce the required algorithms on their control core. After the proper adjustment of the new control loops on the control bench, a huge increase in the damping coefficient was achieved. The comparison of the acceleration response of the tool center point to viscous step command with or without advance control loop shows clearly the magnitude of the improvement.