US20230288537A1 - Mitigating interference for lidar systems of autonomous vehicles - Google Patents

Abstract

An autonomous vehicle having a lidar sensor system is described. A computing system is configured to determine that the lidar sensor system is to update a code that is included in light signals emitted by the lidar sensor system. The computing system transmits a command signal to the lidar sensor system, wherein the command signal causes the lidar sensor system to transition from emitting light signals with a first code therein to emitting light signals with a second code therein, wherein the first code is different from the second code.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This application is a continuation of U.S. patent application Ser. No. 16/731,230, filed on Dec. 31, 2019, and entitled “MITIGATING INTERFERENCE FOR LIDAR SYSTEMS OF AUTONOMOUS VEHICLES”, which is a continuation of U.S. Pat. No. 11,435,444, filed on Sep. 27, 2019, and entitled “MITIGATING INTERFERENCE FOR LIDAR SYSTEMS OF AUTONOMOUS VEHICLES”, the entireties of which are incorporated herein by reference.
BACKGROUND
• An autonomous vehicle is a motorized vehicle that can navigate without a human driver. An exemplary autonomous vehicle includes a plurality of sensor systems such as, but not limited to, a lidar sensor system, a radar sensor system, a camera sensor system, amongst others, wherein the autonomous vehicle is controlled based upon sensor signals output by the sensor systems. For example, a lidar sensor system may emit a light signal comprising a light pulse, wherein light in the light signal has a wavelength in the near infrared range. The light signal reflects off an object and returns to a detector of the lidar sensor system. Based on a time between when the lidar sensor system emits the light signal and when the detector detects the light signal after the light signal has reflected off the object, the lidar sensor system can determine a distance between the object and the lidar sensor system. In operation, the lidar sensor system emits light signals in a plurality of directions within a relatively small window of time, such that the lidar sensor system generates a three-dimensional point cloud that is indicative of positions of objects in an environment surrounding the lidar sensor system. A mechanical system of the autonomous vehicle (such as a steering system, a braking system, or a propulsion system) can then be controlled based upon the generated point cloud.
• Conventionally, the detector of the lidar sensor system is configured to detect light signals that are formed of light having a frequency that is within a predefined frequency band. Hence, a conventional lidar sensor system is susceptible to interference, wherein interference occurs when the detector of the lidar sensor system detects a light signal that was not emitted by the lidar sensor system. In an example, a detector of a first lidar sensor system may detect a light signal emitted by a second lidar sensor system, and thus the point cloud generated by the first lidar sensor system may include an inaccuracy that corresponds to the detected light pulse. Instances of interference can be expected to increase as autonomous vehicles become increasingly popular. Additionally, instances of interference can be expected to increase as autonomous vehicles are configured to include more than one lidar sensor system.
SUMMARY
• The following is a brief summary of subject matter that is described in greater detail herein. This summary is not intended to be limiting as to the scope of the claims.
• Described herein are various technologies pertaining to mitigating interference with respect to a lidar sensor system that is mounted on or incorporated in an autonomous vehicle. Further, the technologies described herein are also applicable to radar sensor systems mounted on or incorporated in autonomous vehicles. With more specificity, aspects described herein involve a lidar sensor system emitting a light signal that is constructed by the lidar sensor system such that the emitted light signal has a code therein, wherein the code can differentiate the emitted light signal from another light signal emitted by another lidar sensor system. The lidar sensor system can include the code in the light signal, for example, by shaping one or more light pulses in the light signal and/or emitting a pattern of light pulses. Hence, when a detector of the lidar sensor system detects a light signal, the lidar sensor system can ascertain whether a code in the detected light signal matches the code in the emitted light signal, and therefore determine whether the detected light signal was emitted by the lidar sensor system.
• In addition, the lidar sensor system can be configured to alter codes in light signals emitted by the lidar sensor system based upon a command signal transmitted to the lidar sensor system by a computing system that is in communication with the lidar sensor system. For example, the command signal can be based upon one or more parameters, including but not limited to detected interference; proximity of another autonomous vehicle to the autonomous vehicle; orientation of the autonomous vehicle; passage of some predefined amount of time; etc. As indicated previously, the command signal can cause the lidar sensor system to transition from emitting light signals having a first code therein to emitting light signals having a second code therein. Altering codes included in light signals emitted by the lidar sensor system facilitates avoiding interference, as a code in a light signal can be altered to reduce a probability that another lidar sensor system will emit a light signal with the (same) code.
• In an exemplary embodiment, as referenced above, the computing system can generate the command signal based upon a determined orientation of the autonomous vehicle, wherein the command signal causes the lidar sensor system to emit a light signal with a code, wherein the code is based upon the orientation of the autonomous vehicle. For example, when the autonomous vehicle is facing west, the computing system can cause the lidar sensor system to emit light signals with a first code; when the autonomous vehicle is facing east, the computing system can cause the lidar sensor system to emit light signals with a second code; when the autonomous vehicle is facing north, the computing system can cause the lidar sensor system to emit light signals with a third code; and when the autonomous vehicle is facing south, the computing system can cause the lidar sensor system to emit light signals with a fourth code. When several autonomous vehicles in a fleet of autonomous vehicles have lidar sensor systems that emit light signals with codes based upon orientations of such autonomous vehicles, probability of a lidar sensor system of any one of the autonomous vehicles being subjected to interference with respect to light signals emitted in the direction of travel of the autonomous vehicle may be reduced when compared to conventional lidar sensor systems.
