Cyclical sensor array
Assignee059312 N.B. Inc.
InventorLee Allen DANISCH
Life of this patent
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Abstract
A non-straight sensor array within a gravity field, within a surface and cyclically surrounding a medial axis. The sensor array includes rigid bodies holding gravimetric tilt sensors, the rigid bodies being connected by flexible joints. The flexibility of the joints is constrained to two degrees of freedom. The shape of the path, the surface, and the medial axis are measured in at least two dimensions, using the tilt sensor data and the geometrical constraints of the joints. The cyclical geometry permits simultaneous measurement of lateral and axial deformations in deployments varying from axially vertical to axially horizontal, as well as improved fit of the array to surrounding surfaces. The field of use includes geotechnical measurements of soil and civil structures.
Claims38
1-37. (canceled)
A non-straight sensor array within a gravity field comprising:
- rigid bodies with known dimensions, separated by joints with known dimensions,
- said joints having flexibility, the flexibility having 5 two degrees of freedom selected from (1) two of bend without twist, and (2) one of bend and one of twist,
- each of said degrees of freedom being monotonic and constant over the joint length,
- said rigid bodies and joints defining a sensor path comprised of straight line segments intersecting in first vertices,
- said straight line segments having lengths equal to the axial center-to-center distance between adjacent joints when the array is straight,
- said straight line segments at tilts operationally associated with tilts of the rigid bodies,
- the sensor path within a surface having at least two dimensions,
- the sensor path cyclically surrounding a medial axis having at least two dimensions,
- second vertices along the medial axis, operationally associated with said first vertices to represent the positions of first vertices of the sensor path along the medial axis,
- the sensor path being extensible and compressible along the medial axis without changing a path length of the sensor path,
- a set of said rigid bodies selected at intervals along said sensor path to represent the shape of said sensor path,
- said selected set of rigid bodies having gravimetric sensors for measuring tilt of said selected rigid bodies in at least one degree of freedom per selected rigid body in the gravity field,
- at least one of said selected rigid bodies having a known position and orientation in the World Coordinate System,
- said array adapted for measuring the at least two-dimensional shape of the surface, the at least two-dimensional shape of the medial axis, and the positions of the second vertices along the medial axis in the World Coordinate System from the
- orientation of each selected rigid body within the gravity field,
- wherein said sensor array forms a non-straight path cyclically surrounding the medial axis within a cylindrical surface, the rigid bodies separated by said flexible joints.
A method of drilling a borehole in a medium, the borehole larger in lateral dimensions than a generally straight sensor array, the borehole selected from lined or unlined, the method comprising:
- inserting a generally straight array into the borehole;
- and
- adding axial compression to the array to form a helix in intimate contact with the inside surface of the borehole or its lining.
A method of forming a ditch for an array, the method comprising:
- placing or forming raised portions along the bottom surface of the ditch to form serrations or sinuations;
- draping an array along the serrations to form an axially extensible shape in a vertical plane;
- and filling in the ditch.
A method of calculating the spatial frequency components of a sinuated, zigzag, or helical path in a surface, the path shape a function of distance along a first cartesian axis, the spatial frequency components being relative to the first cartesian axis and a second cartesian axis orthogonal to the first, the two cartesian axes forming a first plane, the method comprising:
- defining straight line segments from a first location along the waveform of a first spatial frequency component to a second location along said waveform, the first and second locations being separated in phase by 90 degrees;
- defining a midpoint of said line segment;
- repeating the definition of line segments and midpoints for a multiplicity of points at intervals along the waveform of the first spatial frequency component;
- defining a medial axis containing the midpoints;
- repeating the definition of a medial axis for the waveform of each spatial frequency component for another cartesian plane orthogonal to the first cartesian plane and containing the first axis;
- using the medial axes as a measure of the shape of the surface at a first time;
- and
- using medial axes from subsequent times to measure changes to the shape of the surface.
A method of forming a sensor array into a sinuated path on at least a portion of a cylindrical surface, the method comprising:
- placing the sensor array in a containing tube, the sensor array being loose within the containing tube when the tube is straight;
- affixing pins or posts to the cylindrical surface;
- weaving the containing tube between the pins to form sinuations on the cylindrical surface, the inner surface of the sinuated containing tube touching the segments of the array at the ends and near the middle, the curvature of the containing tube within the cylindrical surface less than or equal to the curvature of the cylinder, to set intimate contact between the sensor array and the containing tube during installation;
- and
- applying a compressive axial force from end to end of the containing tube to maintain intimate contact between the containing tube, the surface, and the pins or posts, thereby minimizing fastening hardware, speeding installation and removal, and improving the accuracy of data.
Dependencies are inferred from the claim text.