System and method for detecting electromagnetic signals in a constant interference environment

Abstract

Described herein are systems and methods for detecting electromagnetic signals in a constant interference environment. In one embodiment, the electromagnetic signal is a light signal. The constant interference detector may detect a false signal "hits" generated by a constant interference such as bright light saturation from a valid signal. The constant interference detector determines whether there is a constant interference for a time period greater than the time period of the valid signal. In one embodiment, if the received signal exceeds a programmable threshold for a programmable time period when compared to the previously stored ambient light, a control signal is generated to notify the next higher network layer of the sudden change in ambient light. The control signal can be used to discard the current return or process the signal in a different manner. The constant interference detector may be a component of a LIDAR system.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. patent application serial number 16 / 128,373, filed on September 11, 2018, entitled “SYSTEMS AND METHODS FORDETECTING AN ELECTROMAGNETIC SIGNAL IN A CONSTANT INTERFERENCE ENVIRONMENT,” the subject matter of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to systems and methods for electromagnetic signal reception, and more particularly to improving the accuracy and reliability of detection of optical signals in a constant interference environment. Background Art

[0004] The receiver can be designed to receive periodic signals or pulses from an electromagnetic source. In this environment, if constant interfering signals coexist with the periodic signal, the detection of the periodic signal may be difficult. For example, in a bright sunlight environment, the reception of light pulses may be challenging.

[0005] In some embodiments, a light detection and ranging system such as a LIDAR system may operate by transmitting a series of light pulses that reflect off an object. The reflected signal or return signal is received by the light detection and ranging system. Based on the detected time of flight (TOF), the system determines the range (distance) of the system from the location of the object. Light detection and ranging systems may have a wide range of applications, including autonomous driving and aerial mapping of surfaces. These applications may prioritize safety, accuracy, and reliability of operation. If the LIDAR system is in a bright sunlight environment, the accuracy and reliability may be adversely affected. Similar situations may exist for other natural or artificially generated electromagnetic signals.

[0006] Therefore, what is needed is a system and method for improving the detection of return or pulse signals in a constant interfering signal environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Reference will be made to embodiments of the present invention, examples of which may be shown in the accompanying drawings. These figures are intended to be illustrative, not restrictive. Although the present invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the present invention to these specific embodiments. The items in the drawings are not to scale.

[0008] The accompanying drawing ("FIG.") 1 depicts the operation of a light detection and ranging system according to an embodiment of the present document.

[0009] Figure 2 The operation of the light detection and ranging system and multiple return light signals according to an embodiment of the present document are shown.

[0010] Figure 3A LIDAR signal detection according to an embodiment of the present document is depicted.

[0011] Figure 3B A constant interference detector according to an embodiment of the present document is depicted.

[0012] Figure 3C A LIDAR return signal received by a constant jammer detector according to an embodiment of the present document is shown.

[0013] Figure 4 A constant interference threshold block is depicted in accordance with an embodiment of the present disclosure.

[0014] Figure 5 Depicted is a DC detection block and associated logic according to an embodiment of the present disclosure.

[0015] Fig. 6A and 6B A flow chart is graphically shown describing a method for detecting constant interference in an electromagnetic signal according to an embodiment of the present disclosure.

[0016] Figure 7 Depicted is a simplified block diagram of a computing device / constant interference detection system according to an embodiment of the present document. DETAILED DESCRIPTION

[0017] In the following description, for the purpose of explanation, specific details are set forth in order to provide an understanding of the present invention. However, it will be clear to those skilled in the art that the present invention can be practiced without these details. In addition, those skilled in the art will recognize that the embodiments of the present invention described below can be implemented in a variety of ways, such as a process, an apparatus, a system, a device, or a method on a tangible computer-readable medium.

[0018] The components or modules shown in the figures are illustrations of exemplary embodiments of the present invention and are intended to avoid obscuring the present invention. It should also be understood that throughout this discussion, the components may be described as separate functional units, which may include subunits, but those skilled in the art will recognize that the various components or portions thereof may be divided into separate components or may be integrated together, including in a single system or component. It should be noted that the functions or operations discussed herein may be implemented as components. Components may be implemented in software, hardware, or a combination thereof.

