COLOR STEREO CAMERA SYSTEMS WITH GLOBAL SHUTTER SYNCHRONIZATION

Stereo imaging systems and devices are disclosed. A stereo imaging system can include one or more stereo imaging modules and an image processing module connected to the one more stereo imaging modules by a coaxial cable that carries two-way communication signals and transfers electrical power from the image processing module to the stereo imaging modules. The stereo imaging modules each include a plurality of image sensors positioned to capture images of at least partially overlapping fields of view, and processing circuitry configured to transmit the captured images to the stereo imaging module via the coaxial cable. The processing module includes processing circuitry configured to receive and process the captured images, and power circuitry configured to provide electrical power to the stereo imaging module via the coaxial cable. The plurality of image sensors may be color image sensors configured to collect color images for stereo image processing.

FIELD

The present disclosure relates to camera systems, and more particularly to robust stereo camera systems.

BACKGROUND

Stereo imaging systems, including two or more image capture devices, are useful in a variety of applications. For example, stereo imaging systems may be used in computer stereo vision applications, in the generation of stereoscopic images or video, or in other applications in which it may be useful to capture three-dimensional information in one or more images. In some implementations, it may be desirable to implement stereo imaging within automated or semi-automated systems, such as robots and the like, for monitoring and/or control processes. However, existing stereo camera systems have a number of deficiencies, especially when used in conjunction with devices that experience frequent motion. For example, some stereo cameras are not structurally robust enough to resist relative motion between the imagers, resulting in unreliable three-dimensional information. Existing stereo cameras often only provide greyscale imaging capability, or rely on a third imager to provide color imaging capability. Moreover, shutter synchronization in existing stereo cameras is often not sufficiently reliable for use in implementations with frequent motion.

SUMMARY

The systems and methods of this disclosure each have several innovative aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope as expressed by the claims that follow, its more prominent features will now be discussed briefly.

In a first aspect, a stereo imaging system includes a stereo imaging module and a processing module. The stereo imaging module includes a plurality of image sensors positioned to capture images of at least partially overlapping fields of view, and processing circuitry configured to transmit the captured images via a coaxial cable connected to the stereo imaging module. The processing module is configured to receive the captured images from the stereo imaging module via the coaxial cable. The processing module includes processing circuitry configured to receive and process the captured images, and power circuitry configured to provide electrical power to the stereo imaging module via the coaxial cable.

In some embodiments, the plurality of image sensors are color image sensors. In some embodiments, the image processing module is configured to generate a depth mapping at least a portion of the partially overlapping fields of view based at least in part on color images captured by the color image sensors. In some embodiments, the image processing module is further configured to generate one or more greyscale images based on the color images, the depth mapping generated based at least in part on the one or more greyscale images.

In some embodiments, the processing circuitry of the processing module is further configured to transmit to the stereo imaging module, via the coaxial cable, a timing signal that causes the plurality of image sensors to capture images simultaneously. In some embodiments, the timing signal is a repetitive time-varying signal that causes the plurality of image sensors to capture a series of time-synchronized images. In some embodiments, the stereo imaging system further includes at least a second stereo imaging module connected to the processing module by a second coaxial cable, the second stereo imaging module including a second plurality of image sensors, wherein the processing circuitry of the processing module is configured to simultaneously transmit the timing signal via the coaxial cable and the second coaxial cable such that the plurality of image sensors and the second plurality of images sensors capture images simultaneously.

In some embodiments, the stereo imaging module is mounted to a mechanical component configured to move relative to the processing module, and wherein a stereo imaging module end of the coaxial cable is coupled to a coaxial connector fixed to the mechanical component, the coaxial connector flexibly connected to the processing circuitry of the stereo imaging module such that forces applied from the coaxial cable to the coaxial connector are not transferred to the processing circuitry of the stereo imaging module or to the plurality of image sensors. In some embodiments, the mechanical component includes an end effector of a picking device. In some embodiments, the processing module is connected by a second coaxial cable to a second stereo imaging module. In some embodiments, the second stereo imaging module is mounted to a second end effector or a stationary component of the picking device. In some embodiments, the picking device is a mobile picking device, and wherein the second stereo imaging module is fixed relative to a chassis of the mobile picking device.

In some embodiments, the stereo imaging module further includes a temperature sensor configured to determine a temperature of the stereo imaging module, and a heating element in communication with the temperature sensor and configured to activate when the temperature sensor detects a temperature lower than a predetermined threshold.

