FAQ

General Questions
Performance
Integration
Legal and Privacy
Other Resources

General Questions

What does IndoTraq™ do?

IndoTraq™ provides fast high-precision wireless position tracking technology.

How does the tracking system work?

HSKT™ (high speed kalman tracking)

The system is based on the fusion of an IMU (inertial measurement unit) and wireless radio frequency (RF) signals. It has a precision of +-5mm and updates at 150 times per second (150 Hz). Stationary anchors (minimum of three for 2D positioning, four for 3D positioning) are placed around the perimeter of a space. Each tag within the space actively communicates with the anchors to determine its own location. Each tag also incorporates technology to determine its 3D rotation in space, in the form of a quaternion.

HSVT™ (high speed vision tracking)

The system has sub millimeter precision with 150 updates per second (150 Hz). This technology combines the previous success of the HSKT™ tracking tag with inside-out camera tracking (IOT). In this case, the HSKT™ tag gives the initial starting position and rotation. Then constantly corrects the drift in the IOT so that it always has an accurate 3D position. Using IOT by itself is limited to small spaces. It completely loses tracking when there are changes in lighting, smooth wall or floor textures, or if the cameras are blocked. That’s where the HSKT™ tracking tag becomes critical so that you never lose tracking. When the IOT loses its tracking, the HSKT™ tag takes over and gets the IOT system back on track.

Does the tracking technology work through walls or other obstacles?

Yes. For most applications there are no issues, but for best performance in virtual reality, the system should be set up so the wireless signals don’t have to pass through thick walls. Thick walls cause a small time delay which can affect the precision of the position calculations.

Does the tracking technology work with metal objects in the space?

Yes. There are no issues with metal objects.

Who is this tracking system designed for?

This tracking system is designed to be the fastest, most precise wireless position tracking system in the world. It is designed to be used by other companies to implement their tracking needs, both indoors and outdoors. This technology can help unlock the potential of a host of commercial applications, such as full Virtual Reality immersion, virtual training, virtual shopping and events, wearable tracking, autonomous cars, robots and drones, and more.

Does IndoTraq™ work with customers to help incorporate the tracking solution into their own product?

Absolutely. IndoTraq™ considers this one of their main focus points. IndoTraq™ is a B2B business.

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Performance

What is the tracking range?

The range indoors with a single set of anchors is up to 100 m × 100 m. The range outdoors can reach up to 200 m × 200 m. If greater coverage is required, multiple systems can be linked together in a mesh network to cover almost unlimited range. Note: The tiny antenna included on the development kit tag was chosen so that the tag can be made as small as possible. It may not have as good a range as other antennas. In a real application, an appropriate antenna would be chosen to give you the best results. The antenna is not required to be mounted on the same pcb as the tag processor. It can be a wearable and external to the tag processor.  

What is the power consumption for each tag?

Power consumption depends on the tag update frequency. Typically this will average from 70 mA to 130 mA with update frequencies ranging from 60 Hz to 150 Hz. Power consumption can drop dramatically if the update frequency can be slowed down. For example a 1 Hz update rate will drop the average to 0.26 mA and based on a 500 mAh battery, you can get 400 hours of operation.

What RF frequency does the system operate on?

The RF frequency is Ultra-wideband (UWB) in the range of 3 to 10 GHz. The output level is -41.6 dBm or less, as mandated by the FCC.

What is the update rate for each tag being tracked?

The update rate can be as high as 150 Hz for one tag, but for the development kit with high speed network, it will be up to 100 Hz (10 ms) for each of the four tags. If fewer than 4 tags are used then the update rate will increase up to a max of 150 Hz.  As more tags are added beyond four, the latency will increase 2 ms per tag. For example, if you had eight tags, then the latency would be 10 ms + (4 × 2 ms) = 18 ms per tag. This is a 55.5 Hz update rate. To save battery power, the developer can also choose to slow down the update rate. Many applications don’t require high refresh rates.

We also offer the super speed network firmware that will give 100 Hz (10 ms) minimum for 8 tags and 8 anchors.

Is there a limit to the number of tags / users?

There is no hard limit to the number of tags being tracked although our current high speed firmware supports up to 16 tags and 8 anchors. As tag numbers increase the update rate decreases. See the question “What is the update rate for each tag being tracked?” for the formula to calculate the update rate.

How do the anchors know their positions?

When the system is turned on, each anchor runs an algorithm to determine its own position relative to the other anchors.

How long does it take for the anchors to determine their position?

Their positions are determined in less than a second.

What is the tracking precision of each tag?

It is under 5 mm when the tag has a direct line-of-sight to the anchors. Note: The tiny antenna included on the development kit tag was chosen so that the tag can be made as small as possible. It may not have as a good a range as other antennas. In a real application, an appropriate antenna would be chosen to give you the best results. The antenna is not required to be mounted on the same pcb as the tag processor. It can be a wearable and external to the tag processor.  

What is the tracking accuracy of each tag?

Accuracy depends on the application and conditions, but typically is within 10 cm. Both anchor and tag locations can be calibrated to remove the offset and achieve better accuracy, but for most applications calibration is not necessary. Here is a document showing typical precision vs accuracy data: Precision vs Accuracy

What is the precision of the 3D rotation quaternion?

The quaternion precision is 0.06 degrees.

What is the accuracy of the 3D rotation quaternion?

The quaternion accuracy depends on the application and conditions, but typically is within 2 degrees on startup. In our virtual reality demo application, we have the user face forward when the demo starts. This calibrates the quaternion and then maintains the 0.06 degree precision.

I’m confused. What is the difference between precision and accuracy?

Accuracy is a measure of closeness to a known value. Precision is a measure of reproducibility. For example, in a dart game with 5mm of precision, the dart would typically hit within 5mm of the other darts, but may or may not be hitting the bullseye.

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Integration

What interface is provided to a computer?

A virtual communication port driver is provided to communicate with a computer running Windows or Linux (all versions supported) over USB. An example application is provided that shows where the anchors are located, and the tags being tracked will be shown in real-time. A plugin for Unity running on a computer is also available.

What interface is provided to a mobile device?

A plugin for the Unity game engine is provided, which will allow an Android-based device to communicate with a tag. This plugin allows the tag tracking information to control characters or objects in the game. An example virtual reality application—made with Unity—is provided along with source code. This application is the same one we have demonstrated to people all over the world so you may have already seen it.

What output does the tag generate?

The tag outputs 3D coordinates and quaternion information. Other data such as anchor position, tag to anchor distances, linear acceleration, rotation, etc is also provided.  See the getting started guide located in the support section for more details. Custom data structures will be provided as needed for specific applications.

What output does the anchor generate?

The anchor outputs the same tracking information for each tag, over Wi-Fi, USB, or Bluetooth. This gives you the option of getting the tracking data from the anchor or tag to a PC or android device.

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Legal and Privacy

Is IndoTraq™ tracking technology patented?

Yes. There are multiple patents covering both hardware and software.

I’m concerned about privacy. Where is the location data stored?

The tags and anchors do not store location data. As each tag calculates its location, it is sent to the USB port then it is transmitted back to the anchor. The anchor can then forwards each tag’s location to a centralized place via Wi-Fi, Bluetooth, or direct USB connection. There are adapters that can receive the direct USB connection and forward to other communication systems such as Ethernet.

Other Resources

Where can I find answers to questions not listed here?

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