• In another exemplary embodiment, the computing system can generate the command signal based upon a geospatial position of the autonomous vehicle, wherein a code included in light signals emitted by the lidar sensor system is based upon the geospatial position of the autonomous vehicle. This embodiment is particularly well-suited for avoiding interference when geospatial positions of other autonomous vehicles are known or detected. Hence, when the computing system ascertains that the autonomous vehicle is in proximity to a second autonomous vehicle (e.g., based upon a first reported geospatial position of the autonomous vehicle and a second reported geospatial position of the second autonomous vehicle), the computing system may cause a command signal to be transmitted to the lidar sensor system, wherein the command signal causes a first code to be included in light signals emitted by the lidar sensor system that is different from a second code that is included in light signals emitted by a second lidar sensor system of the second autonomous vehicle. Therefore, when a first autonomous vehicle and a second autonomous vehicle are detected as being in geographic proximity to one another, a first lidar sensor system of the first autonomous vehicle can be caused to emit first light signals with a first code included therein and a second lidar sensor system of the second autonomous vehicle can be caused to emit second light signals with a second code included therein. Thus, for instance, when a light signal with the second code included therein is incident upon a detector of the first lidar sensor system, the first lidar sensor system can ascertain that the light signal was not emitted by the first lidar sensor system, thereby avoiding interference.
• In yet another exemplary embodiment, the computing system can generate the command signal based upon detected interference, such that when interference is detected the lidar sensor system is caused to alter a code included in light signals emitted by the lidar sensor system. The computing system can be configured to detect occurrence of interference based upon one or more point clouds output by the lidar sensor system, and upon detecting occurrence of interference, can transmit a command signal that causes the lidar sensor system to alter a code that is included in light signals emitted by the lidar sensor system. The computing system can detect interference by, for example, comparing a point in a point cloud with surrounding points in the point cloud (including an adjacent point in the point cloud), and if a value assigned to the point is significantly different from values assigned to the surrounding points (e.g., a difference between the value assigned to the point and at least one value assigned to at least one other point in the surrounding points is greater than a predefined threshold), the computing system can transmit the command signal. In another example, the computing system can detect interference by comparing a point in a point cloud with a corresponding point in one or more previously generated point clouds.
• In yet another exemplary embodiment, the computing system is configured to alter a code that is included in light signals emitted by a lidar sensor system after a threshold amount of time has passed since the code was altered. Thus, for example, the computing system can cause the code to be randomly altered every ten minutes.
• In still yet another exemplary embodiment, the computing system can cause the lidar sensor system to emit light signals with different codes in different directions. Hence, light signals emitted in a northerly direction by the lidar sensor system may include a first code, while light signals emitted in a southerly direction by the lidar sensor system may include a second code. When detecting light signals, the lidar sensor system can ascertain whether signals have the first code when such signals are received from the north and can ascertain whether signals have the second code when such signals are received from the south.
• The above summary presents a simplified summary in order to provide a basic understanding of some aspects of the systems and/or methods discussed herein. This summary is not an extensive overview of the systems and/or methods discussed herein. It is not intended to identify key/critical elements or to delineate the scope of such systems and/or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG.1 is a schematic that illustrates autonomous vehicles having lidar sensor systems respectively mounted thereon or incorporated therein, wherein the lidar sensor systems emit light pulses with different codes include therein.
• FIG.2 is a functional block diagram of an exemplary autonomous vehicle.
• FIG.3 illustrates a plurality of light signals emitted by a lidar sensor system, wherein the light signals have different codes included therein.
• FIG.4 is a flow diagram illustrating an exemplary methodology for controlling a lidar sensor system.
• FIG.5 is a flow diagram illustrating another exemplary methodology for controlling a lidar sensor system.
• FIG.6 is a flow diagram illustrating yet another exemplary methodology for controlling a lidar sensor system.
• FIG.7 illustrates an exemplary computing system.
DETAILED DESCRIPTION
• Various technologies pertaining to lidar sensor systems are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more aspects. Further, it is to be understood that functionality that is described as being carried out by certain system components may be performed by multiple components. Similarly, for instance, a component may be configured to perform functionality that is described as being carried out by multiple components.
• Moreover, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B.
• In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form.
• Further, as used herein, the terms “component”, “module”, and “system” are intended to encompass computer-readable data storage that is configured with computer-executable instructions that cause certain functionality to be performed when executed by a processor. The computer-executable instructions may include a routine, a function, or the like. It is also to be understood that a component or system may be localized on a single device or distributed across several devices.
• Moreover, as used herein, the term “exemplary” is intended to mean serving as an illustration or example of something and is not intended to indicate a preference.
• The technologies described herein are related to including codes in light signals emitted by lidar sensor systems that are incorporated in or mounted onto autonomous vehicles, wherein the codes are included to mitigate occurrences of interference. Interference occurs when a lidar sensor system detects a light signal that was emitted by a light source other than an emitter of the lidar sensor system and generates a point cloud based upon such light signal. Hence, when interference occurs, the point cloud generated by the lidar sensor system will include an inaccuracy.
• With reference now toFIG.1, anexemplary environment100 is illustrated, wherein theenvironment100 includes a firstautonomous vehicle102 and a secondautonomous vehicle103. The firstautonomous vehicle102 has a firstlidar sensor system106 mounted thereon or incorporated therein and the secondautonomous vehicle103 has a secondlidar sensor system108 mounted thereon or incorporated therein. The firstautonomous vehicle102 includes componentry depicted in call-out104. As illustrated, the firstautonomous vehicle102 comprises the firstlidar sensor system106, a mechanical system107 (e.g., a vehicle propulsion system, a steering system, a braking system, etc.), and acomputing system110. Thecomputing system110 includes a processor and memory (not shown), wherein acontrol system112 is stored in the memory and executed by the processor. Generally, thecomputing system110 receives output of the firstlidar sensor system106, and thecontrol system112 controls themechanical system107 based upon the output of the first lidar sensor system106 (and optionally outputs of other sensor systems of the firstautonomous vehicle102, such as cameras, a GPS sensor, radar sensor systems, etc.).
