F. Raab, E. Blood, O. Steiner, and H. Jones, "Magnetic position and orientation tracking systems," IEEE Transactions on Aerospace and Electronics Systems, vol. 15, no. 5, pp. 709--717, 1979.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....or warehouses. It has diculty interoperating with the 802.11 wireless networking infrastructure because of radio spectrum collision in the unregulated Industrial, Scienti c, and Medical (ISM) band. 4. 5 MotionStar Magnetic Tracker Electromagnetic sensing o ers a classic position tracking method [33]. The large body of research and products that support virtual reality and motion capture for computer animation often o er modern incarnations of this technology. For example, Ascension o ers a variety of motion capture solutions, including Flock of Birds and, shown in Figure 7, the MotionStar DC ....

F. Raab, E. Blood, T. Steiner, and H. Jones. Magnetic position and orientation tracking system. IEEE Transactions on Aerospace and Electronic Systems, 15(5):709-717, September 1979.

....Ing. C. Olivetti C. S.p.A. Ward97 extent to which applications can adapt based on information from the system. It is therefore pertinent to consider other sensor technologies that might give finer grained location information about objects in the office and home. Electromagnetic trackers [9, 10] can determine object locations and orientations to a high accuracy and resolution (around 1 mm in position and 0.2 in orientation) but are expensive and require tethers to control units. Furthermore, electromagnetic trackers have a short range (generally only a few meters) and are sensitive ....

F. Raab et al., "Magnetic Position and Orientation Tracking System," IEEE Trans. Aerospace and Elect. Syst., vol. AES-15, no. 5, Sept. 1979.

....promote indoor research [1] There are three technologies commonly used for indoor location systems ultrasonics, infrared and RF. Infrared systems tend to rely on the user taking explicit actions to identify their presence [2] and RF systems require sophisticated (and often cumbersome) antenna [3] ultrasonics offer a low cost solution which can operate without any explicit user interaction. Shortcomings of ultrasonic systems arise from loss of direct signal and interference. These can be minimised and sophisticated systems produced by commercial suppliers such as Intersense [4] and AT T ....

F. Raab, E. Blood, T. Steiner, and T. Jones. Magnetic position and orientation tracking system. In IEEE Transactions on Aerospace and Electronic Systems, volume AES-15 no.5, pages 709--718, September 1979.

....signals to improve the accuracy. However, GPS requires a direct line of sight to several satellites and therefore is not working properly inside buildings or in areas covered by trees or tall buildings (appropriately termed city canyons ) Indoors, tethered tracking systems using magnetic [3], ultrasonic [4] and optical technologies [5] achieve high accuracy in the millimeter to centimeter range. These systems are typically able to cover a room and require installations of large devices or dense arrays of beacons or sensors mounted in the covered area. Another research system [1] can ....

F. Raab, E. Blood, T. Steiner and R. Jones. Magnetic position and orientation tracking systerr IEEE Trans. On Aerospace and Electronic Systems, AES-15(5):709--718, September 1979

....contain three mutually perpendicular coils. Changes in strength across the coils are proportional to the distance of each coil from the field emitter assembly. Three sequentially emitted fields create one induced current in each of the three sensor coils, allowing measurement of orientation [2]. Practical optical tracking systems may be separated into two basic categories. Pattern recognition systems sense an artificial pattern of lights and use this information to determine position and or orientation. 3] Image based systems determine position by using multiple cameras to track ....

Raab, F., Blood, E., Steiner, O., and Jones, H., "Magnetic Position and Orientation Tracking System," IEEE Transactions on Aerospace and Electronics Systems, AES-15, No. 5, 1979, pp. 709-717.

....scalable and robust. Unfortunately, the indoor environment is a challenging one in which to implement such a system. Radio based location techniques (e.g. GPS [1] which are successful in the wide area, are afflicted by severe multipath effects within buildings. Electromagnetic methods (e.g. [3]) suffer interference from monitors and metal structures, whilst optical systems (e.g. 4] and [13] require expensive imaging detectors, and are affected by line of sight problems in environments containing opaque objects. However, location systems that use ultrasonic techniques appear to have ....

