Meet the BEAR’s brand new look in this Robot Magazine exclusive.
The awesome strength of this new torso may not be immediately obvious: More compact than the previous aluminum design (shown in the inset at top-right with Vecna Robotics Engineer Josh Ornstein), the new steel torso is over four times stronger. Above: Illustrations of the BEAR in its final form.
ROBOT EXCLUSIVE
VECNA's Battlefield
Extraction-
Assist Robot
BEAR
Photos by Walter Sidas
and Tom Atwood
Below: The four degrees of freedom (DOF) added to the forearms and wrists in the new BEAR prototype (each arm now has six DOF) give it additional dexterity — useful for lifting an
I-beam off a pinned casualty with one arm, while pulling the victim to safety with the other. Black hydraulic hoses converge on the valve manifold on the robot’s back to bring massive power to the joints.
The BEAR’s “backpack” is exposed, showing the hydraulic hoses coupled to the array of valves on the hydraulic manifold.
Vecna founders Daniel and Deborah Theobald are married and busy, as parents of three young children, a rescue robot and a thriving high technology company. The company slogan, “Better Technology, Better World,” isn’t just lip service: Company policy pays employees to spend 10% of work time on community service. Sound like a great place to work? The rapidly growing company is looking for new employees with and without robotics skills. Resumes invited.
Robot recently obtained an up-close peek at the BEAR robot at the Vecna Technologies Cambridge Research Laboratory near Boston. This extended online article offers an overview of this remarkable project, already being funded by Congress with a 2007 grant in excess of $1 million. Vecna proudly notes its commitment to developing technology that will create a better world, and its business ventures extend beyond the BEAR project into automated health systems for hospitals as well as global management of medical care for military veterans.
The Battlefield Extraction-Assist Robot, or BEAR, is an extremely strong, extremely agile robot roughly the size and shape of an adult male human. It is designed to safely lift humans, carry them, and put them down. Specifically, it is built to rescue human casualties from dangerous areas and take them back to safety. More generally, it is designed to lift heavy objects, carry them for long distances as needed, over obstacles such as stairs or rough terrain, and set them down safely.
With initial funding from TATRC, the Army's Telemedicine and Advanced Technology Research Center, the BEAR's primary mission was straightforward, if not simple: Enter a battle zone, find wounded soldiers unable to rescue themselves, and bring them to safety. As the BEAR is developed, the elite team of researchers and engineers building it, as well as representatives from the government and military-medical colleagues at TATRC and elsewhere, are discovering many important new applications for the BEAR.
The BEAR is ideally suited for disaster rescue, such as from buildings rendered unsafe due to fire, mudslide or explosion, as well as areas contaminated with biological or chemical toxins or nuclear radiation. Versions will be adapted for use in healthcare and eldercare, helping to safely lift and transfer patients, and helping to keep seniors and others with mobility impairments living independently.
The proof-of-concept version of the BEAR is capable of a variety of postures critical to rescuing casualties. In situations where speed over level terrain (such as a paved road or inside an airport) is of maximum importance, the BEAR can balance upright and move quickly on wheels. Above, the robot is shown in “centaur” posture — able to travel for miles on its belly if necessary, hidden in tall grass, with an adult human in its arms — impossible for a human rescuer.
THE INVENTOR
The robot is the brainchild of Daniel Theobald, president and CTO of Vecna. Theobald's passion for robotics is longstanding and resolute. Much of his time as a student at MIT was spent building robots. When he and Deborah Theobald, his wife and CEO of Vecna, founded the company in 1998, the primary goal was to build robots. Notwithstanding the company's thriving business creating software and hardware systems for healthcare, enterprise applications and other domains, Theobald remains passionately committed to building robots.
POWER AND MECHANICAL ENGINEERING
This article features two models of the BEAR, an original proof-of-concept configuration in which various systems were tested, and the torso of the next generation BEAR—a slimmer, stronger, sleeker humanoid with greater strength. There have been a number of iterations in the transition as various systems have been tested.
The BEAR robot was originally conceived to be able to lift about 500 lbs.—the weight of a large, male, fully-equipped service member who may have weapons, supplies or other gear attached to his body in some way.
Working with only one prototype at a time, the BEAR's research and development team has been cautious about overexerting the BEAR to see how much it could lift before it began to fail. Perhaps not cautious enough, however: In one trial in November, the BEAR v6 attempted to lift the front end of a Subaru hatchback. The lift was proceeding apace until a weld joint at the waist of this early robot's aluminum torso was strained to the point of failure; it snapped in two. The lift was suddenly and unceremoniously over.
On a side note, fingers were humorously pointed on the test site among the mechanical engineering staff for the waist weld job. In the end the joint was re-welded to be much stronger than the original, and the robot is resting comfortably. Version 7 of the robot is fashioned of much stronger steel, with future versions being planned with a titanium frame.
