Chunjie Duan, CO-CEO, CO-FOUNDER
UWB-based Real-time Location System (RTLS) is quickly becoming mainstream. With its superior accuracy compared to other wireless technologies, such as Bluetooth and WiFi, it enables many applications that were not possible before.
There are many companies offering RTLS products, offering a variety of options for the end-users to choose from. But while most of the RTLS appear to offer similar performance, not all RTLS are created equal. Below are three important details that can help you choose the right RTLS for your applications.
It is important to understand that all systems have latency, and therefore, the location you see at a given moment is never the true location of the trackable object at that moment. A typical RTLS has 1-3 second latency. This is generally acceptable for most of the tracking applications where real-time action is unnecessary (analytics, for example).
For some mission-critical applications, however, latency cannot exceed a fraction of a second. For example, if a forklift traveling at 10 mph (i.e. 4.5 m/s) comes to a complete stop in less than half a second, the stop distance is still 2 meters. This could cause devastating consequences such as pedestrian injury, shelf collapse, and vehicle damage.
When talking about latency, it is also important to understand how a company is measuring it to understand their product marketing claims. You often find subsystem latency is used in these claims instead of end to end latency. Ask the vendor how they are measuring latency – from point A to point B.
The unique characteristics of UWB signal make it possible to achieve 10 cm accuracy in ideal conditions (open space with no signal blockage). Many UWB-based RTLS products, therefore, claim the 10 cm accuracy. The real-world environments, however, are far from “ideal.” A warehouse is generally full of metal racks, and manufacturing facilities are littered with metal parts and machinery. In many cases, the user sees rapid degradation in accuracy in an industrial setting.
Another factor that affects accuracy is when the trackable objects are fast-moving, also known as the update rate. For stationary objects, it is relatively easy to estimate the position accurately through heavy filtering, (e.g. averaging). But when the object is moving constantly, the position needs to be updated more frequently.
Why are we different?
To minimize delay time, Redpoint tags are designed to deliver guaranteed latency of less than 200ms by using our patented technology, making it the best option for safety applications.
To solve the accuracy problem, Redpoint product combines UWB with other sensors that complement UWB signals. Redpoint’s tags use multi-sensor fusion that delivers up to 26 Hz updates per second (i.e., at 90 km/h, the position resolution is within 1 m), which is only made possible by Redpoint’s patented DL-TDoA scheme.
At the end
Before selecting a real-time location system to connect your environment, it is important to understand accuracy and latency and how each vendor measures performance. If you have a use case that requires high accuracy and low latency, including safety applications like collision avoidance, milliseconds and centimeters matter. Click here to learn more about Redpoint’s patented technology and how it can transform your workplace.