| 主权项 |
1. A method for locating a tool in a work space via ultrasound, comprising:
associating at least one ultrasound transmitter to said tool and calculating a position of said tool on the basis of determination of the position of said transmitter; providing at least three ultrasound receivers, set in fixed positions relative to said work space, which are configured for receiving ultrasound signals emitted by said ultrasound transmitter; and measuring, in a first reference system, distances between said ultrasound transmitter and said at least three ultrasound receivers on the basis of propagation times associated to said ultrasound signals received, said calculation of the position of the transmitter comprising using a trilateration procedure comprising applying trilateration formulas as a function of said measured distances and of said fixed positions, said trilateration procedure comprising: carrying out a change of reference of the fixed positions of said at least three receivers to reference them in a second simplified reference system in which said fixed positions lie in a plane associated to a zero value of position coordinate; applying said trilateration formulas to obtain the position of an unknown point in said second simplified reference system as a function of said measured distances and of said fixed positions expressed in said second simplified reference system; carrying out a rototranslation of the position of the unknown point obtained from the second simplified reference system into the first reference system, a corresponding rototranslation matrix being calculated as a function of the fixed positions in the first reference system and in the simplified reference system; and using a position of said unknown point obtained following upon said rototranslation as position of said transmitter. |