• The memory of thecomputing system110 also has acode updater module116 stored therein, wherein thecode updater module116 is configured to update a code included in light signals emitted by thelidar sensor system106. With more specificity, thecode updater module116 causes thecomputing system110 to transmit a command signal to the firstlidar sensor system106 based upon one or more parameters, including orientation of the firstautonomous vehicle102, time, geospatial position of the firstautonomous vehicle102, whether or not interference has been detected, etc. The firstlidar sensor system106, upon receiving the command signal, updates a code that is included in light signals emitted by the firstlidar sensor system106. For instance, upon receiving the command signal, the firstlidar sensor system106 transitions from including a first code in light signals emitted by the firstlidar sensor system106 to including a second code in light signals emitted by the firstlidar sensor system106, wherein the first code and the second code are different. As will be described in greater detail below, the code included in light signals emitted by the firstlidar sensor system106 is updated to mitigate incidences of interference at the firstlidar sensor system106.
• In an exemplary embodiment, the firstlidar sensor system106 is a spinning lidar system that includes an array of light emitters (e.g., laser diodes) and a corresponding array of photodetectors, wherein when the firstlidar sensor system106 is operating, these arrays revolve 360 degrees about a central axis, with the light emitters emitting light signals as the array of light emitters revolves. In another exemplary embodiment, the firstlidar sensor system106 may be a scanning lidar that covers a horizontal field of view (or other suitable field of view), such as a 60-120 degree field of view. Each light signal emitted by each light emitter includes one or more light pulses. The firstlidar sensor system106 further includes a timer, wherein the firstlidar sensor system106 detects distance between the firstlidar sensor system106 and an object in theenvironment100 based upon an amount of time between a first time when a light signal was emitted by a light emitter and a second time when the light signal was detected by a photodetector in the array of photodetectors. In an exemplary embodiment, each light emitter in the array of light emitters may emit roughly 16 light signals per 55 microsecond revolution.
• In addition, the firstlidar sensor system106 includes circuitry that is configured to include a code in an electrical signal, wherein the electrical signal is provided to a light emitter, and further wherein a light signal emitted by the light emitter is based upon the electrical signal (e.g., the light emitter is driven by the electrical signal). Hence, the light signal includes the code. In an example, the circuitry can modulate amplitude and/or a frequency of the electrical signal to form the code. Additionally or alternatively, the circuitry can include variable capacitance filters, variable resistors, diodes, etc. The circuitry can be configured to shape electrical pulses that drive the light emitters, can be configured to generate the light signal to include a sequence of pulses, can be configured to generate the light signal to include a pulse with a particular rise time, magnitude, etc. In an example, the lidar sensor system may include firmware, wherein a finite number of codes are stored in the firmware, and further wherein the circuitry can construct electrical signals that include a code in the finite number of codes stored in the firmware.
• In theenvironment100, theremote computing system114 is in communication with the firstautonomous vehicle102 and the secondautonomous vehicle103. For instance, theremote computing system114 can transmit commands to the firstautonomous vehicle102 and the secondautonomous vehicle103, wherein the commands inform theautonomous vehicles102 and103 of travel destinations for such vehicles. Theremote computing system114 can also transmit information to theautonomous vehicles102 and103 thatsuch vehicles102 and103 can employ while navigating streets, such as locations of heavy traffic, locations of accidents, and so forth. Further, theremote computing system114 can receive geospatial positions of theautonomous vehicles102 and103 as the autonomous vehicles navigate a geographic region. Accordingly, theautonomous vehicles102 and103 may belong to a fleet, wherein each autonomous vehicle in the fleet reports its position to theremote computing system114.
• In operation, the firstlidar sensor system106 of the firstautonomous vehicle102 emits light signals that include one of the finite number of codes defined in the firmware of thelidar sensor system106. A light signal in the light signals (e.g., light signal118) travels into the environment, reflects off of an object, and is detected by the firstlidar sensor system106 upon reflecting off of the object. Thelidar sensor system106, upon detecting the light signal, determines whether the light signal includes the code. When the light signal includes the code, the firstlidar sensor system106 generates a point cloud based upon the detected light signal. When the light signal does not include the code, the firstlidar sensor system106 identifies the detected light signal as being interference (e.g., the firstlidar sensor system106 can filter the detected light signal). For instance, when the detector of the firstlidar sensor system106 detects a light signal emitted by the secondlidar sensor system108, the firstlidar sensor system106 can determine that a code in the light signal is not the same code that is included in light signals emitted by the firstlidar sensor system106, and can ascertain that such light signal is interference. The firstlidar sensor system106 outputs a point cloud based upon detected light signals, and thecontrol system112 controls themechanical system107 based upon the point cloud.
• Because the firmware of the firstlidar sensor system106 supports a limited number of codes, a code may not be unique to a lidar sensor system. For instance, even though thefirst lidar system106 and thesecond lidar system108 can output light signals with different codes, due to the finite number of supported codes, it is possible that both thefirst lidar system106 and thesecond lidar system108 may emit light signals having the same code within a same time window, thus leaving open the possibility of interference. Thecode updater module116 transmits command signals that are configured to update the code included in light signals based upon one or more parameters to mitigate occurrence of interference. Such parameters include, but are not limited to: 1) geospatial position of the first autonomous vehicle102 (e.g., relative to the geospatial position of the second autonomous vehicle103); 2) orientation of the first autonomous vehicle102 (e.g., direction of travel of the first autonomous vehicle102); 3) existence of interference; 4) an amount of time since the code was last updated; and/or 5) direction in which light signals are transmitted (e.g., northerly, southerly, easterly, westerly). Operation of thecode updater module116 with respect to such parameters is described below.