[0019] In addition, the connections between components or systems in the drawings are not intended to be limited to direct connections. Instead, the data between these components can be modified, reformatted or otherwise changed by intermediate components. Similarly, additional or fewer connections can be used. It should also be noted that the terms "coupled", "connected" or "communicatively coupled" should be understood to include direct connections, indirect connections through one or more intermediate devices, and wireless connections.

[0020] References in the specification to "one embodiment," "preferred embodiment," "embodiment," or "embodiments" mean that a particular feature, structure, characteristic, or function described in conjunction with the embodiment is included in at least one embodiment of the invention and may be in more than one embodiment. Likewise, the appearances of the above phrases in various places in the specification do not necessarily all refer to the same embodiment or embodiments.

[0021] Certain terms are used in various places in the specification for the purpose of explanation and should not be interpreted as limiting. Services, functions or resources are not limited to a single service, function or resource; the use of these terms may refer to groupings of related services, functions or resources, which may be distributed or aggregated.

[0022] The terms "comprising," "including," "containing," and "consisting of" should be understood as open-ended terms, and any list below is an example and is not meant to be limited to the listed items. Any headings used herein are for organizational purposes only and should not be used to limit the scope of the specification or claims. Each reference mentioned in this patent document is incorporated herein by reference in its entirety.

[0023] In addition, those skilled in the art will recognize that: (1) certain steps may be performed optionally; (2) the steps may not be limited to the specific order set forth herein; (3) certain steps may be performed in a different order; and (4) certain steps may be performed simultaneously.

[0024] A. Light detection and ranging system

[0025] As discussed herein, in some embodiments, the receiver is designed to receive periodic signals or pulses from an electromagnetic source. In such an environment, detection of the periodic signal may be difficult if a constant interfering signal coexists with the periodic signal. For example, in a bright sunlight environment, reception of light pulses may be a challenge for a LIDAR system.

[0026] Light detection and ranging systems, such as LIDAR systems, can be tools for measuring the shape and contours of the environment surrounding the system. LIDAR systems can be applied to numerous applications, including both autonomous navigation and aerial mapping of surfaces. LIDAR systems emit pulses of light that are then reflected off objects within the environment in which the system operates. The time it takes for each pulse to travel from being emitted to being received (i.e., the time of flight "TOF") can be measured to determine the distance between the object and the LIDAR system. The science is based on the physics of light and optics. References herein to LIDAR systems or light detection and ranging systems can also apply to other light detection systems.

[0027] In a LIDAR system, light can be emitted from a fast-firing laser. The laser travels through the medium and reflects off points of things in the environment, such as buildings, tree branches, and vehicles. The reflected light energy returns to the LIDAR receiver (detector), where it is recorded and used to map the environment.

[0028] Figure 1 Operation 100 of a light detection and ranging component 102 and data analysis and interpretation 109 according to an embodiment of the present document is depicted. The light detection and ranging component 102 may include a transmitter 104 that transmits an emitted light signal 110, a receiver 106 that includes a detector, and a system control and data acquisition 108. The emitted light signal 110 propagates through a medium and reflects off an object 112. A return light signal 114 propagates through the medium and is received by the receiver 106. The system control and data acquisition 108 may control the light emission of the transmitter 104 and the data acquisition may record the return light signal 114 detected by the receiver 106. The data analysis and interpretation 109 may receive output from the system control and data acquisition 108 via a connection 116 and perform data analysis functions. The connection 116 may be implemented with wireless or contactless communication methods. The transmitter 104 and the receiver 106 may include optical lenses and mirrors (not shown). The transmitter 104 may emit a laser beam having a plurality of pulses in a specific sequence. In some embodiments, light detection and ranging component 102 and data analysis and interpretation 109 include a LIDAR system.

[0029] Figure 2 Operation 200 of a light detection and ranging system 202 according to an embodiment of the present document is shown, including multiple return light signals: (1) return signal 203 and (2) return signal 205. The light detection and ranging system 202 can be a LIDAR system. Due to the beam divergence of the laser, a single laser shot often hits multiple objects, thereby generating multiple returns. The light detection and ranging system 202 can analyze the multiple returns and can report the strongest return, the last return, or both returns. According to the Figure 2, the light detection and ranging system 202 emits a laser in the direction of a near wall 204 and a far wall 208. As shown, most of the beam hits the near wall 204 at area 206, resulting in a return signal 203, and another portion of the beam hits the far wall 208 at area 210, resulting in a return signal 205. The return signal 203 may have a shorter TOF and a stronger received signal strength than the return signal 205. The light detection and ranging system 202 may only record two returns if the distance between the two objects is greater than a minimum distance. In both single-return and multi-return LIDAR systems, it is important to accurately correlate the return signal with the transmitted light signal so that an accurate TOF is calculated.