Raab, F., Blood, E., Steiner, T., Jones, H. Magnetic Position and Orientation Tracking System. IEEE Transactions on Aerospace and Electronic Systems, Vol. AES-15, No. 5, September 1979. pp. 709--718

....work. 2 Previous Work Many approaches to position tracking require that the user s environment be equipped with sensors[17] beacons [15] 28] 6] or visual fiducials [20] Tethered position and orientation tracking systems have attained high accuracy for up to room sized areas using magnetic [26], ultrasonic, and optical technologies, including dense arrays of ceiling mounted optical beacons [1] Alternatively, sparsely placed infrared beacons can support tetherless positiononly tracking over an entire building at much lower accuracy [28] 6] Mobile phone technology has also been used ....

F. Raab, E. Blood, T. Steiner, and R. Jones. Magnetic position and orientation tracking system. IEEE Trans. on Aerospace and Electronic Systems, AES-15(5):709--718, September 1979.

....or warehouses. It has di#culty interoperating with the 802.11 wireless networking infrastructure because of radio spectrum collision in the unregulated Industrial, Scientific, and Medical (ISM) band. 4. 5 MotionStar Magnetic Tracker Electromagnetic sensing o#ers a classic position tracking method [33]. The large body of research and products that support virtual reality and motion capture for computer animation often o#er modern incarnations of this technology. For example, Ascension o#ers a variety of motion capture solutions, including Flock of Birds and, shown in Figure 7, the MotionStar DC ....

F. Raab, E. Blood, T. Steiner, and H. Jones. Magnetic position and orientation tracking system. IEEE Transactions on Aerospace and Electronic Systems, 15(5):709--717, September 1979.

....or warehouses. It has di#culty interoperating with the 802.11 wireless networking infrastructure because of radio spectrum collision in the unregulated Industrial, Scientific, and Medical (ISM) band. 2. 5 MotionStar Magnetic Tracker Electromagnetic sensing o#ers a classic position tracking method [26]. The large body of research and products that support virtual reality and motion capture for computer animation often o#er modern incarnations of this technology. For example, Ascension o#ers a variety of motion capture solutions, including Flock of Birds and, shown in Figure 3, the MotionStar DC ....

F. Raab, E. Blood, T. Steiner, and H. Jones. Magnetic position and orientation tracking system. IEEE Transactions on Aerospace and Electronic Systems, 15(5):709--717, September 1979.

....magnetic distortion field. 1 Introduction Electromagnetic tracking systems have been used extensively in virtual reality research and applications. They determine the position and orientation of a receiver relative to a transmitter by generating and measuring orthogonal electromagnetic fields [20, 14]. These systems are preferable to other tracking technologies because they are relatively inexpensive, cover a reasonably large workspace, provide fairly good resolution with acceptable jitter, convenience of use, and do not suffer from line of sight problems [5] However, their accuracy is ....

....have proposed a number of methods to improve magnetic tracking accuracy by measuring and compensating for the field distortions. Calibration is possible provided that the magnetic excitation vectors produced by the transmitter remain linearly independent within the working range of the device [20]. All the reported calibration methods collect a number of measurements in the workspace from which error corrections are derived. We categorize these previous approaches based on the correction technique applied, the metrology system used, and the number of DOF calibrated. 1.1 Error Correction ....

[Article contains additional citation context not shown here]

F. Raab, E. Blood, T. Steiner, and R. Jones. Magnetic position and orientation tracking system. IEEE Trans. Aerospace and Electronic Systems, AES-15(5):709--718, 1979.

....were learned: One where the hand moved in a straight path to the object, another where an obstacle in the direct path was avoided by moving over it, and a third where the obstacle was avoided by moving around it. 12 [Figure 3 about here. The movements were recorded using a Polhemus system [10] running at 120Hz for three sensors, one on the upper arm, one on the forearm, and one on the hand (see Figure 3) From the position data (x(t) y(t) z(t) of these sensors, 3 D velocity v(t) acceleration a(t) curvature k(t) and torsion (t) were extracted. Sample time plots of these ....

