CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. § 119(a) to Patent Application No. 108120796 in Taiwan, R.O.C. on Jun. 14, 2019, the entire contents of which are hereby incorporated by reference.

BACKGROUND

Technical Field

The instant disclosure relates to a positioning technology, in particular, to a tracking method, an electronic device using the same, and a tracking system using the same in which an azimuth detection unit is utilized.

Related Art

Currently, the positioning systems are widely utilized in daily lives, for example, shopping mall guidance, long-term care tracking, and warehousing surveillance. One of the most well-known positioning systems is the global positioning system (GPS). However, the GPS system is expensive. Moreover, the positioning of the GPS may be affected by the weather or by the shielding of buildings and fails to provide a positioning function or provides an improper positioning result.

SUMMARY

In recent decades, along with the advancement of the wireless sensing technologies, a positioning technology using received signal strength indication (RSSI) known to the inventor(s) has been developed. As compared with the GPS technology, the RSSI-based positioning technology takes less cost. However, the signals emitted by a device using the technology have different strengths at different directions, causing errors in the position detection or distance detection.

In view of this, in one embodiment, an electronic device is provided. The electronic device comprises a wireless communication unit, an azimuth detection unit, a storage unit, and a processing unit. The wireless communication unit detects an external wireless communication signal to generate a current RSSI. The azimuth detection unit detects a current azimuth of the electronic device. The storage unit stores a plurality of pattern strength indicators and a previous azimuth. The pattern strength indicators are received signal strength indicators measured from the wireless communication unit rotated at a plurality of different azimuths. The previous azimuth is an azimuth of the electronic device detected by the azimuth detection unit at a previous timing. The processing unit is coupled to the wireless communication unit, the storage unit, and the azimuth detection unit. The processing unit obtains an RSSI adjustment value according to the current azimuth, the previous azimuth, and the pattern strength indicators. The processing unit further obtains an RSSI corrected value according to the RSSI adjustment value and the current RSSI.

In one embodiment, a tracking system is provided. The tracking system comprises a movable device and a tracking device. The movable device comprises a first wireless communication unit, a storage unit, an azimuth detection unit, and a first processing unit. The first wireless communication unit detects an external wireless communication signal to generate a current RSSI. The azimuth detection unit detects a current azimuth of the movable device. The storage unit stores a plurality of pattern strength indicators and a previous azimuth. The pattern strength indicators are received signal strength indicators measured from the first wireless communication unit rotated at a plurality of different azimuths. The previous azimuth is an azimuth of the movable device detected by the azimuth detection unit at a previous timing. The first processing unit is coupled to the wireless communication unit, the storage unit, and the azimuth detection unit. The first processing unit obtains an RSSI adjustment value according to the current azimuth, the previous azimuth, and the pattern strength indicators. The first processing unit further obtains an RSSI corrected value according to the RSSI adjustment value and the current RSSI. The first processing unit controls the first wireless communication unit to output the RSSI correction value. The tracking device comprises a second wireless communication unit and a second processing unit. The second wireless communication unit is in a communication connection with the first wireless communication unit to receive the RSSI correction value. The second processing unit is coupled to the second wireless communication unit. The second processing unit obtains relative position information of the movable device according to the RSSI correction value.

In one embodiment, a tracking method is provided. The tracking method comprises detecting an external wireless communication signal to generate a current RSSI by a wireless communication unit and detecting a current azimuth by an azimuth detection unit; obtaining an RSSI adjustment value according to the current azimuth, a previous azimuth, and a plurality of pattern strength indicators by a processing unit, wherein the pattern strength indicators are received signal strength indicators measured from the wireless communication unit rotated at a plurality of different azimuths, and the previous azimuth is an azimuth detected by the azimuth detection unit at a previous timing; and obtaining an RSSI corrected value according to the RSSI adjustment value and the current RSSI by the processing unit.

As above, according to one or some embodiments of the instant disclosure, the azimuth detection unit detects the azimuths at different timings recurrently, and the RSSI adjustment value can be obtained according to the current azimuth, the previous azimuth, and the pattern strength indicators at different azimuths from the wireless communication unit. Moreover, the current RSSI can be corrected according to the RSSI adjustment value, so that the misjudgment in calculating the relative position or the relative distance can be prevented.

