A data collection method of a system comprising a first node, a second node and a third node, each node equipped with a sensor to acquire respective sensor data, the data collection method comprising: the first node transmitting the sensor data of the first node to the second node; and the second node transmitting the sensor data of the second node to the third node; wherein the method is characterized in that it further comprises: the second node determining whether the sensor data of the first node and the sensor data of the second node are equivalent; the second node, when it is determined that the sensor data of the first node and the sensor data of the second node are equivalent, suspending transmission of the sensor data of the second node to the third node, setting the second node and the first node in a same group, and sending a first message to the first node indicating setting of the second node and the first node in the same group; the second node, when it is determined, after said suspension, that the sensor data of the first node and the sensor data of the second node are not equivalent, resuming transmission of the sensor data of the second node to the third node, removing the second node from the same group as the first node, and sending a second message to the first node indicating removal of the second node from the same group as the first node, and in that the method further comprises: the first node, when the first node and the second node are set to be in the same group, transmitting identification information indicating that the first node and the second node are in the same group with the sensor data of the first node to the third node. the first node transmitting the sensor data of the first node to the second node; and the second node transmitting the sensor data of the second node to the third node; wherein the method is characterized in that it further comprises: the second node determining whether the sensor data of the first node and the sensor data of the second node are equivalent; the second node, when it is determined that the sensor data of the first node and the sensor data of the second node are equivalent, suspending transmission of the sensor data of the second node to the third node, setting the second node and the first node in a same group, and sending a first message to the first node indicating setting of the second node and the first node in the same group; the second node, when it is determined, after said suspension, that the sensor data of the first node and the sensor data of the second node are not equivalent, resuming transmission of the sensor data of the second node to the third node, removing the second node from the same group as the first node, and sending a second message to the first node indicating removal of the second node from the same group as the first node, and in that the method further comprises: the first node, when the first node and the second node are set to be in the same group, transmitting identification information indicating that the first node and the second node are in the same group with the sensor data of the first node to the third node. the second node determining whether the sensor data of the first node and the sensor data of the second node are equivalent; the second node, when it is determined that the sensor data of the first node and the sensor data of the second node are equivalent, suspending transmission of the sensor data of the second node to the third node, setting the second node and the first node in a same group, and sending a first message to the first node indicating setting of the second node and the first node in the same group; the second node, when it is determined, after said suspension, that the sensor data of the first node and the sensor data of the second node are not equivalent, resuming transmission of the sensor data of the second node to the third node, removing the second node from the same group as the first node, and sending a second message to the first node indicating removal of the second node from the same group as the first node, and in that the method further comprises: the first node, when the first node and the second node are set to be in the same group, transmitting identification information indicating that the first node and the second node are in the same group with the sensor data of the first node to the third node.