Yurik V. Nikiforoff wrote > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of > Sent: 27 December 2007 05:15 > To: FlightGear developers discussions > Subject: [Flightgear-devel] heading indicator > > > Hi All! > > It seems, there is error in heading_indicator.cxx, OSG around > month ago line 84 : === dt -= dt * (0.25/60); // 360 deg/day > === But, IMHO, it's should be > > === > double current_lat = getDoubleValue(/* here latitude property > */) dt -= dt * (0.25/60) * sin( current_lat ); // time-based > precession on this > latitude > === > > There is not time-based precession in mrg.cxx, so we have not > poperly heading > gyro at all. > > Second question. In mrg.cxx, we have movement-induced error - > gyro have some > deviation by plane orientation changes and accelerations. > > Can we do property for switch this deviation? Real compass > systems have > stabilizers for body of reference gyro, and it's eliminate > orientation errors > ( introduceed by roll and roll rate, etc ). So, if we have ability of > controls of orientation errors - we can simulate compass > systems more clear, > and simulate failures of stabilizers of gyro... >
The mrg (or Master Reference Gyro) is a particular instrument fitted to UK military ac of the late 1950s/early 1960s (such as the Lightning, Sea Vixen, and Buccaneer), and continued in service until the 1990s. The azimuth gyro axis was automatically maintained relative to the magnetic North, and the vertical gyro to the earth vertical. Time-based precession is inappropriate in normal operation. I have yet to provide either a Fast Erection utility or to investigate plausible failure modes. Of course, if the automatic alignment failed, then time-based precession would apply. Vivian ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Flightgear-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/flightgear-devel
