Abstract:
The present disclosure is directed to a ground survey and obstacle detection system using one or multiple detection devices, such as aerial detection devices. Aerial detection devices are sent ahead of the primary vehicle to survey a territory and map out any obstacles. The aerial detection device is equipped with sensors to scan the ground below it and detect obstacles. The aerial detection device is not affected by or prone to triggering dangerous obstacles. The aerial detection device flies above the ground and may be configured to send a signal back alerting the primary vehicle to the existence of obstacles.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a ground survey and obstacle detection system using one or multiple detection devices. 
       BACKGROUND 
       [0002]    Land transportation is a popular form of transportation. It is cheap and convenient relative to other forms of travel. Land transportation relies on vehicles such as automobiles, trucks, and armored vehicles, e.g., tanks. However, there are many problems associated with land transportation over difficult or unknown terrain, such as a warzone or a karst landscape. Obstacles such as explosives, sinkholes, and dangerous chemicals are often encountered during transportation across such terrains. 
         [0003]    Explosives such as landmines or bombs are a serious threat to land vehicles. Bombs may be placed in or concealed on the ground. Landmines are often concealed on the surface of the ground or underground and designed to disable enemy targets as the targets pass near them. Landmines are typically detonated automatically by way of pressure from the target passing over. Landmines may also be detonated through a trigger mechanism. A landmine causes damages through direct impact from the blast or high speed fragments released from the blast. Similar to a landmine, an “improvised explosive device” (IED) or “roadside bomb” is constructed to cause damages through a blast. IEDs are often homemade and deployed in ways other than in conventional military activity. An TED may be constructed of conventional military explosives, such as an artillery round attached to a detonating mechanism. An TED may also be constructed from nontraditional materials. 
         [0004]    Another type of obstacle is Karst landscapes. Karst landscapes are geological formations composed of soluble bedrock that frequently cause sinkholes to develop. Sinkholes are formed when natural erosion occurs beneath the top surface. When a land vehicle passes over a sinkhole, the top surface may collapse and the vehicle may sink in and become trapped. 
         [0005]    A third type of obstacle is dangerous chemicals. When dangerous chemicals are concealed, they are also difficult to detect. 
         [0006]    The present application discloses advanced methods and apparatus for ground survey and obstacle detection. The methods and apparatus disclosed herein can be used to prevent enemy attacks during transportation across hostile territories, to ensure safe passage through uncharted geographic regions, or to survey uncharted geographic regions. 
       SUMMARY 
       [0007]    This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used in determining the scope of the claimed subject matter. 
         [0008]    The present disclosure is directed to a ground survey and obstacle detection system using one or multiple detection devices, for example, aerial detection devices. Aerial detection devices can be sent in front of a primary vehicle to survey the territory and map out any obstacles. An aerial detection device is equipped with one or more sensors configured to monitor the ground below and detect obstacles. After an obstacle has been detected, the detection device can alert the primary vehicle to the existence of obstacles. The detection device can also be configured to dismantle, mitigate, or neutralize the obstacles. Because an aerial detection device flies above the ground, it is less likely that the detection device will trigger or be affected by any of the aforementioned obstacles. 
         [0009]    In some embodiments, the detection device may be configured to dismantle the obstacle either autonomously or under the control of the primary vehicle. 
         [0010]    In the disclosure herein, aerial detection devices are used as an example to illustrate the advantageous technology of the present application. Other types of detection devices may include, but are not limited to, land-roaming, tunnel-burrowing, or wall-scaling devices that are designed to detect, but not to be affected by, any of the above mentioned obstacles. 
         [0011]    One issue with using an aerial vehicle as the detection device is how to power the detection device for an extended period of time. Small-scale aerial vehicles typically run on batteries. Generally, the larger a battery is, the longer it lasts. Therefore, the flying time of these aerial vehicles is limited by the weight of the battery, which, in turn, is limited by the vehicles&#39; load capacities. 
