Field of the Invention

[0001] The present invention relates to systems and methods for processing audio signals with a vehicle sensory system. Background of the Invention

[0002] Driver assistance systems and sensing systems for semi- or fully-autonomous vehicles may use a variety of sensor types to effectively allow a vehicle to sense its surroundings. However, each sensor type is associated with drawbacks. Optical systems using cameras that capture images, or optical sensors to capture reflected light (lidar), are limited by "line-of- sight", are relatively expensive, and require powerful processors to deal with large amounts of data. Radar systems that detect reflected radio waves are less data-intensive, but provide far less information. Systems that detect reflected ultrasound waves are useful only in short ranges, and are limited to applications such as parking-assist sensors.

[0003] To the knowledge of the inventors, there are no driver assistance systems or autonomous vehicle systems that use microphones or other audio sensors to provide additional data representative of the vehicle surroundings. In order to do so, one challenge to be overcome is integrating the audio sensors with the driver assistance system or autonomous vehicle system. Another challenge is presented by noise created by wind or air-buffeting, which may make it difficult or impossible to detect a target sound of interest. Although, noise can be electronically filtered from a sound sample, this increases computational time and costs to an extent which may not be practical for near real-time sound detection as required in vehicular applications.

Summary of the Invention

[0004] In one aspect, the present invention comprises a system for providing audio-derived information to a vehicle operator, the system comprising:

(a) at least one microphone mounted in or to the vehicle for generating an analog signal in response to sound waves external to the vehicle; and (b) an analysis module associated with the at least one microphone for converting the analog signal to a digital signal, wherein the analysis module is configured to communicate the digital signal to a vehicle data bus for communicating or transferring the digital signal to the vehicle operator or vehicle control system.

[0005] In one embodiment, the vehicle operator is a human driver and the digital signal results in a notification to the driver. In another embodiment, the vehicle operator is a vehicle control system, such as in an autonomous or semi-autonomous vehicle, and the digital signal results in an electronic notification to the vehicle control system.

[0006] In another aspect, the invention may comprise a method for providing audio-derived information to a vehicle operator, the method comprising the steps of:

(a) providing at least one externally facing microphone with the vehicle for

generating an analog signal in response to sound waves external to the vehicle;

(b) converting the analog signal to a digital signal and communicating the digital signal to a vehicle data bus to transfer the digital signal to the vehicle operator.

Brief Description of the Drawings

[0007] In the drawings shown in the specification, like elements may be assigned like reference numerals. The drawings are not necessarily to scale, with the emphasis instead placed upon the principles of the present invention. Additionally, each of the embodiments depicted are but one of a number of possible arrangements utilizing the fundamental concepts of the present invention.

[0008] Figure 1 shows a vehicle equipped with an embodiment of a system of the present invention, and an emergency vehicle emitting a siren sound, while travelling on a roadway. [0009] Figure 2 shows a schematic depiction of a first embodiment of a system of the present invention comprising a single microphone with processing elements and an associated analysis module operatively connected to a vehicle control system via a data bus.

[0010] Figure 3 shows a front view of a vehicle incorporating a plurality of microphones, in accordance with an embodiment of the system of the present invention.

[0011] Figure 4 shows a rear view of a vehicle incorporating a plurality of microphones, in accordance with an embodiment of the system of the present invention.

[0012] Figure 5 shows a vehicle headlight assembly incorporating a microphone, in accordance with an embodiment of the system of the present invention. [0013] Figure 6 shows a vehicle side mirror assembly incorporating a microphone, in accordance with an embodiment of the system of the present invention.

[0014] Figure 7 shows an exploded perspective view of an embodiment of an enclosure of the present invention for an audio sensor in the form of a transducer.

[0015] Figure 8 shows a schematic depiction of an embodiment of a system of the present invention comprising multiple microphones operatively connected to a data bus at multiple nodes.

[0016] Figure 9 shows a schematic depiction of another embodiment of a system of the present invention comprising multiple microphones operatively connected to a data bus at a single node. Detailed Description of Embodiments of the Invention

[0017] Definitions. Any term or expression not expressly defined herein shall have its commonly accepted definition understood by a person skilled in the art. As used herein, the following terms have the following meanings.

[0018] "Audio sensor" refers to a device that detects and converts a sound wave into an electrical signal. In an embodiment, an audio sensor may be a microphone comprising a transducer. [0019] "Computer processor" refers to an electronic device that is capable of processing an input electronic signal to produce an output electronic signal. In embodiments, a computer processor may include one or more devices commonly referred to as a programmable logic controller, a printed circuit board, an integrated circuit, a microcontroller, a processor or the like. A "computing device" comprises at least one computer processor, and may also include computer-readable memory which may include instructions which are executable by the processor.