• In a first example, thecode updater module114 can cause the code included in light signals emitted by the firstlidar sensor system106 to be updated based upon geospatial position of the firstautonomous vehicle102 and geospatial position of the secondautonomous vehicle103. As indicated previously, theremote computing system114 is in communication with both the firstautonomous vehicle102 and the secondautonomous vehicle103, wherein theautonomous vehicles102 and103 report their geospatial positions to theremote computing system114. In addition, theautonomous vehicles102 and103 can report, to theremote computing system114, code identifiers that identify codes that are being included in light signals emitted by the firstlidar sensor system106 and the secondlidar sensor system108, respectively. Theremote computing system114 can ascertain that the firstautonomous vehicle102 and the secondautonomous vehicle103 are in geographic proximity to one another based upon the geospatial positions reported by theautonomous vehicles102 and103 to theremote computing system114. In addition, theremote computing system114 can ascertain that the firstlidar sensor system106 and the secondlidar sensor system108 are emitting light signals that include the same code (or that both the firstlidar sensor system106 and the secondlidar sensor system108 are emitting light signals with no codes therein).
• To prevent occurrence of interference, theremote computing system114 can transmit an instruction to the firstautonomous vehicle102, wherein the instruction instructs the firstautonomous vehicle102 to update the code included in light signals emitted by the firstlidar sensor system106 from a first code to a second code. Thecode updater module114 receives the instruction and causes thecomputing system110 of the firstautonomous vehicle102 to transmit a command signal to the firstlidar sensor system106, wherein the command signal is configured to cause the firstlidar sensor system106 to update the code included in light signals emitted thereby. The firstlidar sensor system106, based upon the command signal, updates the code included in the light signals emitted by the firstlidar sensor system106, such that the firstlidar sensor system106 and the secondlidar sensor system108 are no longer emitting light signals that include the same code. Hence, in an example, when the firstlidar sensor system106 detects a light signal (e.g., light signal124) emitted by the secondlidar sensor system108, the firstlidar sensor system106 can ascertain that thelight signal124 includes a code that is different from a code included in light signals emitted by the firstlidar sensor system106, and interference is avoided.
• In an alternative embodiment, the firstautonomous vehicle102 and the secondautonomous vehicle103 report geospatial positions of theautonomous vehicles102 and103 to each other by way of, for example, a mesh network. Thus, the firstautonomous vehicle102 can receive, from the secondautonomous vehicle103, the geospatial position of the second autonomous vehicle103 (and can additionally receive an identifier for a code included in light signals being emitted by the second lidar sensor system108). Thecode updater module116 can determine that the secondautonomous vehicle103 is within some predefined distance of the firstautonomous vehicle102, can further determine that the firstlidar sensor system106 and the secondlidar sensor system108 are emitting light signals with the same code, and based upon such determinations, can cause the firstlidar sensor system106 to update the code included in light signals emitted by the firstlidar sensor system106.
• In a second example, thecode updater module116 can cause the code included in light signals emitted by the firstlidar sensor system106 to be updated based upon orientation of the firstautonomous vehicle102. For instance, the firstautonomous vehicle102 can include a digital compass (not shown) that can output a direction that the firstautonomous vehicle102 is facing (e.g., a direction of travel). Thecode updater module116 can select the code to be included in light signals emitted by the firstlidar sensor system106 based upon such direction. For example, as the orientation of the firstautonomous vehicle102 changes over time, thecode updater module116 can cause codes included in light signals emitted by the firstlidar sensor system106 to be updated. For instance, when the firstautonomous vehicle102 is facing east, thecode updater module116 can cause thecomputing system110 to transmit a command signal to the firstlidar sensor system106, wherein the command signal causes the firstlidar sensor system106 to emit light signals with a first code therein; when the firstautonomous vehicle102 is facing north, thecode updater module116 can cause thecomputing system110 to transmit a command signal to the firstlidar sensor system106, wherein the command signal causes the firstlidar sensor system106 to emit light signals with a second code therein; etc. Such an arrangement is beneficial in mitigating instances of interference in the direction of travel of the firstautonomous vehicle102, as a lidar sensor system of an autonomous vehicle travelling in the opposite direction will be configured to emit light signals with a different code than the code included in the light signals emitted by the firstlidar sensor system106.
• In an alternative embodiment, thecode updater module116 can control the firstlidar sensor system106 to include a code in a light signal based upon a direction that the light signal is emitted from the firstlidar sensor system106. Hence, the firstlidar sensor system106 can be controlled to emit a first light signal with a first code therein in a first direction and can be controlled to emit a second light signal with a second code therein in a second direction, wherein the first code and the second code are different. In a specific example, thecode updater module116 can cause, in a revolution, the firstlidar sensor system106 to: 1) emit a first light signal with a first code therein in a northerly direction; 2) emit a second light signal with a second code therein in a westerly direction; 3) emit a third light signal with a third code therein in a southerly direction; and 4) emit a fourth light signal with a fourth code therein in an easterly direction. Thefirst lidar system106 can be configured to identify interference based upon a code and a direction from which a light signal is detected. Continuing with the example set forth above, when the detector of the firstlidar sensor system106 detects a light signal from the northerly direction and determines that the light signal has the third code therein (rather than the first code), thefirst lidar system106 can identify the light signal as interference. When both the firstautonomous vehicle102 and the secondautonomous vehicle103 are configured to include codes in light signals in the manner described above, the firstlidar sensor system106 will identify thelight signal124 emitted from the secondlidar sensor system108 as interference, as suchlight signal124 will not include the same code as thelight signal118 emitted from the firstlidar sensor system106.