In some embodiments, the plurality of image sensors are spaced apart by a baseline distance of at least 5 mm and not greater than 50 mm. In some embodiments, the plurality of image sensors are spaced apart by a baseline distance of at least 10 mm and not greater than 40 mm, In some embodiments, the plurality of image sensors are spaced apart by a baseline distance of at least 15 mm and not greater than 30 mm, In some embodiments, the plurality of image sensors are spaced apart by a baseline distance of at least 20 mm and not greater than 25 mm.

in some embodiments, the processing circuitry of the stereo imaging module includes a serializer configured to transmit the captured images to a deserializer of the image processing module via the coaxial cable.

In some embodiments, the processing circuitry of the stereo imaging module is further configured to combine pairs of individual images captured at the same time by the plurality of image sensors prior to transmission to the image processing module.

In some embodiments, the stereo imaging module is mounted to an end effector of a picking device, and wherein the plurality of image sensors are spaced apart by a baseline distance of at least 20 mm and not greater than 25 mm.

DETAILED DESCRIPTION

Embodiments of the present technology provide stereo imaging systems and devices that provide high quality stereo imaging systems. Certain embodiments provide stereo imaging systems with improved synchronization, color processing, robust construction, advantageous distribution of components, light weight, and/or simplified construction. Some stereo imaging systems of the present technology include two or more components such as a stereo imaging module and an image processing module connected by a cable. The cable may be connected to the stereo imaging module at a force-resistant coupling as described herein which prevents the transfer of loads from the cable to the stereo imaging module components. Throughout the following description, various embodiments will be described with reference to the example implementation of robotics. However, it will be understood that any of the systems, devices, or methods described herein may equally be applied to any other application where stereo imaging is desirable.

Existing stereo cameras typically have two lenses and are capable of capturing three-dimensional information. However, existing stereo cameras often are not structurally robust enough to resist relative motion between the imagers, resulting in unreliable three-dimensional information, Existing stereo cameras often only provide greyscale imaging capability, or rely on a third imager to provide color imaging capability.

Moreover, shutter synchronization in existing stereo cameras is often not sufficiently reliable for use in implementations with frequent motion. Existing stereo cameras typically operate in a master-slave synchronization arrangement, in which one of the two imagers operates as a master and the other imager operates in a slave mode. The master imager generates a timing signal intended to cause the slave imager to capture an image at approximately the same time as the master imager captures an image, such that depth mapping or other processing based on multi-image registration can be performed. However, existing master-slave synchronization techniques may be imprecise. In addition, existing synchronization techniques do not allow for the synchronization of multiple stereo cameras. As will be discussed in greater detail, the stereo imaging systems of the present technology provide improvements that address these shortcomings of existing stereo camera technology.

One particular implementation, for which the stereo imaging systems of the present technology may be particularly advantageous, is the field of picking devices such as autonomous assembly line robots or agricultural harvesters, and the like. In many implementations, such devices may use eye-in-hand configurations in which one or more cameras are mounted on an end effector or other moving component of the picking device. Some agricultural implementations may require a relatively high acceleration (e.g., in the range of 3 g-5 g or more), such as to separate a berry or other fruit from a stem. Such rapid motion and/or acceleration may cause problems when existing stereo cameras are used in eye-in-hand configurations. For example, motion or acceleration of an end effector may cause the imagers of a stereo camera to move relative to each other, such as by bending or twisting of the stereo camera housing. If the stereo camera is connected to other systems by a cable connector, the cable connector may exert a force on the stereo camera or components thereof, which may cause damage. Accordingly, the stereo imaging systems of the present technology may be suitable for withstanding such motion and acceleration as may be experienced in high-motion and high-acceleration applications.

Referring now to the drawings,FIG.1schematically illustrates components of an example stereo imaging system100, The stereo imaging system100includes a stereo imaging module200and an image processing module300. The stereo imaging module200and the image processing module300are electrically connected by a cable110, such as a coaxial cable or other conductive connector. As will be described in greater detail, the stereo imaging module200and the image processing module300may be discrete components disposed in different locations and/or at least partially contained within separate housings. In some embodiments, a stereo imaging system100may include two or more stereo imaging modules200connected to an individual image processing module300, may include two or more image processing modules300connected to an individual stereo imaging module200, and/or may include a plurality of stereo imaging modules200and image processing modules300. Accordingly, the stereo imaging module200and/or the image processing module300may be configured to individually receive a plurality of cables110to enable such combinations.

