Location Tracking

Systems for determining object identity and position

The term 'location tracking' refers to the automatic detection of the position of moving objects by means of indoor tracking systems, also referred to as Real Time Location Systems (RTLS) or by satellite tracking in outdoor areas using GPS, Galileo, or similar.

Location Tracking enables automatic, continuous and uninterrupted identification and tracking of objects in real time, comparable to a video recording. Events such as an entry into defined areas from all directions or even a collision of two different objects, can be recorded in the digital model at any time. For example, cross-plant transports, material flows in logistics and production, and the use of tools and assets can be automatically recorded.

Location systems are available on the basis of a wide range of technologies with different characteristics and costs. In outdoor areas, external infrastructures such as satellite networks or data communication networks can usually be used. The accuracies that can be achieved in this way are limited to a maximum resolution of 10 meters with standard antennas. With suitable, special antennas and higher energy consumption, the resolution of GPS/Galileo can be improved to up to one meter. 5G networks promise better accuracies in the future. But it remains to be seen how much additional infrastructure will be needed to achieve this. In any case, a dedicated infrastructure is needed for indoor positioning. The spectrum of possibilities ranges from detecting presence in a building, to simple zone location, to precise location with a resolution of about one meter, to high-precision location with resolutions of a few centimeters or even millimeters. A simple rule of thumb is: the more precise the resolution of the location, the more investment is required to implement the system.

Tracking Technologies

This graph shows, for the different location technologies, the relationship between increasing accuracy (vertical axis) and cost for a reference configuration. There is no one technology that represents an ideal solution. Rather, our objective is to select the appropriate technology for a given application, taking into account the economic constraints. Thus it is important that different technologies can be combined in one application software environment to cover all use cases with one user interface and as little integration effort as possible.

	Ident	Presence	Location Tracking	Precise location
Methodology	Detect entry and exit via gateway/chokepoint or manual scanning	Strongest RSSI at one or more receivers	Weighted RSSI, Triangulation, Multilateration	Triangulation, multilateration
Reliability	Missing an entry or exit is directly a permanent error or human factor	Crosstalk of the signal (false positive) is temporarily a false assignment	Location error is temporarily a misallocation	Location error is temporarily a misallocation
Verification	Manual plausibility check by process instruction	Manual or automatic plausibility check by SW	Automatic plausibility check by SW / geometry	Automatic plausibility check by SW / geometry
Condition	Delimited accesses	Areas separated by signals (e.g. by wall)	Buffer zones between areas (e.g. aisle)	Minimum size range suitable for accuracy
HW Effort	Low (1 gateway per access)	Low (1 to several receivers, depending on room size)	Medium-High	High-Very High
Suitability	Incoming postings logistics, tool output, etc.	Locking storage, tool storage, patterning (counting objects nearby), etc.	Tracking circulation stock, finding objects (also in open areas)	Automation, e.g. posting to storage bin, plausibility check, system configuration, etc.

The spectrum of different technologies and suppliers in the field of location tracking and identification systems is almost impossible to keep track of. Development is proceeding in ever faster cycles. We know the advantages and disadvantages of the most important systems on the market and keep a close eye on further developments.