• In a third example, thecode updater module116 can cause the firstlidar sensor system106 to alter a code included in light signals emitted by the firstlidar sensor system106 upon detection of interference. For example, the firstlidar sensor system106 and the secondlidar sensor system108 may emit light signals that include the same code; accordingly, the firstlidar sensor system106 may (incorrectly) compute a point in a point cloud based upon thelight signal124 emitted by the secondlidar sensor system108 of the secondautonomous vehicle103. Thecomputing system110 processes point clouds output by the firstlidar sensor system106 and determines possible occurrence(s) of interference based upon one or more of the point clouds. For example, an anomalous point in the point cloud can indicate occurrence of interference. In another example, an immediate (and relatively large) change in corresponding points of adjacent point clouds can indicate occurrence of interference. When thecomputing system110 identifies possible interference based upon point clouds output by the firstlidar sensor system106, thecode updater module116 can transmit a command that causes the code included in the light signals emitted by the firstlidar sensor system106 to be updated. This embodiment is particularly well-suited for scenarios where theautonomous vehicles102 and103 do not belong to the same fleet (e.g., theremote computing system114 fails to be in communication with at least one of theautonomous vehicles102 or103). Thus, for example, the firstautonomous vehicle102 may be unaware that theautonomous vehicle103 includes a lidar sensor system that emits light pulses. The firstlidar sensor system106 can detect thelight signal124 emitted by the secondlidar sensor system108 and can generate a point cloud based upon the firstlidar sensor system106 detecting thelight signal124. Thecomputing system110 receives the point cloud and ascertains that the point cloud includes at least one point therein that has a value that is based upon existence of interference. Thecode updater module116 then causes thecomputing system110 to transmit a command to thelidar sensor system106, and thelidar sensor system106 updates the code upon receiving such command signal.
• In a fourth example, thecode updater module116 can cause thecomputing system110 to transmit a command signal that causes the firstlidar sensor system106 to update a code included in light signals emitted by the firstlidar sensor system106 upon a predefined amount of time passing since the code was most recently updated. Hence, for instance, every ten minutes thecode updater module116 can cause the code included in light signals emitted by the firstlidar sensor system106 to be randomly updated (which may be well-suited to mitigate possibility of malicious interference).
• Moreover, thecode updater module116 can cause a code included in light signals emitted by thefirst lidar system106 to be updated based upon a combination of one or more of the parameters referenced above. For instance, thecode updater module116 can cause the code to be randomly updated periodically and can further cause the code to be updated upon detection of interference. In another example, thecode updater module116 can cause the code to be updated based upon geospatial position and orientation of the firstautonomous vehicle102.
• Moreover, it is contemplated that the firstautonomous vehicle102 may have several lidar sensor systems mounted thereon or incorporated therein. Thecode updater module116 can transmit commands to the several lidar sensor systems that cause such lidar sensor systems to emit light signals with different codes therein, thereby precluding interference between the several lidar sensor systems.
• With reference now toFIG.2, a functional block diagram of the firstautonomous vehicle102 is illustrated. The firstautonomous vehicle102 includes several lidar sensor systems: the firstlidar sensor system106 through an Nthlidar sensor system202. Thelidar systems106 and202 havecodes207 stored in firmware of thelidar systems106 and202. In an example, thecodes207 may include five codes, ten codes, fifteen codes, or twenty codes. The firstautonomous vehicle102 additionally includes a plurality of sensor systems204-206 that are arranged about the firstautonomous vehicle102, wherein the sensor systems204-206 may include a camera, a GPS sensor, an accelerometer, etc.
• The firstautonomous vehicle102 further includes several mechanical systems that can be used to effectuate appropriate motion of the firstautonomous vehicle102. For instance, the mechanical systems can include but are not limited to avehicle propulsion system208, abraking system209, and asteering system210. Thevehicle propulsion system208 may include an electric motor, an internal combustion engine, or both. Thebraking system209 can include an engine brake, actuators, and/or any other suitable componentry that is configured to assist in decelerating the firstautonomous vehicle102. Thesteering system210 includes suitable componentry that is configured to control the direction of movement of the firstautonomous vehicle102 during propulsion.
• The firstautonomous vehicle102 additionally comprises thecomputing system110, which is in communication with thelidar sensor systems106 and202, the sensor systems204-206, and the mechanical systems208-210. Thecomputing system110 comprises adata store212, aprocessor214, andmemory216 that includes instructions that are executed by theprocessor214. In an example, theprocessor214 can be or include a graphics processing unit (GPU), a plurality of GPUs, a central processing unit (CPU), a plurality of CPUs, an application-specific integrated circuit (ASIC), a microcontroller, a programmable logic controller (PLC), a field programmable gate array (FPGA), or the like.
• Memory216 has thecontrol system112 stored therein, wherein thecontrol system112 is configured to receive outputs of thelidar sensor systems106 and202 and outputs of the sensor systems204-206 and control one or more of the mechanical systems208-210 based upon such outputs. Thememory216 further has thecode updater module116 stored therein, wherein thecode updater module116 optionally includes aproximity detector module218, anorientation detector module220, aninterference detector module220, and atime interval module222. Theproximity detector module218 is configured to ascertain that another autonomous vehicle is in geographic proximity to the first autonomous vehicle102 (e.g., within some threshold distance of the firstautonomous vehicle102, travelling on a same street as the firstautonomous vehicle102, etc.). In an example, theproximity detector module218 can receive geospatial coordinates of the firstautonomous vehicle102 from one of the sensors204-206 and can receive geospatial coordinates of another autonomous vehicle from another computing system (e.g., theremote computing system114 or a computing system of the another autonomous vehicle directly). When theproximity detector module218 ascertains that the another autonomous vehicle is in geographic proximity to the firstautonomous vehicle102, theproximity detector module218 can ascertain whether, for example, the firstlidar sensor system106 is including codes in light signals emitted by the firstlidar sensor system106. When the firstlidar sensor system106 fails to be including codes in emitted light signals, theproximity detector module218 can cause thecomputing system110 to transmit a command to the firstlidar sensor system106, wherein the command is configured to cause the firstlidar sensor system106 to include a code from thecodes207 in emitted light signals.
• In another example, theproximity detector module218 can receive an identifier for a code that is included in light signals emitted by the firstlidar sensor system106, and can further receive an identifier for a code that is included in light signals emitted by a lidar sensor system of the autonomous vehicle that is in geographic proximity to the firstautonomous vehicle102. Theproximity detector module218 compares the identifiers for the codes, and when the identifiers are the same, theproximity detector module218 causes thecomputing system110 to transmit a command signal to the firstlidar sensor system106, wherein the command signal is configured to cause the firstlidar sensor system106 to alter the code that is included in emitted light signals.
