Tracking drum rotations

A method of tracking rotations of a drum, the method comprising:

• activating a three axis accelerometer located on a side of the drum while keeping a gyroscope deactivated;
• measuring linear accelerations along three orthogonal axes using the accelerometer;
• determining whether a predetermined angle of the drum has been rotated based on the measured linear accelerations from the accelerometer;
• activating the gyroscope in response to determining that the predetermined angle of the drum has been rotated so that the gyroscope is activated based on the measured linear accelerations from the accelerometer;
• measuring angular speed of the drum around a main axis of the drum with the gyroscope;
• calculating a number of rotations of the drum from the angular speed of the drum as measured by the gyroscope;
• and
• deactivating the gyroscope in response to determining that the angular speed measured by the gyroscope is lower than a noise floor level for angular speed of the drum;
• attaching a tracker device with a tracker identifier to a drum with a drum identifier, the drum identifier being associated in a database with drum dimensions and with dimensions of a material stored on the drum, tracker device comprising the three axis accelerometer and the gyroscope;
• associating in the database the drum identifier with the tracker identifier;
• storing the number of rotations in a local memory of the tracker device;
• activating an electronic circuit comprising a communication circuit that connects to a wireless communication system and a positioning circuit that detects the position coordinates of the tracker device and the drum;
• transmitting, to the database via the communication system, the tracker identifier, the detected position coordinates and the number of rotations;
• switching the electronic circuit to a standby mode after the transmitting;
• associating the detected position coordinates and the number of rotations to the tracker identifier and the drum identifier in the database;
• and
• calculating, using the drum dimensions and the dimensions of the material stored in the database, a remaining length of the material stored on the drum, wherein the activating, the associating, and the calculating occur at scheduled time intervals.

A system comprising:

• a tracker device having a tracker identifier configured to be attached to a drum, the tracker device comprising
• a three axis accelerometer located on a side of the drum and configured to measure linear accelerations along three orthogonal axes,
• a gyroscope, and
• one or more controllers configured to
• activate the three axis accelerometer to measure the linear accelerations while keeping the gyroscope deactivated,
• determine whether a predetermined angle of the drum has been rotated based on the measured linear accelerations from the accelerometer,
• activate the gyroscope in response to determining that the predetermined angle of the drum has been rotated so that the gyroscope is activated based on the measured linear accelerations from the accelerometer,
• measure angular speed of the drum around a main axis of the drum with the gyroscope,
• calculate a number of rotations of the drum from the angular speed of the drum as measured by the gyroscope, and
• deactivate the gyroscope in response to determining that the angular speed measured by the gyroscope is lower than a noise floor level for angular speed of the drum.