{"id":25289,"date":"2015-08-06T16:45:03","date_gmt":"2015-08-06T11:15:03","guid":{"rendered":"https:\/\/tothenewco.pro\/blog\/?p=25289"},"modified":"2022-01-11T15:27:06","modified_gmt":"2022-01-11T09:57:06","slug":"indoor-positioning-systemtrilateration","status":"publish","type":"post","link":"https:\/\/tothenewco.pro\/blog\/indoor-positioning-systemtrilateration\/","title":{"rendered":"Indoor Positioning System(Trilateration)"},"content":{"rendered":"

In geometry<\/a>, trilateration<\/b> is the process of determining absolute or relative locations of points by measurement of distances, using the geometry of circles<\/a>, spheres<\/a> or triangles<\/a>.<\/p>\n

In addition to its interest as a geometric problem, trilateration does have practical applications in surveying<\/a> and navigation<\/a>, including global positioning systems<\/a> (GPS). In contrast to triangulation<\/a>, it does not involve the measurement of angles<\/a>.<\/p>\n

\"Untitled\"\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"index\"<\/p>\n

 <\/p>\n

The major disadvantage of GPS navigation is that it does’nt work inside, i.e., inside any building, mall, theatre, mueseums etc.<\/p>\n

With the help of Beacons<\/a>, Indoor positioning can be implemented.
\nWe are assuming here that three Beacons are placed at (0,0), (5.28,0), (0,6.5) points respectively.
\nThe distance to the device is say, 1.2, 2.1, 2.1. All figures in metres.<\/p>\n

[code language=”java”]<\/p>\n

\/**
\n* Calculates the distance from Beacon to device.
\n**\/<\/p>\n

private void calculateBeaconDistance(Beacon beacon) {<\/p>\n

\tfloat txPower = -74.0; \/\/ Manufacture set this power in the device
\n\tif (beacon .rssi == 0){<\/p>\n

\t\treturn -1.0; \/\/ if we cannot determine accuracy, return -1.<\/p>\n

\t}<\/p>\n

\tdouble ratio = beacon.rssi*1.0 \/ txPower;
\n\tif (ratio < 1.0){
\n\t\treturn pow(ratio,10);<\/p>\n

\t}
\n\telse{
\n\t\tdouble accuracy = (0.89976)*pow(ratio,7.7095) + 0.111;
\n\t\treturn accuracy;
\n\t}
\n}<\/p>\n

\/**
\n* It needs distanceA, distanceB, distanceC, pointA1, pointA2, pointB1, pointB2, pointC1, pointC2
\n*\/<\/p>\n

private void getMeetingPoints(distanceA, distanceB, distanceC, pointA1, pointA2, pointB1, pointB2, pointC1, pointC2) {<\/p>\n

\tdouble w,z,x,y,y2;
\n\tw = distanceA * distanceA –\tdistanceB * distanceB – pointA1 * pointA1 – pointA2* pointA2 + pointB1 * pointB1 + pointB2 * pointB2;<\/p>\n

\tz = distanceB * distanceB – distanceC * distanceC – pointB1* pointB1 – pointB2 * pointB2 + pointC1 * pointC1 + pointC2 * pointC2;<\/p>\n

\tx = (w * ( pointC2 – pointB2) – z * ( pointB2 – pointA2)) \/ (2 * (( pointB1 – pointA1) * ( pointC1 – pointB2) – ( pointC1 – pointB1) * ( pointB2 – pointA2)));<\/p>\n

\ty = (w – 2 * x * (pointB1 – pointA1)) \/ (2 * ( pointB2 – pointA2));<\/p>\n

\ty2 = (z – 2 * x * ( pointC1 -pointB1)) \/ (2 * ( pointC1 – pointB2));<\/p>\n

\ty = (y + y2) \/ 2;<\/p>\n

}<\/p>\n

[\/code]<\/p>\n

\"Beacons<\/a>
\n<\/span>
\n<\/span>
\n<\/p>\n","protected":false},"excerpt":{"rendered":"

In geometry, trilateration is the process of determining absolute or relative locations of points by measurement of distances, using the geometry of circles, spheres or triangles. In addition to its interest as a geometric problem, trilateration does have practical applications in surveying and navigation, including global positioning systems (GPS). In contrast to triangulation, it does […]<\/p>\n","protected":false},"author":164,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":43,"footnotes":""},"categories":[518,446,1772,1],"tags":[2184,2842,3953],"class_list":["post-25289","post","type-post","status-publish","format-standard","hentry","category-android","category-java","category-mobility","category-technology","tag-bluetooth","tag-ibeacon","tag-mobile-app"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t