There has been quite some speculation on how the 900/910 units navigate using pulse...

I was curious as to whether anybody really knows how it works ?....

On the other Pioneer units (Z1,2,3, D3) if you have pulse (Vss) hooked up, the primary source for navigation is then pulse and gyroscope, and GPS is only used for corrections (and initial positioning)

On the 900 series, people have speculated that it always uses GPS, and only falls back on pulse & gyroscope when the GPS signal is lost....This would be different from the way Pioneer worked in the past...

It would seem to be a missed opportunity, as in principle navigating with pulse and gyroscope is more accurate (and more responsive certainly at higher speeds), and the hardware is present in the 900/910.

Thoughts/information anyone ?

There has been quite some speculation on how the 900/910 units navigate using pulse...

I was curious as to whether anybody really knows how it works ?....

 

On the other Pioneer units (Z1,2,3, D3) if you have pulse (Vss) hooked up, the primary source for navigation is then pulse and gyroscope, and GPS is only used for corrections (and initial positioning)

 

On the 900 series, people have speculated that it always uses GPS, and only falls back on pulse & gyroscope when the GPS signal is lost....This would be different from the way Pioneer worked in the past...

It would seem to be a missed opportunity, as in principle navigating with pulse and gyroscope is more accurate (and more responsive certainly at higher speeds), and the hardware is present in the 900/910.

 

Thoughts/information anyone ?

Actually sat positioning is more accurate than pulse/gyro, particularly at longer stretches (errors do not accumulate, unlike VSS). Really, I'd be very surprised if other Pioneer units did use pulse primarily...

There has been quite some speculation on how the 900/910 units navigate using pulse...

I was curious as to whether anybody really knows how it works ?....

 

On the other Pioneer units (Z1,2,3, D3) if you have pulse (Vss) hooked up, the primary source for navigation is then pulse and gyroscope, and GPS is only used for corrections (and initial positioning)

 

On the 900 series, people have speculated that it always uses GPS, and only falls back on pulse & gyroscope when the GPS signal is lost....This would be different from the way Pioneer worked in the past...

It would seem to be a missed opportunity, as in principle navigating with pulse and gyroscope is more accurate (and more responsive certainly at higher speeds), and the hardware is present in the 900/910.

 

Thoughts/information anyone ?

 

Actually sat positioning is more accurate than pulse/gyro, particularly at longer stretches (errors do not accumulate, unlike VSS). Really, I'd be very surprised if other Pioneer units did use pulse primarily...

Not really, because in the units that primarily use Vss, it is continually corrected and calibrated over time using map matching, so after calibration it is actually very accurate, and contrary to GPS that updates once per second, and can have a significant inaccuracy, it is very fast (almost continuous)..

Position is of course also regularly compared to GPS position, such as at startup etc.

If I'm driving at 100 km/hour, with a very optimistic inaccuracy of 10 meters for GPS, with an update interval of once per second, the GPS position will already have an inaccuracy of around 20 to 40 meters (and that's with a very optimistic 10 meters inaccuracy of the GPS, as said. Usually it will be significantly higher...)

Not really, because in the units that primarily use Vss, it is continually corrected and calibrated over time using map matching, so after calibration it is actually very accurate, and contrary to GPS that updates once per second, and can have a significant inaccuracy, it is very fast (almost continuous)..

Position is of course also regularly compared to GPS position, such as at startup etc.

 

If I'm driving at 100 km/hour, with a very optimistic inaccuracy of 10 meters for GPS, with an update interval of once per second, the GPS position will already have an inaccuracy of around 20 to 40 meters (and that's with a very optimistic 10 meters inaccuracy of the GPS, as said. Usually it will be significantly higher...)

Well, yeah, except that it still needs to constantly calibrate VSS against GPS position (while moving). And how do youi map matching with VSS anyway?

Well, yeah, except that it still needs to constantly calibrate VSS against GPS position (while moving). And how do youi map matching with VSS anyway?

Simple, the same way you do it with GPS...

The system continuously checks when you go left, right, follow a curve in the road etc.against the position it thinks it is on the map, using the info from Vss for distance and speed, and gyroscope for direction.

If you turn off left, and according to the dead reckoning/map the left turn-off is f.i. 10 meters earlier or later, it corrects the actual position, just like with GPS, and perhaps adjust calibration....

And it does not need to continuously calibrate Vss against GPS position, just do regular checks to see if the two match, and of course determine the start-up position via GPS when the system starts up after it has been switched off....

As said, it will have a harder time with mapmatching and GPS at higher speeds, as the random inaccuracy of GPS and the 1 second update speed will make it more difficult to estimate accurately where a left or right turnoff is....

Simple, the same way you do it with GPS...

The system continuously checks when you go left, right, follow a curve in the road etc.against the position it thinks it is on the map, using the info from Vss for distance and speed, and gyroscope for direction.

If you turn off left, and according to the dead reckoning/map the left turn-off is f.i. 10 meters earlier or later, it corrects the actual position, just like with GPS, and perhaps adjust calibration....

And it does not need to continuously calibrate Vss against GPS position, just do regular checks to see if the two match, and of course determine the start-up position via GPS when the system starts up after it has been switched off....

 

As said, it will have a harder time with mapmatching and GPS at higher speeds, as the random inaccuracy of GPS and the 1 second update speed will make it more difficult to estimate accurately where a left or right turnoff is....

Could be. I wonder how it works when you turn to a street that's not on the map (yet)...

Could be. I wonder how it works when you turn to a street that's not on the map (yet)...

Guess that would screw up the mapmatching...

That would be one instance where it might be necessary to f.i. do a cross-check with the GPS, which it does regularly anyway

It still knows how far and in which direction you're travelling though...

On my HD3 (=Z3) if it gets lost on the map (which happens only very infrequently), I see it continuously trying to map the arrow on the surrounding streets, till it eventually finds a match...

i would think that it primarly uses gps, for the fact that its little brother the 700, has much of the same hardware, except for the DVD drive, msn direct, and VSS input, why would you make two units so similar but use two totally different forms of tracking, that would also make it have to have a lot of differences in the software for the gps between models in the same produce line (f500, f700,and f900). i would have to belive that the f900 would use a very similar tracking system as the other units in the same product family that do not have vss input (f500 and f700). but this is all based off of logic which pioneer seems a little short of these days:)

i would think that it primarly uses gps, for the fact that its little brother the 700, has much of the same hardware, except for the DVD drive, msn direct, and VSS input, why would you make two units so similar but use two totally different forms of tracking, that would also make it have to have a lot of differences in the software for the gps between models in the same produce line (f500, f700,and f900). i would have to belive that the f900 would use a very similar tracking system as the other units in the same product family that do not have vss input (f500 and f700). but this is all based off of logic which pioneer seems a little short of these days:)

Actually I suspect the same, for the reasons you mention, but I have never seen any clear statement from Pioneer one way or the other....