I want to calculate the distance from one point to another point, when I start capturing accelerometer data, and till I stop that, it should gather all samples and should give me distance based on velocity, roll, pitch, yaw and displacement.
I have tried following code based on this link1 and link2 for double integration.
for (int i = 1; i < [arrXData count]; i++)
{
//========================================================================
//Old Velocity
double v0 = [[arrVelocity objectAtIndex:(i-1)] doubleValue];
//Time Data
double t0 = [[arrTimeData objectAtIndex:(i-1)] doubleValue];
double t1 = [[arrTimeData objectAtIndex:(i)] doubleValue];
//Acceleration Data
double x0 = [[arrXData objectAtIndex:(i-1)] doubleValue];
double x1 = [[arrXData objectAtIndex:(i)] doubleValue];
//NewVelocity
double v1 = v0 + (t1 - t0) * (x0 + x1)/2;
//========================================================================
//Old Distance
double d0 = [[arrDistance objectAtIndex:(i-1)] doubleValue];
//New Distance
double d1 = d0 + (x1 - x0) * (v0 + v1)/2;
//========================================================================
//Store Distance & Velocity
[arrVelocity addObject:[NSNumber numberWithDouble:v1]];
[arrDistance addObject:[NSNumber numberWithDouble:d1]];
//========================================================================
}
But the above code gives negative values sometimes, and not sure, whether this gives 100% correct result based on x acclearation values. Here we used x acceleration values after applying filter on it. We used high pass filter for reducing noise on x acceleration.
Does anyone know any algorithm on which we can rely?
Any help will be appreciated.