         [0012]    In some embodiments, an electromagnetic radiation power transmission system is used to remotely re-charge the detection devices, allowing for an extended operating time of the detection devices. Other power supply methods are also disclosed in the present application. 
         [0013]    In some embodiments, a charging system is used to charge one or more detection devices. The charging system may comprise a charging unit that includes an electromagnetic radiation power transmitter and laser range-finding device. Each detection device includes a battery, battery meter and electromagnetic radiation power receiver. In some embodiments, multiple detection devices are used to cover an area more quickly or to cover a wider area. In such case, the power transmission pattern includes a charging schedule for each detection device. The charging unit is configured to select a detection device among one or more multiple detection devices for charging according to a power transmission pattern. The power transmission pattern can be determined by a schedule input by a human operator or an autonomously-determined schedule based on the battery needs of the detection devices. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0014]    The foregoing aspects and many attendant advantages of the technologies disclosed herein will become more readily appreciated through reference to the following detailed description when taken in conjunction with the accompanying drawings. 
           [0015]      FIG. 1  illustrates an exemplary ground survey and obstacle detection system. 
           [0016]      FIG. 2  illustrates a block diagram of an exemplary detection device. 
           [0017]      FIG. 3  illustrates the components of an exemplary detection device. 
           [0018]      FIGS. 4   a  and  4   b  are flow charts illustrating exemplary detection processes in a detection device. 
           [0019]      FIG. 5  illustrates an exemplary block diagram of a primary vehicle. 
           [0020]      FIG. 6  is a flow chart illustrating an exemplary control process in a primary vehicle. 
           [0021]      FIG. 7  illustrates an exemplary use case showing a detection device detecting and locating obstacles and threats in the vicinity of the primary vehicle. 
           [0022]      FIG. 8  illustrates an exemplary power supply system for powering and controlling an aerial detection device using a physical cable. 
           [0023]      FIG. 9  illustrates an alternative power supply system for powering the aerial detection device using a battery charger mounted on the primary vehicle. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    Certain specific details are set forth in the following description and drawings to provide a thorough understanding of various embodiments of the invention. Certain well-known details often associated with computing and software technology are not set forth in the following disclosure to avoid unnecessarily obscuring the various embodiments of the invention. Furthermore, those of ordinary skill in the relevant art will understand that they can practice other embodiments of the invention without one or more of the details described below. Finally, while various methods are described with reference to steps and sequences in the following disclosure, the description as such is for providing a clear implementation of embodiments of the invention, and the steps and sequences of steps should not be taken as required to practice this invention. 
         [0025]    The present application discloses deploying one or more detection devices ahead of a primary vehicle to survey the territory, detect hidden dangers, and map out any obstacles. In some embodiments, an aerial vehicle is used as a detection device. An aerial detection device is configured to travel above the ground or in the air and is equipped with necessary sensors to scan the ground below and detect obstacles. One of the advantages of using an aerial detection device is that it does not usually come into contact with any of the aforementioned obstacles, and therefore does not trigger such obstacles. In addition, the aerial detection device has maneuverability advantages over a land-based detection device. 
         [0026]    A detection device can be unmanned. An unmanned aerial detection device may also be referred to as an unmanned aerial vehicle (UAV). A UAV may be autonomous or under the control of the primary vehicle. In this way, human operators located in the primary vehicle can be kept outside of any potential danger zones. 
         [0027]      FIG. 1  illustrates an exemplary system for ground surveying and obstacle detecting using aerial detection devices. The ground survey and obstacle detection system in  FIG. 1  includes a primary vehicle  102  and three aerial detection devices,  103 ,  104 , and  105 . 
         [0028]    The primary vehicle  102  can be any transportation vehicle, for example, automobiles such as Humvee trucks, or tanks. The primary vehicle  102  comprises a base unit  110  that may include a central computer  101 , a laser range-finding system  107 , and an electromagnetic (EM) radiation transmitter  108 . 
