What is 3D Time of Flight?

The initial operation of a 3D ToF sensor is fairly straightforward: light is emitted from the sensor, bounces off the target, and returns to a multipixel imager.

The next part is a little more complex. As the light returns to the sensor, each individual pixel will report a different distance measurement point because it is receiving its own piece of the emitted light. The distance information for each pixel is determined by measuring the round-trip time from light emission to reception on each pixel. When the distance information for each pixel is combined, the sensor can create a fully three-dimensional picture of what it sees.

When using 3D ToF, a user is given much more information than single point sensors. “This extra data allows a user to make more informed decisions about their application,” says Novak. “It can provide insight that would otherwise be very difficult to gather, such as tracking the volume taken up in an empty space as opposed to just a single height measurement point.” 

For example, a 3D ToF sensor can easily and accurately detect the variances across the aforementioned shipping carts and pallets. In the carts, varying peaks, valleys, and gaps are formed by shipping packages of various shapes, sizes, and orientations. A 3D ToF sensor detects the unpredictable and ever-changing contours of the collected packages as they pile up, regardless of sizes, angles, or positions. Similarly, the top of a pallet load can easily be monitored for items reaching a certain stacking height no matter where the items are placed. Operators can be notified when fill levels and peak heights are reached anywhere across an entire area, something a single point sensor might not be able to catch. 

When precise height measurements across a broad area are needed, 3D time of flight technology can solve many challenging applications in which other technologies would give an incomplete picture.