Multi-sensor measurement system

Abstract

The embodiment of the invention relates to a multi-sensor metrology system. In some implementations, a processing system may cause a plurality of optical sensors to measure a plurality of reference objects. The processing system may receive data indicative of distances between the plurality of optical sensors and the plurality of reference objects. The processing system may compare the data to baseline data indicative of a baseline distance between the plurality of optical sensors and the plurality of reference objects as measured by the plurality of optical sensors. The processing system may perform one or more corrective actions on the plurality of optical sensors based on a difference between the data and the baseline data.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 601,868, entitled “CALIBRATION OF A MULTI-SENSOR METROLOGY SYSTEM,” filed on November 22, 2023. The disclosure of the prior application is considered a part of this patent application and is incorporated by reference into this patent application. Technical Field

[0003] The present disclosure relates generally to metrology and multi-sensor metrology systems. Background Art

[0004] Light detection and ranging (LiDAR) systems, such as time-of-flight (ToF) based measurement systems, transmit optical pulses, detect reflected optical pulses, and determine the distance to an object by measuring the delay between the transmitted and reflected optical pulses. Summary of the invention

[0005] In some implementations, a metrology system includes: a structure defining a compartment in which an object for three-dimensional (3D) measurement is to be positioned; a plurality of reference objects attached to the structure; a plurality of optical sensors attached to the structure, wherein the plurality of reference objects are in a field of view of the plurality of optical sensors; and a processing system communicatively connected to the plurality of optical sensors. The processing system may be configured to cause the plurality of optical sensors to measure the plurality of reference objects. The processing system may be configured to receive data indicating distances between the plurality of optical sensors and the plurality of reference objects from the plurality of optical sensors. The processing system may be configured to compare the data with baseline data indicating baseline distances between the plurality of optical sensors and the plurality of reference objects measured by the plurality of optical sensors. The processing system may be configured to generate a set of offsets to be applied to one or more of the plurality of optical sensors based on differences between the data and the baseline data.

[0006] In some implementations, a method includes causing, by a processing system, a plurality of optical sensors to measure a plurality of reference objects. The method may include receiving, by the processing system, data from the plurality of optical sensors indicating distances between the plurality of optical sensors and the plurality of reference objects. The method may include comparing, by the processing system, the data with baseline data indicating baseline distances between the plurality of optical sensors and the plurality of reference objects measured by the plurality of optical sensors. The method may include performing, by the processing system, one or more corrective actions on the plurality of optical sensors based on differences between the data and the baseline data.

[0007] In some implementations, a measurement system includes: a structure defining a compartment in which an object for 3D measurement is to be positioned. The measurement system may include a plurality of reference objects attached to the structure. The measurement system may include a plurality of lidar sensors attached to the structure. The plurality of reference objects may be in a field of view of the plurality of lidar sensors. A reference object of the plurality of reference objects may be in a field of view of a plurality of lidar sensors of the plurality of lidar sensors. A plurality of reference objects of the plurality of reference objects may be in a field of view of a lidar sensor of the plurality of lidar sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a perspective view of an example multi-sensor measurement system.

[0009] Figure 2 is a diagram of an example environment in which the systems and / or methods described herein may be implemented.

[0010] Figure 3 is a diagram of example components of equipment associated with a multi-sensor metrology system.

[0011] Figure 4 is a flow chart of an example process associated with a multi-sensor measurement system. DETAILED DESCRIPTION

[0012] The following detailed description of example implementations refers to the accompanying drawings.The same reference numbers in different drawings may identify the same or similar elements.

[0013] An object can be measured in three dimensions (3D) using an optical sensor that emits light (e.g., a laser) and detects light reflections from the object to capture data related to the spatial characteristics of the object. Sometimes, the object to be measured in 3D may be larger than the field of view of a single optical sensor and therefore cannot be measured by a single sensor. Various techniques can be used to address this problem. For example, the optical sensor can be mounted on a robotic arm and moved to multiple positions around the object, the object can be mounted on a robotic arm and oriented in multiple positions with respect to the optical sensor, the object can be mounted on a rotating stage and rotated to present different sides of the object to the optical sensor, or the object can be surrounded by multiple optical sensors.

[0014] Using a robotic arm for 3D measurement requires the use of complex safety curtains to prevent damage to the object being measured and / or to prevent harm to people. In addition, programming the robot movement is complex, time-consuming, and requires expertise. In addition, the robotic arm is expensive, uses safety equipment associated with additional costs, lacks high position accuracy (e.g., lacks micron-level accuracy), and has poor position accuracy under temperature changes. Moreover, the robotic arm is prone to wear (e.g., due to friction and / or mechanical joints deteriorating over time, the cables need to be replaced periodically). When a single optical sensor is attached to the robotic arm, effective 3D measurement relies on accurately tracking the position of the robotic arm by using an external sensor (such as a laser tracker) or by using photogrammetry, thereby introducing additional complexity and failure points to the 3D measurement system. Multi-sensor systems are not susceptible to the above-mentioned problems associated with robotic arms. Additionally, multi-sensor systems can provide increased speed relative to other technologies because the optical sensors of the multi-sensor system can operate simultaneously (i.e., in parallel) to capture 3D measurements of an object.

