Patent Publication Number: US-2015088373-A1

Title: Optical communications and obstacle sensing for autonomous vehicles

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a communication system and in particular to a communication system that utilizes modulating light sources to transmit information between surrounding vehicles and/or between vehicles and transportation fixtures. 
     2. State of the Art 
     The design and use of autonomous, or driverless, automobiles has become increasingly popular and poses a tremendous market opportunity. At present, autonomous vehicle technology can reduce traffic collisions, commute time, energy consumption, transportation costs, and the need for complex infrastructure. Autonomous vehicle technology can have an even larger impact in developing countries. Just as cell phones allowed developing countries to avoid building expensive land-line infrastructures, autonomous vehicle technology can also eliminate the need of developing countries to avoid investing in and constructing western-style road systems. 
     At present, an important challenge in autonomous vehicle technology is the ability to communicate with, and receive information about, the surrounding environment of the vehicle. Current approaches to solve this problem have included integrating radios, lasers, cameras and other sensors into the autonomous vehicle. 
     In particular, most automotive manufactures look to radio frequencies (“RF”) to provide vehicle-to-vehicle communications. One problem with the RF systems is the omnidirectional radiation of information and its ability to receive information from any direction. While RF has many advantages, it is subject to “spooking” and provides an entry point into the vehicle control systems. In this later instance, researchers have used a RF link to externally manipulate a vehicle&#39;s air-conditioning system. In spooking, a malicious operator could feed false information into the system. For example, he could feed in information that a number of vehicles are stopped, inducing a traffic jam. 
     Another problem with current systems is that they are very costly. Current estimates on known autonomous automobiles are approximately three hundred thousand dollars. Additionally, these current autonomous automobile designs are not very pleasing to the eye. Moreover, another problem with known autonomous vehicle technology is existing vehicles are difficult to retrofit and will take decades to implement known autonomous vehicle technology approaches. Furthermore, a more significant current drawback is safety. If one portion of the system fails, the autonomous vehicle will become unsafe. 
     As such, a need exists for a communication system that permits vehicle information to be exchanged between vehicles and roadside or transportation fixtures that is less expensive to design and install. A need further exists for inexpensive systems to function as a either a primary communication systems or secondary communication systems to provide back-up in the event of failure by the primary system. In this manner, the safety of autonomous vehicle systems may be greatly increased and more affordable. Lastly, a need further exists for a system with a narrower field to make it more difficult to inject false information into the system. 
     SUMMARY 
     A system is provided that permits optical communication between vehicles or vehicles and roadside furniture and fixtures (e.g., lights, signs, road markings) (collectively “transportation fixtures” or “fixtures”) by modulating an optical source located on either a vehicle or a transportation fixture and transmitting the modulated light source to an environment external the vehicle or furniture. The modulated light source transmits information pertaining to the vehicle or fixture where the light source is located for receipt by a surrounding vehicle or fixture. The system further provides for vehicles and transportation fixtures to include cameras for receiving the modulated light being transmitted from surrounding vehicles and transportation fixtures. 
     The modulating light of the present invention can be incorporated into head lights and tail lights and accompanied by cameras for sensing information about the vehicle surroundings, including detecting modulated light sources being transmitted from surrounding vehicles and transportation fixtures. Together, through the use of the lights and cameras, an external optical communication system is created that can provide a variety of simultaneous functions, including, but not limited to head light illumination, braking and turning indications, speed indicators, inter-vehicle communications, vehicle to roadside fixtures and 3D renditions of the surround. Information such as location, speed, direction, brake activation and turning information can be exchanged. Using this information, accidents can be anticipated, braking can be initiated, speeds can be altered, air bag deployment can be activated (in advance of the accident), among many other things. 
     Other devices, apparatus, systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention may be better understood by referring to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views. 
         FIG. 1  is a block diagram of one example of a system architecture of the present invention as it may be incorporated into a vehicle. 
         FIG. 2  is a block diagram of one example of a system architecture as it may be incorporated into a transportation fixture. 
         FIG. 3  is system diagram showing one example of communication flow between two vehicles. 
         FIG. 4  is system diagram showing one example of communication flow between a vehicle and a transportation fixture. 
         FIG. 5  is a system diagram showing another example of communication flow between a vehicle and a transportation fixture. 
         FIG. 6  is yet another system diagram showing another example of communication flow between a vehicle and a transportation fixture. 
