MOBILE ROBOTIC SNAKE
CROSS-REFERENCE TO RELATED APPLICATION The subject matter of this application is related to the subject matter of U.S. Application No. 60/096,484, which is incorporated herein by reference and priority to which is claimed under 35 U.S.C. Section 119(e).
BACKGROUND OF THE INVENTION
1. Field of the Invention Embodiments of the invention relate to computing devices of two types: wearable computing devices, such as those available from ViA, Inc., Northfield, Minnesota USA, and mobile robotic devices. For the first time, embodiments of the invention combine important features of these two types of computing devices, achieving advantages believed unprecedented in the art.
2. Description of Related Art
Embodiments of the invention have particular application to wearable computing devices available from ViA, Inc., Northfield, MN USA. Attention is directed to ViA's various domestic and international patents, e.g. U.S. Patents Nos. 5,285,398, 5,492,651, 5,555,490, 5,572,401, 5,581,492, and 5,798,907, all of which are incorporated herein by reference and which disclose wearable computing platforms having wide application in a variety of industries. One type of computing platform 10 according to ViA's designs, having flexibly interconnected modules or segments 12, is shown in Figure 1.
ViA, Inc. has a proven track record of developing and deploying innovative and high-quality systems to a diverse set of customers with equally diverse needs and applications. ViA's products can be successfully used in numerous and diverse applications, ranging from automobile assembly lines to the medical industry to the financial markets. As a leading commercial supplier of wearable computers, ViA is committed to continually update its products as new PC technologies become available.
Thus, using ViA's products ensures that users will continually have the best capabilities the PC community offers.
There are also numerous efforts underway to develop small, ground-based mobile robotic systems in a human-packable form factor. These include wheeled and tracked platforms, crab-type devices and hoppers.
The most common approach used in designing such systems is the use of wheeled or tracked devices. The reason for this is that these devices are straightforward in design, robust in deployment and can carry a rather large payload. The difficulty with wheeled and tracked systems is that as the size of these platforms is reduced, their mobility significantly decreases. For example, it is extremely difficult for a human-packable wheeled system to climb a standard staircase. Obstacles commonly found within an urban environment, such as rubble or tall grass, can cause a wheeled /tracked device to bottom out. Thus, in order to achieve obstacle-climbing objectives e.g. 10 cm rubble, >25 cm step, these devices either grow in complexity or grow in size to the point that they are no longer human-packable. Crab-like devices have the same difficulty with the added issue of not being able to achieve adequate speed, e.g. > 100 cm/s. Hoppers are an attractive approach to achieving both climbing and speed requirements. However, compared to the other design options, the design complexity, computation and power requirements are significantly increased while at the same time the payload ratio and robustness significantly decrease. For example, if a hopping device tips over, a "re-righting" mechanism is needed, which adds significant design complexity. Hoppers are also very easy to detect visually; thus stealth issues become extremely difficult.
There are several ongoing efforts to develop snake-like robots. Most of this effort is focused towards the medical industry for use in minimally invasive surgery. These medical systems are all tethered and have very limited motion control capabilities. One development of note is CalTech's collaboration with Cedars Sinai Hospital to develop a human gastrointestinal medical system. This system includes a video camera,
which enables the physician to visually inspect the intestinal lining, plus a microsensor suite which measures parameters such as temperature, pressure, and acidity. Many of these components can be directly applied to a snake according to the invention. Attention also is directed to U.S. Patents Nos. 5,906,591 and
5,662,587, both of which disclose tethered endoscopic robots for use within the human body. Attention also is directed to U.S. Patent No. 5,386,741, entitled "Robotic Snake," and U.S. Patent No. 5,567,110, entitled "Robot Arm Structure." All four of these U.S. patents are incorporated herein by reference; many different type of actuation devices suitable for use in snake-shaped robotic devices are disclosed therein.
Most nonmedical systems are tethered and generally considered to be too large for extended or possible use in a human-packable form factor. Probably the best-known snake-like robot in this category is known as "Boa." This tethered system, which is being developed at Carnegie Mellon
University, is designed to remove asbestos coatings from pipes. Boa was first deployed in December of 1994. Since then, the system has continued to be improved; it appears that it will be a cost-effective solution for asbestos removal as compared to manual approaches. Another well-known system is CalTech's "Snakey." This large, tethered platform is being used to develop motion-control algorithms that are potentially applicable, at least in part, for use in embodiments of the invention. A smaller system of note is the German National Research Center's "GMD-Snake." This is a tethered system with motions very similar to actual snakes. The overall size is 200 cm in length with a 6 cm diameter and a weight of 3 Kg. Besides being tethered, another drawback is that it only is capable of moving approximately 1 cm /sec.
Very few existing snake-like devices are completely self-contained. The Japanese laboratory Hirose and Yoneda has developed a non-tethered snake called the "Korhu II." However, this system again is quite large in size, measuring 3.3 meters in length, 0.5 meters high, and weighing 350 kgs. With its large size it does not crawl, but rather uses a wheeled chassis for locomotion.