[0015] In some examples, the optical sensors of the multi-sensor system can be mounted at various locations on a rigid frame to facilitate coverage of 3D measurements from multiple different angles. The frame can be constructed of a metal such as steel. Although metals are relatively strong, they may experience expansion and contraction as temperature changes, causing the frame to expand and contract. Therefore, the position of the optical sensors mounted to the frame may shift as the frame expands and contracts. As a result, 3D measurements captured using the optical sensors may be less accurate and reliable, or may be completely unusable.

[0016] Some implementations described herein provide a multi-sensor measurement system for 3D measurement that is capable of highly accurate and reliable measurements. The measurement system may include multiple optical sensors and multiple reference objects, such as metal spheres attached to structures such as frames. At various times, the optical sensor may measure the reference object to collect data indicating the distance between the optical sensor and the reference object. The data may be compared with baseline data collected after calibrating the measurement system to identify the movement of the relative position of the optical sensor and / or the reference object. These movements may be corrected by using the calibration offset of the optical sensor. Through regular measurement of the reference object by the optical sensor, the calibration of the measurement system may be adjusted in real time to compensate for the displacement of the optical sensor due to the expansion and contraction of the structure, thereby maintaining the reliability and accuracy of the measurement system. In some implementations, the measurement of the reference object by the optical sensor may be used to detect optical sensors or reference objects that are damaged, out of specification, or severely out of position (e.g., due to impact on the structure). This enables the measurement system to remain in a high-performance state associated with improved efficiency and reduced errors.

[0017] Figure 1 is a perspective view of an example multi-sensor measurement system 100. Figure 1 As shown, the measurement system 100 includes a structure 102 having a plurality of reference objects 104 and a plurality of optical sensors 106. In particular, depending on the size of the object to be measured and the field of view and measurement volume of the optical sensor 106, the measurement system 100 may include two or more reference objects 104 (e.g., dozens of reference objects 104) and two or more optical sensors 106 (e.g., dozens of optical sensors 106). The number of reference objects 104 may be greater than, less than, or equal to the number of optical sensors 106. In some implementations, the reference objects 104 and the optical sensors 106 may be integrated into a single unit. In some implementations, an externally visible component of the optical sensor 106 may be the reference object 104. Additionally, the measurement system 100 includes a processing system 108 that is communicatively connected to the optical sensor 106.

[0018] The structure 102 is disposed (e.g., mounted) on a surface 110 (e.g., a ground surface). The structure 102 defines a compartment between the surface 110 and the structure 102, in which an object 112 for 3D measurement is to be positioned. The structure 102 may include a frame and / or a panel that partially surrounds the object 112 when the object 112 is positioned in the compartment defined by the structure 102. For example, the frame of the structure 102 may include a plurality of interconnected pillars that form an arched shell that is open at opposite ends. The structure 102 may be composed of a material having a thermal expansion coefficient of at least 8 parts per million per degree Kelvin (ppm / K), such as at least 11 ppm / K. For example, the structure 102 may be composed of steel. Therefore, the structure 102 may expand or contract under temperature fluctuations. The surface 110 may be composed of a material having a thermal expansion coefficient lower than the thermal expansion coefficient of the structure 102. For example, the surface 110 may be composed of concrete. Thus, surface 110 may be less susceptible to expansion and contraction under temperature fluctuations than structure 102 .

[0019] The object 112 can be positioned in the compartment defined by the structure 102 manually or by one or more mechanical systems. For example, the measurement system 100 may include a conveyor system (not shown), such as a conveyor belt, a roller conveyor, a chain conveyor, a robotic conveyor, etc., which is configured to transport the object 112 through the compartment. The object 112 may include a machine or a machine part. For example, the object 112 may include a vehicle, as shown. Therefore, the compartment defined by the structure 102 may be large, such as a horizontal dimension of at least 10 feet by 10 feet (e.g., at least 15 feet by 15 feet), and a vertical dimension of at least 10 feet (e.g., at least 15 feet).

[0020] The reference object 104 may be attached to the structure 102. For example, the reference object 104 may be attached to a pillar of the frame of the structure 102. Additionally or alternatively, the measurement system 100 may include one or more additional reference objects 104 attached to the surface 110 (e.g., it is less likely to expand and contract significantly under temperature fluctuations than the structure 102). The reference objects 104 may include an array of objects of uniform size and shape that are relatively small compared to the object 112 being measured. As an example, the reference objects 104 may include any object having a different shape than the object 112 being measured. The reference objects 104 may include a spherical object, a cubic object, a conical object, or an object of another shape. The reference objects 104 may be made of steel. In some implementations, the reference objects 104 may have a retroreflective surface.