         FIG. 7  is a flow diagram illustrating the steps required to facilitate communication between two vehicles or a vehicle and a fixture. 
     
    
    
     DETAILED DESCRIPTION 
     A system and method is provided that permits optical communication between vehicle or vehicles and roadside furniture and fixtures (e.g., lights, signs, road markings) (collectively “transportation fixtures” or “fixtures”) by modulating an optical light source located on either a vehicle or a transportation fixture and transmitting the modulated light source to an environment external the vehicle or fixture. The system and method may also be implemented to receive obstacle avoidance information from the external environment and/or to establish communication links with surrounding objects. 
     The system may include one or more optical sources, a modulator, one or more optical sensors, processor, and, optionally, a navigation system. In an example of operation, the system may perform a process that includes modulating the optical source to create a modulated optical signal, transmitting the modulated optical signal from the optical source to the external environment of a vehicle, receiving an input optical information signal from the external environment, and process the input optical information signal to produce navigation information that the vehicle may utilize to navigate the vehicle autonomously. 
     While the present invention may be particularly useful in driverless or autonomous automobiles, those skilled in the art will appreciate that the system may be utilized in any transportation vehicle, including, but not limited to automobiles, trucks, buses, motorcycles, aircraft, boats, or any other device that is put in motion and could benefit from sensing and/or communicating with its external environment via optical communication. Further, while the invention is described in connection with autonomous vehicles, those skilled in the art will recognize that one or more of the features of the invention may be utilized in connection with any vehicle, whether or not autonomous, to enhance safety and/or provide redundancy to current vehicle safety systems. 
     In general, an autonomous vehicle is a vehicle capable of sensing its external environment and moving and navigating through the external environment without human input. Autonomous vehicles may be land-based, airworthy, or water based vehicles. As far as land-based autonomous vehicles, there is a major push to incorporate autonomous vehicle technology into the automobile and trucking industry. As such, terms as “autonomous automobile”, “autonomous car,” “robotic car,” “driverless car,” “self-driving car,” etc. have been generally utilized interchangeably for land-based autonomous vehicles. 
     In  FIG. 1 , a block diagram  100  of an example of an implementation of an Improved Autonomous Vehicle (“IAV”)  100  is shown in accordance with the present invention. In this example, the IAV  100  may be a ground vehicle with four wheels  102  such as an automobile, truck, or bus. The autonomous vehicle  100  may include a front  104  and back  106 . The front  104  may include a first front optical source  106  and a second front optical source  108 . The front  104  may also include four front optical sensors  110 ,  112 ,  114 , and  116 . Similarly, the back  106  may include a first rear optical source  118 , second rear optical source  120 , and four rear optical sensors  122 ,  124 ,  126 , and  128 . The autonomous vehicle  100  may also include a modulator  130 , demodulator  132 , controller  134 , and, optionally, a navigation system  136 , which may include a dead reckoning or global positioning system. 
     In this example, the modulator  130  may be in signal communication with the first and second front optical sources  106  and  108  and first and second rear optical sources  118  and  120  via signal paths  138  and  140 , respectively. Similarly, the demodulator  132  may be in signal communication with the four front optical sensors  110 ,  112 ,  114 , and  116  via signal path  142  and the four rear optical sensors  122 ,  124 ,  126 , and  128  via signal path  144 . The controller  134  may be in signal communication with the modulator  130 , via signal path  146 , and with the demodulator  132  and navigation system  136  via signal path  148 , respectively. 
     As an example, the front optical sources  106  and  108  may be a pair of headlights and the rear optical sources  118  and  120  may be a pair of taillights. Additionally, the optical sensors  110 ,  112 ,  114 ,  116 ,  122 ,  124 ,  126 , and  128  may be digital imagers such as, for example, charge-coupled device (“CCD”) or complementary metal-oxide-semiconductor (“CMOS”) active pixel sensors. It is appreciated that CCD and CMOS imagers are generally referred to as digital image sensors or digital cameras. The optical sensors  110 ,  112 ,  114 ,  116 ,  122 ,  124 ,  126 , and  128  are devices capable of receiving input optical information signals from the external environment. The input optical information signals may be signals that include modulated optical signals or that include image information of the external environment as of a result of the optical sensors  110 ,  112 ,  114 ,  116 ,  122 ,  124 ,  126 , and  128  capturing images (i.e., taking pictures) of the external environment. 
