# US 11,994,466 B2 · Methods and systems for identifying material composition of moving objects > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,466 B2 - Document ID: US11994466B2 - Status: Granted - Kind: B2 - Application number: 16/981,844 - Filed: 2019-03-19 - Published: 2021-02-04 - Granted: 2024-05-28 - Earliest claimed: 2018-03-19 - Assignees: Iridesense - Applicants: Iridesense - Inventors: Scott Buchter - Web page: https://patentgrep.com/patent/US11994466B2 ## CPC - G01N 21/21: Polarisation-affecting properties (G01N21/19 takes precedence) - G01N 21/55: Specular reflectivity - B60W 30/0956: {the prediction being responsive to traffic or environmental parameters} - B60W 60/001: {Planning or execution of driving tasks} - G01S 7/4802: {using analysis of echo signal for target characterisation; Target signature; Target cross-section} - G01S 7/4814: {of transmitters alone} - G01S 7/4816: {of receivers alone} - G01S 7/4817: {relating to scanning} - G01S 17/08: for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) - G01S 17/50: Systems of measurement based on relative movement of target - G01S 17/89: for mapping or imaging - G01S 17/894: Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar - G06T 17/00: Three-dimensional [3D] modelling for computer graphics - G06T 19/20: Editing of three-dimensional [3D] images, e.g. changing shapes or colours, aligning objects or positioning parts - G06V 20/58: Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads - H04N 1/00827: {Arrangements for reading an image from an unusual original, e.g. 3-dimensional objects} - B60W 2420/408: Radar; Laser, e.g. lidar - B60W 2420/54: Audio sensitive means, e.g. ultrasound - G01N 2021/217: {Measuring depolarisation or comparing polarised and depolarised parts of light} - G01N 2021/4792: {Polarisation of scatter light} - G01N 2201/06113: Coherent sources; lasers - G01S 17/86: Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders - G01S 17/87: Combinations of systems using electromagnetic waves other than radio waves - G06T 2210/56: Particle system, point based geometry or rendering - G06T 2219/2004: Aligning objects, relative positioning of parts - G06V 2201/07: Target detection - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method for identifying a composition material of an object located in an environment surrounding at least one device, the object moving relative to the device, in which at least one sensor is mounted on the device and communicates with at least one central processing unit. ## Claims ### Claim 1 A method for identifying a material composition of an object located in an environment surrounding at least one device, the object moving relative to the device, in which at least one sensor is mounted on the device and communicates with at least one central processing unit, wherein: /A/ the sensor generates a point cloud frame of a continuous stream by emitting a physical signal at a first wavelength, wherein the point cloud frame comprises a set of data points, at least one data point comprising coordinates of the object in a local volume surrounding the sensor at time tj in a local coordinate system of the sensor, said data point also comprising an intensity value of a reflected physical signal corresponding to the emitted physical signal once reflected on the object, /B/ the central processing unit receives the point cloud frame and determines the coordinates of each data point of the point cloud frame in a global coordinate system of the environment surrounding the device, the intensity value being associated with the coordinates of each data point in the global coordinate system, /C/ the central processing unit determines the coordinates of the object at time tj in the global coordinate system, /D/ the central processing unit stores in a memory the coordinates of the object in the global coordinate system at time tj, steps /A/ to /D/ are repeated with the sensor or another sensor generating another point cloud frame by emitting another physical signal at another wavelength, at time tj+1, so that at least two intensity values are associated to coordinates of the object in the global coordinate system at two different times, /E/ the central processing unit determines a reflectivity response of the object from the at least two intensity values, and /F/ the central processing unit identifies the material composition of the object, wherein the central processing unit determines the coordinates of each data point of the point cloud frame in the global coordinate system of the environment surrounding the device by: comparing the point cloud frame with a global cumulated tridimensional map of the environment to determine an aligned point cloud frame in the global coordinate system, and updating the global cumulated tridimensional map by merging the aligned point cloud frame with the global cumulated tridimensional map. ### Claim 2 (depends on 1) Method according to claim 1, wherein the central processing unit determines the coordinates of the object at time tj in a global coordinate system by: comparing the point cloud frame with a global cumulated tridimensional map of the environment to determine an aligned point cloud frame in the global