         [0029]    The central computer  101  can be any commercially available computing system configured with sufficient processing power, memory, a wireless data transmitter/receiver, and Input/Output ports for connecting to peripherals. 
         [0030]    The laser range-finding system  107  may be any of the commercially available laser range-finding systems. The laser range-finding system  107  uses a laser system to monitor or scan the ground ahead. In some embodiments, the laser range-finding system can be used to create a 3-D model of its surroundings. In some embodiments, the laser range-finding system can be used to control and monitor detection devices. The laser range-finding system  107  can be used to manage detection devices  103 ,  104 ,  105 , for example, by measuring the positions of the detection devices  103 ,  104 ,  105 , and directing them in the path ahead. 
         [0031]    The EM radiation power transmitter  108  transmits electromagnetic radiation to deliver power to the detection devices  103 ,  104 ,  105 . The EM radiation power transmitter  108  may be commercially available and already developed. A person skilled in the art would know that the EM radiation transmitters  108  can be replaced with inductive power transmission charging devices, or other types of remote charging techniques. With continuous or periodic power supply from the primary vehicle  102 , the detection devices  103 ,  104 , and  105  can operate for extended periods of time. 
         [0032]    In  FIG. 1 , three detection devices  103 ,  104 , and  105  are shown. But the number of detection devices can vary from one to many. In  FIG. 1 , the detection devices  103 ,  104 ,  105  are depicted as quadrotors. However, the detection devices  103 ,  104 ,  105  can be any type of aerial vehicle, either commercially available or custom developed, including but not limited to vertical takeoff and landing (VTOL) aircraft, and fixed-wing aircraft. VTOL aircraft include helicopters and quadrotors. In some embodiments, one type or different types of detection devices can be deployed at the same time. 
         [0033]      FIG. 2  is a block diagram of an exemplary detection device  200  for ground survey and obstacle detection. The detection device  200  includes three sensors  202 ,  204 , and  206 . In some embodiments, a detection device  200  may include any number of sensors. The sensors  202 ,  204 , and  206 , may be of the same type or different types. 
         [0034]    The detection device  200  also includes a transmitter/receiver  208 , a processing circuit  212 , a motor component  214 , a power supply unit  218 , and an optional GPS system  216 . 
         [0035]    The transmitter/receiver  208  may be connected to an antenna  210  and transmit data/commands to and receive data/commands from the primary vehicle  102 . The processing circuit  212  is configured to control the various components of the detection device  200 , which includes the sensors  202 ,  204 , and  206 , the motor component  214 , and the power supply unit  218 , etc. The processing circuit  212  is also configured to process commands received from the primary vehicle  102 . The motor component  214  controls movements of the detection device  200 . The detection device  200  can be configured to fly, walk, float or perform any other type of motion. 
         [0036]    The power supply unit  218  may include one or more batteries (not shown), a power level detector  220 , and a charging unit  222 . The power level detector  220  is configured to detect if the power level of the batteries is low, and thus if they need to be charged through the charging unit  222 . An example of the power level detector  220  is a battery meter. An example of the charging unit  222  is an EM transmission receiver  303  shown in  FIG. 3 . 
         [0037]    In some embodiments, the detection device  200  may be configured to send a battery status or power level detected by the power level detector  220  to the primary vehicle  102 . The battery status data can be used by the base unit  101  to determine an optimal charging pattern for the detection devices  103 ,  104 , and  105 . For example, the primary vehicle  102  may charge a detection device according to a predetermined timetable, or whenever the power level or battery level is below a certain threshold. 
         [0038]    In some embodiments, the base unit  101  may be configured to charge a detection device  200  by beaming EM radiations at the detection device  200 . In such embodiments, the base unit  101  may rely on the location data of the detection device  200 , for example, provided by the laser range-finding system  107 , to orient and position the EM radiation transmitter  108  accordingly. The location data of the detection device  200  may also be provided by the Global Positioning System (GPS)  216  installed on the detection device  200 . The GPS  216  is optional. The GPS system  216  can be used, in lieu of or along with the laser range-finding system  107 , to obtain location data of the detection device  200  or used to obtain location data for the objects or features detected by the detection device  200  while surveying the terrain. 