....3) bad lifting of a heavy object, and 4) bad lifting of a light object. The movements are quite dicult to discriminate, even for human observers. This was done in order to test the limits of the movement learning system. Figure 5 about here. The movements were recorded using a Polhemus system [10] running at 120Hz for six sensors, located on the hip, above the knee, above the foot, on the upper arm, on the forearm, and on the hand of the left body side (see Figure 5) Each movement type was recorded ve times. From the position data (x(t) y(t) z(t) of these sensors, 3 D velocity v(t) ....

F. H. Raab, E. B. Blood, T. O. Steiner, and H. R. Jones, \Magnetic position and orientation tracking system," IEEE Transactions on Aerospace and Electronic Systems, vol. AES-15, pp. 709{, 1979.

.... 2 ; x sin 2 ; y sin 2 ; z sin 2 ) the magnitude of rotation can be extracted, leaving the unit vector n = x; y; z) as the axis of rotation. Then, employing the assumption that the change of orientation in one sampling period is small, as used by the tracking mechanism itself [Raab79], we temporarily relax the unit length constraint, independently filter x; y, and z, and normalize the filtered x; y; z back to a unit vector n 0 , which is then coupled with the filtered to form the resulting quaternion. 3.2 Head Movement Model User head motion is usually characterized by ....

F. H. Raab, E. B. Blood, T. O. Steiner, and H. R. Jones, "Magnetic position and orientation tracking system," IEEE Trans. on Aerospace and Electronic Systems, Vol. AES-15, No. 5 (Sept. 1979), pp. 709-- 718.

....in the transmitter s coordinate directions. Each of these fields is measured in the sensor s three coordinate dimensions for a total of twelve measurements for each sensor. From this information, the position and orientation of the sensor with respect to the transmitter can be computed [Kuipers80, Raab79] Magnetic systems are robust, fast, and inexpensivecompared to most other technologies, making them one of the most popular choices for both VE and AR [Ascension98, Polhemus98] However, magnetic trackers are inaccurate in practical environments, due to distortion of the magnetic field caused ....

Raab, F., Blood, E., Steiner, T., and Jones, H. (1979). Magnetic Position and Orientation Tracking System. IEEE Transactions on Aerospace and Electronic Systems, AES-15:709--718.

....scalable and robust. Unfortunately, the indoor environment is a challenging one in which to implement such a system. Radio based location techniques (e.g. GPS [1] which are successful in the wide area, are afflicted by severe multipath effects within buildings. Electromagnetic methods (e.g. [3]) suffer interference Figure 1: A Bat unit from monitors and metal structures, whilst optical systems (e.g. 4] and [13] require expensive imaging detectors, and are affected by line of sight problems in environments containing opaque objects. However, location systems that use ultrasonic ....

Raab, F., Blood, E., Steiner, T., Jones, H. Magnetic Position and Orientation Tracking System. IEEE Transactions on Aerospace and Electronic Systems, Vol. AES15, No. 5, September 1979. pp. 709--718

....In this paper we first describe a system for slaving an operator s head motions onto a remote electro mechanical stereo camera platform from which images are returned to the operator. A variety of methods have been proposed for head tracking in the literature including mechanical [6] magnetic [8]; visual inside out [1, 9] where a camera attached to the operator s head views the static environment; and visual outside in [2, 3] where a static camera views the operator. Here we use the last method. Although inherently somewhat more difficult than the others, this method appears to be the ....

F. Raab, E. Blood, O. Steiner, and H. Jones. Magnetic position and orientation tracking systems. IEEE Transactions on Aerospace and Electronics Systems, 15(5):709--717, 1979.

.... (pan, elevation, and two vergence axes) each capable of being driven at high velocities (up to 600 ffi s Gamma1 ) and very high accelerations (up to 25000 ffi s Gamma2 ) A variety of methods have been proposed for head tracking in the literature including mechanical [11] magnetic [14]; visual inside out [1, 15] where a camera attached to the operator s head views the static environment; and visual outside in [2, 3] where a static camera views the operator. Here we investigate the last method. Although inherently somewhat more difficult than the others, this method appears ....

F. Raab, E. Blood, O. Steiner, and H. Jones. Magnetic position and orientation tracking systems. IEEE Transactions on Aerospace and Electronics Systems, 15(5):709-- 717, 1979.