[0020] "Non-transitory computer-readable memory" refers to a tangible medium capable of storing data and/or instructions in a format readable by a computer processor. In embodiments, a non-transitory computer-readable memory may include magnetic media, optical media, or solid-state media.

[0021] "Target sound" refers to a specific sound of interest to be detected. A target sound may be within the human audible spectrum, or outside of the human audible spectrum (e.g., ultrasonic sounds in excess of 20 kHz). As non-limiting examples, in the context of a moving vehicle, a target sound may be the sound produced by an emergency vehicle siren, a horn of another vehicle, a crosswalk assistance sound for visually impaired pedestrians, skidding tires indicating a vehicle losing control, a vehicle colliding with another vehicle or an object, animal noises, or human voices.

[0022] "Vehicle" refers to a machine used to transport people and/or goods. As a non-limiting example, a vehicle may be any self-powered, wheeled vehicle including an automobile, motorcycle, truck, or bus. A vehicle may be non-autonomous, semi-autonomous, or fully autonomous.

[0023] "Vehicle control system" refers to a system that controls, directly or indirectly, any aspect of a vehicle's dynamics, or that provides information relevant to controlling any aspect of a vehicle's dynamics. A vehicle control system is distinguished from a vehicle entertainment system that is used solely to entertain a vehicle's driver or occupants. For example, a GNSS or GPS navigation system may be considered part of a vehicle control system, as it provides useful information to a driver regarding a vehicle's position and direction of travel, even though the satellite navigation system may be integrated into what is conventionally referred to as an "infotainment" system. A vehicle control system may or may not have a human interface.

[0024] In general terms, the invention may comprise a vehicular auditory sensing system to provide an input to a vehicle operator or a vehicle control system, comprising at least one microphone coupled to an analysis module configured to convert an analog signal produced by the microphone to a digital signal and to communicate the digital signal to a vehicle data bus for communicating the digital signal to the vehicle operator or vehicle control system.

[0025] The information contained in the digital signal and derived from the audio sensors of the present invention may be processed and used to provide notification to the driver, a vehicle control system, or a remote entity, and/or processed and used to adjust visual or audio conditions inside the vehicle, and/or used to control the vehicle dynamics without human input or to override human input.

[0026] System. Figure 1 shows a vehicle (10) on a roadway (12) with an approaching emergency vehicle (14) emitting a siren sound as depicted by sound waves (16). The vehicle (10) is equipped with an embodiment of the system (100) of the present invention for detecting the siren sound as a target sound, having a detection range denoted by the zone (18). In this example, the vehicle (10) is also equipped with an optical sensing system, a radar sensing system, and an ultrasound sensing system having detection ranges denoted by zones (20), (22), and (24), respectively. The system (100) may be installed in the vehicle (10) during original manufacturing or as an aftermarket system to interface with existing vehicle data buses and vehicle control systems.

[0027] Figure 2 shows a schematic representation of one embodiment of a system (100) of the present invention for providing audio-derived information to a vehicle control system, using an external microphone (102) or other audio sensor operatively connected to an analysis module (112), which is in turn operatively connected to a vehicle data bus (114) that is connected with a vehicle control system (116). In embodiments, the system (100) may also include a sound-filtering or sound-absorbing device for the external microphone, as shown in Figure 7. The components of the system (100) are described in greater detail below. [0028] Audio sensor. The at least one microphone (102) is outward facing meaning it detects sound waves in the external environment of the vehicle (10), and converts them into an analog signal for processing by the system (100). The microphone may be physically located anywhere on or in a vehicle, provided it is directly exposed externally, or is provided a channel by which external sounds can reach the microphone.