The stereo imaging module200includes two or more imagers210and processing circuitry220in communication with the imagers210. In some embodiments, such as embodiments in which the cable110is a coaxial cable, the stereo imaging module200further includes a serializer230that serializes image data for transmission via the cable110to the image processing module300. The imagers210may be any suitable type of camera, image sensor, or the like, and in some cases may advantageously be color imagers. In some embodiments, the imagers210further include associated components such as lenses or other optical components, as well as image sensors and readout electronics that generate digital image data based on light received at the imagers210. The processing circuitry220may include any one or more suitable processing components, such as one or more controllers, field programmable gate arrays (FPGA), memory devices such as electrically erasable programmable read-only memory (EEPROM), or the like. In operation, the imagers210may capture images simultaneously or near-simultaneously, and may send the captured images to the processing circuitry220in the form of digital image data. The processing circuitry220may perform some initial processing and send the processed image data to the serializer230, which transmits the image data to the image processing module300via the cable110. The stereo imaging module200will be described in greater detail with reference toFIGS.2and4A-5.

The image processing module300includes processing circuitry310configured to perform further image processing on the image data received from the stereo imaging module200or from a plurality of stereo imaging modules200. In embodiments in which the stereo imaging module200includes a serializer230, the image processing module300can further include a deserializer320which receives the serialized data from the cable110and converts the serial data back into a suitable format for the processing circuitry310. A communication device330may communicate with one or more other components, such as by Ethernet or any other suitable computer networking technology. The image processing module300will be described in greater detail with reference toFIG.3.

FIG.2schematically illustrates components of an example stereo imaging module200of a stereo imaging system, such as the stereo imaging module200of the stereo imaging system100illustrated inFIG.1, The stereo imaging module200may be implemented in conjunction with one or more image processing modules300as illustrated inFIG.3. It will be understood that various embodiments of the present technology may equally include stereo imaging modules200having more or fewer components, or different components than those illustrated inFIG.2, without departing from the spirit or scope of the present disclosure.

The stereo imaging module200includes two or more imagers210in communication with processing circuitry220and a serializer230, as described with reference toFIG.1. The stereo imaging module200may further include a memory device225, power circuitry such as a filter and/or DC-to-DC converter245, temperature control components such as a temperature sensor and/or a heating element255, and/or lighting components such as a lighting controller260and/or a lighting interface265. A connector235, such as a SubMiniature version A (SMA) or other coaxial connector (e.g., SMB, SMC, or other RF connector type), is provided for connecting the stereo imaging module200to the cable110.

In order to implement stereo imaging, the imagers210preferably include two imagers210that have at least partially overlapping fields of view. In contrast to existing stereo imaging systems, which typically perform stereo imaging using greyscale imagers and rely on a third imager to provide color, the imagers210may be color imagers capable of capturing color images. Using color images for stereo imaging may be especially advantageous by reducing the amount of processing required for stereo imaging in implementations requiring color detection, such as for berry harvesting applications. In such applications, the images captured by the imagers210may be used immediately for the detection of targets based on color, without requiring the additional processing steps of registering a separate color image to the greyscale images, This immediate use of images for target detection based on color may be particularly advantageous where the picking device has a limited window of time and/or space to recognize and/or pick a target (e.g., targets moving past a stationary picking device on a conveyor, a harvester moving over a bed of stationary targets to be harvested, etc.). In such implementations, any improvement in image processing speed may significantly enhance operational efficiency.

Each of the imagers210may he triggered to capture an image by a timing signal received from an external source. In some embodiments, the timing signal may be, for example, a control signal that causes an imager210to capture an image when the signal is received, or a clock signal that the imager210may use to capture one or more images at a predetermined time or interval. In one example, the timing signal may be a repetitive time-varying signal such as a clock signal, which causes the imagers210to capture a series of time-synchronized images and/or video. In some embodiments, the imagers210may advantageously be controlled in accordance with a synchronized “global shutter” scheme such that the imagers210capture images at exactly the same time, improving the accuracy of stereo image processing. In some embodiments, a timing signal may be generated at the stereo imaging module200to synchronize the imagers210. In other embodiments, the timing signal may be generated external to the stereo imaging module, such as at the image processing module300or other control module, and sent to the stereo imaging module200via the cable110.

