Systems, devices, and methods for volumetric measurement using multiple non-coplanar cameras

A monitoring system for an interior of a container, comprising:

• (a) a housing;
• (b) a plurality of direct time-of-flight (dTOF) imaging modules mounted to the housing in mutually non-coplanar orientations configured such that fields of view of adjacent modules partially overlap to provide coverage of the interior of the container;
• (c) an electronics assembly including a processor and memory, the processor configured to:
• (i) acquire range data from the plurality of dTOF imaging modules;
• (ii) stitch the range data into a concatenated depth representation of at least a portion of the container interior;
• and
• (iii) determine a fill level based on the concatenated depth representation;
• (d) an external power-and-communications module comprising a solar panel, a rechargeable battery electrically coupled to the solar panel, a microcontroller (MCU), and a long-range low-power radio transceiver with an antenna;
• and
• (e) a mounting bracket configured to suspend the housing, the mounting bracket including a hook to engage a rim or collar of the container.

An optical sensor head for interior volume sensing, comprising:

• (a) a generally circular housing having a plurality of bottom-facing protrusions, each protrusion defining a respective sensor plane;
• (b) a plurality of direct time-of-flight (dTOF) imaging modules arranged symmetrically about a central axis of the housing, each mounted in a non-coplanar orientation;
• (c) an array of coverglasses each seated at a respective protrusion and aligned so that a surface normal of each coverglass is collinear with an optical axis of a corresponding imaging module;
• (d) a cleaning mechanism including at least one wiper or brush that is movable across all coverglasses;
• and
• (e) per-module signal processing circuitry configured to output depth frames.