How do RTLS card-type Bluetooth positioning tags work

In modern indoor positioning technology, RTLS (real-time positioning system) card-type Bluetooth positioning tags are widely used in hospitals, factories, warehouses and other scenarios due to their high precision, low power consumption and easy deployment, helping to achieve real-time tracking and management of personnel and assets. So, how do RTLS card-type Bluetooth positioning tags work? The following will be introduced in detail.

Signal transmission mechanism of tags

RTLS card-type Bluetooth positioning tags usually have built-in low-power Bluetooth (BLE) modules. These tags will continuously broadcast Bluetooth signals containing unique identifiers (such as MAC addresses) at preset time intervals. The signal not only contains the tag's own identity information, but may also contain some additional data, such as battery power status. This periodic signal transmission mechanism enables the positioning system to continuously obtain the tag's location information, thereby achieving real-time tracking of the target object.

Take the hospital scene as an example. The Bluetooth positioning tags worn by patients or medical staff will transmit signals every few seconds. In this way, no matter where they are in the hospital, the system can receive the signal in time to ensure the real-time positioning. Moreover, the use of low-power Bluetooth modules prolongs the battery life of the tag and reduces the trouble of frequent battery replacement.

Signal reception of beacon network

A certain number of Bluetooth beacon reference points will be pre-installed in the area where positioning is required. These beacons are fixed at specific locations to form a beacon network covering the entire area. When the signal emitted by the Bluetooth positioning tag reaches the beacon, the beacon receives and records the signal strength (RSSI value) and the timestamp of the signal arrival.

The layout of the beacon network is crucial. Reasonable beacon density and location distribution can improve the accuracy and reliability of positioning. For example, in a large factory workshop, in order to ensure accurate positioning of personnel and equipment in the workshop, a sufficient number of beacons need to be installed in every corner, channel and near key equipment of the workshop. In this way, when the Bluetooth positioning tag moves in the workshop, its signal can be received by multiple beacons, thereby providing richer data for subsequent positioning calculations.

Data transmission and server processing

After receiving the signal from the Bluetooth positioning tag, the beacon will transmit the collected data, including signal strength, timestamp and the location information of the beacon itself, to the base station by wire or wireless means. The base station then forwards the data to the solution server, which runs a special positioning solution algorithm.

The positioning solution algorithm is the core of the entire positioning system. It uses the triangulation positioning principle or other advanced algorithms (such as the angle of arrival AoA algorithm) to calculate the position of the Bluetooth positioning tag based on the data received from multiple beacons. The triangulation positioning principle is to measure the distance from the tag to multiple beacons (estimated based on signal strength), and then draw a circle with these beacons as the center and the estimated distance as the radius. The intersection of multiple circles is the approximate position of the tag. The angle of arrival AoA algorithm calculates the position of the tag by measuring the angle at which the signal reaches the beacon and combining the position information of the beacon.

Taking a shopping mall as an example, multiple Bluetooth beacons are installed in the mall. When the Bluetooth positioning tag worn by the customer enters the mall, the beacon receives the tag signal and transmits it to the server. The server can determine the customer's location in the mall in real time through the positioning solution algorithm, thereby providing the mall with location-based marketing services, such as pushing discount information of nearby stores to customers.

Display and application of location information

The location information of the Bluetooth positioning tag obtained after processing by the solution server will be transmitted to the user interface for display. The user interface can be a software interface on the computer or an APP interface on the mobile phone. Through these interfaces, managers can intuitively see the location, movement trajectory and other information of the located personnel or assets.

These location information has a wide range of application value. In hospitals, medical staff can use the system to understand the patient's location in real time and improve nursing efficiency; in factories, managers can grasp the employees' work positions and the operating status of equipment in real time to optimize production processes; in warehouses, staff can quickly locate goods and improve the efficiency of goods in and out of the warehouse. In addition, location information can also be used for security monitoring. When personnel or assets enter restricted areas, the system can issue an alarm in time.

RTLS card-type Bluetooth positioning tags realize real-time positioning and tracking of personnel and assets through signal transmission, beacon reception, data transmission and server processing, and location information display and application. With the continuous development of technology, the performance of Bluetooth positioning tags will continue to improve, and the application scenarios will be more extensive.