[0021] The optical sensor 106 may be attached to the structure 102. For example, the optical sensor 106 may be attached to a pillar of a frame of the structure 102. The optical sensor 106 may be configured to emit an optical signal and detect reflections of the emitted optical signal from one or more objects, wherein the reflections of the optical signal indicate a corresponding distance between the optical sensor 106 and each of the (multiple) objects. In some implementations, the optical sensor 106 may be configured to detect reflections of an optical signal emitted by another optical sensor 106 or another transmitting device. The optical sensor 106 may include a time-of-flight (ToF) sensor. For example, the optical sensor 106 may include a direct ToF sensor or an indirect time-of-flight (iToF) sensor. In some implementations, the optical sensor 106 may include a lidar sensor. For example, the lidar sensor may use a frequency modulated continuous wave (FMCW) lidar.

[0022] The optical sensors 106 may be arranged on the structure 102 such that the reference objects 104 are in the field of view of the optical sensors 106. For example, one reference object 104 may be in the field of view of multiple optical sensors 106 (e.g., each of the reference objects 104 may be in the field of view of multiple optical sensors 106). As another example, multiple reference objects 104 may be in the field of view of one optical sensor 106 (e.g., each of the optical sensors 106 may have multiple reference objects 104 in its field of view). As described herein, this many-to-one configuration of the reference objects 104 and the optical sensors 106 enables identification of damaged reference objects 104 or optical sensors 106 with high accuracy.

[0023] In some implementations, one or more optical sensors 106 can be dedicated to measuring reference object 104 (e.g., these optical sensors 106 can be configured to measure only reference object 104). For example, a first set of optical sensors 106 can perform measurements of object 112 and reference object 104, and a second set of optical sensors 106 can be dedicated to measuring reference object 104. In some implementations, dedicated optical sensors 106 can be positioned on structure 102, and corresponding reference object 104 can be positioned on structure 102 and / or on surface 110, such that optical sensors 106 have an unobstructed line of sight to reference object 104 regardless of whether object 112 is in a compartment of structure 102 (e.g., the line of sight is not obstructed even if object 112 is in a compartment of structure 102). In some implementations, optical sensors 106 can include multiple types of optical sensors. For example, a first optical sensor set 106 (e.g., a first optical sensor set 106 that performs measurements of object 112 and reference object 104) may be a first type of optical sensor, and a second optical sensor set 106 (e.g., a second optical sensor set 106 that is dedicated to measuring reference object 104) may be a second type of optical sensor. The first and second types of optical sensors may differ in detection technology (e.g., ToF sensor vs. visible light camera), resolution, field of view, etc.

[0024] In some implementations, the optical sensor 106 can have a limited absolute measurement range. For example, the optical sensor 106 can have an unambiguous range (e.g., up to about 2.5 meters), where the absolute distance of objects far from the optical sensor 106 within the unambiguous range can be measured, but the absolute distance of objects farther from the optical sensor 106 than the unambiguous range cannot be measured (e.g., for an unambiguous range of up to 2.5 meters, a measurement of an object 2.6 meters from the optical sensor 106 can indicate a distance of 0.1 meters or 2.6 meters). In some implementations, the distance between the optical sensor 106 and the reference object 104 in the field of view of the optical sensor 106 is greater than the unambiguous range of the optical sensor 106. For example, the reference object 104 and the optical sensor 106 can be located without regard to the unambiguous range of the optical sensor 106, because information related to such positions can be stored by the processing system 108 and / or the optical sensor 106 and used to resolve any such measurement ambiguities.

[0025] In some implementations, the metrology system 100 can include one or more additional sensors 114 that are communicatively coupled to the processing system 108. The additional sensors 114 can be attached to the structure 102 and / or positioned near the structure 102. The additional sensors 114 can be unrelated to the 3D measurements performed by the optical sensor 106. For example, the additional sensors 114 can include temperature sensors, vibration sensors, pressure sensors, and / or accelerometers, among other examples. The additional sensors 114 can be configured to detect conditions that may indicate movement of the structure 102, the reference object 104, and / or the optical sensor 106, as described herein.

[0026] The processing system 108 can be configured to control and / or process the measurements taken by the optical sensor 106. In some implementations, the processing system 108 can perform an initial calibration operation to generate an initial calibration of the metrology system 100. The initial calibration operation can use a calibration object (not shown) for which highly accurate measurements have been previously obtained (e.g., using equipment other than the metrology system 100, such as a coordinate measuring machine). For the initial calibration operation, the calibration object can be positioned in a compartment of the structure 102.

[0027] With the calibration object positioned, the processing system 108 can cause the optical sensor 106 to measure the calibration object. For example, the processing system 108 can send a signal to the optical sensor 106 that causes the optical sensor 106 to emit an optical signal (e.g., an optical pulse or a continuous optical signal) and detect a reflection of the optical signal from the calibration object. The processing system 108 can receive data from the optical sensor 106 indicating measurements collected by the optical sensor 106. Based on the difference between the measurements collected by the optical sensor 106 and the known measurements of the calibration object, the processing system 108 can generate a set of offsets for one or more optical sensors 106 that calibrate the optical sensor 106 to a common coordinate system.

