Integration of GPS Receivers into Existing Inertial Navigation Systems

Abstract

Many inertial navigation systems of both platform and ring laser strapdown types are currently in service. This paper discusses the possibility and desirability of incorporating a small GPS receiver in these systems. Advances in technology such as microprocessors, gate arrays, and surface mount devices allow the existing INS electronics to be replaced in a reduced volume. The remaining space in many cases is sufficient to permit the insertion of a small GPS receiver. Locating the GPS receiver in an inertial navigation system (INS) solves many of the usual system integration problems. Tight coupling between the GPS and INS can be achieved since data latency is minimized and well controlled. In such a configuration, rate aiding of the GPS is easily achieved. This approach also leads to greater flexibility and enhanced overall performance since all GPS and INS data are simultaneously available. While not providing the ultimate in redundancy, the integrated INS/GPS approach does offer greater simplicity with enhanced performance. This discussion primarily focuses on military systems. Nevertheless, the proposed techniques also are applicable to commercial units.

Satellite Positioning

“…The integration may be done simply by logging GPS and inertial data in the same external computer, for either real‐time or post‐mission analysis, or else GPS receivers may be incorporated in the hardware of the inertial navigation unit. A number of advantages may be obtained from this union, benefitting both the operation of the inertial and GPS equipment [Hartman, 1988; Tazartes and Mark, 1988; Soltz et al, 1989]. Moreover, this combination permits (at least in a post‐mission analysis) the separation of the full gravity vector from inertial and rotational accelerations, making a practical proposition of vector gravimetry: the simultaneous determination of gravity anomalies and deflections of the vertical, which in turn can be used to calculate geoid profiles by simple integration along the line traversed by a vehicle thus instrumented [Colombo, 1990c].…”

Integration of Satellite and Inertial Positioning Systems

“…The risk of oscillation or instability in the closed loop configuration (see section 5.3) is also reduced since the date time lag can be precisely accounted for. 12 c.3. Open or closed loop.…”

Bayesian localization for autonomous vehicle using sensor fusion and traffic signs

“…Преимущества обоих методов можно комбинировать с использованием подхода Sensor Fusion: при объединении измерений с GPS и IMU обе системы будут компенсировать ошибки друг друга, что приведет к более точным измерениям [Tazartes, Mark, 1988].…”