         [0039]    In some embodiments, the detection device  200  may be implemented as a mobile improvised explosive device (IED) detector. A mobile IED detector can be deployed in front of an army vehicle traveling in a war zone. Such a mobile IED detector may be carried by a quadrotor aircraft or rotor helicopter equipped with a special sensor designed for detecting buried or hidden IEDs. A mobile IED detector can be made small and nimble with relatively low cost. A plurality of them can be deployed at once in order to provide coverage of a large geographic area. 
         [0040]    In some embodiments, the detection device  200  may be implemented as an aerial detection device  300  shown in  FIG. 3 . 
         [0041]    The aerial detection device  300  in  FIG. 3  is shown to include a microcontroller  302 , an EM radiation power receiver  303 , a sensor  301 , a battery/battery meter  304 , a GPS receiver  305 , and a propulsion system  306 . The microcontroller  302  controls movements of the aerial detection device  300  and manages the other components of the aerial detection device  300 . The microcontroller  302  also includes a wireless data transceiver (transmitter/receiver)  208  (not shown in  FIG. 3 ) for transmitting and receiving signals to and from the primary vehicle  102 . 
         [0042]    The sensor  301  is a threat sensor for detecting threats and obstacles in/on the ground ahead of the primary vehicle  102 . The threat sensor  301  may include ground penetrating radar (GPR), an infrared sensor, a video camera, or others. These sensors are specially designed to detected unobservable threats by measuring variations in ground density, ground temperature, or electronic signal differentials . Electronic signal differentials appear in potential threats when they contain circuits or wires with current running through them; many explosive devices have triggers with electronic circuits or wires. In practice, one or multiple sensors can be mounted on each detection device. Different detection devices may be equipped with different types of sensors. 
         [0043]    The battery and battery meter  304  stores power for the aerial detection device and reports the battery level to the microcontroller  302 . The GPS receiver  305  receives location data from a remote global positioning system. The EM radiation power receiver  303  receives EM energy from the EM radiation transmitter  108  (shown in  FIG. 1 ). The EM radiation power receiver  303  may be shaped as a semi-sphere such that charging of the aerial detection device  300  is not restricted in certain orientations relative to the EM transmitter  108 . Other shapes of the EM radiation power receiver are also feasible or even desirable. The propulsion system  306  generates the lift needed to keep the detection device in flight and controls the motion of the aerial detection device  300 . The propulsion system shown in  FIG. 3  is that of a quadrotor, but other propulsion systems can be used as well. 
         [0044]      FIGS. 4   a  and  4   b  are flow charts that illustrate two exemplary detection processes in the detection device  200 . In  FIG. 4   a,  the detection device  200  receives sensor data from one or more sensors  202 ,  204 ,  206  (step  402 ). The detection device  200  processes the received sensor data, e.g., encoding or encrypting the data (step  404 ). The detection device  200  then transmits the processed data to the primary vehicle (step  406 ). 
         [0045]      FIG. 4   b  illustrates another exemplary detection process in which the detection device  200  is configured to do more than issue a warning to the primary vehicle  102 . In  FIG. 4   b,  the detection device  200  receives sensor data (step  404 ) and analyzes the sensor data to detect a threat level (step  406 ). The threat level is compared to a threshold (step  408 ). The detection device  200  may decide that no warning is needed if the threat level does not exceed the threshold (step  414 ). If the threat level exceeds the threshold, the detection device  200  issues a warning to the primary vehicle (step  410 ). Upon receiving a warning from the detection device  200 , the primary vehicle  102  may take a pre-determined action against the threat (step  412 ). 