[0030] Some embodiments of LIDAR systems may capture range data in a 2D (i.e., single-plane) point cloud format. These LIDAR systems may often be used in industrial applications and may often be repurposed for surveying, mapping, autonomous navigation, and other uses. Some embodiments of these devices rely on the use of a single laser emitter / detector pair in combination with some type of moving mirror to achieve scanning across at least one plane. The mirror reflects not only the emitted light from the diode, but also the return light to the detector. The use of a rotating mirror in this application may be a means of achieving a 90-180-360 degree azimuth view while simplifying both system design and manufacturing. Rotating mirror functionality may also be implemented with solid-state technologies such as MEMS.

[0031] B. Constant interference detection

[0032] The constant interference detector can detect false signal "hits" generated by constant interference such as bright light saturation and distinguish them from valid signals or pulses. Sunlight may cause bright light saturation. Two events that may cause false signal hits are 1) a burst of sunlight or a burst from other light sources, and 2) continuous exposure to sunlight or other light sources. Continuous exposure may be at a high level relative to normal conditions for signal operation. In both cases, the constant interference detector determines whether there is a constant interference such as sunlight for a period of time greater than the period of time of a valid signal or pulse. In one embodiment, if the received signal exceeds a programmable threshold for a programmable period of time when compared to the previously stored ambient light, a control signal is generated to notify the next higher network layer of the sudden change in ambient light. The control signal can be used to discard the current return or process the signal in a different way. Digital logic can be used to determine whether the received signal is valid. If the received signal is not valid, the received signal is discarded. The programmable threshold can be adaptively adjusted based on the changing environmental conditions. This functionality provides a "smart threshold" for the constant interference detector. In other embodiments, the constant interference detector is operable to detect other types of electromagnetic signals.

[0033] 1. Constant disturbance detector

[0034] Figure 3A A LIDAR signal detection 300 according to an embodiment of the present document is depicted. As shown, an optical signal 320 may be received by a transimpedance amplifier (TIA) 302, which in turn generates a TIA signal 324. The TIA signal 324 is an amplified voltage signal representing a received optical signal of the LIDAR system. In some embodiments, the TIA signal 324 may be coupled to a LIDAR signal detector 303. The LIDAR signal detector 303 may detect LIDAR return pulses in a non-blinding environment, but may not be able to detect LIDAR return pulses in a blinding environment. The output of the LIDAR signal detector 303 may be coupled to a LIDAR processor 305. The LIDAR processor 305 controls other components associated with signal generation and detection and one or more of the LIDAR signal detectors. The LIDAR processor 305 then collects all data from the individual detectors to post-process the incoming data from all detectors to form a group of 3D distance data called a point cloud. There may be embodiments where additional capabilities are added to the processor to perform advanced features such as local mapping, object detection, recognition, etc. The LIDAR processor 305 generates an output 344 .

[0035] Figure 3BA constant interference detector 360 is depicted according to an embodiment of the present document. In general, embodiments of the constant interference detector 360 may be applicable to electromagnetic signals. In the following discussion, the operation of the constant interference detector 360 is described with respect to optical signals in a LIDAR system.

[0036] like Figure 3B As shown in , the optical signal 320 from the LIDAR system can be coupled to the TIA 302, which in turn generates a TIA signal 324. The TIA signal 324 is an amplified voltage signal representing the received optical signal of the LIDAR system. The constant interference detector 360 includes the functional blocks of DC detection 310, constant interference threshold 308, filter 304, comparator 306, logic 312, and LIDAR processor 305. Logic 312 may include controller 318, detector 316, filter 314, and filter 315. The functions in logic 312 can be implemented with digital logic. The combination of controller 318 and filter 315 is designated as logic 313.