The older version 6 BEAR (the gray proof-of-concept prototype with the wheeled base, featured in Time Magazine's Best Inventions of 2006 in November) has demonstrated lifting weight in excess of 360 pounds. The robot's next-generation form, painted white, is capable of much more. In fact, in recent demonstrations under relatively low hydraulic pressure of 700 pounds per square inch (PSI), the robot was able to lift 260 pounds with one arm, bringing the total hefting capability to 520 lbs., surpassing the BEAR's target lifting capability.
The Segway RMP base on the current BEAR proof-of-concept model will be removed in subsequent versions, which will feature independent leg joints, possibly with wheels as feet.
However, the version 7 robot's hydraulic system is designed for pressures up to 3,000 PSI, over four times the pressure exerted in that initial test. The engineering team believes that, even with a titanium frame, the BEAR's maximum hydraulic pressure will be set well below the 3,000 PSI limit for most applications. The BEAR's raw (3,000 PSI) strength may outstrip even the latest version’s structural integrity—giving it the ability to literally tear itself apart.
CONTROL SYSTEMS
The BEAR robot's torso uses hydraulics, the same powerful technology normally used in earth-moving equipment, only much smaller. The initial versions of the BEAR are controlled remotely by a human operator. The human can be elsewhere, seeing through the robot's cameras and hearing through the robot's microphones. However, increasingly sophisticated controls, training and other methods will enable an increasing amount of what is called "semi-autonomous" behaviors, in which the robot understands and obeys higher and higher level commands.
The BEAR uses motorized tank-like tracks on its "thighs" and its "calves," although it is capable of using wheels on any of its joints, depending on the task (and the terrain) at hand. The BEAR also employs dynamic balancing behavior (DBB), enabling it to balance on the bottom of its lower tracks or wheels, on its knees, or even on its hips—whether or not it is holding a person.
BEAR sensors will include, but not be limited to:
• Motion control systems
• Rate gyros & accelerometers to enable dynamic balancing
• A web of touch sensors and pressure sensors on its arms, hands, torso and other areas to give it sensitivity to its human cargo
• A variety of cameras, from standard optical to infrared to night vision
• A microphone array to localize based on sound
The robot's automated systems are designed to be completely modular, and will leverage the Army's emerging JAUS (Joint Architecture for Unmanned Systems) standard for software and hardware interoperability: useful for operator control units (OCUs) as well as for payloads, plug-and-play capability for specialized limbs, docking with other vehicles and robots for marsupial travel and other applications.
Left to right: Daniel Theobald, BEAR inventor and President and CTO of Vecna; Jonathan Klein, Director of Usability and Marketing; Deborah Theobald, Vecna CEO; Josh Ornstein, Robotics Engineer; Jamie Nichol, PhD, Robotics R&D Chief; and Scott Kullberg, Robotics Software Engineer. Degree count: MIT five, Stanford University, one.
HYDRAULIC ACTUATION
Interestingly, the delicate proportional control needed by the BEAR has not been developed for backhoes, tractors and other applications in which hydraulics provide the power to get work done. Hydraulic fluid, a greasy, viscous substance resembling automatic transmission fluid, can be a challenge to contain, especially in early prototypes. The laws of current hydraulics technology mandate that the fluid must permeate the entire structure, with two hoses reaching to every piston to actuate it. Thus, any hose not completely tightened and in good working order can quickly become a "bleeder," shooting hydraulic fluid geyser-like into the air.
The BEAR’s current hydraulic valve technology uses solenoids in sudden all-on or all-off switching. Hydraulic fluid is either moving at the maximum speed dictated by the system's overall pressure, or it is not moving at all.
The BEAR's objectives require fine-tuned control, and a more gentle touch, such as that found in proportional control systems like PWM control over standard motor actuation systems. For this challenge, Vecna engineers are designing a control system that will permit very finely resolved proportional movement. New specialized micro hydraulic valves and related systems are being invented by this team of young engineers, and are expected to be patented.
HUMANOID FORM BENEFITS
The BEAR robot's humanoid form enables it to travel most places a human can travel. The robot prototype can move through doorways and through buildings, traveling up and down stairs with or without a fully weighted adult dummy "casualty" in its arms. It is also capable of traversing difficult, rocky or hilly terrain, as well as over rubble, through woods and down narrow paths.
Further, the dynamics of human movement are extremely well understood, and can be leveraged to make controlling a humanoid robot easier. Further, the human operator has a much easier time controlling an otherwise complex machine when the robot's joints, limbs and other aspects resemble those of the operator.
by Tom Atwood and 
THE INVENTOR