Several researchers are believed to have investigated the locomotion of snake-like devices. Chirikjian, for example, has developed kinematic algorithms, and Yin has investigated dynamic motion capabilities. In nature, there are four generally recognized motions by which snakes can move: serpentine, rectilinear, concertina and sidewinding. These are illustrated in Figures 2A - 2D. In serpentine motion, illustrated e.g. at 20 in Figure 2A, the snake forms a series of "S" shapes or waves in its body and pushes from the back of each wave to move forward. Serpentine motion is used to achieve fast speeds and is the only type of motion a snake uses for swimming. In rectilinear or caterpillar movement, illustrated e.g. at 30 in Figure 2B, a snake lifts portions of its body to produce a forward-moving wave where first the tail slides forward, and this wave propagates through the body until the head gets pushed outward. A snake uses this type of motion for moving through narrow regions such as burrows. Both rectilinear and concertina movement, a third method in which the snake pulls itself forward by bunching and lengthening its body in a spring-like manner at e.g. 40 in Figure 2C, are used for climbing. The least common type of locomotion is called sidewinding, illustrated at e.g. 50 in Figure 2D. This motion involves lifting a loop of the body clear of the ground as the snake moves sideways. Sidewinding is used for movement on loose surfaces such as sand.
SUMMARY OF THE INVENTION According to embodiments of the invention, an innovative lightweight mobility platform has "snake-like" motion capabilities. The base for this platform is e.g. a wearable computing system developed by ViA, Inc., Northfield, MN, USA, and/or described or covered by one of ViA's U.S. patents referenced above. By using this base as the snake device's backbone and nerve center, the mobile robot preferably includes a
Pentium class or better processor with ample memory and I/O capabilities including a digital wireless RF interface. Of course, as next-generation processing capabilities arise, far greater processing power is contemplated.
With a snake-like design, as is described herein, each of the disadvantages associated with other mobile robots, e.g. those using wheeled and tracked platforms, hoppers and crab-like devices, are overcome. Embodiments of the invention result in a system with substantially the best combination of speed, climbing ability, payload ratio, and robustness, with minimum weight and size, and the ability to adapt to unknown operational environments and changing mission or other requirements.
More specifically, a device combining the characteristics of a mobile robot and wearable personal computer is provided, according to an embodiment of the invention. This combination device includes a backbone section, at least one actuator operably connected to the backbone section for moving the backbone section, a processing section operably coupled with the at least one actuator for operating the at least one actuator, and structure especially constructed for supporting at least the backbone section on a human body as a wearable personal computer. The backbone section preferably includes a plurality of flexibly connected modules, the modules being connected with e.g. flexible circuitry or other signal-relaying devices or systems, e.g. hardwired or wireless transmission. The at least one actuator preferably is constructed and arranged to move at least one of the flexibly connected modules with respect to another of the flexibly connected modules, and /or is constructed and arranged to move at least one of the modules with respect to an underlying surface. The processing section and the plurality of actuators preferably interact to impart rectilinear, serpentine, concertina, whipping, chimney and /or other types of locomotion to the combination. The combination device also preferably includes cooperating connectors on opposite ends of the backbone section, the cooperating connectors being engageable with each other such that the backbone section is wrapped around a portion of the human body, for example around the waist portion of a human body as a belt. At least one connector can be constructed to connect the backbone section to a remote object, for example to at least one other combination
mobile robot and wearable personal computer. The backbone section also preferably supports at least one sensor for sensing a surrounding environment, and/or is constructed to support a payload.
According to another aspect of the invention, a method embodiment uses a combination mobile robot and wearable personal computer including a backbone section, at least one actuator operably connected to the backbone section for moving the backbone section, a processing section operably coupled with the at least one actuator for operating the at least one actuator, and structure especially constructed for supporting at least the backbone section on a human body as a wearable personal computer. The method includes securing the combination mobile robot and wearable personal computer around a portion of a user's body, removing the combination mobile robot and wearable personal computer from the user's body, and causing the combination mobile robot and wearable personal computer to move independently of the user's body to a location remote from the user.
Removing the combination mobile robot and wearable personal computer from the user's body can include throwing the combination mobile robot and wearable personal computer through the air, causing it to land on an underlying object and move independently. The combination mobile robot and wearable personal computer can move to an electrical outlet and plug itself in, shine a light at the remote location, execute a security patrol routine, stand on end to gain a height advantage, connect with at least one other combination mobile robot and wearable personal computer, and /or ride on another object as a parasite, according to other method embodiments of the invention.
According to another aspect of the invention, a computing device embodiment includes means for actuating the computing device for independent movement, and optional means for using the computing device as a personal computer, e.g. a wearable personal computer.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will be described with reference to the figures, in which like reference numerals denote like elements and in which:
Figure 1 shows a wearable computing device according to the designs of ViA, Inc., Northfield, MN USA;
Figures 2A-2D shows methods of snake locomotion known in nature;
Figure 3 shows rectilinear motion with a simplified wave pattern, according to an embodiment of the invention; Figure 4 shows serpentine and concertina locomotion, according to an embodiment of the invention;
Figure 5 shows whipping locomotion, according to an embodiment of the invention;
Figure 6 shows chimney locomotion, according to an embodiment of the invention;
Figure 7 shows self-righting motion, according to an embodiment of the invention;
Figure 8 is a schematic illustration of a mobile robotic snake device according to an embodiment of the invention; Figure 9 is a schematic, cross-section view of a snake device according to an embodiment of the invention;
Figure 10 is shows a snake device according to an embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The flexible and modular packaging developed by ViA for wearable belt applications makes its PC well-suited for use as a mobile snake-like device. Thus, the backbone and nerve center of the device preferably is a ViA PC. Preferably coupled to this powerful computing backbone are actuators, e.g. crawling-type actuation mechanisms, which enable the system to traverse terrain in substantially the same manner as a snake. This includes a variety of motion types such as a pulsing mode for precise and quiet motions and a whipping action for added speed. For increased
versatility, multiple snakes can be coupled together to form longer chains. This is particularly useful if a mission or commercial objective requires the snake to perform tasks such as looking on top of a counter or crawling into ceiling-mounted ductwork. One baseline design, which according to one embodiment of the invention weighs approximately ten pounds or less, preferably has seventeen modules: seven for a standard flexible PC design, four for additional sensors and six for extra batteries. However, fewer or additional modules may be used without departing from the spirit or the scope of the invention. Assuming 50% motion and 100% sensor duty cycles (i.e., the robot is moving half of the time with the sensors always turned on), this system is expected to have a range of at least about 800 meters and a mission duration of at least about three hours. By adding or deleting batteries, the snake can be tailored to meet specific mission or commercial requirements regarding weight, range and duration. For example, the preferred system configuration for a one-hour mission has a range of approximately 300 meters and weighs only about four pounds.