[0037] The DC detection 310 can store ambient DC values ​​(ambient DC voltages) that represent one or more previous values ​​of the TIA signal 324. To perform this function, one or more previous values ​​of the TIA signal 324 and a control signal 334 from the controller 318 can be coupled to the DC detection 310. The control signal 334 provides control to determine the level of ambient light. The output of the DC detection 310, namely the previously stored voltage 326, represents the value of the previously stored voltage based on the ambient light, which is the calculated DC output. For example, the previously stored voltage 326 can be a DC value with a small offset compared to the DC value of the TIA signal 324. In one embodiment, the previously stored voltage 326 can be 95% of the DC value of the TIA signal 324. In the case of Figure 5 Additional details for DC detection 310 are disclosed in the discussion of .

[0038] The constant interference threshold 308 may determine a programmable percentage of DC detection, such as 40%, depending on the season, time of day, etc. The determination may be based on the TIA signal 324, the previously stored voltage 326, and a programmable percentage control 333. The programmable percentage control 333 may be generated by the controller 318. The output of the constant interference threshold 308 may be a threshold voltage 328 that represents a ratio of the current measurement of the TIA signal 324 to the previously stored ambient light, i.e., the previously stored voltage 326. The threshold voltage 328 may be used to determine, via the comparator 306, whether the optical signal 320 includes a constant interference environment during the current time period. The threshold voltage 328 is a DC voltage. Relative to Figure 4 The constant interference threshold 308 is discussed further.

[0039] Filter 304 may be an optional analog filter to detect a real-time signal or a filtered signal based on TIA signal 324. In one embodiment, filter 304 may be used at startup and then bypassed thereafter. Thus, signal 325 may be a filtered or unfiltered version of TIA signal 324.

[0040] To determine whether the optical signal exceeds the programmable threshold for a programmable period of time, the TIA signal 324 and the threshold voltage 328 are coupled to the comparator 306, which generates a threshold comparison signal 330 based on these signals. The threshold comparison signal 330 indicates whether the optical signal exceeds the programmable threshold. The threshold voltage 328 is a DC voltage and the signal 325 is an AC voltage.

[0041] Logic 312 may determine whether the optical signal 320 in the current time period, as represented by the TIA signal 324, is not a valid signal and may be discarded. Logic 312 may include a filter 314 and a detector 316 and logic 313. Logic 313 may include a filter 315 and a controller 318. Controller 318 may control the length of time to sample (i.e., listen to) the optical signal 320. Controller 318 receives a digital signal 332 coupled from the DC detection 310 via the filter 315, which is a digital output to calculate the TIA DC common mode. Controller 318 may generate the following outputs:

[0042] • A control signal 334 which provides controls for determining the level of ambient light.

[0043] • A programmable percentage control 333 which may determine a programmable percentage of DC detection implemented in the constant interference threshold 308 .

[0044] • A programmable filter control 336 coupled to the filter 314. The programmable filter control 336 controls the length of time that may be helpful in determining a sudden increase in electromagnetic interference.

[0045] Filter 314 receives programmable filter control 336 and threshold comparison signal 330. Filter 314 is a low pass filter and implements a counter function. In one embodiment, the sampling rate can be 8 ns (nanoseconds), operating with 64 counts of 8 ns. Therefore, constant interference detector 360 operates for a time period T of 512 ns before determining whether light signal 320 includes a constant interference environment, i.e., a bright sunlight environment. Filter 314 can generate an output 338 coupled to detector 316.

[0046] Detector 316 may generate detection signal 342, which represents decoded light signal 320, i.e., decoded LIDAR return signal. NoShould the light signal 320 be discarded, a detection signal 342 may be generated. The detector 316 may also generate a calibration signal 340 that controls the periodic calibration and provides the result of the constant interference detection to a memory (not shown). The memory may be a point cloud.

[0047] Figure 3C A LIDAR return signal 380 is shown received by a receiver such as a constant jammer detector 360 in accordance with an embodiment of the present document. Figure 3C The voltage levels in the vertical axis and the time in the horizontal axis are shown. The voltage levels indicated are DC Voltage 1 and DC Voltage 2, where DC Voltage 2 is a programmable value that is less than the value of DC Voltage 1. For example, DC Voltage 2 can be 60% of the value of DC Voltage 1. Figure 3C There is also a relative Figure 3B The threshold voltage discussed is based on previously stored voltage 326 and the threshold voltage based on threshold voltage 328. These threshold voltages may be constant during time period T. Time period T is an operation interval for determining whether optical signal 320 includes a constant interference environment.

