System for managing plurality of warning devices and warning system for emergency vehicle

Abstract

The present disclosure provides a system for managing a plurality of warning devices associated with an emergency vehicle, comprising: a first warning device for a first emergency vehicle, the first warning device having a first plurality of warning functions controlled by a first controller, the first controller communicating over a wireless network via a first transceiver; a first sensor for providing a position of the first emergency vehicle; a second warning device for a second emergency vehicle, the second warning device having a second plurality of warning functions controlled by a second controller, the second controller communicating over the wireless network via a second transceiver; a second sensor for providing a position of the second emergency vehicle; wherein the first transceiver and the second transceiver transmit data to each other through the wireless network, so as to indicate the relative position of the first emergency vehicle and the second emergency vehicle; and each of the first controller and the second controller controls a corresponding warning function according to a relative position of the first emergency vehicle and the second emergency vehicle.

Description

[0001] Related Applications This application is a divisional application of the Chinese invention patent application with the application date of November 7, 2017, application number 201780068682.1, and invention name “NETWORK AND CONNECTION DEVICES FOR EMERGENCY RESPONSE AND ROADSIDE OPERATIONS”. Background Art

[0002] The present application relates to systems, apparatus and methods that employ self-assembling wireless local area network devices to enhance the safety of personnel performing operations such as law enforcement, emergency response, worksites and roadside service provision, such as towing, on or near work roads.

[0003] It is well known that maneuvers performed on or beside traffic are extremely dangerous and can result in collisions with devices and personnel, resulting in injury or death to other motorists. Visual and audible warnings are commonly used to alert motorists and pedestrians of approaching roadside maneuvers, and these warnings have been successful in reducing accidents. However, significant risks remain, and there are opportunities to deploy recently developed communications and sensor technologies to further improve the safety of roadside personnel.

[0004] Currently, devices used to operate on or near work roads are stand-alone devices whose operation is not coordinated with other devices. For example, if two or more emergency vehicles are stopped in a line at an accident scene, it is common for all vehicles to display various types of warning light signals. These warning light signals are not coordinated and may cause confusing glare to approaching motorists, pedestrians or other emergency responders. It is common for the emergency vehicle at the front of the line to continuously project warning light signals to the rear, which may blind emergency responders approaching the accident from behind the first vehicle. Ideally, only the rearmost vehicle would display warning lights to the rear to warn approaching traffic. Coordinated traffic guidance signals could also reduce confusion for approaching traffic. Currently, there is no way to effectively coordinate warning signal activity between several emergency vehicles at an accident scene other than manually setting each vehicle's warning system to the desired setting. Even then, the flashing pattern emitted by each vehicle's lights is not coordinated in time with the flashing patterns of the other vehicles.

[0005] Warning signals from emergency vehicles, service vehicles, and construction equipment can be enhanced by traffic guidance devices such as cones, portable barriers, and portable lights that produce traffic guidance light signals or illuminated characters. The effectiveness of such devices is enhanced when the activities of traffic guidance devices are coordinated. Further improvements are possible if the traffic guidance devices include sensors for detecting approaching vehicles or objects that will enter the safety margin around the work zone. Information from these sensors is most effective if it is coordinated and communicated to personnel within the work zone.

[0006] It is now common for motor vehicles used for road service, construction, and emergency response to have computerized devices that control and coordinate the available audio and visual warning signals generated by each vehicle. These computerized devices have a computer processor, memory, and limited communication capabilities. Communications are usually limited to controlling the signaling devices on the motor vehicle from a central module. Some communications between the central module and the vehicle communication bus may be employed to obtain information about the status of the vehicle, including whether the vehicle is parked or moving, braking, speed, heading, etc.

[0007] There is an opportunity to improve the safety of emergency responders, construction crews, and road service personnel by connecting devices to wireless LANs to exchange information and coordinate warning signals and other activities at crime scenes, emergency response locations, and in work zones when responding to emergencies. Summary of the invention

[0008] The present disclosure provides a system for managing a plurality of warning devices associated with an emergency vehicle, comprising: a first warning device for a first emergency vehicle, the first warning device having a first plurality of warning functions controlled by a first controller, the first controller communicating over a wireless network via a first transceiver; a first sensor for providing a location of the first emergency vehicle; a second warning device for a second emergency vehicle, the second warning device having a second plurality of warning functions controlled by a second controller, the second controller communicating over the wireless network via a second transceiver; a second sensor for providing a location of the second emergency vehicle; The first transceiver and the second transceiver transmit data to each other through the wireless network to indicate the relative positions of the first emergency vehicle and the second emergency vehicle, and each of the first controller and the second controller controls a corresponding warning function according to the relative positions of the first emergency vehicle and the second emergency vehicle.