With its slim profile, the snake already has a very low observable design. To further improve its stealth characteristics, an option can be included such that the snake is enhanced so that it is nearly invisible in both the visible and infrared bands. The system also preferably includes unique hands-free operator interfaces, e.g. those that ViA deploys with its wearable systems.
The snake, which preferably has both teleoperation and semiautonomous capabilities, is remotely controlled by an operator wearing e.g. a ViA computer. A pocket-sized touchscreen display and speech-recognition software preferably are included in the system to provide a compact, low-power, unobtrusive interface. An additional feature of ViA's speech-recognition software is Voice Print Identification. This adds additional security and prevents non-approved individuals from operating the system.
Embodiments of the invention are constructed and designed to enable active sensing, command and control of geographic areas, by using
single mobile robots or teams of mobile robots in potentially complex terrains, e.g. urban, indoor and rugged terrains.
According to the invention, a human-packable tactical mobile robotic platform substantially matches or exceeds the ability of a human to move undetected, in adverse conditions such as military environments and harsh commercial environments, both in large spaces and in small spaces that are inaccessible to humans, over indoor and outdoor terrain. Of course, embodiments of the invention have utility in both military and nonmilitary situations, e.g. consumer/commercial applications. Specific systems according to embodiments of the invention now will be described.
Variations of the four types of motions described with respect to Figure 2A - 2D are contemplated according to the invention, along with some additional motions not found in nature. Although multiple snake devices can be joined together to form longer chains, for simplicity the following descriptions each assume a single snake device with a baseline design of seventeen modules. The only exception to this is the chimney-mode operation, where making the system as light as possible is a crucial factor and, thus, a smaller set of modules, e.g. seven modules, is used.
Rectilinear Motion: The simplest method, and the method of choice for a majority of operations, is rectilinear motion. One form of this motion type is illustrated in Figure 3. For rectilinear motion, the flexible
PC "ribbon" 100, including flexibly connected modules or segments 110, is lying flat on the surface with only one side of the system having actuators 120, according to one embodiment. By modifying the shape of the wave (e.g., having the snake fold on top of itself) larger forward movement per cycle can be achieved. This type of motion preferably and advantageously provides low power consumption, a low profile, a good payload capability, the ability to crawl through tight spaces and excellent climbing ability. One
possible drawback to this type of motion in certain circumstances is reduced speed.
Serpentine and Concertina Motions: A combination of serpentine and concertina locomotion preferably is used when faster speeds are required. Here the flexible PC, which is now placed on its edge versus lying flat as in rectilinear motion, will repeatedly bunch together and then lengthen its body in a spring-like manner. This is depicted in Figure 4. In nature, snakes using this type of motion can achieve speeds of approximately 360 cm/sec (8 miles/hour). Because of the desire to simplify the design of the mechanism and conserve power, a snake device using this mode of locomotion reaches speeds up to about 35 cm/sec (1 mile/hour), according to one embodiment. Of course, faster speeds are contemplated as well.
Sidewinder Motion: Other types of snake motion are used for higher speed. Because, unlike in nature, the snake device does not care which end is forward, a derivation of the previously mentioned sidewinder motion can be implemented to create a whipping motion where alternate ends of the snake are thrown in front of the other. This is illustrated in Figure 5. Because of the controls issues regarding the use of this motion on differing terrain (e.g., pavement versus grass), successful implementation of this mode of motion can be more difficult than the others. A successful implementation produces speeds of up to at least about 100 cm /sec.
Coil and Chimney Motions: Two additional capabilities are coil and chimney modes of operation. For the coil mode, the tail of the snake device preferably forms a stable base which enables the snake device 100 to lift its "head", e.g. its sensor packages 130, over an obstacle to gain better information. This may be used for example to see what is on top of a counter or down inside of a sewer grate. This motion type also enables the snake device to climb large obstacles such as the steps of a staircase. The ability to link multiple snakes together to form chains is extremely useful for this mode of operation.
The chimney motion, which is illustrated in Figure 6, preferably enables the snake device to climb inside objects such as rain gutter downspouts, sewers, ductwork for heating and ventilation systems, and, of course, chimneys. Using a seven-module unit, a pipe of up to approximately 3 inches in diameter can be climbed. By adding additional modules and /or linking multiple snakes, the size of the pipe can be increased up to the limit of the actuators to lift the weight of the snake device itself.