[0048] The LIDAR return signal 380 is shown by the “previous value” of the TIA signal 324 and the “new value” of the TIA signal 324. The “previous value” of the TIA signal 324 occurs in a previous time period relative to the “new value” of the TIA signal 324. As shown, the “previous value” of the TIA signal 324 represents a valid LIDAR return signal. The pulse of the “previous value” of the TIA signal 324 may exceed the threshold based on the threshold voltage 328, but only lasts for a period of time t. The period of time t is relatively short compared to the period of time T, which is an operating interval for determining whether the optical signal 320 includes a constant interference environment. Therefore, the logic 312 can determine the “previous value” of the TIA signal 324 as a valid LIDAR return signal.

[0049] The “new value” of the TIA signal 324 may be a signal that occurs immediately after the “previous value” of the TIA signal 324. Thus, the “previous value” of the TIA signal 324 may be the basis for determining the threshold voltage 328 through the DC detection 310 and the constant interference threshold 308. Figure 3C As shown in FIG, the “new value” of the TIA signal 324 includes a constant voltage, DC voltage 2, which exceeds a threshold based on a previously stored voltage 326. Additionally, the “new value” of the TIA signal 324 exceeds a threshold based on a threshold voltage 328. Since the “new value” of the TIA signal 324 exceeds a threshold duration period T based on the threshold voltage 328, the calculations of the controller 318 may determine that the “new value” of the TIA signal 324 may be discarded. Note that “exceeding a threshold” means that the voltage decreases to a level below the threshold.

[0050] The threshold based on threshold voltage 328 may be adaptively adjusted based on previously received LIDAR signals and other environmental conditions. Examples of environmental conditions may include, but are not limited to, season, weather, time of day. Thus, the subject threshold may be considered a "smart threshold." Threshold voltage 326 may be periodically adjusted.

[0051] 2. Constant Interference Threshold Block

[0052] Figure 4 The functional blocks of the constant interference threshold 400 according to an embodiment of the present disclosure are depicted. The constant interference threshold 400 discloses Figure 3B 404. The constant disturbance threshold 400 includes a resistor R1 402 coupled to a variable resistor R2 404. A previously stored voltage 326 may be coupled to one end of the resistor R1 402. The constant disturbance threshold 308 receives the TIA signal 324 and a programmable percentage control 333, which is used to determine the value of the variable resistor R2 404. Thus, the ratio of the resistor R1 402 and the variable resistor R2 404 may detect a voltage that determines a threshold voltage 328. The threshold voltage 328 may be a sunlight threshold or a blinding light threshold.

[0053] C. DC detection block

[0054] Figure 5 Depicted are two functional blocks 500 including DC detection 310 and associated logic 313 according to an embodiment of the present disclosure. Figure 5 Public Figure 3B 310 and logic 313 of the DC detection. DC detection 310 includes filter 502, digital-to-analog converter (DAC) 506, and comparator 504. DAC 506 can receive a digital signal control signal 334 from controller 318, which provides control to determine the level of ambient light. In turn, DAC 506 can generate digital signal 332 and previously stored voltage 326 (calculated DC output). DAC 506 can also generate signal 528, which is used as a reference to find the incoming signal. A variation of signal 528 is previously stored voltage 326, which is the calculated DC output.

[0055] Filter 502 may be an optional analog filter to detect a real-time signal or a filtered signal based on TIA signal 324. In one embodiment, filter 502 may be used at startup and then bypassed thereafter. Thus, signal 525 may be a filtered or unfiltered version of TIA signal 324. Comparator 504 may receive signal 525 and signal 528 to generate digital signal 332. Digital signal 332 is then filtered by filter 315 to generate control signal 339. Control signal 339 may be coupled to controller 318. Filter 315 also generates output 535.