[0028] With the metrology system 100 calibrated (e.g., and with the calibration object removed from the compartment of the structure 102), the processing system 108 may cause the optical sensors 106 to measure (e.g., using 3D sensing) the reference object 104. For example, in a manner similar to that described above, the processing system 108 may send a signal to the optical sensor 106 that causes the optical sensor 106 to emit an optical signal (e.g., an optical pulse or a continuous optical signal) and detect reflections of the optical signal from the reference object 104. The processing system 108 may receive data from the optical sensors 106 indicating distances between the plurality of optical sensors 106 and the reference objects 104. For example, the data received from each optical sensor 106 may indicate measurements associated with one or more reference objects 104 in the field of view of the optical sensor 106. The processing system 108 may store baseline data indicating distances.

[0029] The optical sensor 106 may remeasure the reference object 104 from time to time, which may allow the processing system 108 to detect movement of one or more optical sensors 106 and / or one or more reference objects using baseline data. In some implementations, the optical sensor 106 may measure the reference object 104 periodically (e.g., according to a predefined schedule). In some implementations, the optical sensor 106 may measure the reference object 104 in response to the occurrence of an event. For example, the processing system 108 may monitor sensor data (e.g., temperature data, acceleration data, etc.) from the additional sensor 114 and identify the occurrence of an event based on the sensor data. The event may be a temperature change greater than a threshold (e.g., relative to a temperature setting), an acceleration greater than a threshold (e.g., indicating a potential impact on the structure 102), etc. The optical sensor 106 may measure the reference object 104 when a compartment of the structure 102 is empty (e.g., during a time period between objects 112 positioned in the compartment, during a time period between displacements of a facility using the measurement system 100, etc.). Additionally or alternatively, optical sensor 106 may measure reference object 104 when object 112 is positioned in a compartment of structure 102 (eg, using a dedicated optical sensor 106 and corresponding reference object 104 , as described herein).

[0030] According to a schedule (e.g., periodically) for measuring the reference object 104, or in response to detecting the occurrence of an event, the processing system 108 can cause the optical sensors 106 to measure (e.g., using 3D sensing) the reference object 104. For example, in a manner similar to that described above, the processing system 108 can send a signal to the optical sensor 106 that causes the optical sensor 106 to emit an optical signal (e.g., an optical pulse or a continuous optical signal) and detect a reflection of the optical signal from the reference object 104. The processing system 108 can receive data from the optical sensors 106 indicating the distance between the plurality of optical sensors 106 and the reference object 104. For example, the data received from each optical sensor 106 can indicate a measurement associated with one or more reference objects 104 in the field of view of the optical sensor 106.

[0031] As described above, the processing system 108 and / or the optical sensor 106 may store information indicating the approximate locations of the reference object 104 and the optical sensor 106. This information may enable the processing system 108 and / or the optical sensor 106 to distinguish the reference object 104 from other objects in the scene measured by the optical sensor 106. For example, the processing system 108 and / or the optical sensor 106 may discard or ignore portions of the data associated with locations other than the location where the reference object 104 is approximately located (e.g., based on the information). Additionally or alternatively, the processing system 108 and / or the optical sensor 106 may employ a shape discovery algorithm and / or a machine learning model that may identify a particular shape in the data that is associated with the reference object 104 (e.g., a sphere).

[0032] The processing system 108 may compare the data to baseline data indicating a baseline distance between the optical sensor 106 and the reference object 104 measured by the optical sensor 106. The processing system 108 may compare the data to the baseline data on a sensor-by-sensor basis. For example, the processing system 108 may compare data collected by a first optical sensor 106 to the baseline data collected by the first optical sensor 108, may compare data collected by a second optical sensor 106 to the baseline data collected by the second optical sensor 106, and so on.

[0033] The processing system 108 may compare the data to the baseline data to identify differences between the data and the baseline data. For example, the difference between the data and the baseline data may indicate that the optical sensor 106 and / or the reference object 104 have moved from their previous positions (e.g., due to thermal expansion of the structure 102, impact to the optical sensor 106, impact to the reference object 104, impact to the structure 102, etc.). As an example, the difference between the data and the baseline data may be due to temperature fluctuations that cause the structure 102 to expand or contract. The processing system 108 may perform one or more corrective actions on the optical sensor 106 based on the difference between the data and the baseline data.

[0034] As an example of a corrective action, the processing system 108 can generate an offset set based on the difference between the data and the baseline data to apply to one or more optical sensors 106. In some implementations, the offset set can be with respect to a common coordinate system of the initial calibration. For example, the offset set can correct for any movement of the optical sensor 106 away from its calibrated position in the common coordinate system. In some implementations, the offset set can include a distance offset applied to the distance measurements collected by the optical sensor 106. The offset set can include an offset value for each of the optical sensors 106. The offset value for the optical sensor 106 can be zero (e.g., indicating that no offset is to be applied to the optical sensor 106) or a non-zero value (e.g., indicating an offset amount to be applied to the optical sensor 106).

