3 ms·
That sounds overly optimistic. From what I know, 15-20cm is the best accuracy you can achieve — which is still fantastic, mind you. There is a lot of confusion
by jwr 7y ago
That sounds overly optimistic. From what I know, 15-20cm is the best accuracy you can achieve — which is still fantastic, mind you.
There is a lot of confusion around UWB positioning. Some articles describe TDoA (time difference of arrival) systems, which can indeed be very precise and the device being positioned can be low-power, but these require a nwetwork of beacons with precisely synchronized clocks, which is very difficult to achieve in practice.
Also, the DW1000 chip is a power hog. Yes, if you compare it to a GPS receiver it is still fantastic, but in low-power devices it is not easy to manage. As an example problem, you can't power a DW1000 from a coin battery: the internal resistance of the battery is too large, and it can't deliver the peak current that the chip needs.
- vaxman 7y agoWhat of the OEM specs of 10cm accuracy, only 31mA during transmission, 64mA in receive --which is usually not battery powered-- and its claims of months-to-years battery life using a coin cell? Did you overlook this or are you testifying anecdotally oR about your direct experience?
- skykooler 7y ago31mA is significantly more than most coin cells are designed to supply - while a new one may be able to reach peak currents of 50-100mA this significantly reduces battery capacity, and is only possible with a new battery (once it's partially discharged it cannot sustain these current levels any more).
- vaxman 7y agowouldn't you pair it with an inertia detector so it only transmits a pulse (at 31mA) when it moves by a significant amount?
- jwr 7y agoI designed and built devices based on the DW1000, so I'm not "testifying anecdotally". If you have specific questions, please ask, but I won't be baited with generalities.
- Rosiefox 7y agoThe DW3000 is accurate to under 4cm -10cm actually., indoors in line of sight.... and works for years in a watch battery.