....rate increase and decrease respectively. For the Selspot optical tracking system, beacons are observed sequentially per estimate (for position and orientation of a single target) 11] For the Polhemus Fastrak magnetic tracking system, sequential excitations are performed and sensed per estimate [12]. For the University of North Carolina (UNC) wide area optoelectronic tracking system, beacons are observed sequentially per estimate [13,14] The one step at a time method seeks to improve the latencies and data rates of such systems by updating the current estimate with each new (individual) ....

....s 20 s 2 magnetic tracker is given in Figure 1. Each estimate occurs only after sensing an excitation pattern composed of three linearly independent excitation vectors. The complete excitation pattern contains information sufficient to determine the 3D position and orientation of the target [12]. A diagram depicting the timing of a (hypothetically) modified one step at a time Polhemus Fastrak is given in Figure 2. In this case an estimate is available after sensing each individual excitation vector. Each such vector does not contain information sufficient to determine the 3D position and ....

[Article contains additional citation context not shown here]

Raab, F. H., E. B. Blood, T. O. Steiner, and H. R. Jones. 1979. "Magnetic Position and Orientation Tracking System," IEEE Transactions on Aerospace and Electronic Systems, Vol. AES-15, 709-718.

....option (MCO) interface for output of 60 HZ stereo pairs. These are sent to a Virtual Research head mounted display that contains two color LCD displays and associated lenses. User position and orientation are determined with an Ascension Technology Flock of Birds electromagnetic tracking system [7] with an extended 12 foot range transmitter and two receivers. One of the receivers is located atop the head mounted display, where it tracks the position and 4 Pablo is a trademark of the Board of Trustees of the University of Illinois. 5 The CAVE version of Avatar executes on a four ....

Raab, F. H. Magnetic Position and Orientation Tracking Systems. IEEE Transactions on Aerospace and Electronic Systems AES-15, 5 (May 1979).

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F. Raab, E. Blood, O. Steiner, and H. Jones, "Magnetic position and orientation tracking systems," IEEE Transactions on Aerospace and Electronics Systems, vol. 15, no. 5, pp. 709--717, 1979.

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F. Raab, E. Blood, O. Steiner, and H. Jones. Magnetic position and orientation tracking systems. IEEE Transactions on Aerospace and Electronics Systems, 15(5):709--717, 1979.

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F. Raab, E. Blood, O. Steiner, H. Jones, Magnetic position and orientation tracking systems, IEEE Transactions on Aerospace and Electronics Systems 15 (5) (1979) 709-- 717.

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F. Raab, E. Blood, O. Steiner, and H. Jones. Magnetic position and orientation tracking systems. IEEE Transactions on Aerospace and Electronics Systems, 15(5):709--717, 1979.

No context found.

F. Raab, E. Blood, O. Steiner, and H. Jones, "Magnetic position and orientation tracking systems," IEEE Transactions on Aerospace and Electronics Systems, vol. 15, no. 5, pp. 709--717, 1979.

No context found.

Frederick H. Raab, Ernest Blood, Terry O. Steiner, and Herbert R. Jones. Magnetic position and orientation tracking system. IEEE Transactions on Aerospace and Electronic Systems, 15(5):709--718, 1979.

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Raab, F., Blood, E., Steiner, O., and Jones, H., "Magnetic Position and Orientation Tracking System," IEEE Transactions on Aerospace and Electronics Systems,AES- 15, No. 5, 1979, pp. 709-717.

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F. H. Raab, E. B. Blood, T. O. Steiner, and H. R. Jones. Magnetic Position and Orientation Tracking System. IEEE Transactions on Aerospace and Electronic Systems , AES15(5):709-718, September 1979.

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F. Raab et al., "Magnetic Position and Orientation Tracking System," IEEE Trans. Aerospace and Electronic Systems, Sept. 1979, pp. 709-717.

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Raab, F.H., Blood, E.B., Steiner, T.O., Jones, R.J. "Magnetic Position and Orientation Tracking System", IEEE Transactions on Aerospace and Electronic Systems, Vol AES-15 #5. September 1979 pp709-718.

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