[0035] In some cases, the distance measurements made by optical sensor 106 to reference object 104 indicated in the data may differ from baseline distance measurements made by optical sensor 106 to reference object 104 in the baseline data by a threshold amount (e.g., an amount greater than a difference that might reasonably occur due to thermal expansion). Accordingly, processing system 108 may identify that the data regarding optical sensor 106 and reference object 104 differ from the baseline data by the threshold amount. Data and the baseline data that differ by the threshold amount may indicate that optical sensor 106 and / or reference object 104 are compromised (e.g., broken, out of specification, or significantly moved out of position).

[0036] In some implementations, the processing system 108 may identify which optical sensor 106 or reference object 104 is damaged by using distance measurements of the reference object 104 made by other optical sensors 106 or by using distance measurements of other reference objects 104 made by the optical sensor 106. For example, if three different optical sensors 106 have made distance measurements of the same reference object 104, and if the data and the baseline data agree for two of the optical sensors 106, but differ for one of the optical sensors 106, then the processing system 108 may identify that a different optical sensor 106 is damaged. As another example, if the optical sensor 106 has made distance measurements of three different reference objects 104, and if the data and the baseline data agree for two of the reference objects 104, but differ for one of the reference objects 104, then the processing system 108 may identify that a different reference object 104 is damaged.

[0037] As an example of a corrective action, the processing system 108 may send a notification indicating that the optical sensor 106 and / or the reference object 104 is damaged (e.g., in response to data regarding the optical sensor 106 and the reference object 104 differing from the baseline data by a threshold amount). For example, the notification may identify which optical sensor 106 or reference object 104 is damaged (e.g., using a sensor identifier or a reference object identifier, using a graphical depiction of the metrology system 100, etc.). The notification may be configured for presentation on a display of the metrology system 100, or for transmission as an email, text message, push notification, etc. In some implementations, the processing system 108 may cause activation of a warning indicator (e.g., an audible indicator and / or a visual indicator) of the metrology system 100 indicating that the optical sensor 106 and / or the reference object 104 is damaged. For example, each optical sensor 106 and reference object 104 may have a corresponding nearby warning light, and the processing system 108 may cause activation of the warning light associated with the damaged optical sensor 106 and / or reference object 104. In some implementations, in response to damage to the optical sensor 106 and / or the reference object 104, the processing system 108 can discard collected object measurement data (e.g., collected since the last valid measurement of the reference object 104) and / or output a list identifying the objects 112 measured since the last valid measurement (e.g., using object identifiers).

[0038] By periodically measuring the reference object 104 using the optical sensor 106, the processing system can take appropriate corrective actions to account for deviations of the reference object 104 and / or the optical sensor 106 from their expected positions due to expansion and contraction of the structure 102, shocks to the structure 102, etc. In this manner, the metrology system 100 can achieve consistent and reliable 3D measurements.

[0039] As indicated above, Figure 1 are provided as examples. Other examples may differ from those regarding Figure 1 as described.

[0040] Figure 2 2 is a diagram of an example environment 200 in which the systems and / or methods described herein may be implemented. Figure 2 As shown, environment 200 may include a plurality of optical sensors 106, processing system 108, one or more additional sensors 114, and network 210. The devices of environment 200 may be interconnected via wired connections, wireless connections, or a combination of wired and wireless connections.

[0041] The optical sensor 106 may include one or more wired or wireless devices capable of receiving, generating, storing, transmitting, processing, detecting, and / or providing information associated with 3D measurements of an object, as described elsewhere herein. For example, the optical sensor may include a ToF sensor, a LiDAR sensor, etc., as described herein. The optical sensor 106 may sense or detect the distance between the optical sensor 106 and the object, and send an indication of the detected distance to the processing system 108 directly or via the network 210 using a wired or wireless communication interface.

[0042] The processing system 108 may include one or more devices capable of receiving, generating, storing, processing, providing, and / or routing information associated with measurements collected by the optical sensor 106, as described elsewhere herein. The processing system 108 may include a communication device and / or a computing device. For example, the processing system 108 may include a server or a client device.

[0043] The additional sensors 114 may include one or more wired or wireless devices capable of receiving, generating, storing, transmitting, processing, detecting, and / or providing information associated with a condition of the measurement system 100 or an environment of the measurement system 100, as described elsewhere herein. For example, the additional sensors 114 may include temperature sensors, moisture sensors, humidity sensors, accelerometers, gyroscopes, and / or pressure sensors, among other examples. The additional sensors 114 may sense or detect a condition or information and transmit an indication of the detected condition or information to the processing system 108 directly or via the network 210 using a wired or wireless communication interface.

[0044] The network 210 includes one or more wired and / or wireless networks. For example, the network 210 may include a wireless wide area network (e.g., a cellular network or a public land mobile network), a local area network (e.g., a wired local area network or a wireless local area network (WLAN), such as a Wi-Fi network), a personal area network (e.g., a Bluetooth network), a near field communication network, a telephone network, a private network, the Internet, and / or a combination of these or other types of networks. The network 210 enables communication between devices in the environment 200.

