Characterization of RAL bipedal robot capacitive MEMS accelerometer using electrical impedance measurements

A capacitive microelectromechanical systems (MEMS) accelerometer was developed to improve the dynamic balancing capability of the bipedal robot developed by Robotics and Automation Laboratory (RAL) of the University of the Philippines Diliman. Experiments were conducted to validate the actual behavior of the accelerometer prior to utilization in the main robot system by the characterization of the mechanical resonance frequency using electrostatic actuation and series of impedance (admittance) measurements. The calculated mechanical resonance frequency showed excellent agreement with both the theoretical and simulated values, showing only 4% and 7% deviation, respectively. Such accuracy serves to highlight the applicability of the MEMS accelerometer in obtaining precise and reliable performance for this intended application.