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Set hard compass threshold constant to 10 degrees. We can't assign it from declination (it's not an accuracy for Android).

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vng 2012-10-08 23:58:31 +03:00 • committed by Alex Zolotarev
parent d59a746437
commit 595d46b6a1
2 changed files with 14 additions and 19 deletions
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29
map/compass_filter.cpp
View file

@ -7,23 +7,24 @@
#include "../platform/location.hpp"
#define LOW_PASS_FACTOR 0.5
CompassFilter::CompassFilter()
{
m_headingRad = m_smoothedHeadingRad = 0;
m_headingHalfErrorRad = ang::DegreeToRad(5);
// Set hard smoothing treshold constant to 10 degrees.
// We can't assign it from location::CompassInfo::accuracy, because actually it's a
// declination between magnetic and true north in Android
// (and it may be very large in particular places on the Earth).
m_smoothingThreshold = ang::DegreeToRad(10);
m_lowPassKoeff = 0.5;
}
void CompassFilter::OnCompassUpdate(location::CompassInfo const & info)
{
// Avoid situations when offset between magnetic north and true north is too small
double const MIN_SECTOR_RAD = ang::DegreeToRad(10); //< 10 degrees threshold
double newHeadingRad = ((info.m_trueHeading >= 0.0) ? info.m_trueHeading : info.m_magneticHeading);
double newHeadingDelta = fabs(newHeadingRad - m_headingRad);
double newHeadingHalfErrorRad = (info.m_accuracy < MIN_SECTOR_RAD ? MIN_SECTOR_RAD : info.m_accuracy);
double const newHeadingRad = ((info.m_trueHeading >= 0.0) ? info.m_trueHeading : info.m_magneticHeading);
double const newHeadingDelta = fabs(newHeadingRad - m_headingRad);
#ifdef OMIM_OS_IPHONE
@ -32,8 +33,8 @@ void CompassFilter::OnCompassUpdate(location::CompassInfo const & info)
m_headingRad = newHeadingRad;
#else
// if new heading lies outside the twice headingError radius we immediately accept it
if (newHeadingDelta > m_headingHalfErrorRad * 2)
// if new heading lies outside the twice treshold radius we immediately accept it
if (newHeadingDelta > 2.0 * m_smoothingThreshold)
{
m_headingRad = newHeadingRad;
m_smoothedHeadingRad = newHeadingRad;
@ -42,7 +43,7 @@ void CompassFilter::OnCompassUpdate(location::CompassInfo const & info)
{
// else we smooth the received value with the following formula
// O(n) = O(n-1) + k * (I - O(n - 1));
m_smoothedHeadingRad = m_smoothedHeadingRad + m_lowPassKoeff * (newHeadingRad - m_smoothedHeadingRad);
m_smoothedHeadingRad = m_smoothedHeadingRad + LOW_PASS_FACTOR * (newHeadingRad - m_smoothedHeadingRad);
// if the change is too small we won't change the compass value
if (newHeadingDelta > m_smoothingThreshold)
@ -50,9 +51,6 @@ void CompassFilter::OnCompassUpdate(location::CompassInfo const & info)
}
#endif
m_headingHalfErrorRad = newHeadingHalfErrorRad;
m_smoothingThreshold = m_headingHalfErrorRad * 2;
}
double CompassFilter::GetHeadingRad() const
@ -62,6 +60,5 @@ double CompassFilter::GetHeadingRad() const
double CompassFilter::GetHeadingHalfErrorRad() const
{
return m_headingHalfErrorRad;
return m_smoothingThreshold;
}

4
map/compass_filter.hpp
View file

@ -8,9 +8,7 @@ namespace location
class CompassFilter
{
private:
double m_headingRad;
double m_headingHalfErrorRad;
// Compass smoothing parameters
// We're using technique described in
@ -19,7 +17,7 @@ private:
// small orientation changes and a threshold filter to get big changes fast.
// @{
// k in the following formula: O(n) = O(n-1) + k * (I - O(n - 1));
double m_lowPassKoeff;
//double m_lowPassKoeff;
// smoothed heading angle. doesn't always correspond to the m_headingAngle
// as we change the heading angle only if the delta between
// smoothedHeadingRad and new heading value is bigger than smoothingThreshold.