[0045] Figure 2 The number and arrangement of devices and networks shown are provided as examples. Figure 2 There may be additional devices and / or networks, fewer devices and / or networks, different devices and / or networks, or differently arranged devices and / or networks than those shown. Figure 2 Two or more of the devices shown may be implemented in a single device, or Figure 2 The single device shown may be implemented as multiple distributed devices. Additionally or alternatively, a set of devices (eg, one or more devices) of environment 200 may perform one or more functions described as being performed by another set of devices of environment 200.

[0046] Figure 3 is a diagram of example components of a device 300 associated with a multi-sensor measurement system. Device 300 may correspond to optical sensor 106, processing system 108, and / or additional sensor 114. In some implementations, optical sensor 106, processing system 108, and / or additional sensor 114 may include one or more devices 300 and / or one or more components of device 300. Figure 3 As shown, device 300 may include a bus 310 , a processor 320 , a memory 330 , an input component 340 , an output component 350 , and / or a communication component 360 .

[0047] The bus 310 may include one or more components that enable wired and / or wireless communications between components of the device 300. The bus 310 may include: Figure 3Two or more components of a computer program product may be coupled together, such as via operational coupling, communication coupling, electronic coupling, and / or electrical coupling. For example, bus 310 may include electrical connections (e.g., wires, traces, and / or leads) and / or wireless buses. Processor 320 may include a central processing unit, a graphics processing unit, a microprocessor, a controller, a microcontroller, a digital signal processor, a field programmable gate array, an application specific integrated circuit, and / or another type of processing component. Processor 320 may be implemented in hardware, firmware, or a combination of hardware and software. In some implementations, processor 320 may include one or more processors that can be programmed to perform one or more operations or processes described elsewhere herein.

[0048] The memory 330 includes volatile and / or non-volatile memory. For example, the memory 330 may include a random access memory (RAM), a read-only memory (ROM), a hard drive, and / or another type of memory (e.g., flash memory, magnetic memory, and / or optical memory). The memory 330 may include an internal memory (e.g., RAM, ROM, or hard drive) and / or a removable memory (e.g., removable via a universal serial bus connection). The memory 330 may be a non-transient computer-readable medium. The memory 330 may store information, one or more instructions, and / or software (e.g., one or more software applications) related to the operation of the device 300. In some implementations, the memory 330 may include one or more memories such as coupled (e.g., communicatively coupled) to one or more processors (e.g., processor 320) via bus 310. The communicatively coupled between the processor 320 and the memory 330 may enable the processor 320 to read and / or process information stored in the memory 330 and / or store information in the memory 330.

[0049] Input component 340 can enable device 300 to receive input, such as user input and / or sensed input. For example, input component 340 can include touch screen, keyboard, keypad, mouse, button, switch, sensor and / or optical receiver. Output component 350 can enable device 300 to provide output such as via display, speaker and / or light source. Communication component 360 can enable device 300 to communicate with other devices via wired connection and / or wireless connection. For example, communication component 360 can include receiver, transmitter, transceiver, modem, network interface card and / or antenna.

[0050] The device 300 may perform one or more operations or processes described herein. For example, a non-transient computer-readable medium (e.g., memory 330) may store an instruction set (e.g., one or more instructions or codes) for execution by a processor 320. The processor 320 may execute the instruction set to perform one or more operations or processes described herein. In some implementations, the execution of the instruction set by one or more processors 320 causes one or more processors 320 and / or the device 300 to perform one or more operations or processes described herein. In some implementations, a hardwired circuit device may be used in place of an instruction or in combination with an instruction to perform one or more operations or processes described herein. Additionally or alternatively, the processor 320 may be configured to perform one or more operations or processes described herein. Therefore, the implementation described herein is not limited to any specific combination of hardware circuit devices and software.

[0051] Figure 3 The number and arrangement of components shown are provided as examples. Figure 3 The device 300 may include additional components, fewer components, different components, or components arranged differently than the components shown. Additionally or alternatively, a set of components (e.g., one or more components) of the device 300 may perform one or more functions described as being performed by another set of components of the device 300.

[0052] Figure 4 is a flow chart of an example process 400 associated with a multi-sensor measurement system. In some implementations, Figure 4 One or more process blocks of are performed by a processing system (e.g., processing system 108). In some implementations, Figure 4 One or more process blocks of are performed by another device or group of devices separate from or including the processing system, such as an optical sensor (e.g., optical sensor 106). Additionally or alternatively, Figure 4 One or more process blocks of may be performed by one or more components of device 300, such as processor 320, memory 330, input component 340, output component 350, and / or communication component 360.

[0053] like Figure 4 As shown, process 400 may include causing multiple optical sensors to measure multiple reference objects (block 410). For example, a processing system (eg, using processor 320, memory 330, and / or communication component 360) may cause multiple optical sensors to measure multiple reference objects, as described above.

[0054] like Figure 4As further shown, process 400 may include receiving data indicating distances between the plurality of optical sensors and the plurality of reference objects (block 420). For example, the processing system (e.g., using processor 320, memory 330, and / or communication component 360) may receive data indicating distances between the plurality of optical sensors and the plurality of reference objects, as described above.