[0009] The present disclosure also provides a warning system for an emergency vehicle, comprising at least one warning device having multiple warning functions; a controller for controlling the plurality of warning functions of the at least one warning device and communicating over a wireless network via a transceiver; The controller receives data from at least one sensor, the data including the location and status of the emergency vehicle; The transceiver transmits the data via the wireless network and receives data regarding at least one of the position and status of the second emergency vehicle via the wireless network to indicate the relative position of the emergency vehicle and the second emergency vehicle, and the controller controls the warning function of the at least one warning device according to the relative position.

[0010] The present disclosure includes methods of using networked devices to enhance first responder safety, systems of networked programmable devices programmed to perform the disclosed methods, and devices including computer usable media having computer readable program code for performing the disclosed methods. The programmable device may include a user interface that allows a user to receive information from the device and input commands to the device, a memory for storing program code, a processor for executing the code, and a communication interface for communicating with other devices on the network.

[0011] Self-organizing networks are configured to automatically and dynamically connect devices used in operations performed on or near roads carrying vehicular and pedestrian traffic. Automatic self-organizing (ad hoc) networks connecting existing and new devices can be used to enhance safety by collecting and exchanging safety-critical information. In some cases, existing devices can be augmented with network controllers and radio frequency communications to allow the devices to join a wireless local area network and exchange information over the network. New devices, including wearable devices, can be configured to act as nodes on a wireless local area network.

[0012] According to various aspects of the present disclosure, emergency vehicles from first responder organizations such as state, county or city police or fire departments are provided with wireless communication devices (transceivers) and are configured to automatically join an ad hoc local area network when they are within the range of wireless communication devices of other nodes. Vehicles can be nodes on the network, and communication between vehicles on the network can be used to coordinate the functions of warning devices on the vehicles. Vehicles on the network can also exchange information related to vehicle location, speed, heading, braking (commonly referred to as "vehicle telematics") to coordinate the functions of warning devices on the vehicles based on the relative positions of the vehicles. Vehicle telematics transmitted between vehicles can also be used to improve the safety of first responders by providing enhanced warnings to trailing vehicles of rapidly decelerating leading vehicles. Peripheral devices such as devices worn by first responders are wirelessly connected to the vehicle and extended to the network. Portable devices such as traffic safety cones or barriers are wirelessly connected to the network and are configured to transmit messages and commands between connected devices. Portable devices can be equipped with sensors to detect intrusion or intrusion into a safe zone at the scene of an emergency or work zone.

[0013] Position detection can be determined by global positioning satellites (GPS), or more accurately by differential global positioning satellites (DGPS), as is well known in the art. Position accuracy can be improved using dead reckoning, vehicle telematics, and sensors placed on vehicles, wearable devices, or portable nodes (such as traffic cones or obstacles). Sensors include microelectromechanical (MEM) sensors, accelerometers, gyroscopes, magnetometers, cameras, ultrasonic sensors, infrared or lidar, and RFID tags. Vehicle navigation systems can also provide information that can be used to improve position detection accuracy. Vehicle navigation systems and associated map databases allow vehicles to detect their position on the road and can be used in conjunction with other position sensing methods to determine the position of vehicles relative to each other. Establishing the relative position of vehicles, sensors, wearable devices, and other nodes on the disclosed ad hoc wireless network allows functions to be coordinated based on location. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Graphically illustrates the layers in the communications protocol stack and the relevant international standards applicable to each layer in the stack; Figure 2 An example of a system of devices connected by a wireless local area network according to aspects of the present disclosure is shown; Figure 3 is a functional block diagram of an exemplary controller for use with the disclosed system and devices in a wireless local area network; Figure 4 is a graphical representation of a representative traffic directing cone or barrier suitable for use in the disclosed system and wireless local area network; Figure 5 is a graphical representation of a representative wearable device suitable for use in the disclosed system and wireless local area network; Figure 6 is a functional block diagram showing a representative vehicle control unit that may interact with the disclosed system and wireless local area network; and Figure 7 is a block diagram of representative steps in a method of operating a system according to aspects of the present disclosure. DETAILED DESCRIPTION

[0015] The wireless local area network 10 is used to automatically and dynamically connect vehicles, traffic guidance devices, and wearable devices to the system 200 to enhance the safety of first responders operating on or near the road. An example of a network topology compatible with the disclosed system 200 and method is a wireless mesh network. A mesh network is a local network topology in which nodes are directly, dynamically, and non-hierarchically connected to as many other nodes as possible, and collaborate with each other to efficiently route data between nodes. Mesh networks dynamically self-organize and self-configure, which can reduce installation overhead. The ability to self-configure can dynamically distribute workloads, especially when some nodes fail. This in turn helps to improve fault tolerance and reduce maintenance costs. The disclosed wireless local area network is self-configuring and performs many functions without the intervention of personnel using devices connected to the network, allowing them to focus on their work.