• In yet another example, thecontrol system112 can ascertain that an image output by one of the sensor systems204-206 includes another autonomous vehicle, and thecontrol system112 can pass a message to thecode updater module116 that the image includes the another autonomous vehicle. In response to receiving such message, theproximity detector module218 can determine whether the firstlidar sensor system106 is including a code in light signals emitted thereby. When the light signals fail to include a code, theproximity detector module218 can cause thecomputing system110 to transmit a command to the firstlidar sensor system106, wherein the command is configured to cause the firstlidar sensor system106 to include a code in light signals emitted thereby.
• Theorientation detector module220 is configured to determine an orientation of the firstautonomous vehicle102 based upon output of a sensor in the sensor systems204-206 and is further configured to cause thecomputing system110 to transmit command signals to the firstlidar sensor system106 based upon the orientation of the firstautonomous vehicle102. Thus, theorientation detector module220 can cause thecomputing system110 to transmit a command signal that causes a code included in light signals emitted by the firstlidar sensor system106 to alter as the orientation (e.g., direction of travel) of the firstautonomous vehicle102 alters. In addition, as described above, theorientation detector module220 can cause thecomputing system110 to transmit command signals to the firstlidar sensor system106 that cause the firstlidar sensor system106 to include codes in light signals as a function of direction that the light signals are emitted.
• Theinterference detector module222 is configured to identify instances of interference, wherein, for example, the firstlidar sensor system106 detects a light signal emitted by another lidar sensor system of another autonomous vehicle. Theinterference detector module222 can identify instances of interference based upon point clouds generated by the firstlidar sensor system106. In another example, when the first autonomous vehicle includes multiple lidar sensor systems, theinterference detector module222 can identify instances of interference based upon a comparison between point clouds generated by the lidar sensor systems. For instance, a field of view of the firstlidar sensor system106 and the Nthlidar sensor system202 may partially overlap, and theinterference detector module222 can identify interference when points in the point clouds in an overlapping region are inconsistent (e.g., a threshold distance disparity exists between points that correspond to a single scene location). Upon detecting interference, theinterference detector module222 can cause thecomputing system110 to transmit a command signal to the firstlidar sensor system106, wherein the command signal is configured to cause the firstlidar sensor system106 to begin including codes in light signals emitted by the firstlidar sensor system106 or to alter a code included in light signals emitted by the first lidar sensor system.
• Thetimer module224 is configured to periodically cause thecomputing system110 to transmit a command signal to one or more of thelidar sensor systems106 and202, wherein the command signal is configured to cause thelidar sensor systems106 and202 to alter codes included in light signal emitted thereby. An amount of time between when thetimer module224 causes thecomputing system110 to transmit commands can depend upon, for example, a number of codes in thecodes207, time of day, a density of autonomous vehicles within a given area, a geographic location of theautonomous vehicle102, etc.
• While the modules218-224 are illustrated as being included in thecomputing system110 of the firstautonomous vehicle102, it is to be understood that one or more of the modules218-224 may execute on other computing systems. For example, one or more of the modules218-224 may be executed by a microprocessor of one or more of thelidar sensor systems106 and202. In another example, one or more of the modules218-224 may be executed by theremote computing system114. Moreover, while operation of the modules218-224 was set forth with respect to the firstlidar sensor system106, it is to be understood that the modules218-224 can perform similar acts with respect to other lidar sensor systems in thelidar sensor systems106 and202. Further, thecode updater module116 can maintain a list of codes emitted in signals output by several lidar systems of the firstautonomous vehicle102 and can command such lidar sensor systems to include different codes in light signals emitted thereby (thus preventing the lidar sensor systems from generating a point cloud based upon light signals emitted by another of the lidar sensor systems).
• With reference now toFIG.3, a schematic300 that illustrates a plurality of codes that can be included in light signals emitted by different lidar sensor systems is illustrated. In the example shown inFIG.3, the codes are depicted as being respective sequences of pulses, wherein the sequences of pulses are each different from one another. For example, as illustrated, a firstlidar sensor system302 emits a first light signal that comprises a first sequence ofpulses304, a secondlidar sensor system306 emits a second light signal that comprises a second sequence ofpulses308, and a thirdlidar sensor system310 emits a third light signal that comprises a third sequence ofpulses312. As can be ascertained, each of the sequence ofpulses304,308, and312 is different from each of the other sequences of pulses; thus, if the firstlidar sensor system302 were to receive a light signal that includes the second sequence ofpulses308, the firstlidar sensor system302 can filter such light signal as the light signal does not include the first sequence ofpulses304. While codes are illustrated as being a sequence of pulses, it is to be understood that through pulse shaping a code may be a parameter of a single light pulse, such as rise time, pulse shape (e.g., square versus sawtooth), pulse duration, and so forth.
• FIGS.4-6 illustrate exemplary methodologies relating to mitigating interference with respect to lidar sensor systems. While the methodologies are shown and described as being a series of acts that are performed in a sequence, it is to be understood and appreciated that the methodologies are not limited by the order of the sequence. For example, some acts can occur in a different order than what is described herein. In addition, an act can occur concurrently with another act. Further, in some instances, not all acts may be required to implement a methodology described herein.
• Moreover, the acts described herein may be computer-executable instructions that can be implemented by one or more processors and/or stored on a computer-readable medium or media. The computer-executable instructions can include a routine, a sub-routine, programs, a thread of execution, and/or the like. Still further, results of acts of the methodologies can be stored in a computer-readable medium, displayed on a display device, and/or the like.