     If the input optical information signal received by an optical sensor  110 ,  112 ,  114 ,  116 ,  122 ,  124 ,  126 , and  128  is a modulated optical signal, the signal is passed to the demodulator  132 , which demodulates the modulated optical signal and produces a demodulated input signal that is passed to the controller  134 . The controller  134  then processes the sensor information and optionally passes it to the navigation system  136  or alters other vehicle systems based upon the processed data (e.g., apply the brakes, deploy the air bag, cause the vehicle to alter direction or speed). The data may be received in the form of a demodulated input optical information signal or may be in the form of an image signal. Further, when the data is a demodulated input optical information signal, the processor may establish a communication link with an external object that sent the modulated input optical information signal to initiate communication with the external object. The external object may be another vehicle or a transportation fixture such as, for example, a traffic signal, stop sign, speed limit sign, warning signs, etc. 
     Generally, only a single front optical source  106  and a single front optical sensor  110  are needed for the present invention; however, since the IAV  100  in  FIG. 1  represents an example of an implementation in automobile, truck, or bus, more front optical sensors  112 ,  114  and  116  and an additional front optical source  108  is shown for greater performance. Similarly, only a single rear optical source  118  and a single rear optical sensor  122  are needed for the present invention; however, more rear optical sensors  124 ,  126  and  128  and an additional rear optical source  120  is shown for greater performance. In this example, the pair of optical sensors  110  and  112 ,  114  and  116 ,  122  and  124 , and  126  and  128  are positioned near each side of each front optical source (i.e., each headlight)  106  and  108  and each rear optical source (i.e., each taillight)  118  and  120 . 
     The controller  134  may be any type of processor capable of interfacing with and controlling the operations of the modulator  130 , demodulator  132 , optical sensors  110 ,  112 ,  114 ,  116 ,  122 ,  124 ,  126 , and  128 , and navigation system  136 . The navigation system  136  is a system that receives all the sensor information from the optical sensors  110 ,  112 ,  116 ,  122 ,  124 ,  126 , and  128  and any other sensors or location devices (not shown) such as GPS receivers, radio location systems, dead recognizing systems, image recognition system, etc. and in response produces the navigation information necessary to control the movement of the IAV  100 . The navigation system  136  may be implemented in hardware, software, or both and the navigation system  136  may be part of the processor/controller  134 . 
     In the illustrated example, all the optical sources  106 ,  108 ,  118 , and  120  are devices that are capable of simultaneously producing illumination and a modulated optical signal that can be transmitted from the optical sources to an external environment of the IAV  100 . As an example, the optical sources  106 ,  108 ,  118 , and  120  may be light-emitting diodes (“LEDs”) light sources that are capable of transmitting the modulated light at frequencies that are high enough that the human eye is incapable of perceiving anything besides a transmission of steady light (i.e., an illuminating light). For example, the optical sources  106 ,  108 ,  118 , and  120  may transmit the modulated light at a frequency close to 15 kilohertz (“KHz”), which would be perceived as a steady light source by a human eye. 
     Alternatively, the optical sources  106 ,  108 ,  118 , and  120  may include multiple light sources per optical source  106 ,  108 ,  118 , or  120  that would allow for both straight illumination (i.e., a steady light source) from one sub-light source and transmission of modulated light at another sub-light source per optical source, multiple simultaneous transmissions of modulated light (say one sub-light source at 15 KHz and another at 45 KHz), or multiple simultaneous transmissions of modulated light plus straight illumination. 
     Turning back to the optical sources  106 ,  108 ,  122 , and  124 , these optical sources may be modulated using IEEE Standard 802.15.7 using either or both PHY I or PHY III specification. The referenced PHYI and PHY III specifications are detailed in the IEEE Standards Association publication, Part 15.7:  Short - Range Wireless Optical Communication Using Visible Light,  which is incorporated by reference in this application in its entirety. The 802.15.7 standard defines the MAC layer and several PHY layers for short-range optical wireless communications using visible light (extending from 380 nm to 780 nm in wavelength) in optically transparent media. 
     In particular, PHY I is intended for outdoor usage with low data rate applications. This mode uses on-off keying (OOK) and variable pulse position modulation (VPPM) with data rates in the tens to hundreds of kb/s. PHY III is intended for applications using color-shift keying (CSK) that have multiple light sources and detectors. This mode uses CSK with data rates in the tens of Mb/s. Further, PHY I and PHY III occupy different spectral regions in the modulation-domain spectrum, with different data rates and different optical rate support, which allow for coexistence. 