[0016] Mesh topology can be contrasted with traditional star / tree local network topologies, where devices are directly linked to only a small subset of other devices, and the links between devices are hierarchical. Mesh is a network topology in which each node relays data for the network. All mesh nodes collaborate in the distribution of data in the network, so devices that are out of range of each other can communicate through other devices between them. Mesh networks can be designed to have no single point of failure. Devices that perform specific functions can be replaced by other devices equipped with specific functions. There may be some specific functions that do not have backup functions, such as a device that acts as a gateway between the mesh network and the Internet. If such a gateway loses power, it may not be possible to switch to another gateway.

[0017] One example of a protocol for device-to-device communication over a wireless local area network is the Thread stack developed by the Thread Group, and used in this disclosure as a representative standard that can be used as the basis for security, communication, and data transfer on a mesh network. Figure 1 On the left is a graphical representation of the layers in the Thread protocol, with the standard related to the content and operation of each layer on the right. Radio frequency (RF) communications between nodes on a Thread-based mesh network are governed by IEEE802.15.4, which defines a media access control (MAC) layer operating in the 2.4 GHz band at a data rate of 250 kbps. The MAC layer includes MAC security, which is used to encrypt communications on the mesh network for enhanced security.

[0018] Thread uses the IEEE 802.15.4 communications standard as its RF (radio frequency) connectivity protocol, which is designed for low-rate, low-power WPANs (wireless personal area networks). Thread employs IPv6 connectivity, which allows devices to communicate with each other, access services in the cloud, or interact with users through the Thread mobile app. The need to unify IPv6 and 802.15.4 technologies was addressed by developing a layer that can smoothly adapt between IPv6 network layer requirements and 802.15.4 link layer capabilities. This layer is called 6LoWPAN, as Figure 1 shown.

[0019] MAC layer encryption and integrity protection are used on messages based on keys established and configured by higher layers of the software stack. Nodes are authenticated to the network by authorized personnel using a device called a commissioner and must share the same network key. The commissioner is typically a device separate from the network, such as a smartphone, that can communicate with the network and provide new devices with the security information needed to join the network. The commissioner device can also be part of the network itself, or a dedicated node.

[0020] The wireless local area network in this disclosure will be discussed in terms of "nodes," which may be used interchangeably with "devices" or "vehicles." Each node represents a point in the mesh network. Figure 2 A representative mesh network is shown in which three emergency vehicles 12 are connected to each other. A representative road 14 includes an incident 16 to which the emergency vehicles 12 respond. The emergency vehicles 12 may include police cars, fire trucks, ambulances / EMTs, and rescue vehicles, as well as DOT, wreckers, and tow trucks. Each emergency vehicle 12 includes a controller 18 having a memory 20, a processor 22, and program instructions stored in the memory 20 for execution by the processor 22, such as Figure 3 . The controller 18 also includes a presentation interface 24 for presenting information to a user and a user input interface 26 for the user to interact with the controller 18. The controller 18 includes a communication interface 28 for managing communications between the controller and other devices, including devices on the disclosed wireless local area network 10, via a wireless transceiver 30. The controller 18 is operably connected to an antenna 32 for accessing the Internet 34 via a cellular communication system known in the art. According to aspects of the present disclosure, each emergency vehicle 12 is equipped with a dedicated wireless transceiver 30 that is compatible with a low-power local area network such as a wireless mesh network. The controller 18 of each emergency vehicle 12 can be configured to dynamically and automatically connect to other emergency vehicles 12 when the wireless transceiver 30 is within range. Figure 2Three emergency vehicles 12 are shown within range of each other and are all connected to each other in a full mesh topology to form a wireless local area network 10. A smart device such as a cell phone may be a node on the wireless local area network 10.

[0021] Each emergency vehicle 12 is equipped with at least one multifunctional audio warning device 36 (e.g., an electronic siren) and at least one multifunctional visual warning device 38 (e.g., a light bar). The multifunctional audio device 36 is capable of producing a number of audible warning sounds, such as sirens known as wails, roars, and air horns. The multifunctional visual warning device 38 may be a light bar equipped with a number of lights capable of producing a variety of visual warning signals, which may include flashing lights, steady lights, alternating warning flash patterns, and continuous traffic guidance patterns as known in the art. The light bar may be configured to produce visual warning light signals that protrude away from the front 38a and / or rear 38b of the light bar. The light bar is also capable of selectively producing light to illuminate the area around the emergency vehicle 12, wherein the illumination light is directed to the area in front of, to the side of, and / or to the rear of the emergency vehicle 12. Three emergency vehicles 12 may implement a coordinated flashing pattern, wherein the pattern incorporates the visual warning signal devices of all three emergency vehicles 12. When another emergency vehicle 12 comes within range of the wireless transceiver 30 and automatically joins the wireless local area network 10, its visual warning signal device may be incorporated into a flashing pattern according to program instructions in the controller 18. Warning lights that may distract personnel on the scene may be modified or turned off, while traffic guidance signals or lights may be turned on.

