Editor’s Note: The following was written by Keith Feltenstein.
In our next “Versus” round up, we have two suits of armor and weapons. Lately, we have been seeing a lot of films and video games that involve men and women stepping into suits of armor or exoskeletons, and fighting to try to get an advantage in the fields of battle. So today, we have a battle between a couple of iconic movie suits. We have the Amplified Mobility Platform (Avatar) vs. the Exoskeleton suit (Edge Of Tomorrow). If we had two soldiers step into these suits, which suit do you think would stand the test? We will let you decide! Here is a little something about each suit!
Amplified Mobility Platform (Avatar)
The Mitsubishi MK-6 Amplified Mobility Platform (or “AMP” suit) is a distant descendant of the first military exoskeletons used on Earth in the mid-21st century. It was improved during military service in a myriad of combat theaters – from arctic to jungle to desert – over the decades. Sealed and pressurized models for toxic environments were developed as well. The suit is used extensively on the Moon and Mars colonies (where they are powered by fuel cells and/or monopropellant ceramic turbines). Its well-tested capabilities have proved invaluable in the deadly environment of Pandora. The Na’vi name for it roughly translates as “shield that walks” or “not-demon walking”.
The human-operated multi-purpose machine amplifies the strength and mobility of a soldier or civilian worker while providing protection from military and environmental threats. Unlike earlier designs in which weapons were integrated into limbs, the AMP suit is a multi-purpose machine, able to duplicate all functions of the infantry soldier. Since soldiers spend much of their time loading and unloading equipment, and performing other tasks besides operating weapons, it was determined that the AMP suit needed the same functionality as a human: two legs, two arms, and highly dexterous hands. This allows not only a wide range of functions, but allows the suit to operate a variety of weapons systems.
Arms operate in a directly scaled relationship to the operator’s arms, which allows better spatial positioning of the hands. The fingers and thumb are in direct 1:1 ratio. The servo armature has force feedback, and resists the movement of the operator’s arms when the suit’s limbs meet an obstacle. The operator can “feel” what the suit is doing. It is said that the suit can be operated in full darkness, by a skilled driver, by “feel” alone. The legs are actuated by foot-pedals which amplify on an even larger ratio. In fact the leg sensors work slightly differently than the arms. Due to the confining spatial envelope around the feet and legs of the operator, the pedals cannot move in long strides, even on a scaled relationship. Instead, they sense the force and direction of the input and the on board computer triggers a corresponding programmed movement of the legs. So the operator creates pressure and direction “cues” which trigger leg movements. The suit executes the “intention” of the pilot, calculating terrain factors and momentum to perform balanced movement. While an average pilot can learn to manipulate the AMP suit in combat conditions, it takes months longer to master the transition from supine to an upright position. However, through the use of gyroscopes and stability chips, AMP suits rarely topple. Auto stability programming maintains center of balance. If the operator happens to be injured or killed, the AMP suit has an automated “walk back” feature. This was developed to protect the AMP suit, as it is a significant investment to the RDA.
Using the suit, a driver is able to punch through a tree trunk, lift a half ton cargo crate, or rapidly build prefab units without a construction crew. In combat, the suit can provide heavy fire support to infantry units.
AMP suits are seen in many parts of the film, where they are assigned mainly to base defense and patrol duties. Jake Sully is assigned to Col. Quaritch and finds him at the hangar ready to enter and activate his AMP suit.
In the Assault on the Tree of Souls, Col. Quaritch’s forces used small arms and 30mm cannon-armed AMP suits to cut down Na’vi warriors and their direhorse mounts, but were unable to kill the near-bulletproof hammerhead titanotheres as they charged, wiping out the entire AMP suit complement. Lyle Wainfleet was one of the RDA soldiers killed while in his AMP suit.
Unlike other more exotic military suit designs in which weapons were integrated into the limbs, the AMP suit is a multi-purpose machine, able to mimic all the abilities of the infantry soldier. This allows a wide range of functions, including the ability to operate a variety of weapons systems.
The suit’s weapons are even more lethal than its raw strength. The suit tends to be heavily armored and can be armed with a hip-fired GAU-90 30mm autocannon, fed via an ammo belt at the back.
The other non-standard weapon is a combat knife of self-sharpening diamond-hard ceramic, as well as an optional flamethrower. To match the scale of the suit, the knife’s blade is over three feet long and cuts through many metals. The AMP suit knife is especially favored by Special Forces AMP pilots. Prior to 2152, they were also seen throwing mines, which would explode after a short delay.