     Regardless of which specification is utilized, modulation will be rapid enough so that the primary purposes of illumination source will not be affected. The data rates in either case will be sufficient to transmit a signal to the vehicle surrounding in a direction either ahead or behind a vehicle, or both. The modulated signal may transmit critical data about the IAV  100  to its surroundings, including but not limited to vehicle position, vehicle speed, rate of acceleration, rate of deceleration, braking information, and/or air bag deployment. GPS information may also be added to transmit location data. In other words, different information can be coded, transmitted and then later decoded by a receiving sensor (e.g., camera), demodulator and controller/processor, enabling external optical communications between vehicles and other mobile and stationary objects. The transmitted data can take many forms, including, but not limited to, audio and video data. 
     It is appreciated that the IAV  100  may communicate via modulated optical signals with different types of external objects that include other autonomous vehicles, roadside fixtures, law enforcement vehicles, etc. These communications would be via modulated optical signals utilizing a modulation scheme such as the one described by IEEE 802.15.7. 
     As mentioned earlier, the optical sensors  110 ,  112 ,  114 ,  116 ,  122 ,  124 ,  126 , and  128  may also be utilized for sensing information about the IAV  100  surroundings. For example, in certain implementations, optimized optical sensors may be utilized for the detection of near infrared light that will enable the creation of 3D images of the surrounding volume of the external environment. In this example, the optical sources  106 ,  108 ,  118 , and  120  may utilize structured infrared (“IR”) light to allow the optical sensors  110 ,  112 ,  114 ,  116 ,  122 ,  124 ,  126 , and  128  to receive images that the controller  134  may utilize to create 3D images of certain parts of the external environment and to calculate depth and surface information. 
     Based on the above discussion, by using both optical sources  106 ,  108 ,  118 , and  120  and optical sensors  110 ,  112 ,  114 ,  116 ,  122 ,  124 ,  126 , and  128  in the IAV  100 , an external optical communication system is created that can provide a variety of simultaneous functions, including, but not limited to head light illumination, braking and turning indications, speed indicators, inter-vehicle communications, vehicle to roadside furniture communication and 3D renditions of surround. Information such as vehicle identification, location, speed, direction, brake activation and turning information can be exchanged with other vehicles or fixtures. Using this information, accidents can be anticipated, braking can be initiated, speeds can be altered, air bag deployment can be activated (in advance of the accident), among many other things. 
     Turning to  FIG. 2 ,  FIG. 2  is a block diagram of one example of a system architecture  200  as may be incorporated into a transportation fixture, such a sign, light and other fixtures utilized to control or direct vehicle traffic. In the illustrated example, the fixture is a traffic light  202 . In the example, the traffic light  202  includes three optical light sources  208  as well as an optical sensor  212 . Like the system described in relation to IAV  100 , the system  200  is controlled by a controller  216 . A demodulator  218  is in communication with the optical sensor  212  to demodulate any modulated light sensed by the camera  212  from its surroundings. The optical lights  208  are further in communication with a modulator  214  for modulating light emitted from each signal light  208 . Although the illustrated example shows the modulator  214  connected to all three traffic lights  208 , those skilled in the art will recognize that only one or a select number of the lights  208  may be modulated. The modulated light may be utilized to transmit information to the surrounding environment about the signal light  202 , which information may include, but not be limited to, information related to the timing of the lights  208 . The optical sensor  212  may be utilized to sense approaching vehicles, as well as determine the speed of approaching vehicles. This information may be processed by the controller  216  to control the timing of the traffic lights  208  for particular intersections based upon actual traffic flow conditions. 
       FIG. 3  is system diagram  300  showing one example of communication flow between two autonomous vehicles  302   a  and  302   b.  In this regard, although generally described in the context of two autonomous vehicles such as automobiles, the example is likewise applicable to autonomous vehicles such as airborne or aerial vehicles such as aircraft that are manned or unmanned. In this example, communication flow is illustrated between a front headlight  304  and optical sensor or camera  306  of autonomous vehicle  302   a  and the taillight  308  and rear camera  310  of autonomous vehicle  302   b.    