[0022] The emergency vehicle 12 may also be equipped with at least one sensor 40 for collecting information about the emergency vehicle 12 or the environment surrounding the emergency vehicle 12. The sensors 40 include, but are not limited to, cameras, radars, ultrasonic or sound-based sensors, distance measuring devices, accelerometers, and the like. The sensors 40 may be selected to supplement position sensing devices such as GPS or DGPS to determine the location of the emergency vehicles 12 relative to each other. One example of a sensor is a radar or proximity detection device disposed at the front of the vehicle, wherein the sensor detects the distance between the vehicle and the vehicle ahead. If the distance between the vehicles suddenly decreases, this information may be used to provide a warning to the vehicle operator, indicating the possibility of a collision.

[0023] The relative positions of the nodes (devices) in the disclosed system 200 are used to coordinate the activities of the devices or nodes on the wireless local area network 10. For example, the second (and later) emergency vehicles 12 arriving at the scene can be configured to extinguish their forward warning light signals in favor of forward lighting to improve visibility at the scene. The first and second emergency vehicles 12 can be configured to extinguish their rear warning lights because another emergency vehicle 12 has joined the group and will maintain the rear warning lights to warn oncoming traffic. In this case, the first and second emergency vehicles 12 can be configured to project an alternative warning signal pattern on the rear of each light bar, such as a traffic guidance (continuous amber light) pattern or a steady low-intensity pattern.

[0024] Figure 2 Also depicted are peripheral devices that are nodes on the disclosed wireless local area network. A row of traffic directing cones or barriers 42 are shown arranged in a row extending from the rear left corner of the rearmost (rear) emergency vehicle 12. Figure 4As shown, each traffic guiding cone or barrier 42 includes a power source 44, a controller 19, and a wireless transceiver 30, thereby allowing the traffic guiding cone or barrier 42 to join the self-organizing wireless local area network 10, wherein the controller 19 includes a processor 22 and a memory 20. Each traffic guiding cone or barrier 42 may also include a visual warning device, such as a light 46 for generating a visible light signal and / or a speaker or tone generator 48 for generating an auditory signal. Each traffic guiding cone or barrier 42 may also include a sensor 40 or other hardware for determining the relative position of the traffic guiding cone or barrier 42 relative to other traffic guiding cones or barriers 42 and relative to one or more emergency vehicles 12. The function of the traffic guiding cone or barrier 42 may be determined in part by their relative position. For example, the warning light 46 of each traffic guiding cone or barrier 42 may be illuminated in a sequential mode to guide the oncoming traffic around the scene. The traffic guiding cones or barriers 42 may be connected to each other by an infrared laser or beam 50, which allows the detection of objects passing between the traffic guiding cones or barriers 42. This feature can be used to form a "virtual fence" around the response scene, and the traffic guiding cones or barriers 42 can be configured to warn first responders at the scene of such an intrusion. One or more of the traffic guiding cones or barriers 42 can also include a sensor, such as a radar or lidar, which is arranged to detect the speed and trajectory of vehicles approaching the response scene, and the system 200 is programmed to use the information from the radar to calculate the possibility of an intrusion and issue a warning to the first responders at the scene of the vehicle that may enter the scene. Each traffic guiding cone or barrier 42 can include an RFID tag 54 to authenticate the traffic guiding cone or barrier 42 to the system 200. Optionally, an authentication token or code can be provided in firmware or hardware on the traffic guiding cone or barrier 42 and exchanged with other nodes on the wireless local area network 10.

[0025] Figure 2 Another node on the disclosed wireless local area network 10 is also depicted in the form of a wearable device 52 on the person of the first responder. Figure 5As shown in more detail in , the wearable device 52 will include a power source 44, a controller 19, and a wireless transceiver 30 to allow the wearable device 52 to join the disclosed wireless local area network 10, wherein the controller 19 includes a processor 22 and a memory 20. The wearable device 52 may include a tactile device 56 for generating vibrations to warn first responders of dangerous conditions, including intrusions or possible intrusions on the response scene. The wearable device 52 may include sensors 58 for detecting the condition and orientation of a person, for example, whether the person is upright and moving or has fallen and is not moving. The wearable device 52 may detect the vital signs of a person through one or more sensors 58. The wearable device 52 may include an RFID tag 54 or other mechanism for identifying a specific first responder wearing the wearable device 52. The responder identification may be reported to the wireless local area network 10 so that people can be tracked as they join or leave the scene and the condition of these people while they are on the scene can be obtained. The system 200 and the wireless local area network 10 can be configured to report and update the identification of the emergency vehicles 12 and personnel responding to the scene to one or more emergency response coordination centers via the Internet and / or via a cellular network. The wearable device 52 can include an auditory tone generator 48 and a homing beacon 60 to facilitate locating first responders in darkness, dense foliage, steep vertical terrain, smoke, or other environments where it may be difficult to locate a person who may be unconscious and immobile. The signal strength from the homing beacon 60 can be used to guide search efforts in a manner similar to the function of avalanche beacons known in the art. The wearable device 52 can be programmed to report the activation of the homing beacon to the wireless local area network 10, and the system 200 is configured to pass this information along to the response coordinator and commander.