[0029] In embodiments, the microphone (102) may be incorporated into the vehicle (10) in a variety of ways and locations. Preferably, there are four or more microphones (102), which provides 360° of coverage around the vehicle. For example, as shown in Figures 3 and 4, microphones (102) may be conveniently integrated with light assemblies around the periphery of the vehicle (10), such as a headlight, fog light or driving light, taillight, side marker or signal light assembly, in side-mirrors, in bumpers, and/or in a lower fairing. As another example, a microphone (102) may be located in a housing that is attached to the vehicle (10), such as a separate discrete housing, a headlight housing (103) as shown in Figure 5, or in a side-mirror housing (105) as shown in Figure 6. The housings may include other sensing devices such as cameras, radar, lidar and ultrasonic sensors, or other devices on the exterior of the vehicle (10) such as side-mirrors, antennas, headlights, taillights, bumpers or flashing lights. While the microphones (102) may be physically integrated with other sensors in the same housing, data may be transmitted from the different microphones using the same or different vehicle data bus networks. [0030] Enclosure for audio sensor. In one embodiment of the system, a sound-filtering or sound-absorbing device may be provided to mechanically filter or absorb sound waves impinging on a microphone (102) which is externally exposed to the environment, so as to reduce the amount of noise detected by the transducer (101) of the microphone (102). The device comprises an enclosure (202) filled with a sound-attenuating material (206), which preferably is relatively effective in absorbing low frequency sounds, for example, sounds with a frequency less than about 500 Hz.

[0031] In one embodiment, as shown in Figure 7, the device includes a rear enclosure (200) behind the transducer (101). The device also includes a front enclosure (202) in front of the transducer (101) of the microphone (102), which contains the sound-attenuating material (206) and forms an acoustic chamber (204) in front of the transducer (101). Port openings (208) in the front enclosure (202) allow sound-waves to travel into the acoustic chamber (204) and impinge on the transducer. The port openings (208) should be configured to avoid resonant frequencies caused by air movement around or into the port openings (208).

[0032] In one embodiment, as shown in Figure 7, the front enclosure (202) is cylindrical, but may also be parabolic, conical or prismatic. Preferably, the acoustic chamber (204) formed by the front enclosure (202) has a length greater than its width, such that sound waves must travel some distance through the sound absorbing material before reaching the transducer. The enclosure (200, 202) itself is preferably an acoustical material which displays some sound absorption characteristics. Alternatively, either or both the inner and outer surfaces of the front enclosure (202) may also be coated with a suitable material having sound absorption characteristics.

[0033] Road and wind noise produced by a moving vehicle has substantial components in the range below about 500 Hz. In one embodiment, the sound-attenuating material (206) is preferably a low-density porous or fibrous material which attenuates sound waves having a frequency less than about 500 Hz. High absorption at low frequencies is achieved by inserting a low-density fibrous or porous material in the acoustic chamber (204). The low-density sound-attenuating material (206) provides a sufficiently tortuous path so that sound waves cannot directly reach the transducer (101) from any of the port openings (208).

[0034] In one embodiment, the sound-attenuating material (206) may preferably be easily shapeable, be stable through a large temperature range, and should not be toxic or a pollutant. It would be further preferable if the sound-attenuating material (206) is easily recyclable and is cost-efficient to manufacture and handle.

[0035] In one embodiment, the sound-attenuating material (206) may comprise insulation products such as mineral wool, fiberglass wool, cellulose or cotton. It is preferred that the material be waterproof, in that it does not absorb water or has a hydrophobic surface. A representative material comprises stone (basalt) wool products such as Roxul Safe 'n' Sound ™ (Roxul Inc.; Milton, Ontario, Canada), which has a density of about 40 kg/m ³ . Table 1, below, shows the sound absorption coefficient (SAC) of 3 -inch thick Roxul Safe 'n' Sound™ insulation at different frequencies when tested in accordance with the ASTM C423 standard (ASTM International; West Conshohocken, Pennsylvania, USA). In Table 1, the Noise Reduction Coefficient (NRC) is the average of the SACs at the 6 different frequencies.

[0036] Table 2, below, summarizes the acoustical performance characteristics and density of other materials that may also be used for the sound-attenuating material (208). The products branded Roxul™ are available from Roxul Inc., Milton, Ontario, Canada; the products branded by ATS Acoustics™ are available from ATS Acoustics, Piper City, Illinois, USA; the products branded Owens Corning™ are available from Owens Corning Canada Inc., Edmonton, Alberta, Canada; the products branded Applegate™ are available from Applegate Insulation, Webberville, Michigan, USA.