Self-Righting: There are various methods for self-righting. One simple and robust approach is to have the snake device fold back on itself. This is illustrated in Figure 7. Another alternative is to use the same approach that caterpillars in nature use to right themselves. The snake device according to this embodiment preferably has a rounded back so if it flips over, it naturally rolls to one side. Just as a caterpillar does, the snake device preferably then coils into a circle to achieve a position where it is completely on one edge. It then slowly straightens itself out until a slight arc is achieved. Because this arc causes the center of gravity to be positioned slightly towards the "feet" side of the snake device, the snake device naturally rolls over to a "feet down" position. The actuators preferably coupled to the computing backbone, e.g. crawling-type actuation mechanisms, enable the system to traverse terrain in the same or similar manner as a snake, as referenced earlier. This offers several advantages over conventional small truck-like robots with wheels or tracks. For example, a snake device according to embodiments of the invention has the ability to substantially maneuver through, underneath, inside and/or around objects (e.g., scrub brush, tall grass, urban debris, etc.), which larger wheeled devices must attempt to climb over. Using a chimney mode, the snake device is substantially able to crawl inside objects such as chimneys, sewer lines, rain gutter downspouts or ventilation ducts. By coiling its tail, the snake is substantially able to lift its head to see countertops, look through windows, or climb stairs. Finally, to further enhance mobility, multiple snakes can be linked together to form long chains.
It should also be noted that prior art actuation mechanisms can be used according to embodiments of the invention, for example those disclosed in U.S. Patents Nos. 5,906,591, 5,662,587, 5,386,741, and /or 5,567,110, or elsewhere in e.g. the mobile robotic arts.
Although much theoretical work has been performed in the area of controlling snake-type manipulators, very few devices have been actually deployed and even fewer are in actual use on a daily basis. The primary focus of commercial usage of snake-type manipulators has been in the medical industry for endoscopic procedures. The control approach for a snake device according to embodiments of the invention leverages the theoretical base that has been developed for controlling modular robot systems. Two examples of note are the work done by Chen and Matsumaru.
Each motion type requires a unique controls implementation which preferably is driven by the PC's embedded Pentium or higher class processor. For rectilinear motion, the controls implementation is substantially straightforward since the terrain variations (e.g., grass versus carpeting) have minimal impact on system performance. On the other hand, the whipping motion presents difficult control issues requiring rapid updating from the snake device's navigational sensors. With the chimney mode, an additional element of a motion planner is required. To accomplish this task, the device can use e.g. the SANDROS path planner, developed by Wang. Other planner types are possible for use as well, of course.
Since the focus of the snake device according to embodiments of the invention is on tactical mobility, sensing /perception receives less emphasis. However, since the ability to autonomously detect obstacles and pathways may be of critical importance for effective operation of the snake device, designs according to the embodiments of the invention
substantially ensure that such systems can be easily integrated into the platform. Since one type of PC available from ViA preferably comes standard with at least a PCI and 27-pin full-access interface, for most sensor systems this integration is already enabled. In addition to ensuring a smooth integration path for future sensor systems, two hazard detection systems are described: ultrasonic and LADAR (LAser Detection And Ranging).
Ultrasound has been used on many vehicles, both large and small, for proximity sensing. The advantages of ultrasound include robustness in harsh environments, reliability for e.g. short-range measurements, reduced weight and size, and relatively low cost. For example, the Migitron RPS-401, which is frequently used to automate car washes, is of relatively low cost. Some of the difficulties with ultrasound can include handling the multi-path signals and interference caused by environmental effects (e.g., wind gusts). Nevertheless, ultrasonics can be very beneficial for short-range obstacle detection.
LADAR uses the same fundamental principles as radar except at wavelengths in the InfraRed (IR) spectrum. Since light travels approximately 30 cm in one nanosecond, the difficulty with implementing such systems has been measuring the sub-nanosecond reflection of the laser. Recent advances in electronics and laser systems have enabled such systems to be built at a very low cost, however. For example, the Bushnell "Yardage Pro", which is marketed towards golfers and hunters, costs around $300. The size of this current system is considered likely too large for the snake device, but by removing the binocular portion of the system and retaining just the IR emitter and receiver, such a system can be integrated. The advantages of an IR approach are that the systems are very robust, substantially lightweight, relatively inexpensive, inherently stealthy, and require low power. One of the difficulties with current commercial systems is that they use a single pulsed signal with a resolution of only one meter. However, combining the efficient long-range capabilities of a LADAR system such as the Yardage Pro with
the short-range capabilities of an ultrasonic system produces a commercially feasible, low-cost and reliable hazard detection system.
Positioning As previously mentioned, the primary focus of snake devices according to embodiments of the invention is on tactical mobility, positioning receiving less emphasis. However, the ability to easily integrate positioning systems as they become available is certainly contemplated. The ability to integrate can be accomplished by using the existing interfaces of a PC available from ViA. In addition to providing a smooth integration path for future positioning systems, two approaches are described herein: GPS and inertial sensor navigation.
Several GPS systems have been integrated and deployed in wearable computer systems, for example those available from ViA. In recent years, the selection, size and performance of these commercially available GPS units have continually improved, while at the same time cost has been reduced. Handheld GPS units with ten meter resolution are currently available at relatively low cost. Additional improvements are contemplated, such as multichip GPS components which can be directly embedded onto a computer system and may be included in snake devices according to the invention.