[0026] The wearable device 52 and the emergency vehicle 12 can be configured to detect the proximity of the wearable device 52 (and thereby the person) relative to the emergency vehicle 12. The connection of the RFID tag 54 to the emergency vehicle 12 can be used as a proxy for the presence of the first responder at the emergency vehicle 12, because the operating range of the RFID tag is relatively small. The system 200 combining the emergency vehicle 12 and the wearable device 52 can be programmed to enable certain vehicle functions only when the first responder is present at the vehicle 12. For example, when the wearable device 52 is within a predetermined distance from the emergency vehicle 12, the vehicle will operate normally, but if the wearable device 52 leaves the predetermined distance (or the emergency vehicle 12 moves beyond the predetermined distance), the emergency vehicle 12 can be disabled or limited to a limited speed. When the wearable device 52 is not present, other functions of the emergency vehicle 12 can be disabled, such as the trunk lock and / or any locks that protect the firearms in the emergency vehicle 12. The wearable device 52 can be used to associate a specific person with a specific emergency vehicle 12 at the beginning of each shift. The officer's command role can be used to change the function or role of the emergency vehicle 12 as a node on the disclosed wireless LAN 10. For example, if the officer is in a command role, the emergency vehicle 12 can be configured to assume a leading role in the wireless LAN 10 and have different functions than other vehicles on the wireless LAN 10. The wearable device 52 can also include a hardware or software token or other security device to allow a vehicle occupied by the officer to join an adjacent local wireless network. For example, a command vehicle of a police department or fire department can be authorized to join an adjacent police or fire department wireless network, assuming that the officer's command status has been verified to the local wireless LAN 10.

[0027] All nodes in the disclosed network have some common features: each node includes a processor 22 (which may be referred to as a computer processor) for executing program instructions, a machine-readable storage medium (memory) 20 for storing program instructions, and a wireless transceiver 30 for receiving and sending data on the wireless local area network 10. For example, in the Thread network, each node in the mesh network is assigned a role that can change depending on the location of the node in the network. As used in the present disclosure, the location in the network is different from the physical location of the device or node relative to other devices. Each device can act as a router, whereby it can forward data from one node to another. A node (device) can be designated as a leader and handle certain routing and other information on the network. If the leader in the disclosed wireless local area network 10 leaves the network, another device is elected as the leader. According to aspects of the present disclosure, the process of joining and leaving the disclosed mesh network is automatic and does not require human intervention. This allows products compatible with the disclosed wireless local area network 10 to form a "self-organizing" network when mesh-equipped devices arrive or are deployed at a specific location. The disclosed autonomous formation and operation of the wireless local area network 10 and system 200 of connected devices assists in information exchange, first responders, and public safety while freeing first responders from some of their routine functions.

[0028] According to aspects of the present disclosure, the functionality of each device may be altered based on its physical location relative to other devices on the wireless local area network 10. Various implementations of this concept have been described above with respect to vehicle location, proximity of people, and devices such as traffic cones or obstacles 42. Position sensing via GPS may not be sufficient for the system 200 to determine Figure 2 The relative position of the emergency vehicle 12 shown in FIG.

[0029] Multiple partitions of the same network can exist simultaneously. Each partition can have its own leader and operate independently of any other partition. If the partitions come within range of each other, they can merge together seamlessly and designate a single leader for the merged network. The design of the wireless LAN and the design of the program instructions in each node or device will establish the rules for joining and leaving the network and when and whether adjacent networks merge.

[0030] The security of a mesh network is best managed within the organization that operates the network, and the network's security information should not be shared outside of the organization. Therefore, unrelated networks may not be able to merge directly and automatically with each other as is the case with nodes and devices that share the same network keys. For example, a network operated by the County Sherriff's Department may not be able to merge directly with a network operated by the State Police Department because security keys will not be shared between them. A secure method of communicating between disclosed mesh networks can be established through border routers that act as gateways to the Internet of available data networks. Secure communications can also be established within network protocols. Examples include software controlled and maintained passwords or tokens. Designated nodes such as command vehicles can be allowed to "participate" in communications with other networks.

[0031] Reliable communication and data transmission between devices or nodes in a wireless local area network 10 may require a common time reference for synchronization. In addition, time synchronization on a wireless network allows the use of a time division multiple access "TDMA" method on a multi-hop wireless network. One aspect of the disclosed self-organizing network is to wirelessly connect sensors deployed on emergency vehicles 12, personnel or traffic guidance devices. Each node (device) may include one or more sensors, a computer processor 22 with a memory 20, signal processing, a wireless transceiver 30, and a power source 44 such as a battery with limited capacity. These nodes must quickly report results to a data collection node or access point. Since these nodes are battery-powered, a media access control (MAC) protocol helps determine the network lifetime. The proposed MAC protocol for sensor networks provides contention-based access or time division multiple access (TDMA). The former (such as IEEE 802.11 (Carrier Sense Multiple Access CSMA)) consumes more energy than TDMA protocols because they waste energy in collisions and idle listening. Moreover, they do not provide delay guarantees. TDMA protocols are more energy efficient because nodes in the network can go into an inactive (sleep) state until their assigned time slot. More recent standards, such as IEEE 802.15.4, allow designers to configure their own timing patterns. Regarding channel access, 802.15.4 uses carrier sense multiple access with collision avoidance (CSMA-CA). This multiplexing method allows multiple users or nodes to access the same channel at different times without interference.