     As the modulated light  312  is directed outward and external to the autonomous vehicle  302   a  from the headlight  304 . Surrounding cameras  310  in surrounding autonomous vehicles  302   b  are used to sense the modulated light  312  produced by modulator  313 . Using demodulators  314  in communication with the cameras  310 , critical information about the surrounding or approaching autonomous vehicle  302   a  is received and processed by the controller  316 . The controller  316  may then modify the autonomous vehicle  302   b  response or behavior based upon the information received about the surrounding environment  312 . Optionally, the information received may also be passed to a navigations system (not shown) or a communication link may be established with vehicle  302   a.    
     In the same matter that modulated light  302  is directed outward and external to the autonomous vehicle  302   b  from the headlight  308 , modulated light  318 , produced by modulator  319 , is directed outward and external to the autonomous vehicle  302   b  from the taillight  308 . Surrounding cameras  306  in surrounding vehicles  302   a  are used to sense the modulated light  318 . Again, using demodulators  320  in communication with the cameras  306 , critical information about the surrounding or approaching autonomous vehicle  302   b  is received and processed by the controller  322 . The controller  322  may then modify the autonomous vehicle  302   a  response or behavior based upon the information received about the surrounding environment  318 . 
     Optionally, the lights  304  may also utilize structured infrared light  324  to allow the cameras  306  to determine depth and surface information about the surrounding environment. In this case, light  304  can emit modulated signals  312  as well as optionally, structured infrared light  324 . The infrared light  324  reflecting off a surrounding fixture may be sensed by the cameras  306  and processed through the processor  322  to create 3D images of the fixture. While the flow diagram in  FIG. 3  only illustrates the structured infrared light  324  being emitted from light  304  and sensed by camera  306  of autonomous vehicle  302   a,  the taillight  308  and camera  310  of autonomous vehicle  302   b  may also be designed to perform the same functions. 
       FIG. 4  is system diagram showing one example of communication flow between a vehicle  400  and a fixture  402 . In this example, the fixture  402  includes both a light  406  and a optical sensor or camera  404 . As such, the communication flow between the vehicle  400  and the fixture  402  is very similar to the communication flow described between the two vehicles  302   a  and  302   b  in connection with  FIG. 3 . The optical lights  408 ,  406  are modulated by modulators  413 ,  415 , respectively, and the modulated optical signals  412 ,  414  are transmitted outward from both lights  408  and  406  to communicate critical information about the autonomous vehicle  400  and the fixture  402 , respectively. Cameras  410 ,  404  in the autonomous vehicle  400  and in the fixture  402 , respectively, sense the modulated light  414  and  412 . The light is then demodulated by the respective demodulators  416 ,  418  and the information is processed by the respective controllers  420 ,  422 . Optionally, structured infrared light  424  may be emitted from one or more of the lights  408 . The reflection of which light  426  may be captured by one or more cameras  410  to create a 3D images and determine information about surrounding objects such as distance and type of object. 
       FIG. 5  is a flow diagram showing another example of communication flow between an autonomous vehicle  500  and a transportation fixture  502 . In this example, the fixture  502  only includes a sensor or camera  514  and does, itself, emit modulated light. Thus, the fixture  502  is collecting and processing information about its surroundings, but is not sharing information. For example, the camera  514  may sense and process modulated lighted  504  being emitting from approaching vehicles  500 . The modulated light  504  or input optical information signal is then demodulated using a demodulator  518  and then processed by controller  522 . In this regard, a signal light  502  may, for example, collect information about the surround traffic to use for controlling the traffic lights or signal without providing any information to the surrounding vehicles  500  about the operation of the light. 
     Further, the light  508  in the autonomous vehicle  500  may transmit, in addition to a modulated light signal  504  created by modulator  513 , structured infrared light  505  that can be read by an onboard optical sensor or camera  512 . In this manner, the camera  512  can sense and process the detected light  506  to determine information about its surroundings, for example, if the autonomous vehicle  500  is approaching a lighted intersection. The sensor  506  may also capture other input optical information signals from other sources (not shown), which may include modulated light from other vehicles. The captured light may be demodulated and processed by the demodulator  516  and the controller  520 . 
       FIG. 6  is yet another flow diagram showing another example of communication flow between an autonomous vehicle  600  and a transportation fixture  602 . In this example, the transportation fixture  602  does not include a sensor. Thus, the communication is passive communication, rather an active communication, as illustrated in  FIGS. 1-4  above. The fixture  602  only includes a light  606  and a modulator  615  for modulating light to create a modulated optical signal to be transmitted externally via the optical light  606 . In this example, the transportation fixture  602  could be a sign indicating the speed of the road, an approaching speed change (e.g., school zone) or other information relevant to the traffic flow or vehicle operation in the particular surrounding environment. In these examples, it is not important for the fixtures  602  to provide two-way communication with the vehicles  500  as the information that the fixtures are conveying are generally static or will not be altered by approaching vehicles  600 . 