[0055] like Figure 4 As further shown, process 400 may include comparing the data to baseline data indicating baseline distances between the plurality of optical sensors and the plurality of reference objects measured by the plurality of optical sensors (block 430). For example, the processing system (e.g., using processor 320 and / or memory 330) may compare the data to baseline data indicating baseline distances between the plurality of optical sensors and the plurality of reference objects measured by the plurality of optical sensors, as described above.

[0056] like Figure 4 As further shown, process 400 may include performing one or more corrective actions on the plurality of optical sensors based on the difference between the data and the baseline data (block 440). For example, the processing system (e.g., using processor 320, memory 330, output component 350, and / or communication component 360) may perform one or more corrective actions on the plurality of optical sensors based on the difference between the data and the baseline data, as described above.

[0057] Process 400 may include additional implementations, such as any single implementation or any combination of implementations of one or more other processes described below and / or in conjunction with those described elsewhere herein.

[0058] In a first implementation, performing the one or more corrective actions includes generating a set of offsets to be applied to one or more optical sensors of the plurality of optical sensors based on differences between the data and the baseline data.

[0059] In a second implementation, either alone or in combination with the first implementation, performing one or more corrective actions includes sending a notification indicating that at least one of the optical sensor or the reference object is damaged in response to data regarding an optical sensor among the plurality of optical sensors and a reference object among the plurality of reference objects differing from baseline data by a threshold amount.

[0060] In a third implementation, alone or in combination with one or more of the first and second implementations, a plurality of optical sensors and a plurality of reference objects are attached to the structure, and the plurality of reference objects are in a field of view of the plurality of optical sensors.

[0061] In a fourth implementation, either alone or in combination with one or more of the first to third implementations, the difference between the data and the baseline data is due to temperature fluctuations causing the structure to expand or contract.

[0062] In a fifth implementation, alone or in combination with one or more of the first to fourth implementations, the plurality of optical sensors are iToF sensors.

[0063] although Figure 4 Example blocks of process 400 are shown, but in some implementations, Figure 4 Process 400 may include additional blocks, fewer blocks, different blocks, or blocks arranged differently than those depicted. Additionally or alternatively, two or more blocks of process 400 may be performed in parallel.

[0064] The foregoing disclosure provides illustrations and descriptions, but is not intended to be exhaustive of implementations or to limit the implementations to the precise forms disclosed. Modifications and variations may be made in light of the foregoing disclosure, or may be obtained from the practice of the implementations. In addition, any implementation described herein may be combined, unless the foregoing disclosure explicitly provides reasons why one or more implementations may not be combined.

[0065] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. It will be apparent that the systems and / or methods described herein can be implemented in different forms of hardware, firmware, or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods does not limit the implementation. Therefore, the operation and behavior of the systems and / or methods are described herein without reference to specific software codes - it is to be understood that software and hardware can be designed to implement the systems and / or methods based on the description herein.

[0066] As used herein, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0067] Even though specific combinations of features are listed in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of the various implementations. In fact, many of these features can be combined in ways that are not specifically listed in the claims and / or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of the various implementations includes each dependent claim in combination with each other claim in the claim set. As used herein, a phrase referring to "at least one of" a list of items refers to any combination of these items, including single members. As an example, "at least one of the following: a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical items.

[0068] When a component or one or more components (e.g., a memory, processor, or optical sensor) is described or claimed (either within a single claim or across multiple claims) as performing multiple operations or being configured to perform multiple operations, such language is intended to broadly cover a variety of architectures and environments. For example, unless otherwise expressly claimed (e.g., via the use of "first component" and "second component" or other language that distinguishes components in a claim), the language is intended to cover a single component that performs or is configured to perform all operations, a group of components that collectively perform or are configured to perform all operations, a first component that performs or is configured to perform a first operation and a second component that performs or is configured to perform a second operation, or any combination of components that perform or are configured to perform these operations. For example, when a claim is of the form "one or more components are configured to: perform X; perform Y; and perform Z," the claim should be interpreted to mean "one or more components are configured to perform X; one or more (possibly different) components are configured to perform Y; and one or more (possibly different) components are configured to perform Z."

[0069] Unless explicitly described in this way, the elements, actions or instructions used herein should not be interpreted as key or necessary. Moreover, as used herein, the articles "one" and "an" are intended to include one or more projects, and can be used interchangeably with "one or more". Further, as used herein, the article "the" is intended to include one or more projects quoted in conjunction with the article "the", and can be used interchangeably with "one or more". In addition, as used herein, the term "set" is intended to include one or more projects (such as related projects, unrelated projects or a combination of related projects and unrelated projects), and can be used interchangeably with "one or more". In the case of meaning only one project, the phrase "only one" or similar language is used. Moreover, as used herein, the terms "have", "have", "have (having)" etc. are intended to be open terms. Further, unless otherwise explicitly stated, the phrase "based on" is intended to mean "based at least in part on". Furthermore, as used herein, the term "or" when used in tandem is intended to be inclusive and may be used interchangeably with "and / or" unless expressly stated otherwise (eg, if used in combination with "either" or "only one of...").