• Referring now toFIG.4, anexemplary methodology400 for preemptively mitigating interference with respect to a lidar sensor system is illustrated. Themethodology400, in an example, is performed by thecomputing system110 of the firstautonomous vehicle102. Themethodology400 starts at402, and at404 an orientation of an autonomous vehicle that has the lidar sensor system mounted thereon or incorporated therein is determined. The determination may be based on a sensor signal from a sensor system of the autonomous vehicle. At406, a code that is to be included in a light signal to be emitted by the lidar sensor system is identified based on the orientation of the autonomous vehicle. As described previously, the code is employed to disambiguate a source of the lidar sensor system (e.g., identify the lidar sensor system as the source of the light signal). At408, the lidar sensor system is caused to emit a light signal that includes the code. For example, the computing system may transmit a command to the lidar sensor system to generate a light signal that includes the code. At410, subsequent to causing the lidar sensor system to emit the light signal with the code, a point cloud generated by the lidar sensor system is received, wherein the point cloud is generated based upon the light signal emitted by the lidar sensor system. At412, a mechanical system of the autonomous vehicle is controlled based upon the point cloud. Themethodology400 completes at414.
• Referring now toFIG.5, anexemplary methodology500 for causing a lidar sensor system to update a code included in light signals emitted thereby is illustrated. Themethodology500, in an example, can be performed by thecomputing system110 of the firstautonomous vehicle102. Themethodology500 starts at502, and at504 a point cloud is received from a lidar sensor system, wherein the point cloud is generated by the lidar sensor system based upon detected light signals. At506, a determination is made, based upon the point cloud, whether the point cloud was generated based upon interference (e.g., the lidar sensor system detecting a light signal not emitted by the lidar sensor system). When it is determined at506 that the point cloud was not generated based upon interference, themethodology500 returns to504. When it is determined at506 that the point cloud was generated based upon interference, at508 a command is transmitted to the lidar sensor system, wherein the command is configured to cause the lidar sensor system to include a code in light signals emitted thereby or update a code in light signals emitted thereby from a first code to a second code. The lidar system, in response to receiving the command, includes the code in the light signals or includes the second code in the light signals. Themethodology500 then returns to act504.
• Referring now toFIG.6, anexemplary methodology600 that facilitates mitigating interference at a lidar sensor system is illustrated. Themethodology600 is performed, for example, by thecomputing system110 of the firstautonomous vehicle102. Themethodology600 starts at602, and at604 a first command is transmitted to the lidar sensor system, wherein the first command is configured to cause the lidar sensor system to update a code included in light signals emitted by the lidar sensor system. Therefore, prior to receiving the command, the lidar sensor system includes a first code in light signals emitted by the lidar sensor system, while after receiving the command, the lidar sensor system includes a second code in light signals emitted by the lidar sensor system.
• At606, a comparison is made between an amount of time that has lapsed since the first command was transmitted and a threshold amount of time. When the amount of time that has lapsed since the first command was transmitted reaches the threshold, themethodology600 proceeds to608, where a second command is transmitted to the lidar sensor system. The second command is configured to again cause the lidar sensor system to update the code included in light signals emitted by the lidar sensor system. Thus, as noted previously, after the first command is transmitted but prior to the second command being transmitted, the lidar sensor system can include the second code in light signals emitted by the lidar sensor system. After the second command is transmitted to the lidar sensor system, the lidar sensor system includes a third code in light signals emitted by the lidar sensor system. Themethodology600 completes at612.
• Referring now toFIG.7, a high-level illustration of anexemplary computing device700 that can be used in accordance with the systems and methodologies disclosed herein is illustrated. For instance, thecomputing device700 may be or include thecomputing system110. Thecomputing device700 includes at least oneprocessor702 that executes instructions that are stored in amemory704. The instructions may be, for instance, instructions for implementing functionality described as being carried out by one or more modules discussed above or instructions for implementing one or more of the methods described above. Theprocessor702 may access thememory704 by way of asystem bus706. In addition to storing executable instructions, thememory704 may also store information related to geospatial positions, interference, codes, orientations, and the like.
• Thecomputing device700 additionally includes adata store708 that is accessible by theprocessor702 by way of thesystem bus706. Thedata store708 may include executable instructions, codes, and the like. Thecomputing device700 also includes aninput interface710 that allows external devices to communicate with thecomputing device700. For instance, theinput interface710 may be used to receive instructions from an external computer device, from a user, etc. Thecomputing device700 also includes anoutput interface712 that interfaces thecomputing device700 with one or more external devices. For example, thecomputing device700 may transmit command signals to lidar sensor systems, mechanical systems, etc. by way of theoutput interface712.
• Additionally, while illustrated as a single system, it is to be understood that thecomputing device700 may be a distributed system. Thus, for instance, several devices may be in communication by way of a network connection and may collectively perform tasks described as being performed by thecomputing device700.
• Various functions described herein can be implemented in hardware, software, or any combination thereof. If implemented in software, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer-readable storage media. A computer-readable storage media can be any available storage media that can be accessed by a computer. By way of example, and not limitation, such computer-readable storage media can comprise RAM, ROM, EEPROM, 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. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and blu-ray disc (BD), where disks usually reproduce data magnetically and discs usually reproduce data optically with lasers. Further, a propagated signal is not included within the scope of computer-readable storage media. Computer-readable media also includes communication media including any medium that facilitates transfer of a computer program from one place to another. A connection, for instance, can be a communication medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio and microwave are included in the definition of communication medium. Combinations of the above should also be included within the scope of computer-readable media.
• Alternatively, or in addition, the functionally described herein can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (ASICs), Application-specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc.
• What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable modification and alteration of the above devices or methodologies for purposes of describing the aforementioned aspects, but one of ordinary skill in the art can recognize that many further modifications and permutations of various aspects are possible. Accordingly, the described aspects are intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the details description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.