The processing circuitry220receives images captured by the imagers210and may perform one or more image signal processing operations before the captured images are sent to the image processing module300. In some embodiments, the processing circuitry220is programmed to receive two simultaneously captured images from the imagers210(e.g., by receiving one image from each imager210) and to combine the two simultaneous images prior to transmission. Combining pairs of images may have a variety of advantages, for example, by improving transmission efficiency and/or by simplifying image registration and/or other aspects of image processing to be performed at the image processing module300.

The stereo imaging module200may receive electrical power from the image processing module300via the cable110. In the case of a coaxial cable110, electrical power for the stereo imaging module200may be provided through the same central conductor of the coaxial cable110that is used for transmission of signals between the stereo imaging module200and the image processing module300. For example, electrical power may be sent through the coaxial cable110as a low-frequency signal, while communications between the stereo imaging module200and the image processing module300may be sent in a high-frequency domain such that the power transmission does not interfere with communications.

Electrical power may be transmitted at a relatively high voltage (e.g., 24 volts) and low current. Thus, the stereo imaging module200can include a power signal filter240and a converter245which operate to select the low-frequency power signal and decrease the voltage to a suitable level for use by the components of the stereo imaging module.

In some applications, low temperatures may interfere with the operation of imagers210by causing condensation of water from the atmosphere on exterior or interior surfaces of lenses or other components of the stereo imaging module200. Additionally, temperature changes can cause material expansion and/or contraction that may result in deformation or other changes in the mounting and optics of the imagers, potentially introducing error into operations performed based on the acquired stereo images. Thus, it may be desirable to keep the stereo imaging module200above a low threshold temperature and/or at a relatively constant temperature. Accordingly, in some embodiments, the stereo imaging module200includes a temperature sensor250and a heating element255, such as a resistive heater. Control circuitry in communication with the temperature sensor250and the heating element255can cause activation of the heating element255when a temperature below a set low threshold is detected at the temperature sensor250. The low threshold may be, for example, a predetermined constant threshold, an adjustable threshold, or a threshold determined based on atmospheric conditions such as a reported dew point or other known atmospheric conditions, associated with condensation of water.

FIG.3schematically illustrates components of an example image processing module300of a stereo imaging system, such as the image processing module300of the stereo imaging system100illustrated inFIG.1. The image processing module300may be implemented in conjunction with one or more stereo imaging modules200ofFIG.2. It will be understood that various embodiments of the present technology may equally include image processing modules300having more or fewer components, or different components than those illustrated inFIG.3, without departing from the spirit or scope of the present disclosure.

The image processing module300includes processing circuitry310, a deserializer320, and a communication device330such as an Ethernet port or the like, as described with reference toFIG.1. The image processing module300may further include a power injector340, and one or more interfaces such as a user interface350and/or a memory device port360.

The processing circuitry310may include any one or more computer processing devices such as a CPU, controller, system on module (SoM) or system on chip (SoC) device, or other processing component. Example functions of the processing circuitry310may include, but are not limited to, control of the image processing module300, processing and/or analysis of images received from the stereo imaging modules200, and control functions related to the stereo imaging modules200, such as generation and/or control of timing signals to the imagers of the stereo imaging modules200. In some embodiments,

The deserializer320receives the serialized data transmitted by the serializer230of a stereo imaging module200, and converts the serial data back into a suitable format for the processing circuitry310. As shown inFIG.3, the image processing module300may include two or more connectors325, such that the image processing module300may be used in conjunction with a plurality of stereo cameras simultaneously. In such embodiments, a single deserializer320may be in communication with all of the connectors325. In other embodiments, the image processing module300may include two or more deserializers.

In some embodiments, the deserializer320may also transmit data to the stereo imaging modules200, such as to implement a global shutter timing across multiple imagers. In such embodiments, the deserializer320may send a synchronized timing signal to all of the stereo imaging modules200via the cables110, For example, in some embodiments the deserializer320may generate imager control signals, such as shutter timing signals, a clock signal, or the like, which may be used by the imagers210of the individual stereo imaging modules200. In another example, the timing signals may be generated at the processing circuitry310. Accordingly, the present technology provides an improved global shutter functionality that can be used to capture highly synchronized images both among imagers of an individual stereo imaging module200and/or across a plurality of stereo imaging modules200that are connected to the image processing module300.