coordinate system, and identifying a set of data points of the point cloud frame that cannot be aligned in the global coordinate system, so that this set of data points corresponds to the moving object. ### Claim 3 (depends on 1) Method according to claim 1, also comprising an additional step of obtaining a three-dimensional reconstruction of the object from the coordinates of the object in the global coordinate system and generated at at least two different times. ### Claim 4 (depends on 1) The method according to claim 1, wherein the sensor comprises at least one emitter and at least one receiver, the emitter being configured to emit a physical signal and the receiver being configured to receive the emitted physical signal once reflected on the object. ### Claim 5 (depends on 4) The method according to claim 4, wherein the sensor comprises the emitter and the receiver as a single unit. ### Claim 6 (depends on 1) The method according to claim 1, wherein the central processing unit identifies the material composition of the object by comparing the reflectivity response determined at step /E/ with reference reflectivity responses of known materials stored in a library. ### Claim 7 (depends on 1) The method according to claim 1, wherein the wavelengths of the physical signals emitted for the point cloud frames are selected in a random manner. ### Claim 8 (depends on 1) The method according to claim 1, wherein the wavelengths of the physical signals emitted for the point cloud frames are selected in a predetermined order. ### Claim 9 (depends on 1) The method according to claim 1, wherein the device comprises a plurality of sensors, wherein the sensors can respectively generate a point cloud frame by emitting a physical signal at a wavelength comprised in different spectral domains. ### Claim 10 (depends on 9) The method according to claim 9, wherein the sensors all communicate wirelessly with the central processing unit. ### Claim 11 (depends on 1) The method according to claim 1, wherein a point cloud frame corresponds to a full scan of the local volume of the sensor. ### Claim 12 (depends on 1) The method according to claim 1, wherein the coordinates of the object in the local coordinate system of the sensor comprises two angular coordinates and one radial coordinate. ### Claim 13 (depends on 12) The method according to claim 12, wherein the radial coordinate corresponds to the distance from the sensor to the data point (Mi), the distance being computed by comparing timing of the emitted physical signal and the reflected physical signal. ### Claim 14 (depends on 1) The method according to claim 1, wherein steps /A/ to /D/ are repeated at least four times, so that at least four intensity values are associated to coordinates of the object in the global coordinate system. ### Claim 15 (depends on 1) The method according to claim 1, wherein the physical signal is a laser signal. ### Claim 16 (depends on 1) The method according to claim 1, wherein the device is a vehicle able to move in the environment. ### Claim 17 A system for identifying the material composition of an object located in an environment surrounding at least one device, the object moving relative to the device, the system comprising: a plurality of sensors configured to be mounted on said at least one device, each sensor of the plurality of sensors being configured to generate a continuous stream of point cloud frames, in parallel and asynchronously with the other sensors of the plurality of sensors, by emitting a physical signal at a first wavelength, and at least a second wavelength, wherein the point cloud frame comprises a set of data points, each data point comprising coordinates of the object in a local volume of the environment surrounding the sensor at time tj in a local coordinate system of the sensor, each data point also comprising an intensity value of a reflected physical signal corresponding to the emitted physical signal once reflected on the object, a central processing unit configured to communicate with each sensor to continuously receive the continuous streams of successive point cloud frames from each sensor, determine the coordinates of each data point of the point cloud frame in a global coordinate system of the environment surrounding the device, determine the coordinates of the object in the global coordinate system at the time tj, wherein the central processing unit determines the coordinates of each data point of the point cloud frame in the global coordinate system of the environment surrounding the device by: comparing the point cloud frame with a global cumulated tridimensional map of the environment to determine an aligned point cloud frame in the global coordinate system, and updating the global cumulated tridimensional map by merging the aligned point cloud frame with the global cumulated tridimensional map, wherein the central processing unit is configured to store in a memory the intensity value and the coordinates in the global coordinate system, for at least the first wavelength and the second wavelength, the central processing unit being configured to determine a reflectivity response of the object from the intensity values and to identify the