     As illustrated, in this example, the fixture  602  includes a light source  606 , a modulator  615  and a controller  622 . The autonomous vehicle  600  may detect the modulated light  604  via optical sensor or camera  610  and then demodulate the optical light signal using demodulator  118 . The data is then processed by the controller  620  to determine the information being conveyed to the surround by the transportation fixture  602  using controller  622 . 
     Like in prior examples, the vehicle  600  includes an optical light source  608  that may emit either or both a modulated optical light signal  603  or structured infrared light  506 . The modulated light signal  603  is created using a modulator  613  controlled by a controller or processor  620 . 
     Optionally, instead of a light source  608 , the light source  608  could be replaced with or supplement by reflective strips  650 . In this example, the reflective strips  650  could be affixed to the transportation fixture  602  to provide additional information about the road or the fixture  602 . While shape recognition software could provide similar information, the systems capable of image recognition are often expensive, subject to ambient lighting conditions and do not operate at suitable speeds for highway operation. In this example, the reflective strips  650  could provide, in additional to a primary means of communication, backup communication, for example, to supplement or replace GPS information if unavailable. 
     The reflective strips  650 , in the case of a moving instruction, could indicate the type of movement to which is relates, e.g., a stop sign or a speed limit sign. In the case of a speed limit sign, it could further provide the associated speed limitations. Additionally, the reflect strips  650  could also provide location information, giving an indication of distance from a certain point or object (i.e., a barrier ten meters from the center of the road). 
     In operation, light from a light source  608  or ambient light, for example, would reflect off the strip  650 . The camera  610  can then sense and process the detected light  655  to determine the information being transmitted by the reflectors. 
       FIG. 7  is a flow diagram illustrating the steps required to facilitate basic communication between two vehicles or vehicle and a transportation fixture. In summary, a modulated optical light signal is first generated for communicating certain information about the condition of the vehicle or fixture, at  702 . The modulated light signal is then transmitted external to the vehicle, at  704  using a optical light source. Surrounding transportation fixtures or vehicles may be then receive the modulated optical light signal, at  706 , and demodulate the light signal and process the information received from demodulating light signal, at  708 . As necessary, operation of the vehicle or the transportation fixture may then be adjusted based upon the received information, at  710 . 
     Optionally, and as illustrated in connection with  FIGS. 1-6 , structured infrared light may also be emitted by the light source for detection by an on-board sensor or camera to determine the identity, distance and physical structure of surrounding objects external to the vehicle. With this information and utilizing on-board software to help interpret the images, the operation of the vehicle may further be altered. For example, the brakes of the vehicle may be applied, a warning signal may be generated or an air bag may be deployed if an impact is detected as being eminent based upon the speed of the vehicle. 
     For purposes of this application, it should be understood that the system described above could operate a primary means of communicating information between vehicles and fixtures, but is designed generally as a secondary or redundant system to address issues of failure and safety. Further, vehicles could be any moving object, include but no limited to cars, trucks or even aerial or water vehicles. The vehicles are not required to be autonomous or unmanned. The features of the invention may be utilized for additional safety and control in manned vehicles. 
     While most of the examples above are given in terms of ground vehicles, the application of the IAV system of the invention may be quite effective in commercial airline applications as current flight operations use radar, visual signals and human control both on the ground and in the air. In unmanned aircraft, redundancy of the these systems may be lost and time lags in communications between the air craft and ground control in both manned and unmanned aircraft may reduce effective safety measures. Incorporating the system of the invention in aircraft control communications by replacing current lights systems with LED lighting systems and facilitating communication between the runway and aircraft lights, for example, could increase safety and add further redundancy to air traffic control. In the same manner as illustrated in connection with  FIGS. 1-6 , aircraft can be equipped with the system and can communicate using illumination sources with other aircraft, ground communications, and can traffic fixtures (e.g., runway lighting, control tower lighting, etc). 
