A method for monitoring a working situation using a system, said system comprising at least one mobile sensor unit configured to be carried by an individual, at least one communication node, at least one sensor node which is provided additionally to the communication node, and a central evaluation unit, the method comprising:
- measuring, using at least one sensor of the at least one mobile sensor unit, at least one first physical variable describing an activity or a state of an individual carrying the mobile sensor unit;
- transmitting via wireless transmission, using a transmitter included in the at least one mobile sensor unit a measurement value of the at least one first physical variable to the at least one communication node;
- supplying electricity to the transmitter from an energy store included in the at least one mobile sensor unit;
- measuring at least one second physical variable describing a state of an environment of the at least one sensor node using at least one sensor of the at least one sensor node, the at least one sensor of the at least one sensor node being different than the at least one sensor of the mobile sensor unit;
- receiving, at the mobile sensor unit a measured value of the at least one second physical variable detected by the at least one sensor of the at least one sensor node;
- transmitting, using the mobile sensor unit, when the mobile sensor unit is located in the environment of the at least one sensor node, the received measurement value of the at least one second physical variable and the measurement value of the at least one first physical variable to the receiver of the communication node when the communication node is in reach of the transmitter,
- receiving, with a receiver coupled to the at least one communication node, the measurement value of the at least one first physical variable and the measurement value of the at least one second physical variable which are transmitted by the transmitter of the mobile sensor unit;
- transmitting, using a communication unit coupled to the at least one communication node, the measurement value of the at least one first physical variable received by the receiver of the communication node, and measurement value of the at least one second physical variable detected by the at least one sensor of the sensor node, to the central evaluation unit;
- receiving, at a communication unit coupled to the central evaluation unit the measurement value of the at least one first physical variable and the measurement value of the at least one second physical variable transmitted by the communication unit of the communication node;
- assigning the measurement value of the at least one second physical variable detected by the at least one sensor of the at least one sensor node, to the mobile sensor unit located in the environment of the at least one sensor node, at least at one point in time, wherein the at least one second physical variable identifies a property of the environment, the property describing the state of the environment of the sensor node;
- transferring the assigned measurement value and the measurement value of the at least one first physical variable detected by the at least one sensor of the mobile sensor unit located in the environment of the sensor node, at least at the point in time, to the central evaluation unit as being assigned to one another;
- storing the transferred assigned measurement value and the transferred measurement value of the at least one first physical variable detected by the at least one sensor of the mobile sensor unit at the central evaluation unit;
- arranging the at least one mobile sensor unit and the at least one communication node at one or more locations of at least one working site, wherein at least one of the at least one mobile sensor unit is carried by an individual or each by one of several individuals while moving about the working site;
- assigning, with a machine learning algorithm, a certain activity to the stored transferred assigned measurement value of the at least one first physical variable detected by the at least one sensor of the mobile sensor unit in the environment;
- and
- identifying with the machine learning algorithm, based on the transferred measurement value of the at least one first physical variable measured with the mobile sensor unit in the environment, the assigned certain activity, and the property describing the state of the environment of the sensor node, a working process;
- wherein, when the at least one mobile sensor unit is in the environment of the at least one sensor node, the at least one mobile sensor unit receives the measurement value of the second physical variable gathered at the sensor node and at the same time gathers the measurement value of the first physical variable, and intermediately stores the measurement value of the second physical variable gathered at the at least one sensor node and the gathered measurement value of the first physical variable in a paired and time-resolved manner and, when the at least one mobile sensor unit is brought into the environment of the communication node, the intermediately stored measurement values are forwarded to the communication node and then forwarded from the communication node to the central evaluation unit.