Localization and attitude estimation method using magnetic field and system thereof

A localization and attitude estimation method using magnetic fields to localize a moving carrier, on which one set of at least five tri-axes magnetic sensors is disposed, the localization and attitude estimation method comprising:

• selecting at least three magnetic landmarks arbitrarily disposed around the moving carrier in three-dimensional coordinates, wherein any two of the at least three magnetic landmarks have different magnetic directions, wherein position information and magnetic moment information of the at least three magnetic landmarks in the three-dimensional coordinates are unknown information;
• using the set of at least five tri-axes magnetic sensors to sense the magnetic fields of the at least three magnetic landmarks, and respectively generating three magnetic components on three axes of a current position of each of the tri-axes magnetic sensors using a demagnetization method, wherein three-dimensional coordinates of the set of at least five tri-axes magnetic sensors are not located on a same plane;
• obtaining five non-linear magnetic equations according to the three magnetic components on the three axes of the current position of each of the tri-axes magnetic sensors, and then solving the five non-linear magnetic equations according to magnetic moment vectors of the at least three magnetic landmarks in a null space to obtain the position information and the magnetic moment information of the at least three magnetic landmarks in the three-dimensional coordinates, and estimating position vectors and attitude vectors of the set of at least five tri-axes magnetic sensors in the three-dimensional coordinates according to tri-axes magnetic moment vectors of the at least three magnetic landmarks, and
• estimating position information and magnetic moment information of at least one unknown magnetic landmark in the three-dimensional coordinates according to the position vectors and the attitude vectors of the set of at least five tri-axes magnetic sensors at a new position in the three-dimensional coordinates when the moving carrier moves to the new position,
• when a distance of at least one of the three magnetic landmarks exceeds a predetermined range from the moving carrier and the at least one unknown magnetic landmark is disposed around the moving carrier, the method re-estimates the position vectors and the attitude vectors of the set of at least five tri-axes magnetic sensors in the three-dimensional coordinates by selecting the at least one unknown magnetic landmark, and obtaining position information and magnetic moment information of the at least one unknown magnetic landmark in the three-dimensional coordinates.