A limitation with GPS systems is that they generally are perceived as not working well in an indoor environment. Consistently, a second type of navigation and positioning system is provided for indoor environments. There are many approaches contemplated for indoor environments. These can basically be divided into three groups: swarms of mobile devices using line-of-sight to communicate, the building of a relay network where "bread crumbs" (e.g., fixed communication relay modules which serve as RF or IR transmitters) are left behind to determine position, and internal sensors. The difficulty with both the swarm and bread-crumb approaches is that they require line-of-sight, or, for RF, nearly line-of-sight, communication paths between the neighboring platforms. For a laboratory setting this is certainly not a
problem, but for an urban environment, particularly one which is in a conflict type of situation, such a pristine condition is very unlikely. Instead, rubble, smoke and other obstructions can prevent such an approach from being reliable. Even if multi-path issues for RF or line-of-sight issues for IR can be overcome, the robustness of such a system can be dubious since the severing of one portion of the network (e.g., by someone shutting a door) could cause the entire system to fail. Therefore, the third approach of internal sensors will now be described.
The two most common internal sensor approaches used for navigation are dead reckoning and inertial. Dead reckoning is useful for rectilinear motion of snake device embodiments. However, for other modes of motion where slip is expected, the usefulness of such an approach may be limited. Thus, in addition to implementing dead reckoning for rectilinear motion, commercially available inertial sensors are implemented for other types of motion. For example, the InterSense
300 Series is a 1-cubic-inch, 2-ounce, 3-axis device with a 500 Hz update rate resulting in 0.02 degree RMS angular resolution, 3 degree RMS dynamic accuracy and a 1200 degree /second angular rate. One potential downside is that these systems can be relatively expensive. However, for reliable autonomous indoor positioning capabilities in urban battleground environments, a combination of dead-reckoning and inertial sensors, coupled with GPS when it is available, may be advantageous.
Operator Interfaces Snake devices according to embodiments of the invention, which preferably have both teleoperation and semiautonomous capabilities, are remotely controlled by an operator wearing a wearable computer system and /or operating a non-wearable computer system, according to embodiments of the invention. Preferably included in this system are at least one or more of the following: RF or other modems for communicating with the snake device platform, at least about 8 GB of memory, a Pentium class or better processor, batteries for at least eight hours of continuous use, and unique interfaces which ViA and its
partners have developed. Four types of operator interfaces will be described below: pocket-sized touchscreen displays, wireless wrist-mounted interfaces, heads-up displays, and speech-recognition input and speech output. A pocket-sized touchscreen display and speech-recognition software, preferably including Voice Print
Identification, are included in the baseline system design to provide a secure, compact, low-power and preferably unobtrusive interface. However, the system may include options for incorporating numerous other interfaces without departing from the spirit or scope of the invention.
Pocket-Sized Touchscreen Displays: Pocket-sized displays, such as those developed at least in part by ViA, work very well for detailed images, e.g. diagrams and maps. For missions where stealth is a critical issue, reflective one-half and full VGA screens e.g. from Sharp are readable in bright sunlight, yet non-emitting at night. Both of these products have been successfully integrated with ViA PC's.
Wrist-Mounted Interface: A wireless wrist-mounted interface can be extremely useful. The wrist system preferably uses a low-power RF interface to communicate from the wrist to the "belt" or other wearable computer. The screen of the interface is preferably readable in bright sunlight, yet non-emitting at night so stealth is not compromised.
Heads-up Displays: Commercially available heads-up display units from e.g. Copin, Virtual Vision, Virtual IO and Display Tech that are substantially superior in both performance and power savings are preferred for use according to the invention.
Voice Recognition and Speech Output: ViA, Inc. is the leader in integrating voice-recognition software with wearable computer platforms. This includes systems which are operating in environments with significant background noise. For example, a ViA system has been used successfully from inside a helicopter to control drone aircraft. One of the issues with many voice-recognition software packages is the inability to modify the system to meet changing demands. ViA's software allows this modification to happen "in-the-field" and "on-the-fly," without having to
reboot the computing system. Although any dialect can be supported, in particular ViA has developed extensive voice-recognition capabilities for U.S. English, British English, and Spanish. To further improve the robustness of the speech-recognition systems, ViA has developed the capability to use remote servers for processing. Thus, if one particular
"belt" should fail, another can be readily used to maintain the voice-input capability. An additional feature of ViA's approach to voice recognition is Voice Print Identification. This adds additional security and prevents unauthorized users from accessing the system. Two advantages to using voice-recognition software are that it provides hands-free input capability and additional system security. One of the potential concerns for military applications is that using voice input can be difficult in stealth-type missions. To overcome issues such as this one, ViA has developed seamless integration between graphic touchpad screens and voice input. Thus, if a situation mandates that silence be maintained, then the pocket-sized touchpad can be used to enter commands instead of the voice system.
Power Systems One of the significant limitations to the performance of small mobile robots is the power supply system. The problem, of course, is that electrochemical batteries simply do not scale well to small sizes. However, power supply technology is always improving and is easily incorporated into the snake device design. Thus, batteries generally are the power supply of choice with embodiments of the invention. An additional point to note is that with the "ribbon-like" design of the snake device, additional battery modules can be added if mission requirements call for extended range and duration.
Additionally, or optionally, a snake device according to the invention can be given a charging command, e.g. at the end of a work day or mission. Upon receiving the command, after e.g. being removed from a user's waist or other area and thrown through the air to the ground or otherwise placed on the ground or other underlying surface, the device
travels to a charging unit and/or data-transfer device and/or docking station, plugs itself in or otherwise electrically "docks" with the unit, and returns to a desired location when charging is complete. Other algorithms and programming can cause the device to enter a roving or stationary "security" mode, to secure e.g. a perimeter, a building, or other location. Other tool packages carried by the device can include light/ video /photo projection mechanisms, laser or other projection mechanisms for e.g. target sighting, cameras, microphone /speaker arrangements, drills, ground, air or other environmental samplers, cord, grappling hook or other projectile/tool/payload launchers, payload dispensers for e.g. gas, explosives, medical supplies, or other payloads, to name a few examples. Communication can be provided with e.g. a cellular-phone, RF, or other preferably wireless link. A human operator can also use such a communications interface directly.