[0032] Some time synchronization methods may not be available on a mesh network because the MAC layer cannot timestamp the exact moment a message is sent / received. This causes MAC layer delays, or the time between a message being sent and hitting the air is completely uncertain. One possible method to coordinate timing on the disclosed mesh network is receiver-receiver synchronization (RRS), as known in the art. In the RRS method, a "reference node" sends a message that is witnessed by multiple receivers almost at the same time. The receivers then exchange timestamps of this jointly witnessed event. In this synchronization method, delays on the sender side are irrelevant because multiple receivers detect the message at the same time, thereby establishing a common time reference. RRS in a mesh network requires three devices, one device for sending and at least two devices for receiving, and these three devices must be "fully meshed" to avoid delays associated with multi-hop communications. The term "fully meshed" refers to the situation where the three network nodes (devices) involved in the RRS method are directly connected to each other network node (device).

[0033] GPS timing eliminates the need for at least three full mesh devices for synchronization. Any number of GPS-equipped devices can be synchronized even without a connection to the disclosed wireless LAN 10. Where GPS signals are available, GPS receivers can provide an accurate time synchronization alternative in the form of pulses. However, such signals are not always reliable in urban, mountainous terrain, or indoor environments. A dedicated GPS timing module extends timing capabilities to environments where GPS signals are unavailable. By using a high-precision temperature-controlled crystal oscillator (TCXO), devices can maintain accurate clock pulses for long periods of time after losing GPS signals. In most environments, GPS signals are interrupted for short periods of time by tunnels, garages, and high-rise buildings, and a GPS timing module can be used to provide the necessary time reference between nodes on a mesh network.

[0034] Modern motor vehicles include advanced electronic systems coordinated by one or more electronic control units. Figure 6A representative control unit 62 and associated peripherals, sensors, and vehicle systems are shown. The control unit 62 includes a memory 63 for storing executable computer code and a precise clock 65 for coordinating internal vehicle functions. The vehicle may include a GPS receiver 64, a DGPS receiver 66, inter-vehicle communications 68, and infrastructure communications 70 for interacting with smart infrastructure. Vehicle sensors include one or more of an accelerometer 72, a gyroscope 74, a camera 76, a radar 78, a lidar 80, a speed sensor 82, a weather sensor 84, and a stoplight sensor 86. The vehicle includes at least one display 88 for providing information and operator controls 90 for providing input to direct vehicle operation. The vehicle may be equipped to generate warning light signals and audible tones 92 that are perceptible to an operator within the vehicle, or in the case of an emergency vehicle 12, visual signals and audible tones that are perceptible to pedestrians and motorists outside the emergency vehicle 12. The vehicle system may include a map database 94 for tracking the location of the vehicle on a map that may be displayed to the vehicle operator. The vehicle systems receive power 96 from the vehicle electrical system, which is typically a DC system including a battery and an engine driven alternator, as is known in the art. The control unit 62 may communicate with a brake servo 98, a steering servo 100, a throttle servo 102, and vehicle diagnostics 104. The vehicle may include an RFID 54 or other identifier to provide an electronically readable identifier that may be used in electronic communications and over a network such as the disclosed wireless local area network 10.

[0035] The computer code running in the control unit 62 can be configured to process data from some or all of the connected systems and devices to calculate the vehicle position and place the vehicle on a map displayed to the operator. The control unit 62 can supplement GPS and DGPS information with data from vehicle sensors 72, 74, 76, 78, 80, 82 to perform accurate positioning calculations and issue warnings to the operator about dangerous vehicle movements or road conditions. According to aspects of the present disclosure, the control unit 62 can share some vehicle data, location information or other data and calculations with the controller 18, wherein the controller 18 is associated with the disclosed wireless local area network 10 and the connected peripheral devices. Alternatively, the disclosed system 200 can include its own sensors and perform calculations separately from the control unit 62. Each node on the disclosed mesh network can use a GPS receiver, a DGPS receiver, or one of these supplemented by sensor feedback from an accelerometer, a gyroscope, a radar, or signals from other nodes to determine its own location and broadcast its location to other nodes on the network.