Owens Corning 703™ (2" thickness) 1.00 0.17 1.14 1.07 0.98 3.0

Owens Corning 705™ (1 " thickness) 0.65 0.02 0.63 0.85 0.95 6.0

Owens Corning 705™ (2" thickness) 0.95 0.16 1.02 1.01 0.99 6.0

Other material

Applegate™ Cotton Batts 1.05 0.27 1.17 1.15 1.06 2.5

[0037] In one embodiment, an outer protective cover (not shown) may be provided in front of a microphone enclosure or channel, to prevent water and debris from reaching the sound- attenuating material and/or the microphone. The cover must still allow sufficient sound to pass through to the microphone. In one embodiment, the cover can made from any membranous material that is waterproof or water resistant, and preferably waterproof and breathable, such as a tightly woven fabric bonded with a polytetrafluoroethylene polymer (Gore-Tex™). The membrane may also be made from other polymer or elastomer materials such as latex, tightly woven synthetic textile, or a nonwoven product such as spunbond olefin or flashspun polyethylene fiber (Tyvek™), and may be coated or uncoated.

[0038] Analysis Module. Conventional vehicle data buses (114) are not capable of transmitting analog sound signals. Therefore, each microphone (102) of the present invention is preferably bundled with an analysis module (112) to convert an analog signal produced by the microphone (102) to a digital representation of sound and, in one embodiment, to identify the digital sample as a sound of interest. Thus, the vehicle data bus need only to communicate a signal which is a positive identification of a sound of interest, rather than any analog or digital auditory data.

[0039] Multibit digital encoding of sound can produce streams of data in the range of hundreds of kilobits per second, which can overwhelm conventional data buses in a vehicle. Therefore, each microphone is associated with an analysis module comprising a computing device (e.g., a microcontroller that provides a computer processor on a single integrated circuit) which implements algorithms to produce a digital signal, representative of sound and having a manageable size, which carries characteristic information about the sound, or comprises confirmation of detection or identification of a target sound, and which can be transmitted or streamed over the vehicle data bus (114). In one embodiment, the microcontroller may also analyze the analog input to determine power and signal strength, in which case amplitude information of the analog signal is derived and transferred to the vehicle data bus for communication to the vehicle control system.

[0040] Vehicle data bus. A "vehicle data bus" refers to a specialized internal communications network that interconnects components inside a vehicle. Networking protocols must account for special requirements for vehicle control, such as assurance of message delivery, non- conflicting messages, minimum time of delivery, low cost, and EMF noise resilience, as well as redundant routing and other characteristics. Known protocols and buses include the Controller Area Network (CAN), Local Interconnect Network (LIN), and others. CAN is a mid-level control bus for which there is a power supply as part of the nominal specification. High speed CAN buses offers baud rates from 40 Kbit/s to 1 Mbit/sec, while low speed/fault tolerant CAN offers baud rates from 40 Kbit/s to 125 Kbits/sec. [0041] LIN is a lower performance, non-critical bus which is typically used to control accessories such as side mirrors. A low-speed network such as a LIN bus could be used as a communication path for a vehicle control system which communicates only a notification of detection of a particular target sound. For example, microphones (102) placed in the side view mirrors (as shown in Figure 6) may be polled periodically, or push a notification, regarding target sound detection.

[0042] Figure 8 shows a schematic representation of an embodiment of a system (100) having multiple microphones (102a to 102d), each with an associated analysis module which is physically integrated with the microphone (112a to 112d). Preferably, a microphone (102a to 102d) will be connected to the vehicle data bus (114) at a location that is physically proximate to where the microphone is placed. For example, microphones (102a, 102b) installed as part of a headlight assembly are connected to locations of the vehicle data bus (114) near the headlight assemblies, while microphones (102c, 102d) installed on vehicle side mirrors are connected to locations of the vehicle data bus near the side-view mirrors. The data buses may not necessarily be the same data bus. In particular, it may be advantageous to connect directly to an existing vehicle data bus (114), to avoid adding additional wiring. [0043] Other known devices or systems may be connected to the bus (114) in conventional fashion, and may potentially be used to deliver notifications to a vehicle operator, in the case of a sound system (stereo system or a chime) or display system (dashboard or display screen). Other sensors and control systems (e.g. the ECU) may be connected to the bus, as is well known in the art.

