Electromagnetic tracking

A Viper TX2 electromagnetic coil source

Electromagnetic tracking is a kind of 3D tracking that generates magnetic fields and detects them from a sensor. It is a technology for 6DOF tracking. It can be implemented in an electromagnetic tracking system. Examples of electromagnetic tracking are the Magic Leap 1 controller and the Razer Hydra. The Magic Leap 1 uses magnetic tracking for its handheld controller, but in a poor form.

It can work with a headset if the headset is small enough.

Magnetic tracking preserves high frequency transients in movement, like a flick of a finger. However, there must not be any metal objects in the tracking area; A metal object has to be at least a foot or two away from a tracking area so that it doesn't interfere with the tracking measurements. Metal objects cause jitter and drift.

Companies

Electromagnetic tracking was invented by Polhemus, which originally was researching navigation in aircraft. Another company that has made electromagnetic tracking gadgets is Ascension Technologies.

• Polhemus
• NDI (previously called Ascension)
• AmfiTrack
• Radwave Technologies
• Sixense

Premo is a company in Spain that markets electromagnetic tracking parts, including coils. Premo's electromagnets are in some AmfiTrack products.

Types

• AC magnetic tracking (Polhemus)
• pulsed DC magnetic tracking (Used by Ascension, later NDI)

Components

SEU stands for system electronics unit. It is used in the context of electromagnetic tracking systems such as the Polhemus Viper and the Polhemus Patriot. It is a box that the sources and sensors plug into.

Industry Standard Coil Architecture

An ISCA coil

Industry Standard Coil Architecture is the use of three colocated orthogonal quasi-dipole transmitter coils and three colocated quasi-dipole receiver coils.

Examples of this type of system are:

• Polhemus Viper
• Polhemus Fastrak
• Polhemus Patriot