material composition of the object. ### Claim 18 (depends on 17) An autonomous or semi-autonomous vehicle comprising a system according to claim 17. ### Claim 19 (depends on 17) A non-transitory computer readable storage medium, having stored thereon a computer program comprising program instructions, the computer program being loadable into a central processing unit of the system according to claim 17 and configured to cause the central processing unit to determine the coordinates of each data point of the point cloud frame in the global coordinate system. ### Claim 20 A method for identifying a material composition of an object located in an environment surrounding at least one device, the object moving relative to the device, in which at least one sensor is mounted on the device and communicates with at least one central processing unit, wherein: /A/ the sensor generates a point cloud frame of a continuous stream by emitting a physical signal at a first wavelength, wherein the point cloud frame comprises a set of data points, at least one data point comprising coordinates of the object in a local volume surrounding the sensor at time tj in a local coordinate system of the sensor, said data point also comprising an intensity value of a reflected physical signal corresponding to the emitted physical signal once reflected on the object, /B/ the central processing unit receives the point cloud frame and determines the coordinates of each data point of the point cloud frame in a global coordinate system of the environment surrounding the device, the intensity value being associated with the coordinates of each data point in the global coordinate system, /C/ the central processing unit determines the coordinates of the object at time tj in the global coordinate system, /D/ the central processing unit stores in a memory the coordinates of the object in the global coordinate system at time tj, steps /A/ to /D/ are repeated with the sensor or another sensor generating another point cloud frame by emitting another physical signal at another wavelength, at time tj+1, so that at least two intensity values are associated to coordinates of the object in the global coordinate system at two different times, /E/ the central processing unit determines a reflectivity response of the object from the at least two intensity values, and /F/ the central processing unit identifies the material composition of the object, wherein the central processing unit determines the coordinates of the object at time tj in a global coordinate system by: comparing the point cloud frame with a global cumulated tridimensional map of the environment to determine an aligned point cloud frame in the global coordinate system, and identifying a set of data points of the point cloud frame that cannot be aligned in the global coordinate system, so that this set of data points corresponds to the moving object. ### Claim 21 A method for identifying a material composition of an object located in an environment surrounding at least one device, in which at least one sensor is mounted on the device and communicates with at least one central processing unit, wherein: /A/ the sensor generates a point cloud frame of a continuous stream by emitting a physical signal at a first wavelength, wherein the point cloud frame comprises a set of data points, at least one data point comprising coordinates of the object in a local volume surrounding the sensor at time tj in a local coordinate system of the sensor, said data point also comprising an intensity value of a reflected physical signal corresponding to the emitted physical signal once reflected on the object, /B/ the central processing unit receives the point cloud frame and determines the coordinates of each data point of the point cloud frame in a global coordinate system of the environment surrounding the device, the intensity value being associated with the coordinates of each data point in the global coordinate system, /C/ the central processing unit determines the coordinates of the object at time tj in the global coordinate system, /D/ the central processing unit stores in a memory the coordinates of the object in the global coordinate system at time tj, steps/A/to/D/are repeated with the sensor or another sensor generating another point cloud frame by emitting another physical signal at another wavelength, at time tj+1, so that at least two intensity values are associated to coordinates of the object in the global coordinate system at two different times, /E/ the central processing unit determines a reflectivity response of the object from the at least two intensity values, and /F/ the central processing unit identifies the material composition of the object, wherein the central processing unit determines the coordinates of each data point of the point cloud frame in the global coordinate system of the environment surrounding the device by: comparing the point cloud frame with a global cumulated tridimensional map of the environment to determine an aligned point cloud frame in the global coordinate system, and updating the global cumulated tridimensional map by merging the aligned point cloud frame with the global cumulated tridimensional map.