[0044] Figure 9 shows a schematic representation of an alternative embodiment of a system (100) having multiple microphones (102a to 102d). In one embodiment, the system may comprise circuitry that combines the digital signals of the plurality of microphones/analysis modules to produce a combined signal, and presents the combined signal to a single node of the vehicle data bus. In some cases, it may be advantageous to provide a separate bus for the microphones (102). In one embodiment, a plurality of microphones (102a to 102c) and associated circuitry are powered from a single module or box (118) which provides power to sensors, combines their output signals and presents this as a single node on the vehicle data bus (114). [0045] Additional processing components. In one embodiment, as shown in Figure 2, the system (100) includes a first analog filter (104), a second analog filter (106), and an amplifier (108) which may be a logarithmic amplifier, to process the analog signal produced by the microphone (102). The analog signal is then received by the comparator (110) where the analog form is converted to a digital signal in a voltage level detector which effectively functions as an analog-to-digital (A/D) converter. The amplifier (108), the first analog filter (104), and the second analog filter (106) may be arranged to process a signal in a different order from that shown in Figure 2. The analysis module (112) then checks if the processed signal contains any sounds of interest, and communicates their identification and presence to a vehicle operator or to a vehicle control system (1 16) via the vehicle data bus interface (114). Other important characteristics (such as timing and signal strength) may also be identified and communicated.

[0046] The system (100) may be tuned to detect and report specific sounds of interest to a driver or a vehicle control system. A non-limiting list of such sounds may include emergency vehicle sirens, other vehicle horns, crosswalk assistance sounds for visually impaired pedestrians or other sounds associated with pedestrians, skidding tires which may be indicative of a vehicle losing control, sounds associated with vehicles colliding with other vehicles or obstructions. Exemplary systems include the siren detection systems as described in co-pending U.S. Patent Application No. 15/909,709, filed March 1, 2018, the entire contents of which are incorporated herein by reference, where permitted. In general, such systems include a computer processor configured to compare the digital signal produced by the analog-to-digital converter to a stored digital target sound template to determine a degree of similarity between the digital signal and the template, and to generate an output signal if the degree of similarity exceeds a threshold.

[0047] Sensory data received from the plurality of microphones may be synchronized with an onboard computing device to derive directional, geo-spacing or identification information regarding the vehicle surroundings as primary or redundant perception sensors. The synchronization between audio sensing devices may be through the onboard computing device, may be self-synchronized in the vehicle network, or may be synchronized by peer-to- peer synchronization. In one embodiment, a central module (118) periodically, for example every few seconds, sends out a synchronization pulse to all the microphones on the bus. Upon receipt of this synchronization pulse, the microphones reset their time counters to essentially synchronize themselves to the same time reference and avoid drifts between the clocks in each microphone. The microphones send timestamps to the central module indicating when they detected signals, and the differences in these timings are what the central module uses to calculate direction.

[0048] Interpretation. Aspects of the present invention may be described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

[0049] The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

[0050] The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims appended to this specification are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. [0051] References in the specification to "one embodiment", "an embodiment", etc., indicate that the embodiment described may include a particular aspect, feature, structure, or characteristic, but not every embodiment necessarily includes that aspect, feature, structure, or characteristic. Moreover, such phrases may, but do not necessarily, refer to the same embodiment referred to in other portions of the specification. Further, when a particular aspect, feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of one skilled in the art to affect or connect such module, aspect, feature, structure, or characteristic with other embodiments, whether or not explicitly described. In other words, any module, element or feature may be combined with any other element or feature in different embodiments, unless there is an obvious or inherent incompatibility, or it is specifically excluded. [0052] It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for the use of exclusive terminology, such as "solely," "only," and the like, in connection with the recitation of claim elements or use of a "negative" limitation. The terms "preferably," "preferred," "prefer," "optionally," "may," and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.

[0053] The singular forms "a," "an," and "the" include the plural reference unless the context clearly dictates otherwise. The term "and/or" means any one of the items, any combination of the items, or all of the items with which this term is associated. The phrase "one or more" is readily understood by one of skill in the art, particularly when read in context of its usage.

[0054] The term "about" can refer to a variation of ± 5%, ± 10%, ± 20%, or ± 25% of the value specified. For example, "about 50" percent can in some embodiments carry a variation from 45 to 55 percent. For integer ranges, the term "about" can include one or two integers greater than and/or less than a recited integer at each end of the range. Unless indicated otherwise herein, the term "about" is intended to include values and ranges proximate to the recited range that are equivalent in terms of the functionality of the composition, or the embodiment.

[0055] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges recited herein also encompass any and all possible sub-ranges and combinations of sub-ranges thereof, as well as the individual values making up the range, particularly integer values. A recited range includes each specific value, integer, decimal, or identity within the range. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, or tenths. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc.

[0056] As will also be understood by one skilled in the art, all language such as "up to", "at least", "greater than", "less than", "more than", "or more", and the like, include the number recited and such terms refer to ranges that can be subsequently broken down into sub-ranges as discussed above. In the same manner, all ratios recited herein also include all sub-ratios falling within the broader ratio.