RELATIVE MOTION and NOT POSITION
PROBLEM: The system captures motion and not position. Therefore the captured motion is not in the context of the stage or setting.
- The production of hybrid systems which add a GPS to acquire outdoor location for sports capture such as golf, or a very simplified optical or other marker to obtain position within a studio set or arena.
- Although the conventional architecture is to locate the base reference antennas centrally to the body with the target antennas at the tracked locations, It is possible for reference antennas to be located externally to provide triangulation within a static location such as a studio set or arena and so capture motion relative to the stage.
- PROBLEM: Since the system is radio based it is necessarily degraded in electronically noisy environments.
- RESPONSE: The system uses an unmodulated pure sine signal which is relatively immune to noise.
MULTIPLE UNITS in CLOSE PROXIMITY
PROBLEM: Broadcasts from units in close proximity may give lead to the detection of spurious position values.
- Channel select frequencies to avoid collisions
- Modulate ID into carrier
PROBLEM: Assumed not to be suitable for factory deployment due to high radio reflective problems causing multipath detection issues.
RESPONSE: Although the working assumption is that this is a limitation, research could prove that for short line-of-sight distances or increased power, this may be a workable solution for targeted applications.
PROBLEM: Requires calibration at start-up, not only of distance, but of position within the Cartesian model.
RESPONSE: This is current practice in model-relative motion capture methods.
PROBLEM: The size of the antenna is a serious concern for biologic instrumentation since it needs to be as unobtrusive and inconspicuous as possible.
RESPONSE: My working assumption is that this is an issue that can be solved with development investment and that antenna size can be reduced through a combination of antenna design and frequency selection. In other words, antenna size and form-factor is principally a function of cost and not of physics.
PROBLEM: Like the antennas, the wiring to the target antennas needs to be both robust and inconspicuous. This requirement is why the target antennas are receivers and not transmitters. Most transmitter solutions require shielded coax from the signal source to the antennas.
RESPONSE: Due to this requirement, we are using transmitters for our centrally located base antennas. The receiving antennas, not carrying a power signal, have much fewer restrictions, and can use the thread-sized wiring currently used for clothing that feature embedded electronics.
WIRED CONNECTION REQUIRED between CORE and TARGETS
PROBLEM: Both the transmitting and receiving antennas need to be directly wired to the central processor.
RESPONSE: Requiring the wired connections between the target connection and the core containing the transmit signal significantly simplifies the computation of the target displacement. This not the only solution however, just the simplest and most expedient. There are a number of other approaches enumerated in the patent which may be appropriate for specialized applications.
ABILITY to CAPTURE ONLY 3 DEGREES and NOT 6
PROBLEM: The system tracks a point in 3D space and does not capture rotation (roll, yaw and pitch).
RESPONSE: While it's true that we are tracking only returning 3D Cartesian coordinates, if 6 degrees of motion is required then multiple targets in known relationship, such as each side of the wrist, will, when viewed together allow the other degrees of motion to be computed otherwise this can be achieved using hybrid systems that also integrate inertial tracking.