FIGS.4A-4Dillustrate an example implementation of a stereo imaging module400in accordance with the present technology,FIGS.4A and4Bare front and rear perspective views, respectively, of the stereo imaging module400.FIG.4Cis a front perspective view in which the housing is hidden, illustrating internal components of the stereo imaging module400.FIG.4Dis a rear elevation view of the stereo imaging module400. The stereo imaging module400may be an implementation of the stereo imaging module200schematically illustrated inFIGS.1-3. It will be understood that stereo imaging module400is one non-limiting example of the stereo imaging module200, and other examples can be suitably implemented in accordance with the present technology. The stereo imaging module400may be implemented in conjunction with any of the image processing modules300and/or stereo imaging systems100disclosed herein.

The stereo imaging module400includes a housing402at least partially surrounding a stereo imaging module board404. The imagers410, processing circuitry420, serializer430, and connector435can be coupled to the stereo imaging module board404. Lenses406are coupled to, or integrally formed with, the housing402and are located in a spaced configuration on a front of the housing402so as to direct light from the environment to photodetectors415of the imagers410. In some embodiments, the lenses406, the housing402, and a component to which the housing402is coupled, may form a complete housing that is sufficiently sealed against environmental contaminants so as to prevent dust or other particulate matter from intruding and damaging optical or electrical components of the stereo imaging module400. Environmentally sealed embodiments may be especially advantageous where the stereo imaging module400is implemented in conjunction with agricultural harvesters where dirt and dust may be kicked up by harvesting operations.

The spacing of the lenses406, and the corresponding spacing of the photodetectors415of the imagers410, define a center-to-center baseline distance of the stereo imaging module400. In some embodiments, the baseline distance of the stereo imaging module400may be, for example, between 5 mm and 50 mm, between 10 mm and 40 mm, between 15 mm and 30 mm, between 20 mm and 2 5mm, or any other suitable range for the intended application of the stereo imaging module400. In one particular implementation, a baseline distance of at least 20 mm and not more than 25 mm may be especially advantageous for eye-in-hand applications in which the stereo imaging module400is mounted to an end effector of a harvesting robot. Specifically, a baseline distance of 20 mm-25 mm has been found to be desirable for close viewing of objects (e.g., at a distance of approximately 150 min to 500 mm from the stereo imaging module400), while also avoiding occlusion of the imagers410and/or lenses406by leaves or other parts of plants such as strawberry plants or other crops. In some cases, even if a portion of the field of view of one of the imagers410is occluded by a plant, the occluded region may be imaged by the other imager410of the stereo imaging module400for target detection, even if the occlusion prevents reliable depth mapping of that portion of the field of view.

The housing402may include a single integrally formed piece of a suitably rigid material, such as a hard plastic, a metal, wood, or the like. Preferably, the housing402is sufficiently rigid as to resist bending or twisting even at accelerations of up to 3 g, 5 g, 10 g, or more, depending on the intended application, as such bending or twisting may result in slight changes in baseline distance or the relative angles of the imagers410, which may detrimentally affect stereo imaging quality. For example, a stereo imaging module400for use in an autonomous agricultural harvester may have a hard plastic housing402of sufficient thickness to prevent relative motion of the imagers410at acceleration forces of 5 g or more.

Moreover, the stereo imaging module400may be advantageously small and/or lightweight so as to avoid interfering with or inhibiting such motion or acceleration as may be desired for the mounting location of the stereo imaging module400. For example, where the stereo imaging module400is mounted in conjunction with an end effector manipulated by a robot, it may be desirable for the stereo imaging module400to be small enough so as to avoid interfering with the motion of the end effector or the robot It may further be desirable for the stereo imaging module400to be light enough so as not to substantially increase the amount of force necessary to achieve an intended motion of the end effector.

In some embodiments, the stereo imaging module400has a total weight of less than 500 g, less than 200 g, less than 100 g, etc. In some embodiments, the stereo imaging module400has a total length (along the x-direction inFIG.4B) of less than 100 mm, a total width (along the y-direction inFIG.4B) of less than 30 mm, a housing thickness (along the z-direction inFIG.4B) of less than 20 mm, and/or a total thickness of less than 30 min including the lenses406. In one example, the stereo imaging module400has a weight of approximately 75 g (e.g., between 74 g and 76 g), a length of approximately 77 mm (e.g., between 76 mm and 78 mm), a width of approximately 27 mm (e.g., between 26 min and 28 mm), a housing thickness of approximately 13 min (e.g., between 12 min and 14 mm), and a total thickness of approximately 27 mm (e.g., between 26 mm and 28 mm). It will be understood that these are example weights and dimensions, and other examples can be suitably implemented in accordance with the present technology.

