1. A safety helmet comprising:
an outer shell;
an energy-absorbing liner within said outer shell; and
wherein said energy-absorbing liner includes a cellular textile composite material in which at least a portion is a porous textile material supported in a matrix material wherein a plurality of pores are retained in said portion of the composite.
2. A safety helmet as claimed in claim 1 wherein said cellular textile composite includes a textile fabric and a matrix material saturating strands of said textile material and retaining pores between strands of said textile material.
3. A safety helmet as claimed in claim 2 wherein said textile fabric includes a fabric manufactured from yarns or fibres of high-density polymeric materials.
4. A safety helmet as claimed in claim 2 wherein said matrix material comprises a polymer resin.
5. A safety helmet as claimed in claim 1 wherein said cellular textile composite provides a plurality of cells in the form of flat-top conical cell structures.
6. A safety helmet as claimed in claim 1 wherein a linkage structure is provided to link adjacent cells such that impact energy may be dissapated by a plurality of adjacent cells.
7. A safety helmet as claimed in claim 6 wherein an interlocking linkage is provided in the form of a reversibly facing nested textile composite.
8. A safety helmet as claimed in claim 6 wherein a linkage is provided in the form of a thin layer of material surrounding and interconnecting individual cells with adjacent cells.
9. A safety helmet as claimed in claim 6 wherein a linkage is provided in the form of a foam material surrounding individual cells and interconnecting adjacent cells.
10. A method of manufacturing a liner for a safety helmet comprising the steps of:
providing a sheet of textile fabric;
forming said textile fabric at controlled temperatures to provide a plurality of projecting cells;
forming said fabric with said cells into a generally hemispherical shape for use as a helmet liner;
forming linkages of adjacent cells;
applying resin as a matrix material at one or more stages throughout the method to form a textile fabric composite structure retaining a plurality of pores of the fabric in at least a portion of the resulting composite; and
curing said composite for use as a helmet liner.
11. A method of manufacturing a helmet liner as claimed in claim 10 wherein a flat textile fabric sheet is formed into a substantially planar preform with projecting cells prior to formation into a generally hemispherical three-dimensional shape for use as a liner.
12. A method of manufacturing a liner as claimed in claim 10 wherein a substantially flat textile fabric is applied directly to a three-dimensional generally hemispherical mold for simultaneous formation into the generally hemispherical shape for a liner and formation of the projecting cells.
13. A method of manufacturing a liner as claimed in claim 10 wherein said controlled temperatures comprises controlling the temperature during formation of the cells to a temperature below the melting point of the fibres in the textile fabric but above the glass transition temperature.
14. A method of manufacturing a liner as claimed in claim 10 wherein said step of applying resin as a matrix material is performed at more than one stage throughout the method.
15. An apparatus for the manufacture of a textile composite structure for use in a liner of a safety helmet comprising:
at least a first temperature controlled mould having co-operating moulding services to form a plurality of projecting cells into a substantially planar sheet of textile fabric;
a generally hemispherical head-shaped base shell having a plurality of projecting mandrels to receive said textile fabric wherein said mandrels support some or all of said projecting cells; and
means to apply resin at one or more stages throughout the process to form a textile composite structure.
16. An apparatus for the manufacture of a textile composite structure as claimed in claim 15 wherein said generally hemispherical head-shaped base shell is provided as an inflatable or compressible base shell that may be collapsed after formation of the textile composite structure for removal.
17. An apparatus for manufacture of a textile composite structure as claimed in claim 15 wherein said generally hemispherical head-shaped base shell is provided as a substantially solid hemispherical base shell carrying a plurality of mandrels, at least some of said mandrels being removable to assist in release of the composite structure from said base shell.
18. An apparatus for the manufacture of a textile composite structure for use as a liner in a safety helmet comprising:
at least one temperature controlled mould having two co-operating moulding surfaces having a generally hemispherical head-shaped configuration and carrying a plurality of mandrels to form a textile fabric into a generally hemispherical head-shaped structure and simultaneously form a plurality of projecting cells in said fabric; and
means to apply resin before, during or after said moulding process.
19. An apparatus for the manufacture of a textile composite structure as claimed in claim 18 wherein one or both of the co-operating moulds are provided in connectable portions to form the generally hemispherical head-shaped surface such that, upon disconnection, said moulding surface can be removed.
20. An apparatus for the manufacture of a textile composite structure as claimed in claim 18 or 19 wherein at least a portion of a surface of one of said moulding surfaces is provided with a biased portion to assist in the release of the composite structure from said moulding surface.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for processing data, comprising:
receiving a temporal sequence of depth maps of a scene containing a humanoid form, the depth maps comprising a matrix of pixels having respective pixel depth values;
using a digital processor, processing at least one of the depth maps so as to find respective three-dimensional (3D) medial axes of segments of limbs of the humanoid form in a 3D space;
identifying joints in the limbs by finding approximate intersection points of the 3D medial axes of adjoining segments of the limbs, wherein for at least some of the adjoining limb segments, the respective 3D medial axes do not precisely intersect in the 3D space; and
tracking movements of the humanoid form over the sequence using the medial axes and the joints of the limbs.