         [0046]      FIG. 5  illustrates an exemplary primary vehicle  500 . In  FIG. 5 , the primary vehicle  500  includes a transmitter/receiver  502 , processing circuit/CPU  504 , memory  506 , power supply unit  508 , server  512 , laser range-finding system  514  (optional), warning system  510 , and I/O device  516 . 
         [0047]    The transmitter/receiver  502  is connected to an antenna  524  and is configured to communicate with the detection device  200 . The data received from the detection device  200  is forwarded to the processing circuit  504 . The processing circuit  504  also issues commands or provides information to the detection device  200  through the transmitter/receiver  502 . The processing circuit  504  is connected to the memory  506 , which may include a database for storing survey data, maps, and other relevant information. The processing circuit  504  is also connected to the power supply unit  508  which provides power supply to the detection device  300 . An example of the power supply unit  508  is the EM radiation transmitter  108  shown in  FIG. 1 , or the battery charger  902  shown in  FIG. 9 . 
         [0048]    When multiple detection devices are deployed, the power supply unit  508  needs to supply power to the multiple detection devices. In some embodiments, the power supply unit  508  may be implemented as a charging system that comprises a charging unit. The charging unit includes an electromagnetic radiation power transmitter and laser range-finding device. The charging system supplies power to the multiple detection devices according to a power transmission pattern. The power transmission pattern includes a charging schedule for each detection device. The charging unit is configured to select a detection device among one or more multiple detection devices for charging according to the power transmission pattern. The power transmission pattern can be determined by a schedule input by a human operator or an autonomously-determined schedule based on the battery needs of the detection devices. 
         [0049]    The processing circuit  504  may also be optionally connected to the I/O device  516 , the warning system  510 , the server  512 , and the laser range-finding system  514 . In  FIG. 5 , the server  512  is shown to be located on the primary vehicle  500 . The server  512  may be located remotely. If the server  516  is remote, the processing circuit  504  may communicate with the server  512  via a long distance wireless connection, such as mobile satellite communications. 
         [0050]      FIG. 6  illustrates an exemplary process to be executed on the primary vehicle  500 . In  FIG. 6 , the primary vehicle  500  receives sensor data from a detection device  300  (step  602 ). The primary vehicle  500  may calculate a threat level based on the sensor data (step  604 ) and compare the threat level to a threshold (step  606 ). If the threat level exceeds the threshold, a warning may be issued through the warning system  510  (step  608 ). If the threat level does not exceed the threshold, no warning may be issued (step  610 ). As explained above, in some embodiments, the detection device can directly issue a warning message to the primary vehicle after calculating the threat level and comparing the threat level to the threshold. 
         [0051]    The communication between the primary vehicle  500  and the detection device  200  can be carried out over a number of different wireless data communication methods ranging from short-range to long-range types. Wireless local area networks such as Wi-Fi and Bluetooth could both transmit wireless data at a maximum transmission range of about 100 feet. Cellular data service can offer data transmission coverage at ranges of up to 20 miles from the cell site. Mobile satellite communication technologies can transmit data anywhere on earth. Even farther, a detection device could use a high-frequency X-band radio wavelength to communicate with the central computer thousands of miles away. The invention presented here would typically use short-range data transmission methods including Wi-Fi and Bluetooth. 
         [0052]      FIG. 7  illustrates an exemplary use case of the ground survey and obstacle detection system disclosed herein. The system includes a primary vehicle  701  and a detection device  703 . The detection device  703  is equipped with one or more sensors  704 , such as ground penetrating radar, night vision detector/sensor, or infrared sensors for detecting threats such as landmines and IEDs  705 . Upon detecting the threat  705 , the detection device  703  transmits the GPS coordinates of the threat  705  to the primary vehicle  701 . The primary vehicle  701  may store the GPS coordinates into the database ( 506  shown in  FIG. 5 ) or send the GPS coordinates to the server  512  for further actions or removal. In  FIG. 7 , the detection device  703  flies ahead of the primary vehicle  701  so any potential threats can be detected early and avoided. In some embodiments, multiple detection devices can collaborate and work in conjunction with each other. 