In addition to bending or twisting forces, the coaxial cable connection also presents a risk for misalignment or damage to the stereo imaging module400and the components thereof. For example, because the coaxial cable110(FIGS.1-3) is securely attached to the stereo imaging module400, significant forces may be exerted at the connector435(e.g., if the stereo imaging module400is move to an extreme position far from the image processing module300such that the cable110becomes taut, and/or if the cable110becomes tangled or obstructed by one or more other objects).

Accordingly,FIG.5illustrates an example motion and force resistant coaxial connector arrangement that can be implemented in accordance with any of the embodiments disclosed herein. The motion and force resistant connector arrangement includes an intermediate cable440that connects the connector435with a second connector445. The second connector445is a suitable connector for receiving the cable110(FIGS.1-3) that connects the stereo imaging module400to an image processing module300(FIGS.1-3). In this configuration, the housing402of the stereo imaging module400can be mounted to a mechanical component that is movable relative to the image processing module300(for example, a component of a robot or end effector of a picking device or harvester). The second connector445may be mounted to a portion of the same mechanical component or another component rigidly fixed thereto, such that the second connector445is fixed relative to the housing402and the stereo imaging module board404. Thus, any motion or force imparted by the cable110connected to the second connector445will be transferred primarily to the mechanical component to which the stereo imaging module400and the second connector445are mounted. The motion or force accordingly will not be transferred to the intermediate cable440or the connector435, such that damage to or misalignment of the internal components of the stereo imaging module400is avoided.

Example Applications of Stereo Imaging Systems According to the Present Disclosure

As discussed previously, the stereo imaging systems of the present technology may be advantageously suitable for use in conjunction with autonomous devices such as harvesters and other picking devices or other robotic applications.FIGS.6and7illustrate example systems in which the presently disclosed stereo imaging systems may be implemented.

FIG.6illustrates an example robot600that may be used in conjunction with the stereo imaging systems of the present technology. The example robot600is illustrated as a t-type robot600configured to support an end effector610and to move the end effector610as desired within a harvester work cell or other picking area. The robot600generally includes a radial member620, a carriage630, and a longitudinal member640. The longitudinal member640may be a gantry or other generally linear component, and may be mounted to a harvester, such as the harvester700ofFIG.7.

FIG.7is a cross-sectional view schematically illustrating components of an example harvester700according to the present disclosure including two robots consistent with the robot600ofFIG.6. The harvester700includes a plurality of wheels705supporting a platform710. The harvester700is configured to travel within an agricultural field. Accordingly, the platform710is positioned relative to the wheels705such that the platform710is supported above a row55while the wheels705travel along the bottom of furrows50surrounding the row55.

In various embodiments, the stereo imaging modules200and image processing modules300disclosed herein may be mounted at various locations on or around the robots600and/or the harvester700. For example, in an eye-in-hand configuration, each robot600may have a stereo imaging module200disposed thereon, The stereo imaging module200may be mounted to the end effector610, a radial member620, a carriage630, or a longitudinal member640of a robot. In addition, one or more stereo imaging modules200may be a global camera mounted to the platform710of the harvester700. In one particular configuration, as shown inFIG.7, the harvester700may include two stereo imaging modules200for each robot600, including one stereo imaging module200mounted to the robot600or end effector610, and a second stereo imaging module200mounted to the platform710to provide an overhead view of the picking area that is stationary relative to the chassis of the harvester700. In some embodiments, each robot may have its own stereo imaging system including a robot-specific image processing module300. In other embodiments, an image processing module300may be connected to more than two stereo imaging modules (e.g., the example configuration illustrated inFIG.7may include four total stereo imaging modules200and one image processing module300). Other combinations are possible.