Embodiments of the invention can incorporate existing and future sensor technologies. Because of the flat and flexible nature of the PC's available from ViA, Inc., additional sensor technologies and modules can be inserted anywhere along the length of the snake device. The baseline design preferably includes the sensors previously mentioned in Sections 2.7 and 2.8 (GPS, inertial, ultrasound and LADAR), plus a video camera, a microphone /speaker and a chemical detection sensor. For the video system, a system similar to the Panasonic GP-KF462HM 1/4" color camera can be integrated. This video camera, which was developed for the dental industry, measures approximately 0.2" in diameter and 2" in length. An RF modem is preferably included to transmit images back to a remote control station. The microphone and speaker are preferably included to transmit audio between the snake platform and the operator. For the chemical detection sensor, the snake device embodiments ensures operating capability with a chip from e.g. Sandia National Laboratories Chemlab.
The primary means of communication for the snake device preferably is RF. One commercially available device is the Personal Messenger(r) 100C Wireless Modem Card. This shirt-pocket-sized, self-powered Cellular Digital Packet Data (CDPD) modem requires a single PC Card slot to operate. Because PC cards are wider than the baseline design body, the RF chip set preferably is mounted directly to the PC's circuitry rather than using the PCI slot.
The actual operating range of the snake device is generally dependent on the type of RF modem used. In a similar sized mobile robot platform, a 0.5 Watt Dell Star system can produce an effective range of 800 meters. A similar modem can be integrated into the snake platform but may require design modifications to the modem. Using military-reserved bands, with higher power devices, may increase this range.
Stealth and Security
Snake devices according to the invention, with their thin profile and quiet operation, already have a very low observable design. To further enhance stealth characteristics, stealth technologies from e.g. Sandia National Laboratories may be incorporated. Sandia's stealth technologies can enhance the snake device to make it nearly invisible in both visual and infrared bands. The visible and infrared treatments preferably include low-power semi-active surfaces which use electrically switched bistable polymers (power is applied only when switching between colors), reflection techniques, coatings, including thin film for signature control, and other techniques.
The snake device's dimensions are approximately 2" x 1" x 30", according to one embodiment, preferably with 16 flex points and a total weight of less than ten pounds. However, other dimensions, flex points, and weights may be used without departing from the spirit and scope of the invention. If desired, the snake device may be worn around the waist in the same manner as ViA's line of wearable computers as described and claimed in the above-referenced patents, for example, secured with a belt
buckle or other type of fastener. In addition to a soldier carrying the platform, the snake device also has the ability to conform to other objects so it can be easily deployed as a parasite, riding on a track- or wheel-style robot, friendly or enemy tank, jeep or other vehicle, also including those in nonmilitary environments, until the terrain requires the snake to move out on its own.
The snake device, which preferably has both teleoperation and semiautonomous capabilities, preferably is remotely controlled by an operator wearing a personal computer. A pocket-sized touchscreen display and speech-recognition software preferably are included in the baseline system to provide a compact, low-power, unobtrusive interface. An additional feature of speech-recognition software available from ViA, Inc. is voice print identification. This adds additional security and prevents non-approved individuals from operating the system.
It should also be noted that obstacle-drilling capabilities are contemplated according to the invention, e.g. with an auger positioned on the base PC. Tactical grappling-hook/ cord-launching devices for climbing and/or suspending are also contemplated, as are other tools/payloads as referenced above, for example.
Embodiments of the invention include e.g. a human-packable, tactical, mobile, robotic platform which substantially matches or exceeds the ability of a human to move undetected, in e.g. battle or other adverse conditions, both in large spaces and in spaces which are inaccessible to humans, over indoor and outdoor terrain. According to one embodiment, a human-packable system is transported by a human to its place of use as part of his or her other equipment. A human-portable system may require the exclusive effort of the person transporting to its place of use. Snake devices according to the invention are preferably small, lightweight, completely self-contained (i.e., non-tethered) systems. The backbone and nerve center of the device preferably is a flexible PC, available from ViA, Inc. and /or protected by ViA's U.S. patents referenced
above. The overall size of one such computer, which preferably consists of seven modules mounted on flexible circuitry, is a ribbon approximately 13 inches in length, 1.75 inches in width, and 0.5 inches thick.
As one of the leading commercial suppliers of wearable computers, ViA is committed to continually updating its product line to include the latest in PC technologies. Thus, by building the snake device on top of a ViA wearable platform, a clear path is ensured for continued acceptance of and compatibility with new technologies and commercial PC components (e.g., processors, memory storage, peripheral interfaces, etc.).
The Robotic Snake Platform
Robotic snake devices according to embodiments of the invention preferably have one or more of the following design features and capabilities, in addition to or instead of those described above: Computing Capabilities: The snake device preferably is based on a
PC available from ViA, Inc. This type of PC for this application generally includes, at a minimum, at least one or more of the following items: a Pentium class 200+ MHz processor with MMX capabilities including Zoom video capacity, 1 GB Hard Disk or Flash Memory, USB, PCI and optional Firewire (IEEE 1394), Custom 27-Pin full access docking, Dual smart battery ports, and a digital wireless RF interface providing remote communication capabilities. The processor provides ample processing for many types of control, communications, and real-time sensor gathering and interpretation. If additional processing power is needed, e.g., for vision-interpretation algorithms, multiple snakes can be coupled together to provide additional processors. As mentioned previously, however, greater processing capabilities for complex, next-generation tasks are contemplated for use according to the invention. A variety of memory configurations are also contemplated, including up to at least 8 or more GB Hard Disk and 1 or more GB of Standard Flash Memory storage.