[0056] D. Detection Methods

[0057] Fig. 6A and 6B Flowcharts 600 and 620 are graphically shown, which describe a method for detecting constant interference in an electromagnetic signal according to an embodiment of the present disclosure. The method includes the following steps:

[0058] Receiving a first electromagnetic signal in a first time period; (step 602)

[0059] Storing the environmental DC value of the first electromagnetic signal to define a first threshold; (step 604)

[0060] Receiving a second electromagnetic signal in a second time period occurring after the first time period; (step 606)

[0061] Generate a second threshold based on the first threshold, the second electromagnetic signal and the programmable percentage control; (step 608)

[0062] Generate a threshold comparison signal based on the second threshold and the second electromagnetic signal; (step 610)

[0063] Detecting whether the second electromagnetic signal includes constant interference based on the second threshold and the second electromagnetic signal; (step 611)

[0064] If the second electromagnetic signal exceeds the second threshold, the second electromagnetic signal includes constant interference, and the second electromagnetic signal is then discarded; (steps 612, 614)

[0065] If the second electromagnetic signal does not exceed the second threshold, the second electromagnetic signal does not include constant interference, and then the second electromagnetic signal continues the detection process (steps 612, 616).

[0066] E. System Example

[0067] In an embodiment, aspects of the present patent document may relate to or be implemented on a signal detection system / computing system. For the purposes of this disclosure, a computing system may include any instrumentality or aggregation of tools that can be operated to calculate, compute, determine, classify, process, transmit, receive, retrieve, initiate, route, switch, store, display, transmit, indicate, detect, record, copy, process or utilize any form of information, intelligence or data for commercial, scientific, control or other purposes. For example, a computing system may be a personal computer (e.g., a laptop), a tablet computer, a tablet phone, a personal digital assistant (PDA), a smart phone, a smart watch, a smart package, a server (e.g., a blade server or a rack server), a network storage device, or any other suitable device, and may differ in size, shape, performance, functionality, and price. A computing system may include random access memory (RAM), one or more processing resources, such as a central processing unit (CPU) or hardware or software control logic, ROM, and / or other types of memory. Additional components of a computing system may include one or more disk drives, one or more network ports for communicating with external devices, and various input and output (I / O) devices, such as a keyboard, a mouse, a touch screen, and / or a video display. The computing system may also include one or more buses operable to transmit communications between the various hardware components.

[0068] Figure 7 Depicted is a simplified block diagram of a computing device / signal detection system (or computing system) according to an embodiment of the present disclosure. It will be understood that the functionality shown for system 700 is operable to support various embodiments of the signal detection system - although it should be understood that the signal detection system may be configured differently and include different components.

[0069] like Figure 7 As shown in , the system 700 includes one or more central processing units (CPUs) 701, which provide computing resources and control the computer. The CPU 701 can be implemented with a microprocessor or the like, and can also include one or more graphics processing units (GPUs) 717 and / or floating point coprocessors for mathematical calculations. The system 700 can also include a system memory 702, which can take the form of a random access memory (RAM), a read-only memory (ROM), or both.

[0070] like Figure 7As shown in , multiple controllers and peripherals may also be provided. Input controller 703 represents an interface to various input devices 704 (one or more) such as a keyboard, mouse, or stylus. There may also be a scanner controller 705 that communicates with a scanner 706. System 700 may also include a storage controller 707 for docking with one or more storage devices 708, each storage device 708 including a storage medium such as a tape or disk or an optical medium that may be used to record a program of instructions for an operating system, utility program, and application, which may include an embodiment of a program that implements various aspects of the present invention. (One or more) storage devices 708 may also be used to store processed data or data to be processed according to the present invention. System 700 may also include a display controller 709 for providing an interface to a display device 711, which may be a cathode ray tube (CRT), a thin film transistor (TFT) display, or other type of display. Computing system 700 may also include a signal detection controller 712 for communicating with signal detection 713. The communication controller 714 can interface with one or more communication devices 715, which enables the system 700 to connect to remote devices through any of a variety of networks or through any suitable electromagnetic carrier signals including infrared signals, and the various networks include the Internet, cloud resources (e.g., Ethernet cloud, Fibre Channel over Ethernet (FCoE) / Data Center Bridging (DCB) cloud, etc.), local area network (LAN), wide area network (WAN), storage area network (SAN).

