Wireless Remote Control Station for Acoustic Underwater Modems
Communication under water is a mandatory requirement for small autonomous underwater robots, used for monitoring the environment or port areas. A small, lowpower and low-cost acoustic modem has been developed at the our institute for this purpose. As this modem is still under development, outdoor tests for improvements or channel measurements are necessary. For these tests, multiple modems are deployed on jetties with distances of several meters. As these tests are very time-consuming, they have to be monitored extensively during the run. Furthermore, every test configuration has to be set up on every modem separately as they are not connected via radio. This whole procedure is inefficient, time-consuming, and error-prone. It also only allows tests when a researcher is present, a long-term, unattended deployment is not possible. To solve these issues, a wireless control center for our acoustic modem is desirable. It connects all the modems via WiFi to a base station, so that they can be controlled in one-single place, in the best case even from the office. As the actual experiment of underwater communication should not be affected, communication between the modems and the control center has to be absolutely reliable.
Smart & LoRa-enabled Sensor Buoy for Environmental Monitoring
An essential task of the Hamburg Port Authority is to monitor water quality and the condition of underwater structures, bridge pillars and sheet pilings. Doing this manually, e.g. by sending out divers, is time-consuming, expensive and dangerous. It is desirable to automate these tasks by using intelligent systems. Measured sensor data underwater can be transmitted to the surface by the use of acoustic communication. Over water, the data has to be processed and sent to a base station, e.g. harbor control center. As ports are covering large areas with a huge number of sensor nodes, technologies like WiFi oder Bluetooth are not applicable. The availability of newly developed radio standards like LoRa enables the transmission over a large distance with sufficient data rates, simultaneously achieving low energy consumption. Combining sensors, acoustic underwater communication devices and LoRa radio chips on smart buoys enables low maintenance and low-cost environmental monitoring for smart port areas.
Solar-powered Fine Dust Sensor
Recent investigations in inner cities but also in production plans, as the harbor of Hamburg, show a significant air pollution by fine dust particles. Since this influences the ecological system and also the health of habitants or workers, a fine-grained resolution of pollution measurements is needed for further investigations and taking countermeasures. Until now, most of these fine dust sensors are powered with wires from main supplies or exchangeable batteries. However, costs and maintenance effort increase strongly with high numbers of supplied sensors. Especially in outdoor sensor networks, solar panels and large capacitors are a popular choice to substitute batteries. Since solar energy harvesting delivers only a limited amount of energy during daytime, careful adjustment of sensing activity is needed.