Referring again toFIG.6, the robot600is configured to accommodate motion along and about several axes. For example, the longitudinal member640may be rotated about its longitudinal axis (parallel to the y-axis illustrated inFIG.6). The carriage630may move linearly along the longitudinal member640in the y-direction. The radial member620may move linearly perpendicular to the y-axis, along a direction in the x-z plane dependent on the rotational orientation of the longitudinal member640. Additionally, the end effector610may be rotatable relative to the radial member620. Thus, the robot600is movable along a number of axes that could potentially cause stress or forces to act on the stereo imaging modules200mounted on the robot600. Accordingly, the motion and force resistant coaxial connector arrangement discussed with reference toFIG.5may be desirable in these implementations. In one non-limiting embodiment, the stereo imaging modules200withstand more than 5 g acceleration on a continual basis when the harvester is operational over a period of one or more hours.

FIGS.8A-8Cillustrate one example implementation of a stereo imaging module400(FIGS.4A-5) in conjunction with an end effector such as the end effector610illustrated inFIG.6.FIG.8Ais a side view of the end effector610;FIGS.8B and8Care perspective views of a baseplate612and an additional rigid component615to which the stereo imaging module400and second connector445are attached. As shown inFIGS.8A-8C, the housing402of the stereo imaging module400is mounted to an underside of a substantially rigid, planar baseplate612of the end effector610. The intermediate cable440passes through the baseplate612(e.g., around an edge or through a slot614or aperture) and connects to the second connector445, which is rigidly mounted to a surface616of the component615. In some embodiments, the second connector445may be connected directly to the top side of the baseplate612, or to any other component proximate the stereo imaging module400that is suitably rigid to reduce the force transmitted to the intermediate cable440.

In the configuration illustrated inFIGS.8A-8C, a first end of a coaxial cable can be connected to the second connector445, and a second end of the coaxial cable can be connected to an associated image processing module300(e.g., mounted to the longitudinal member640, or a component of the harvester external to the robot600, as shown inFIGS.6and7) such that the stereo imaging system can be operated through motion of the robot600without risking damage to the stereo imaging module400or the components thereof.

Implementing Systems and Terminology

Implementations disclosed herein provide systems, methods, and devices for stereo imaging. One skilled in the art will recognize that these embodiments may be implemented in hardware or a combination of hardware and software and/or firmware.

Embodiments of stereo imaging systems according to the present disclosure may include one or more sensors (for example, image sensors), one or more signal processors (for example, image signal processors), and a memory including instructions or modules for carrying out the processes discussed above. The systems may also have data, a processor loading instructions and/or data from memory, one or more communication interfaces, one or more input devices, one or more output devices such as a display device and a power source/interface. The device may additionally include a transmitter and a receiver. The transmitter and receiver may be jointly referred to as a transceiver. The transceiver may be coupled to one or more antennas for transmitting and/or receiving wireless signals.

The functions described herein may be stored as one or more instructions on a processor-readable or computer-readable medium. The term “computer-readable medium” refers to any available medium that can be accessed by a computer or processor. By way of example, and not limitation, such a medium may comprise RAM, ROM, EEPROM, flash memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. It should be noted that a computer-readable medium may be tangible and non-transitory. The term “computer-program product” refers to a computing device or processor in combination with code or instructions (e.g., a “program”) that may be executed, processed or computed by the computing device or processor. As used herein, the term “code” may refer to software, instructions, code or data that is/are executable by a computing device or processor.

The various illustrative logical blocks and modules described in connection with the embodiments disclosed herein can be implemented or performed by a machine, such as a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor can be a microprocessor, but in the alternative, the processor can be a controller, microcontroller, or state machine, combinations of the same, or the like. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Although described herein primarily with respect to digital technology, a processor may also include primarily analog components. For example, any of the signal processing algorithms described herein may be implemented in analog circuitry. A computing environment can include any type of computer system, including, but not limited to, a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a personal organizer, a device controller, and a computational engine within an appliance, to name a few.

It will be understood by those within the art that, in general, terms used herein are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). Further, the term “comprising” as used herein is synonymous with “including,” “containing,” or “characterized by,” and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. Accordingly, the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

it should be noted that the terms “couple,” “coupling,” “coupled” or other variations of the word couple as used herein may indicate either an indirect connection or a direct connection. For example, if a first component is “coupled” to a second component, the first component may be either indirectly connected to the second component or directly connected to the second component. As used herein, the term “plurality” denotes two or more. For example, a plurality of components indicates two or more components.

The above description discloses several systems and devices of the present disclosure. Embodiments of the present disclosure are susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the present disclosure. Consequently, it is not intended that the present disclosure be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the present disclosure as embodied in the attached claims.