Technical challenges
Indoor localization and warehouse logistics may involve monitoring environmental parameters such as temperature, humidity and motion of assets during transit. Accelerometers can be used to detect various events such as motion and wake-up, vibration, impacts or shocks, freefall events, and orientation. Some extremely low power accelerometers are capable of always-on operation and allow more power-hungry microcontrollers to remain in sleep mode until an exceptional event is detected.
Sensors are key devices in asset tracking applications as they can detect conditions and events to trigger remedial actions, such as activating de-humidification systems. Sensors can be used to ensure goods remain appropriately sealed and verify consistent cold chain conditions, ensuring temperature and humidity never breach set thresholds for given amounts of time.
Other examples include airplane take-off and landing detection with pressure sensors, as well as seal detection and altitude detection. Microphones can be employed for security purposes and emerging applications to detect noise or record messages. Proximity and light sensor to monitor opening and closing of container doors and shipment security in general.
Connectivity network infrastructure is also critical for ensuring high location precision of assets such as industrial tools inside or around factories and warehouses. GPS localization for indoor environments is generally not appropriate, so it is usually necessary to create a beacon or satellite connectivity infrastructure. The most common technologies used today for these applications are Bluetooth® Low Energy, Wi-Fi and Ultra-Wide Band (UWB) protocols.
Smart pallets in warehouses can communicate via short range connectivity either using indoor satellite infrastructure or exchange information with hand-held readers such as smart phones. A pallet can communicate condition status information directly with the black box on a transport vehicle before commencing shipment. The black box can collect the data from the pallets via Bluetooth Low Energy connectivity and send them to the cloud using a Low Power Wide Area Network (LPWAN) protocol such as LoRa, NB-IoT, or Sigfox. The most recent trend is to embed both short-range and long-range connectivity to communicate via indoor satellite infrastructure and to communicate directly with centralized servers, respectively.
ST solutions
To support the design of ultra-low-power tracking and monitoring solutions, ST offers an extensive range of temperature, humidity and pressure sensors, inertial measurement units (accelerometers, gyroscopes and magnetometers), and proximity sensors.
Accelerometers can detect if packages are subjected to falls or impacts and some can be very good at saving battery life by allowing sensor node systems to remain in sleep mode until a significant motion event is detected. The ultra-low-power LIS2DW12 MEMS accelerometer with measurement scale up to 16g is also available in a version with embedded temperature sensor (LIS2DTW12). For high impact detection up to 400g, ST offers the H3LISxxx range. The HTS221 humidity sensor also comes with embedded temperature sensor and can be used to monitor goods and foodstuff to ensure they are stored and transported in appropriate ambient conditions. If high accuracy temperature monitoring is required, the STTS22H delivers 0.5°C accuracy between -10°C to +60°C. The LPS2 family of pressure sensor barometers includes water-resistant absolute pressure sensors also able to sense altitude changes.
Inertial modules with machine learning cores like the LSM6DSOX with gyroscope and accelerometer are able to determine certain events such as free-fall in standalone mode while the rest of the system remains in sleep mode to conserve energy. MP34DT05-A microphones are useful for recording and sharing voice and sound data for security and other new applications.
ST also produces high performance Time-of-Flight ranging sensors, such as the VL6180X and VL6180 proximity sensors, offering up to 20cm and 60cm ambient light sensing, respectively, the VL53L0X and VL53L1X ranging sensors up to 2m and 4m distances, respectively, and the VL53L3CX and VL53L1CB proximity and multi-target sensors up to 5m and 8m distances, respectively. ST provides comprehensive software support for its sensors, including C-drivers, sensor fusion middleware and SW source code examples such as motion software libraries for Airplane Detection and Tilt Sensing, and many industrial applications from data logging to Learning Core and AI development in the STM32CubeMX environment.
In terms of short-range communication, ST offers the ST25 family for NFC communication, and for the Bluetooth® Low Energy protocol, we offer the choice of dedicated BlueNRG chips and STM32WB dual-core microcontrollers with embedded wireless transceiver. ST is also heavily committed to long range LPWAN communication and sub-1GHz frequencies with LoRa, Sigfox, and upcoming NB-IoT solutions, with ultra-wide-band (UWB) soon to be available.
The Sigfox technology offers native geo-localization (Atlas) and cross-continent (Monarch) support and can be deployed on our S2-LP chips and STM32WL microcontrollers for long-range and ultra-low power communication, or any application involving small and infrequent data packets.
The Long Range Wide Area Network (LoRaWAN) open communications protocol is also supported on the STM32WL microcontroller. This sub-GHz wireless technology allows data transmission over long distances and is easy to deploy due to its simple architecture. LoRa is in general a popular option because users can set up and manage their own networks for smart farm, warehouse logistics and smart city applications.
Power management is almost always a critical factor in asset tracking applications because of the frequent implementation of battery-powered solutions. Power management devices such as the ST1PS01/02 are therefore critical for optimizing system power consumption and saving energy.
For all the above-mentioned technologies, ST provides complete end-to-end solutions and development environments with evaluation boards and application firmware for different uses case scenario, including a dedicated ST Asset tracking app and the DSH-ASSETRACKING Web-based cloud dashboard, which provides an intuitive graphic monitoring interface and facilitates the management of multi-technology solutions.