[0036] Refinements of GPS are generally known in the art. The accuracy of GPS and DGPS can be improved by a wide area augmentation system (WAAS), a local area augmentation system (LAAS), or other systems that utilize carrier phase. Additional details on GPS and DGPS accuracy improvements are provided by Breed et al. US 6,405,132. Precise positioning can be achieved by improving GPS position using vehicle telematics, infrastructure-based positioning aids, radio frequency identification ("RFID") tags, cameras, infrared or optical sensors, radar and lidar, or other sensors that establish relative or absolute position as described above.

[0037] Each node can be programmed to maintain a database (or other record) of the current location of other nodes on the network. This information can be used to generate a virtual "map" of the relative locations of nodes on the network, which can be used to coordinate node activities. For example, warning signals generated by emergency vehicles 12 parked or arriving at the scene can be coordinated to improve safety. A single police car at the scene should use its forward-pointing and rear-pointing warning lights to warn upcoming traffic in both directions. However, the arrival of a second police car at the scene changes this situation, and coordination between the emergency vehicles 12 will allow the rear-facing warning lights of the leading vehicle to be turned off or changed to a less dynamic traffic guidance mode, while the forward-facing lights of the following vehicles can be turned off or changed to illuminate the scene.

[0038] This coordination between nodes on a mesh network may require higher positioning accuracy than is typically available using GPS alone, which is typically limited to about 3 meters. Positioning accuracy can be improved by accessing vehicle speed and heading information from the vehicle's internal communications bus (also known as the CAN bus). Other position and proximity sensors can be used in tandem with the software to determine the relative position and orientation of other vehicles (nodes) on the network. One situation where relative position and vehicle orientation information can be used to improve safety is a chase or response situation where emergency vehicles are following one another. This information can be used to control the warning lights of the leading vehicle so they do not blind the vehicle immediately behind. The warning lights can also be configured to warn the leading vehicle to brake or slow down suddenly to help avoid a collision.

[0039] Mesh network capability can be added to existing control modules through logic inputs and network controllers. New "scalable" warning signal patterns can be added to the existing library of warning light signals. Traffic advisory patterns can be sequenced by activating segments at allocated time slots based on synchronized time signals available to nodes (in this case emergency vehicles 12 and / or traffic guidance equipment).

[0040] Mesh network connectivity and information transmission can be implemented so that the exchange of information and control is a seamless process handled by the system 200 with little or no human intervention. Network capabilities can be integrated into existing devices rather than as an additional add-on system. Nodes are programmed to join and leave the wireless local area network 10 according to the rules established for the network. The wireless local area network 10 is configured to be self-organizing and autonomous to a large extent. This frees up first responders to do their jobs while the connected devices automatically provide safety enhancements. An example is a system 200 programmed to periodically report emergency vehicles 12 and personnel at a specific response scene. Response coordinators will obtain accurate and timely information about the resources at a specific scene, which enables them to assess whether additional resources are needed or even redirect resources to other higher priority situations.

[0041] Another example is a work zone where vehicles located at the beginning of the work zone are equipped with sensors that detect the speed and trajectory of oncoming vehicles. Vehicles approaching at excessive speed or on a trajectory to enter the work zone trigger an alarm on the disclosed wireless local area network 10. In this case, police officers and workers in the work zone wearing wearable devices 52 configured to receive alarms are provided with auditory and / or vibration signals of the expected intrusion. Such warnings can provide valuable time for personnel in the work zone to take evasive action. In addition, the wearable device 52 can implement motion sensors such as accelerometers to detect when a worker or person falls to the ground. In a law enforcement situation, this event can trigger the opening of a car door to allow a police dog to assist the police or trigger a specific pattern of light and / or sirens to draw attention to the scene. Wearable connected devices can also be configured to report health and status information of personnel, such as heart rate and problem alarms when such information indicates that help is needed.

[0042] The proposed wireless local area network 10 can be extended within a structure by way of portable and wearable nodes to help track the location of emergency personnel. In this embodiment, the nodes may include waypoints, such as wedges deployed to hold doors open, and may also include wearable devices 52 on personnel moving within the structure. This embodiment of the disclosed wireless local area network will employ the same infrastructure as described above for the other embodiments, and will dynamically connect sensors, wearable devices, and waypoints. Location sensing can be used to track the location of personnel within the structure, including altitude. The wearable device 52 can monitor conditions such as temperature, compounds in the air, vital signs of the personnel, and report this information to a situation manager outside the building. Knowing the location of personnel within the structure helps to assist personnel in distress and can be used to guide personnel on how to get out of a dangerous situation.

[0043] Figure 7Representative steps in a method for operating a system of devices on a wireless local area network according to aspects of the present disclosure are shown. In step 110, the device is configured to automatically join a local wireless network of compatible devices, including at least one emergency vehicle. In step 112, the device transmits data over the network. In step 114, the system processes data from the connected devices to determine the positions of the devices relative to each other. In step 116, the system records the relative positions of the connected devices, and in step 118, the system transmits the identification of the device and the position of the device to a command center located remotely from the wireless local area network. Such transmission of devices and positions at step 118 may also include the absolute position of one or more emergency vehicles included in the wireless local area network corresponding to the position on the map. In step 120, the system operates the connected device according to the relative position of the connected device. The location-based substitution function is described in detail above. The system is programmed to periodically repeat steps 112-118 to ensure that the information about the vehicles and equipment at the response scene is accurate when conditions change. Step 120 uses updated device and location information to change the operation of the device on the network according to the latest device and location information.