Claims

1. A measurement system, comprising: a structure defining a compartment in which an object for three-dimensional 3D measurement is to be positioned; a plurality of reference objects attached to the structure; a plurality of optical sensors attached to the structure, wherein the plurality of reference objects are in the field of view of the plurality of optical sensors; as well as a processing system communicatively coupled to the plurality of optical sensors, the processing system being configured to: causing the plurality of optical sensors to measure the plurality of reference objects; receiving data from the plurality of optical sensors indicating distances between the plurality of optical sensors and the plurality of reference objects; comparing the data to baseline data indicating baseline distances between the plurality of optical sensors and the plurality of reference objects as measured by the plurality of optical sensors; as well as Based on differences between the data and the baseline data, a set of offsets is generated to be applied to one or more optical sensors of the plurality of optical sensors.

2. The measurement system according to claim 1, wherein the processing system is further configured to: identifying that the data regarding an optical sensor of the plurality of optical sensors and a reference object of the plurality of reference objects differs from the baseline data by a threshold amount, wherein the data differing from the baseline data by the threshold amount indicates damage to at least one of the optical sensor or the reference object; and A notification is sent indicating that the at least one of the optical sensor or the reference object is damaged.

3. The measurement system of claim 1 , further comprising one or more additional sensors communicatively coupled to the processing system, Wherein the one or more additional sensors include one or more of a temperature sensor or an accelerometer.

4. The measurement system according to claim 3, wherein the processing system is further configured to: monitoring sensor data from the one or more additional sensors; and identifying an occurrence of an event based on the sensor data, Wherein the processing system is configured to cause the plurality of optical sensors to measure the plurality of reference objects in response to the occurrence of the event.

5. The metrology system of claim 1 , wherein the structure is on a surface, and One or more additional reference objects are attached to the surface. The metrology system of claim 1 , wherein the plurality of optical sensors are indirect time-of-flight (iToF) sensors. 7 . The metrology system of claim 1 , wherein a reference object of the plurality of reference objects is within a field of view of a plurality of optical sensors of the plurality of optical sensors.

8. The metrology system of claim 1, wherein a plurality of reference objects of the plurality of reference objects are within a field of view of an optical sensor of the plurality of optical sensors.

9. A method comprising: causing the plurality of optical sensors to measure the plurality of reference objects by the processing system; receiving, by the processing system, from the plurality of optical sensors data indicating distances between the plurality of optical sensors and the plurality of reference objects; comparing, by the processing system, the data with baseline data indicating baseline distances between the plurality of optical sensors and the plurality of reference objects as measured by the plurality of optical sensors; as well as One or more corrective actions are performed, by the processing system, on the plurality of optical sensors based on differences between the data and the baseline data.

10. The method of claim 9, wherein performing the one or more corrective actions comprises: Based on the difference between the data and the baseline data, a set of offsets is generated to be applied to one or more optical sensors of the plurality of optical sensors.

11. The method of claim 9, wherein performing the one or more corrective actions comprises: In response to the data regarding an optical sensor of the plurality of optical sensors and a reference object of the plurality of reference objects differing from the baseline data by a threshold amount, sending a notification indicating that at least one of the optical sensor or the reference object is damaged.

12. The method of claim 9, wherein the plurality of optical sensors and the plurality of reference objects are attached to a structure, and Wherein the plurality of reference objects are in the field of view of the plurality of optical sensors.

13. The method of claim 12, wherein the difference between the data and the baseline data is due to temperature fluctuations causing expansion or contraction of the structure. The method of claim 9 , wherein the plurality of optical sensors are time-of-flight (ToF) sensors.

15. A measurement system comprising: a structure defining a compartment in which an object for three-dimensional 3D measurement is to be positioned; a plurality of reference objects attached to the structure; as well as a plurality of lidar sensors attached to the structure, wherein the plurality of reference objects are in the field of view of the plurality of lidar sensors, wherein one of the plurality of reference objects is in a field of view of a plurality of lidar sensors among the plurality of lidar sensors, and Wherein multiple reference objects among the multiple reference objects are in the field of view of one of the multiple lidar sensors. 16 . The measurement system of claim 15 , wherein a distance between a lidar sensor among the plurality of lidar sensors and a reference object among the plurality of reference objects in the field of view of the lidar sensor is greater than an unambiguous distance of the lidar sensor.

17. The metrology system of claim 15, further comprising one or more additional sensors attached to the structure, Wherein the one or more additional sensors include one or more of a temperature sensor or an accelerometer.

18. The metrology system of claim 15, wherein the structure is composed of a material having a coefficient of thermal expansion of at least 8 parts per million per degree Kelvin.

19. The metrology system of claim 15, wherein the plurality of reference objects are uniform in size and shape.

20. The metrology system of claim 15, wherein a first set of the plurality of lidar sensors are lidar sensors of a first type and a second set of the plurality of lidar sensors are lidar sensors of a second type.

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