[0071] In the system shown, all major system components can be connected to bus 716, which can represent more than one physical bus. However, various system components may or may not be physically close to each other. For example, input data and / or output data can be remotely transmitted from one physical location to another physical location. In addition, programs that implement various aspects of the present invention can be accessed from a remote location (e.g., a server) via a network. Such data and / or programs can be transmitted through any of a variety of machine-readable media, including but not limited to: magnetic media such as hard disks, floppy disks, and tapes; optical media such as CD-ROMs and holographic devices; magneto-optical media; and hardware devices specifically configured to store or store and execute program codes, such as application specific integrated circuits (ASICs), programmable logic devices (PLDs), flash memory devices, and ROM and RAM devices.

[0072] Embodiments of the present invention may be encoded on one or more non-transitory computer-readable media having instructions for one or more processors or processing units to cause the steps to be performed. It should be noted that one or more non-transitory computer-readable media should include volatile and non-volatile memory. It should be noted that alternative implementations are possible, including hardware implementations or software / hardware implementations. The functions of hardware implementations can be implemented using (one or more) ASICs, programmable arrays, digital signal processing circuits, or the like. Therefore, the term "device" in any claim is intended to cover both software and hardware implementations. Similarly, the term "one or more computer-readable media" used herein includes software and / or hardware with an instruction program embodied thereon, or a combination thereof. In view of these implementation alternatives, it should be understood that the drawings and the accompanying descriptions provide the functional information required for those skilled in the art to write program code (i.e., software) and / or manufacture circuits (i.e., hardware) to perform the desired processing.

[0073] It should be noted that embodiments of the present invention may further relate to computer products having non-transitory tangible computer-readable media having computer code thereon for performing various computer-implemented operations. The media and computer code may be those specially designed and constructed for the purposes of the present invention, or they may be of a kind known or available to those skilled in the relevant art. Examples of tangible computer-readable media include, but are not limited to: magnetic media such as hard disks, floppy disks, and tapes; optical media such as CD-ROMs and holographic devices; magneto-optical media; and hardware devices specially configured to store or store and execute program code, such as application-specific integrated circuits (ASICs), programmable logic devices (PLDs), flash memory devices, and ROM and RAM devices. Examples of computer code include machine code, such as machine code produced by a compiler, and files containing higher-level code executed by a computer using an interpreter. Embodiments of the present invention may be implemented in whole or in part as machine executable instructions, which may be in program modules executed by a processing device. Examples of program modules include libraries, programs, routines, objects, components, and data structures. In a distributed computing environment, program modules may be physically located in a local, remote, or both setting.

[0074] Those skilled in the art will recognize that no computing system or programming language is essential for implementing the present invention. Those skilled in the art will also recognize that many of the above elements can be physically and / or functionally separated into submodules or combined together.

[0075] In summary, a method for detecting a constant interference environment by an electromagnetic receiver may include receiving an electromagnetic signal; and determining whether the electromagnetic signal exceeds a programmable threshold for a programmable time period, wherein the programmable threshold is based on a previously received electromagnetic signal. If the electromagnetic signal exceeds the programmable threshold for a programmable time period, the electromagnetic signal is discarded. Exceeding the programmable threshold for a programmable time period indicates that the electromagnetic signal includes a constant interference environment. If the electromagnetic signal does not exceed the programmable threshold for a programmable time period, the detection process continues. Likewise, if the electromagnetic signal does exceed the programmable threshold for a programmable time period, a control signal is generated to notify the next higher OSI network layer of the processor of the controller 318 of the sudden change in the electromagnetic signal.

[0076] The programmable thresholds can be adaptively adjusted based on changing environmental conditions. In some embodiments, the environmental conditions include season, weather, and / or time of day.

[0077] In some embodiments, the electrical detection signal is a light signal, and the light signal is detected by the LIDAR system. The light signal may exceed the programmable threshold due to a burst of sunlight or other light source. The light signal may exceed the programmable threshold due to continuous exposure to sunlight or other light source.

[0078] A system for detecting a constant interference environment in an electromagnetic signal may include:

[0079] 1) a DC detection block that may store ambient DC values ​​representing one or more previous input values ​​of the input signal and store a voltage based on the previous input values, wherein the stored voltage defines a first threshold value (previously stored voltage 326);

[0080] 2) a constant disturbance threshold block that can generate a threshold voltage for determining a constant disturbance, wherein the threshold voltage defines a second threshold (threshold voltage 328), which can be based on an ambient DC value of a previous input signal, i.e., the first threshold (previously stored voltage 326), a current input value of a current input signal, and a programmable percentage control;

[0081] 3) a comparator that generates a threshold comparison signal based on the second threshold (threshold voltage 328) and the current input signal, and

[0082] 4) A logic block that can determine whether the electromagnetic signal in the current time period includes constant interference. Generally, if the received electromagnetic signal includes constant interference, the electromagnetic signal can be discarded. If the electromagnetic signal does not include constant interference, the electromagnetic signal in the current time period can continue the detection process.