Claims

1. A system for managing a plurality of warning devices associated with an emergency vehicle, comprising: a first warning device for a first emergency vehicle, the first warning device having a first plurality of warning functions controlled by a first controller, the first controller communicating over a wireless network via a first transceiver; a first sensor for providing a location of the first emergency vehicle; a second warning device for a second emergency vehicle, the second warning device having a second plurality of warning functions controlled by a second controller, the second controller communicating over the wireless network via a second transceiver; a second sensor for providing a location of the second emergency vehicle; The first transceiver and the second transceiver transmit data to each other through the wireless network to indicate the relative positions of the first emergency vehicle and the second emergency vehicle, and each of the first controller and the second controller controls a corresponding warning function according to the relative positions of the first emergency vehicle and the second emergency vehicle.

2. The system according to claim 1, wherein: Each of the first warning device and the second warning device includes a warning light, wherein each of the first plurality of warning functions and the second plurality of warning functions includes a light mode, wherein the first controller activates a light mode in the first warning device that is different from a light mode activated in the second warning device based on the relative position.

3. The system according to claim 2, wherein: The light pattern activated in the first warning device is complementary to the light pattern activated in the second warning device.

4. The system according to claim 1, wherein: The first controller activates one of the first plurality of warning functions according to the relative position, and the second controller deactivates one of the second plurality of warning functions according to the relative position.

5. The system according to claim 1, wherein: Each of the first warning device and the second warning device includes a row of forward-facing warning lights and a row of rearward-facing warning lights, wherein the first controller deactivates one of the row of forward-facing warning lights and the row of rearward-facing warning lights in the first warning device based on the relative position.

6. The system according to claim 1, wherein: The data communicated over the wireless network includes a status of at least one of the first emergency vehicle and the second emergency vehicle.

7. The system according to claim 6, wherein: The first controller also controls a warning function of the first warning device according to the status of the second emergency vehicle.

8. The system according to claim 6, wherein: The status includes at least one of a speed, a heading, and a braking status of at least one of the first emergency vehicle and the second emergency vehicle.

9. The system according to claim 1, wherein: Each of the first sensor and the second sensor is a GPS sensor.

10. The system of claim 1, further comprising a third warning device independent of any emergency vehicle, wherein the third warning device has a third plurality of warning functions controlled by a third controller, the third controller communicating on the wireless network via a third transceiver; in, The third transceiver transmits data with at least one of the first transceiver and the second transceiver through the wireless network to indicate the relative position of the third warning device and at least one of the first emergency vehicle and the second emergency vehicle, and the third controller controls the corresponding warning function according to the relative position of the third warning device.

11. The system according to claim 10, wherein: The third warning device is one of a traffic cone and a traffic barrier.

12. A warning system for an emergency vehicle, comprising: at least one warning device having multiple warning functions; a controller for controlling the plurality of warning functions of the at least one warning device and communicating over a wireless network via a transceiver; The controller receives data from at least one sensor, the data including the location and status of the emergency vehicle; The transceiver transmits the data via the wireless network and receives data regarding at least one of the position and status of the second emergency vehicle via the wireless network to indicate the relative position of the emergency vehicle and the second emergency vehicle, and the controller controls the warning function of the at least one warning device according to the relative position.

13. The system according to claim 12, wherein: The controller also controls a warning function of the at least one warning device according to the status of the second emergency vehicle.

14. The system according to claim 13, wherein: The status includes at least one of speed, heading, and braking status.

15. The system of claim 12, wherein: The at least one warning device includes a visual warning device and an audio warning device.

16. The system of claim 12, wherein: The controller activates a warning function of the at least one warning device that is different from a warning function activated in a warning device of the second emergency vehicle based on the relative position.

17. The system of claim 12, wherein: The at least one warning device comprises a warning light, the plurality of warning functions comprise light patterns, wherein the controller activates a light pattern in the at least one warning device that is different from a light pattern activated in the warning device of the second emergency vehicle based on the relative position.

18. The system of claim 12, wherein: The light pattern activated in the first warning device is complementary to the light pattern activated in the warning device of the second emergency vehicle.

19. The system of claim 12, wherein: The controller disables one of the first plurality of warning functions based on the relative position.

20. The system of claim 12, wherein: The at least one warning device includes a row of forward-facing warning lights and a row of rearward-facing warning lights, wherein the controller deactivates one of the row of forward-facing warning lights and the row of rearward-facing warning lights based on the relative position.

Images