     As noted above, light may be modulated to convey a wide range of vehicle and fixture information, which may include, but not be limited to, vehicle position, vehicle speed, rate of acceleration, rate of deceleration, direction of travel, braking information, road speed and flow control information. In response to the communication of such information, responses of neighboring vehicles, traffic signals and traffic conditions may be altered. 
     It will also be noted that the system controllers schematically depicted in  FIGS. 1-6  represent one or more modules configured for controlling, monitoring, timing, synchronizing and/or coordinating various functional aspects of the system such as, for example (as seen in  FIG. 1 ), controlling the operation of the modulator  130 , demodulator  132 , cameras  110 ,  112 ,  114 ,  116 ,  122 ,  124 ,  126 , and  128  and the autonomous vehicle or any of its components. The system controllers, such as  134  of  FIG. 1 , are also configured for processing information received from all the communicating components and for control the operation of the autonomous vehicle based the receipt of such information. 
     For all such purposes, the system controllers may include a computer-readable medium that includes instructions for performing any of the methods disclosed herein. The system controllers are schematically illustrated as being in signal communication with various components of the system via wired or wireless communication links represented by lines. Also for these purposes, the system controllers may include one or more types of hardware, firmware and/or software, as well as one or more memories and databases. The system controllers typically include a main electronic processor providing overall control, and may include one or more electronic processors configured for dedicated control operations or specific signal processing tasks. The system controllers may also schematically represent all voltage sources not specifically shown, as well as timing controllers, clocks, frequency/waveform generators and the like as needed for controlling the components of the system. The system controllers may also be representative of, of in communication with one or more types of user interface devices, such as user input devices (e.g., keypad, touch screen, mouse, and the like), user output devices (e.g., display screen, printer, visual indicators or alerts, audible indicators or alerts, and the like), a graphical user interface (GUI) controlled by software, and devices for loading media readable by the electronic processor (e.g., logic instructions embodied in software, data, and the like). The system controllers may include an operating system for controlling and managing various functions of the system controllers. 
     It will be understood that the term “in signal communication” as used herein means that two or more systems, devices, components, modules, or sub-modules are capable of communicating with each other via signals that travel over some type of signal path. The signals may be communication, power, data, or energy signals, which may communicate information, power, or energy from a first system, device, component, module, or sub-module to a second system, device, component, module, or sub-module along a signal path between the first and second system, device, component, module, or sub-module. The signal paths may include physical, electrical, magnetic, electromagnetic, electrochemical, optical, wired, or wireless connections. The signal paths may also include additional systems, devices, components, modules, or sub-modules between the first and second system, device, component, module, or sub-module. 
     Terms such as “communicate” and “in . . . communication with” (for example, a first component “communicates with” or “is in communication with” a second component) are used herein to indicate a structural, functional, mechanical, electrical, signal, optical, magnetic, electromagnetic, ionic or fluidic relationship between two or more components or elements. As such, the fact that one component is said to communicate with a second component is not intended to exclude the possibility that additional components may be present between, and/or operatively associated or engaged with, the first and second components. 
     It will be understood, and is appreciated by persons skilled in the art, that one or more processes, sub-processes, or process steps described in connection with  FIGS. 1-7  may be performed by hardware and/or software. If the process is performed by software, the software may reside in software memory (not shown) in a suitable electronic processing component or system such as, one or more of the functional components or modules schematically depicted in  FIGS. 1-7 . The software in software memory may include an ordered listing of executable instructions for implementing logical functions (that is, “logic” that may be implemented either in digital form such as digital circuitry or source code or in analog form such as analog circuitry or an analog source such an analog electrical, sound or video signal), and may selectively be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that may selectively fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. 
     In the context of this disclosure, a “computer-readable medium” is any means that may contain, store or communicate the program for use by or in connection with the instruction execution system, apparatus, or device. The computer readable medium may selectively be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device. More specific examples, but nonetheless a non-exhaustive list, of computer-readable media would include the following: a portable computer diskette (magnetic), a RAM (electronic), a read-only memory “ROM” (electronic), an erasable programmable read-only memory (EPROM or Flash memory) (electronic) and a portable compact disc read-only memory “CDROM” (optical). Note that the computer-readable medium may even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory. 
     It will be understood that various aspects or details of the invention may be changed without departing from the scope of the invention. It is not exhaustive and does not limit the claimed inventions to the precise form disclosed. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation. Modifications and variations are possible in light of the above description or may be acquired from practicing the invention. The claims and their equivalents define the scope of the invention.