Claims (20)

What is claimed is:

1. A remote computing system, comprising:

a processor; and

memory that stores instructions that, when executed by the processor, cause the processor to perform acts comprising:

receiving a first indication specifying a first geospatial position of a first autonomous vehicle;

receiving a second indication specifying a second geospatial position of a second autonomous vehicle;

determining that the first autonomous vehicle and the second autonomous vehicle are in geographic proximity based on the first indication specifying the first geospatial position of the first autonomous vehicle and the second indication specifying the second geospatial position of the second autonomous vehicle; and

based on determining that the first autonomous vehicle and the second autonomous vehicle are in geographic proximity, transmitting an instruction to the first autonomous vehicle that causes the first autonomous vehicle to update a code included in light signals emitted by a first lidar sensor system of the first autonomous vehicle such that the first lidar sensor system transitions from a first code being included in the light signals emitted by the first lidar sensor system to a second code being included in the light signals emitted by the first lidar sensor system, wherein the first code is different from the second code.

2. The remote computing system ofclaim 1, the acts further comprising:

determining that the first lidar sensor system and the second lidar sensor system are emitting light signals including a same code;

wherein the instruction that causes the first autonomous vehicle to update the code included in the light signals emitted by the first lidar sensor system is further transmitted to the first autonomous vehicle based on determining that the first lidar sensor system and the second lidar sensor system are emitting light signals including the same code.

3. The remote computing system ofclaim 2, wherein the first lidar sensor system and the second lidar sensor system are determined to be emitting light signals including the same code based on respective code identifiers received from the first autonomous vehicle and the second autonomous vehicle, wherein the respective code identifiers identify respective codes included in the light signals emitted by the first lidar sensor system and the second lidar sensor system.

4. The remote computing system ofclaim 1, wherein the instruction is transmitted to the first autonomous vehicle to facilitate avoidance of interference with respect to light signals emitted by a light source other than the first lidar sensor system.

5. The remote computing system ofclaim 1, the acts further comprising:

based on determining that the first autonomous vehicle and the second autonomous vehicle are in geographic proximity, transmitting a second instruction to the second autonomous vehicle that causes the second autonomous vehicle to update a code included in light signals emitted by a second lidar sensor system of the second autonomous vehicle.

6. The remote computing system ofclaim 1, wherein the first code is a first sequence of pulses and the second code is a second sequence of pulses.

7. The remote computing system ofclaim 1, wherein the instruction that causes the first autonomous vehicle to update the code included in the light signals emitted by the first lidar sensor system is further transmitted to the first autonomous vehicle based on an orientation of the first autonomous vehicle.

8. The remote computing system ofclaim 1, wherein the instruction that causes the first autonomous vehicle to update the code included in the light signals emitted by the first lidar sensor system is further transmitted to the first autonomous vehicle based on detected interference.

9. The remote computing system ofclaim 1, wherein the instruction that causes the first autonomous vehicle to update the code included in the light signals emitted by the first lidar sensor system is further transmitted to the first autonomous vehicle based on a comparison between a time when the code included in the light signals emitted by the first lidar sensor system was last updated and a threshold.

10. A method performed by a remote computing system in communication with a first autonomous vehicle and a second autonomous vehicle, comprising:

receiving a first indication specifying a first geospatial position of the first autonomous vehicle;

receiving a second indication specifying a second geospatial position of the second autonomous vehicle;

determining that the first autonomous vehicle and the second autonomous vehicle are in geographic proximity based on the first indication specifying the first geospatial position of the first autonomous vehicle and the second indication specifying the second geospatial position of the second autonomous vehicle; and

based on determining that the first autonomous vehicle and the second autonomous vehicle are in geographic proximity, transmitting an instruction to the first autonomous vehicle that causes the first autonomous vehicle to update a code included in light signals emitted by a first lidar sensor system of the first autonomous vehicle such that the first lidar sensor system transitions from a first code being included in the light signals emitted by the first lidar sensor system to a second code being included in the light signals emitted by the first lidar sensor system, wherein the first code is different from the second code.

11. The method ofclaim 10, further comprising:

determining that the first lidar sensor system and the second lidar sensor system are emitting light signals including a same code;

wherein the instruction that causes the first autonomous vehicle to update the code included in the light signals emitted by the first lidar sensor system is further transmitted to the first autonomous vehicle based on determining that the first lidar sensor system and the second lidar sensor system are emitting light signals including the same code.

12. The method ofclaim 11, wherein the first lidar sensor system and the second lidar sensor system are determined to be emitting light signals including the same code based on respective code identifiers received from the first autonomous vehicle and the second autonomous vehicle, wherein the respective code identifiers identify respective codes included in the light signals emitted by the first lidar sensor system and the second lidar sensor system.

13. The method ofclaim 10, wherein the instruction is transmitted to the first autonomous vehicle to facilitate avoidance of interference with respect to light signals emitted by a light source other than the first lidar sensor system.

14. The method ofclaim 10, further comprising:

based on determining that the first autonomous vehicle and the second autonomous vehicle are in geographic proximity, transmitting a second instruction to the second autonomous vehicle that causes the second autonomous vehicle to update a code included in light signals emitted by a second lidar sensor system of the second autonomous vehicle.

15. The method ofclaim 10, wherein the first code is a first sequence of pulses and the second code is a second sequence of pulses.

16. The method ofclaim 10, wherein the instruction that causes the first autonomous vehicle to update the code included in the light signals emitted by the first lidar sensor system is further transmitted to the first autonomous vehicle based on an orientation of the first autonomous vehicle.

17. The method ofclaim 10, wherein the instruction that causes the first autonomous vehicle to update the code included in the light signals emitted by the first lidar sensor system is further transmitted to the first autonomous vehicle based on detected interference.

18. The method ofclaim 10, wherein the instruction that causes the first autonomous vehicle to update the code included in the light signals emitted by the first lidar sensor system is further transmitted to the first autonomous vehicle based on a comparison between a time when the code included in the light signals emitted by the first lidar sensor system was last updated and a threshold.

19. An autonomous vehicle, comprising:

a lidar sensor system that comprises a lidar emitter; and

a computing system in communication with the lidar sensor system, wherein the computing system comprises:

a processor; and

memory that stores instructions that, when executed by the processor, cause the processor to perform acts comprising:

receiving an instruction from a remote computing system, wherein the instruction specifies an identity of a code to be employed by the lidar sensor system; and

responsive to receiving the instruction, controlling the lidar sensor system to employ the code such that the lidar sensor system transitions from including a first code in light signals emitted by the lidar sensor system to a second code being included in the light signals emitted by the lidar sensor system, wherein the first code is different from the second code.

20. The autonomous vehicle ofclaim 19, the acts further comprising:

transmitting a code identifier to the remote computing system, wherein the code identifier identifies the first code included in the light signals emitted by the lidar sensor system, and wherein the instruction is received based on the code identifier.

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