Spectral Subtraction of Robot Motion Noise for Improved Event Detection in Tactile Acceleration Signals

Abstract

New robots for teleoperation and autonomous manipulation are increasingly being equipped with highbandwidth accelerometers for measuring the transient vibrational cues that occur during con-tact with objects. Unfortunately, the robot's own internal mechanisms often generate significant high-frequency accelerations, which we term ego-vibrations. This paper presents an approach to characterizing and removing these signals from acceleration measurements. We adapt the audio processing technique of spectral subtraction over short time windows to remove the noise that is estimated to occur at the robot's present joint velocities. Implementation for the wrist roll and gripper joints on a Willow Garage PR2 robot demonstrates that spectral subtraction significantly increases signal-to-noise ratio, which should improve vibrotactile event detection in both teleoperation and autonomous robotics. Abstract. New robots for teleoperation and autonomous manipulation are increasingly being equipped with high-bandwidth accelerometers for measuring the transient vibrational cues that occur during contact with objects. Unfortunately, the robot's own internal mechanisms often generate significant high-frequency accelerations, which we term ego-vibrations. This paper presents an approach to characterizing and removing these signals from acceleration measurements. We adapt the audio processing technique of spectral subtraction over short time windows to remove the noise that is estimated to occur at the robot's present joint velocities. Implementation for the wrist roll and gripper joints on a Willow Garage PR2 robot demonstrates that spectral subtraction significantly increases signal-to-noise ratio, which should improve vibrotactile event detection in both teleoperation and autonomous robotics.

Jointonation

“…A robot's own internal motors and gears inevitably generate highfrequency vibrations that contaminate measurements of the robot's movement and sound [Ince et al, 2009][McMahan et al, 2012. We believe that these "ego-vibrations" are essential in the induction of a robot-like feeling.…”

Multi-Modal Haptic Rendering Based on Genetic Algorithm

“…We used serial communication to enable the computer to communicate with the STM32 microcontroller to transmit control commands and receive sensory signals. The SensAble Phantom Omni device can sense position, velocity in the x, y, z direction [17]. Displacement data were collected through Omni.…”

Tactile feedback system of high-frequency vibration signals for supporting delicate teleoperation of construction robots

“…Therefore, before the main process, the noisy vibration will be extracted from the measured signal using a noise subtraction technique. McMahan et al proposed a method in which the spectrum of vibration in the non-contact condition is subtracted from that of the measured vibration when the robot is active [22]. In this method, the measured signal is transformed into frequency domain information (power spectral) using a short-term Fourier transform (STFT), and then the power of the noise signal, which is defined previously, is subtracted from that of the measured signal.…”