Ultrasound Tool Localization Using Arbitrary Receiver Trilateration
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Solution Overview
Problem
Existing ultrasound-based systems for locating tools in a workspace face challenges in fast, effective, and flexible arrangement due to the requirement of fixed receivers positioned in specific criteria, leading to precision issues in measuring the position of moving objects.
Innovation Solution
A method and system that uses a minimal configuration of three ultrasound receivers arranged above the workspace, calculating the position of a transmitter on a tool using trilateration, allowing for flexible receiver placement and minimizing measurement errors through calibration and temperature compensation, and enabling precise positioning without requiring the receivers to be in a specific reference plane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If receivers are positioned in fixed points meeting particular criteria (reference plane with height zero and origin positioning), then trilateration calculation can be implemented, but the arrangement of the measuring system becomes slow, ineffective, and inflexible
Solution Approach 1:
The patent changes the parameters of the reference system by introducing arbitrary positioning of receivers without requiring them to lie in a reference plane with height zero. The method modifies the trilateration calculation to work with receivers positioned at arbitrary coordinates, thereby improving flexibility while maintaining measurement precision through mathematical transformation of the position calculation formulas.
2Productivity
If receivers are positioned in fixed points meeting particular criteria, then trilateration calculation can be implemented, but the measuring system arrangement becomes complex and time-consuming
Solution Approach 1:
The patent extracts the constraint requirement from the traditional trilateration method by removing the necessity for receivers to be positioned in a reference plane with height zero. This extraction simplifies the positioning requirements, allowing receivers to be placed arbitrarily in space, thereby reducing arrangement complexity and increasing productivity without compromising the core trilateration functionality.
3Measurement precision
If fixed points are positioned according to specific criteria, then distance measurement can be performed, but errors in measurement of fixed points positions have remarkable effect on precision of identification
Solution Approach 1:
The patent implements a feedback mechanism where the system measures the actual positions of the receivers and uses these measured positions as input for the trilateration calculation. By using the actual measured positions rather than theoretical or pre-defined positions, the system compensates for measurement errors and maintains high reliability in position identification despite uncertainties in fixed point positioning.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables a fast, effective, and flexible arrangement of the measuring system, improving precision and reducing measurement uncertainties, allowing for accurate tool positioning in machining environments, even with arbitrary receiver placement.
Implementation Method 1
A transmitter of ultrasound signals T is associated to a part of the tool U
Implementation Method 2
measuring times of flight of ultrasound signals transmitted by transmitters associated to the moving tool and received by fixed receivers so as to assess the distance
Data Source
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AI summary
A method for locating a tool in a work space via ultrasound, comprising: associating at least one ultrasound transmitter (T) to the aforesaid tool (U) and calculating a position of the tool (U) on the basis of determination of the position (Pz) of the aforesaid transmitter (T); providing, at least three ultrasound receivers (R1, R2, R3), set in fixed positions (P1, P2, P3) relative to the aforesaid work space (WS), which are configured for receiving ultrasound signals emitted by the aforesaid ultrasound transmitter (T); and measuring, in a first reference system (IRS), distances (r1, r2, r3) between the aforesaid ultrasound transmitter (T) and the aforesaid at least three ultrasound receivers (R1, R2, R3) on the basis of propagation times associated to the aforesaid ultrasound signals received, the aforesaid calculation of the position (Pz) of the transmitter comprising using a trilateration procedure (100) that comprises applying trilateration formulas as a function of the aforesaid measured distances (r1, r2, r3) and the aforesaid fixed positions (P1, P2, P3), the aforesaid trilateration procedure (100) comprising: carrying out (110) a change of reference of the fixed positions (P1, P2, P3) of the aforesaid at least three receivers to reference them in a second simplified reference system (TRS) in which the aforesaid fixed positions (P1, P2, P3) lie in a plane associated to a zero value of position coordinate; applying (120) the aforesaid trilateration formulas to obtain the position of an unknown point (Pz) in the aforesaid second simplified reference system (TRS) as a function of the aforesaid measured distances (r1, r2, r3) and of the aforesaid fixed positions (P1, P2, P3) expressed in the aforesaid second simplified reference system (TRS); carrying out (130) a rototranslation (R) of the position (Pz) of the unknown point obtained from the second simplified reference system (TRS) into the first reference system, a corresponding rototranslation matrix (R) being calculated as a function of the fixed positions (P1, P2, P3) in the first reference system (IRS) and in the simplified reference system (TRS); and using a position of the aforesaid unknown point obtained following upon the above rototranslation as position of the aforesaid transmitter (T).