[0083] The logic block includes a controller that controls the length of time the input signal is sampled. The controller generates:

[0084] • A control signal 334 which provides a control to determine the level of ambient light.

[0085] • Programmable percentage control 333, which can determine the programmable percentage of DC detection implemented in the constant interference threshold block.

[0086] • A programmable filter control 336 coupled to the filter 314 .

[0087] Those skilled in the art will appreciate that the foregoing examples and embodiments are exemplary and do not limit the scope of the present disclosure. It is intended that all permutations, enhancements, equivalents, combinations and improvements thereof that are clear to those skilled in the art upon reading the specification and studying the drawings are included within the true spirit and scope of the present disclosure. It should also be noted that the elements of any claim may be arranged differently, including having multiple dependencies, configurations and combinations.

Claims

1. A method comprising: receiving a first electromagnetic signal at a LIDAR signal detector; determining, by the LIDAR signal detector, whether the first electromagnetic signal exceeds a programmable threshold for at least a programmable period of time, wherein the programmable threshold is based on a second previously received electromagnetic signal; and generating a first control signal to prevent the LIDAR processor from generating range data based on the first electromagnetic signal and generating a second control signal to indicate a change in ambient light based on a determination that the first electromagnetic signal exceeds a programmable threshold for at least a programmable period of time, Wherein exceeding the programmable threshold for at least a programmable period of time indicates that the first electromagnetic signal is generated by a constant interference.

2. The method according to claim 1, further comprising: receiving a third electromagnetic signal at the LIDAR signal detector; determining, by the LIDAR signal detector, whether the third electromagnetic signal exceeds a programmable threshold for at least a programmable period of time; and Based on a determination that the third electromagnetic signal did not exceed the programmable threshold for at least a programmable period of time, range data is generated by the LIDAR processor based on the third electromagnetic signal. 3 . The method of claim 1 , further comprising adaptively adjusting the programmable threshold based on changing environmental conditions.

4. The method according to claim 3, wherein: Environmental conditions include season, weather and / or time of day.

5. The method according to claim 1, wherein: The first electromagnetic signal is derived from the optical signal.

6. The method according to claim 5, wherein: The first electromagnetic signal exceeds the programmable threshold for at least a programmable period of time due to a burst of sunlight or other light source or continuous exposure to sunlight or other light source.

7. A system comprising: a DC detection circuit operable to store a first voltage corresponding to a level of ambient light, wherein the first voltage defines a first threshold; a constant interference threshold circuit operable to determine a second threshold based on the first threshold; a comparator operable to generate a threshold comparison signal based on the second threshold and the first electromagnetic signal; and A logic circuit is operable to control the DC detection circuit to determine the level of ambient light and further determine whether the first electromagnetic signal exceeds a second threshold for at least a programmable time period based on the threshold comparison signal, wherein exceeding the second threshold for at least the programmable time period indicates that the first electromagnetic signal is generated by a constant interference.

8. The system according to claim 7, wherein: Based on determining that the first electromagnetic signal is generated by the constant interference, the logic circuit is further operable to generate a control signal to prevent the LIDAR processor from generating range data based on the first electromagnetic signal.

9. The system according to claim 7, wherein: Based on determining that the first electromagnetic signal is not generated by a constant interference, the logic circuitry may be further operable to signal the LIDAR processor to generate range data based on the first electromagnetic signal.

10. The system according to claim 7, wherein: The logic circuit may also be operable to control the length of time that the electromagnetic signal is sampled.

11. The system according to claim 7, wherein: The logic circuit is further operable to adjust the second threshold based on environmental conditions.

12. The system according to claim 7, wherein: The first electromagnetic signal is derived from the optical signal.

13. The system according to claim 12, wherein: The first electromagnetic signal exceeds the second threshold for at least a programmable period of time due to a burst of sunlight or other light source or continuous exposure to sunlight or other light source.

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