         [0053]    In some embodiments, the calculation of the probability of a potential threat may be carried out by the primary vehicle  701 . In other embodiments, the calculation may be carried out by the detection device  703 . The calculated probability may be compared to a threshold to determine whether a warning is warranted. The comparison may be performed by the detection device or the primary vehicle. If the comparison is performed by the detection device and the detection device determines that the probability of a potential threat exceeds a threshold, it may issue a warning message to the primary vehicle. The primary vehicle, upon receiving the warning message, may gather necessary data, such as the location of the threat, before generating an alarm to alert human operators or sending an alert message to a server. A team may be dispatched from the primary vehicle  701  to neutralize or dismantle the threat. Alternatively, the detection device  703  may be configured to mitigate or neutralize the threat itself, either autonomously or under the command of the primary vehicle  701 . 
         [0054]      FIG. 8  illustrates an alternative power supply system installed on a primary vehicle  801  for powering and controlling an aerial detection device  803  using a physical cable  802 . The electromagnetic radiation transmitter  108  on the base unit  101  and the electromagnetic radiation receiver  303  on the detection device  300  are replaced with the power cable  802 . The power cable  802  connects the battery  804  of the aerial detection device  803  to the power source  805  of the base unit  101 . This power cable  802  is sometimes referred to as a tether. The power source may be direct current (DC) or alternating current (AC). 
         [0055]    In some embodiments, data between the detection device  803  and the primary vehicle  801  can be transmitted through the use of a data transmission wire. The data transmission wire may share the same physical cable with the power cable  802  or use a physical cable separate from the power cable  802 . When using a separate physical cable, the data transmission wire may share its housing with the power cable  802 . 
         [0056]      FIG. 9  illustrates yet another alternative power supply system for powering the aerial detection device  904 . The power supply system shown in  FIG. 9  comprises a battery charger  902  mounted on the primary vehicle  901  which includes a central computer  906 , a base unit  907 , a laser range-finding system  908 , and a charged backup battery  903 . The aerial detection device  904  carries a detachable rechargeable battery  909 . The battery charger  902  on the primary vehicle  901  may charge more than one battery at a time. When the battery charge of the detection device  904  is low, the detection device  904  returns to the primary vehicle  901  for re-charging its battery  909 . The detection device may remain with the primary vehicle  901  while the battery  909  is charged by the battery charger  902 . Alternatively, the detection device  904  can drop its depleted battery  909  and pick up a freshly charged battery  903 . A variety of methods are known for swapping batteries while keeping the detection device powered. The battery of the detection device may be swapped by an automatic mechanism or manually. There is no limit to how many charging batteries or charging aerial detection devices each system may use. The battery charger  902  may be configured to charge two or more batteries simultaneously. Although the present application discloses several exemplary charging methods using EM radiation, a physical power line, and battery charger to power the detection device, it is not intended that the disclosure be limited to these power supply methods. 
         [0057]    Although the present system has been described as a threat detection system, it is not intended that the disclosure be limited to this application. This system could be used for other applications. For example, it can be used to survey unexplored territories, particularly territories that are potential construction sites. It can be used to examine potential construction sites that require density differential inspections of the ground to determine stiffness, composition, and other characteristics indicating viability of construction. It can be used to locate and uncover potential objects in the ground that may pose as obstacles during construction. It can be used as a pollution monitoring system to monitor and measure pollution levels for environment protection applications. It can be used as a border security device to check for the presence of underground tunnels. It can be used to check for the presence of underground water. It can be used for geological terrain mapping for cartographic purposes. It can be used to detect underground pipes and power lines. Finally, while the systems described herein show surveying territory in front of the primary vehicle, the techniques can also be feasibly used to survey territory behind and next to the primary vehicle.