Sonicfinger: low-cost, compact, proximity and contact sensor for reactive positioning

A method for performing reactive positioning by an apparatus, comprising:

• generating vibrational energy based on an input signal;
• converting an acoustic reflection of the vibrational energy from an object into a voltage signal;
• extracting, from the voltage signal, an interference signal comprising a low amplitude signal corresponding to the acoustic reflection;
• obtaining a proximity signal proportional to undulations of the interference signal by mixing the interference signal with an in-phase copy of the input signal;
• generating a reflection data by performing an analog-to-digital conversion of a low frequency portion of the proximity signal;
• performing pre-touch proximity detection on the reflection data;
• performing grasp positioning on the reflection data;
• performing contact detection from the reflection data;
• and
• providing, to an external device, results of the pre-touch proximity detection, the grasp positioning, and the contact detection.

An apparatus for performing reactive positioning of a robot gripper, comprising:

• one or more fingers disposed on an end-effector of a robot, each of the one or more fingers comprising:
• a flat end surface configured to couple with the end-effector of the robot using a mounting fastener;
• a first surface comprising a circular indentation;
• a transducer disposed in the circular indentation and configured to:
• generate vibrational energy based on an input signal;
• and
• convert an acoustic reflection of the vibrational energy from an object into a voltage signal;
• an acoustic layer disposed in the circular indentation, provided between the first surface and the transducer, and attaching the transducer to the first surface;
• a sprue disposed in the circular indentation and configured to allow excess adhesive of the acoustic layer to flow out of the circular indentation;
• a first foam part disposed on the first surface and the transducer;
• and
• a second foam part disposed on a second surface opposite to the first surface;
• and
• a signal processing circuit configured to:
• provide the input signal to each transducer of the one or more fingers;
• and
• perform signal processing on the voltage signal of each transducer of the one or more fingers resulting in reflection data.