Locomotion: The following motion types are preferably implemented as the minimum set of motion types: a variety of rectilinear motions, one to minimize power consumption and maximize stealth
characteristics, another to maximize speed, and another to maximize climbing abilities; a coil mode which enables the snake to stand on its tail to gain increased surveillance and obstacle climbing capabilities; and a self-righting capability. The following motion types are generally perceived as more difficult to implement but may be included if desired: serpentine and concertina locomotion.
The following motion types are even more difficult to implement but may be included if desired: whipping or sidewinder motion and chimney motions.
Hazard Detection: Preferably included in the system design are an ultrasonic system and a LADAR system. These are preferably used to detect potential hazards. The snake device's design preferably includes multiple buses and full access interfaces which provide straightforward compatibility.
Position Determination: Preferably included in the system design are a GPS system and an inertial sensor system. These components are used to provide position information for outdoor and indoor environments, respectively. Again, the snake device's design preferably includes multiple buses and full access interfaces which provide straightforward compatibility.
Additional Sensor Systems: Three additional sensor capabilities are preferably included in the baseline snake design: a color video camera, a microphone /speaker, and the ability to integrate e.g. the "Chemlab on a Chip" system being developed by Sandia National Laboratories. Again, the snake device's design preferably includes multiple buses and full access interfaces which provide straightforward compatibility.
Additional Item for the Snake Platform: As an option, the stealth characteristics of the snake device may be enhanced by using stealth technology developed by e.g. Sandia National Laboratories.
The Operator Interface
The operator interface has at least one and preferably all of the following design features and capabilities:
Computing Capabilities: Computing capabilities are preferably based on a ViA PC. This platform preferably is worn by the operator. Preferably included in this PC are at least one, and preferably all, of the following items: a Pentium class 200+ MHz processor with MMX capabilities including Zoom video capacity, 8 GB Hard Disk or 1 GB of Standard Flash Memory storage, USB, PCI and optional Firewire (IEEE 1394), custom 27-Pin full access docking, dual smart Battery Ports, and a digital wireless RF interface providing remote communication capabilities.
Display Interface: The baseline design preferably includes a pocket-sized touchscreen display with speech-recognition input. Features of the speech-recognition software preferably include one or more of the following: noise reduction (e.g., ability to function in noisy environments), ability to modify vocabulary "on-the-fly" without rebooting the computer system, ability to use remote servers as platforms for the speech software, voice print identification software to prevent unauthorized users from gaining access to the platform, ability to seamlessly move between the pocket-sized touch screen and voice input. Optional Items for Operator Interfaces: At least two operator interface options may be utilized: a wrist-mounted interface and a heads-up display.
Complete System Operation Semiautonomous Command Set: Snake device embodiments according to the invention preferably have both semiautonomous and teleoperation capabilities. The semiautonomous capabilities preferably include one or more of the following commands: move forward/backwards/to-the-side (X) meters, move forward/backwards/to-the-side (X) seconds, move until an obstacle is detected, set motion type to be (X), lift sensor package. Additional commands may be added with departing from the spirit and scope of the invention.
Touchpad Display and Voice Recognition: These commands may be input using either a pocket-sized touchpad or by voice-recognition software.
System Operation: Substantially all system capabilities may be seen in the performance of the following tasks using both the above semiautonomous commands and in a teleoperation mode: as the system moves in an outdoor environment, the task of accurate GPS positioning (within 10 meters), the task of potential hazard detection with ultrasonic and LADAR sensors, the task of motion, including raising the snake's "head" to look over or around an object or through a window and climbing a 3" diameter pipe, the task of the system moving to a range of 800 meters over a period of 3 hours, as the system moves in an indoor environment, the task of providing positioning information (approximately less than 10% error with respect to total displacement) using the inertial system, coupled with dead reckoning, the task of motion, including having the platform climb a typical staircase and raise its head to look on top of a surface. For both environments, video and audio links are preferably fully functional, and operation of two or more joined snakes is contemplated. Figure 8 schematically illustrates a mobile robotic snake device according to an embodiment of the invention. Device 200, which can e.g. be a combination mobile robot and wearable personal computer, includes backbone section 205. One or more of each module or segment 208 of device 200 preferably is flexibly connected to adjacent modules or segments 208. Device 200 includes, or is operably connected with, sensor package or sensing section 210, processing section 220, memory section 230, communications section 240, microphone and /or speaker section 250, payload section 260, tool section 270 for accommodating e.g. the tool types described above, battery or other power unit section 280, and additional sections 290, 300, 310, 320, 330 and so on to the end of device 200. Any of the sections can be located at any point along the length of device 200, and one or more of any type of section can be provided. Segments 208 can each
have a different purpose or capability, or can share purposes or capabilities as needed.
Connectors 350 are provided for e.g. connecting ends of device 200 around a user's waist or other body portion, to a docking station or charging station or other fixed or mobile object, or to one or more other devices 200 to achieve greater length (e.g. for traversing higher objects or gaining greater surveillance height), processing power or other capabilities. Of course, connectors 350 can include not only appropriate mechanical coupling, but also electrical, power and /or other signal connections as well.