2. The method according to claim 1, wherein finding the approximate intersection points comprises locating an elbow at an approximate intersection of the 3D medial axes of an upper arm and a forearm of the humanoid form.
3. The method according to claim 1, wherein processing the at least one of the depth maps comprises identifying, using the identified joints and limbs, left and right arms of the humanoid form, and searching to find a head of the humanoid form between the arms.
4. The method according to claim 3, wherein identifying the left and right arms comprises capturing the at least of the depth maps while the humanoid form stands in a calibration pose, in which the left and right arms are raised.
5. The method according to claim 4, wherein the left and right arms are raised above a shoulder level of the humanoid form in the calibration pose.
6. The method according to claim 1, wherein processing the at least one of the depth maps comprises extracting edges of the humanoid form from the at least one depth map, and finding the 3D medial axes and extreme points of limbs of the humanoid form based on the edges.
7. The method according to claim 6, wherein finding the 3D medial axes comprises:
fitting straight lines in the 3D space to the extracted edges;
defining the segments of the limbs by matching pairs of the straight lines that are approximately parallel; and
identifying a respective 3D medial axis between each of the matched pairs.
8. The method according to claim 1, wherein identifying the joints comprises locating left and right shoulders of the humanoid form, and wherein the method comprises computing a width between the shoulders, and estimating dimensions of other parts of the humanoid form based on the width.
9. The method according to claim 8, and comprising refining the estimated dimensions responsively to the depth maps in the sequence while tracking the movements.
10. Apparatus for processing data, comprising:
an imaging assembly, which is configured to capture a temporal sequence of depth maps of a scene containing a humanoid form, the depth maps comprising a matrix of pixels having respective pixel depth values; and
a digital processor, which is configured to process at least one of the depth maps so as to find respective three-dimensional (3D) medial axes of segments of limbs of the humanoid form in a 3D space, to identify joints in the limbs by finding approximate intersection points of the 3D medial axes of adjoining segments of the limbs, wherein for at least some of the adjoining limb segments, the respective 3D medial axes do not precisely intersect in the 3D space, and to track movements of the humanoid form over the sequence using the medial axes and the joints of the limbs.
11. The apparatus according to claim claim 10, wherein the digital processor is configured to locate an elbow at an approximate intersection of the 3D medial axes of an upper arm and a forearm of the humanoid form.
12. The apparatus according to claim 10, wherein the digital processor is configured to identify, using the identified joints and limbs, left and right arms of the humanoid form, and to search to find a head of the humanoid form between the arms.
13. The apparatus according to claim 10, wherein the digital processor is configured to extract edges of the humanoid form from the at least one depth map, and to find the 3D medial axes and extreme points of limbs of the humanoid form based on the edges.
14. The apparatus according to claim 13, wherein the digital processor is configured to find the 3D medial axes by fitting straight lines in the 3D space to the extracted edges, defining the segments of the limbs by matching pairs of the straight lines that are approximately parallel, and identifying a respective 3D medial axis between each of the matched pairs.
15. The apparatus according to claim 10, wherein the identified joints comprise left and right shoulders of the humanoid form, and wherein the digital processor is configured to compute a width between the shoulders, and to estimate dimensions of other parts of the humanoid form based on the width.
16. A computer software product, comprising a non-transitory computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to receive a temporal sequence of depth maps of a scene containing a humanoid form, the depth maps comprising a matrix of pixels having respective pixel depth values, to process at least one of the depth maps so as to find respective three-dimensional (3D) medial axes of segments of limbs of the humanoid form in a 3D space, to identify joints in the limbs by finding approximate intersection points of the 3D medial axes of adjoining segments of the limbs, wherein for at least some of the adjoining limb segments, the respective 3D medial axes do not precisely intersect in the 3D space, and to track movements of the humanoid form over the sequence using the medial axes and the joints of the limbs.
17. The product according to claim 16, wherein the instructions cause the computer to identify, using the identified joints and limbs, left and right arms of the humanoid form, and to search to find a head of the humanoid form between the arms.
18. The product according to claim 16, wherein the instructions cause the computer to extract edges of the humanoid form from the at least one depth map, and to find the 3D medial axes and extreme points of limbs of the humanoid form based on the edges.
19. The product according to claim 16, wherein the identified joints comprise left and right shoulders of the humanoid form, and wherein the instructions cause the computer to compute a width between the shoulders, and to estimate dimensions of other parts of the humanoid form based on the width.
20. The product according to claim 18, wherein the instructions cause the computer to find the 3D medial axes by fitting straight lines in the 3D space to the extracted edges, defining the segments of the limbs by matching pairs of the straight lines that are approximately parallel, and identifying a respective 3D medial axis between each of the matched pairs.