Actuators such as illustrated at 370, 380 can also be provided at any desired position along backbone 205. For ease of illustration and description, only a few actuators are illustrated, at the righthand end of device 200 as viewed in Figure 8. In the illustrated embodiment, actuators 370 are intra-segment actuators for turning one segment with respect to another. Actuator 380 is an actuator for moving one or more segments with respect to the ground or other underlying or surrounding object. Actuators 370, 380 and the other features of device 200 are not necessarily illustrated to scale in Figure 8. Further, actuators can be placed on one or more sides of each segment 208, depending on the type of movement desired for a particular environment or application. Particular actuators are shown and described in the U.S. patents described above, as well as with respect to Figures 9 and 10 herein.
According to embodiments of the invention, actuator 380 on one or more segments 208 can be or can include one or more ribs with a flexible covering 390 over them. The ribs can fold or recess to a flat configuration when actually worn as e.g. a belt, or otherwise when a substantially flat profile is desired. When an in-use configuration is desired, the ribs fold or pop out. The ribs are driveable to produce a forward and /or backward motion, allowing locomotion as a snake. The covering optionally is waterproof, and device 200 optionally includes air /gas tubes for flotation, allowing use of device 200 in an amphibious manner. The covering also can have various amounts of scale structure, e.g. as on the bottom of a
waxless cross country ski, to help propel device 200 forward or otherwise better grip the underlying or surrounding surface. Of course, other friction-inducing or gripping surface types are also contemplated.
Actuator(s) 380, e.g. the illustrated ribs, can be operated by processing section 220 or by a remotely operated computing device, to effect sequential or other motion and various amounts of motion to move deλάce 200 in the most practical direction or speeds. The actuators can cause device 200 to lay all the way flat for e.g. traversing stairs or other objects that require more "gripping" locomotion than "slithering" locomotion. Additionally, for climbing purposes, device 200 can go flat for at least a section thereof, grab onto a stair step or other elevated surface, and "flop" or pull itself over. For traversing e.g. metallic areas such as pipes, actuators 380 or other areas on device 200 can include magnetic devices for greater gripping or adhering capabilities, e.g. for adhering along the water line of a ship to place a charge, to be the charge, or to otherwise effectively deliver an explosive device or other payload.
Sensing section 210 is operably coupled with processing section 220, according to one embodiment, and can include location sensing (e.g. GPS) for e.g. location validation, air quality sensing, heat sensing, distance sensing, movement or motion detectors, color sensing, smell sensing, RF, IR, laser, sonar or other energy sensing, and /or video conferencing (in sensing section 210 or elsewhere in device 200) to enable device 200 to function as a remote scout or reconnaissance device.
Communications section 240 can include RF, IR, laser, sonar or other communication capabilities, for communication with one or more other mobile robotic snake devices 205 or remote computing devices, e.g. wearable computing devices. Microphone /speaker section 250, which optionally can be included in communications section 240, can be used when device 200 is used to move to a remote person or other object and communicate therewith, as controlled, by e.g. a user operating device 200 from afar.
One or more payload sections 260 can be used to deliver a desired payload, e.g. medical supplies, oxygen, foodstuffs, water, replacement
electronic or other parts, etc. The payload can also be used for hostile purposes, as in the case of explosives or other enemy-reduction payload as reference above.
Certain areas of device 200 can be flexible and other can be stiffer, to protect e.g. certain processing, communications or storage devices. Processing section 220 can control which areas are stiff and which are flexible, through e.g. intra-segment actuators 370, according to one embodiment.
Figure 9 schematically illustrates a cross-section of a segment 400 according to an embodiment of the invention. Segment 400 includes e.g. slot/gear "pancake" arrangement 410 and/or other motor /actuator drive systems, optionally offset to each side of segment 400. Flex/push band 420 provides actuation capabilities and control, optionally interfacing with an exterior section 430 via loop /pivots 440. External section 430 optionally includes bands, ribs, and /or "skin" with directional "scales" or other gripping features described above. Stand bands or cables 450 assist in drawing device 200 into e.g. an upright or other configuration.
As shown in Figure 10, opposing motions of actuation mechanisms associated with segments of snake device 455, e.g. in the form of cables or cords 460 extending therethrough, cause snake-like action and motion.
Summary and Conclusion
In summary, snake devices according to embodiments of the invention are able to maneuver substantially undetected, through very tight spaces, over rough and unknown terrain. With its embedded computing power and I/O capabilities, real-time sensor information preferably is gathered, interpreted, and transmitted back to the control station. All of this is substantially contained in a human-packable/ wearable system capable of both indoor and outdoor operations. A flexible, wearable PC with actuators, sensors and stealth technologies yield a mobile, invisible, rugged, versatile, lightweight and adaptable, tactical mobile robot with a host of commercial, military and other uses.
The specification is intended to be illustrative of the many variations and equivalents possible according to the invention. For example, communication with non-wearable computing devices, Local Area Networks, Wide Area Networks, repeater-transmission stations, and vehicles and/or vehicle-mounted electronic devices is contemplated.
Embodiments of the invention also can be mounted on other parts of the body, including the leg, arm, chest or head. Multiple features from the various described embodiments can be combined in accordance with the invention. For example, the features of the various embodiments described throughout the application can be implemented in the embodiments of Figures 8-10. Various other modifications in and changes to the above-described devices and methods will be apparent to those of ordinary skill and can be made without departing from the spirit and scope of the invention.