Exoskeleton Suit / Combat Jacket (Edge Of Tomorrow)
A powered exoskeleton, also known as combat jacket, exoframe, or exosuit, is a mobile machine consisting primarily of an outer framework (akin to an insect’s exoskeleton) worn by a person, and powered by a system of motors or hydraulics that delivers at least part of the energy for limb movement. The main function of a powered exoskeleton is to assist the wearer by boosting their strength and endurance. They are commonly designed for military use, to help soldiers carry heavy loads both in and out of combat. In civilian areas, similar exoskeletons could be used to help firefighters and other rescue workers survive dangerous environments. The medical field is another prime area for exoskeleton technology, where it can be used for enhanced precision during surgery, or as an assist to allow nurses to move heavy patients. An electric-powered leg exoskeleton developed at MIT reduces the metabolic energy used when walking and carrying a load. The exoskeleton augments human walking by providing mechanical power to the ankle joints.
Various problems remain to be solved, the most daunting being the creation of a compact power supply powerful enough to allow an exoskeleton to operate for extended periods without being plugged into external power.
A fictional mech(a) is different from a powered exoskeleton in that a mecha is typically much larger than a normal human body and does not directly enhance the motion or strength of the physical limbs. Instead, the human operator occupies a cabin or pilot’s control seat inside a small portion of the larger system. Within this cabin the human may wear a small lightweight exoskeleton that serves as a haptic control interface for the much larger exterior appendages.
One of the proposed main uses for an exoskeleton would be enabling a soldier to carry heavy objects (80–300 kg) while running or climbing stairs. Not only could a soldier potentially carry more weight, he could presumably wield heavier armor and weapons. Most models use a hydraulic system controlled by an on-board computer. They could be powered by an internal combustion engine, batteries or potentially fuel cells. Another area of application could be medical care, nursing in particular. Faced with the impending shortage of medical professionals and the increasing number of people in elderly care, several teams of Japanese engineers have developed exoskeletons designed to help nurses lift and carry patients.
Exoskeletons could also be applied in the area of rehabilitation of stroke or Spinal cord injury patients. Such exoskeletons are sometimes also called Step Rehabilitation Robots. An exoskeleton could reduce the number of therapists needed by allowing even the most impaired patient to be trained by one therapist, whereas several are currently needed. Also training could be more uniform, easier to analyze retrospectively and can be specifically customized for each patient.
Exoskeletons could also be regarded as wearable robots: A wearable robot is a mechatronic system that is designed around the shape and function of the human body, with segments and joints corresponding to those of the person it is externally coupled with. They also considered human force sensitivities in the design and operation phases. Teleoperation and power amplification were said to be the first applications, but after recent technological advances the range of application fields is said to have widened. Increasing recognition from the scientific community means that this technology is now employed in telemanipulation, man-amplification, neuromotor control research and rehabilitation, and to assist with impaired human motor control One of the largest problems facing designers of powered exoskeletons is the power supply. There are currently few power sources of sufficient energy density to sustain a full-body powered exoskeleton for more than a few hours.
Non-rechargeable primary cells tend to have more energy density and store it longer than rechargeable secondary cells, but then replacement cells must be transported into the field for use when the primary cells are depleted, of which may be a special and uncommon type. Rechargeable cells can be reused but may require transporting a charging system into the field, which either must recharge rapidly or the depleted cells need to be able to be swapped out in the field, to be replaced with cells that have been slowly charging.
Internal combustion engine power supplies offer high energy output, but they also typically idle, or continue to operate at a low power level sufficient to keep the engine running, when not actively in use which continuously consumes fuel. Battery-based power sources are better at providing instantaneous and modulated power; stored chemical energy is conserved when load requirements cease. Engines which do not idle are possible, but require energy storage for a starting system capable of rapidly accelerating the engine to full operating speed, and the engine must be extremely reliable and never fail to begin running immediately.
Small and lightweight engines typically must operate at high-speed to extract sufficient energy from a small engine cylinder volume, which both can be difficult to silence and induces vibrations into the overall system. Internal combustion engines can also get extremely hot, which may require additional weight from cooling systems or heat shielding.
Wireless energy transfer, an emerging technology, is a very plausible solution to this issue. One could have a large (possibly nuclear) reactor in a remote location transferring energy wirelessly to the suit.
Flexibility of the human anatomy is another design issue, and which also affects the design of unpowered hard shell space suits. Several human joints such as the hips and shoulders are ball and socket joints, with the center of rotation inside the body. It is difficult for an exoskeleton to exactly match the motions of this ball joint using a series of external single-axis hinge points, limiting flexibility of the wearer.
A separate exterior ball joint can be used alongside the shoulder or hip, but this then forms a series of parallel rods in combination with the wearer’s bones. As the external ball joint is rotated through its range of motion, the positional length of the knee/elbow joint will lengthen and shorten, causing joint misalignment with the wearer’s body. This slip in suit alignment with the wearer can be permitted, or the suit limbs can be designed to lengthen and shorten under power assist as the wearer moves, to keep the knee/elbow joints in alignment.
A partial solution for more accurate free-axis movement is a hollow spherical ball joint that encloses the human joint, with the human joint as the center of rotation for the hollow sphere. Rotation around this joint may still be limited unless the spherical joint is composed of several plates that can either fan out or stack up onto themselves as the human ball joint moves through its full range of motion.
Spinal flexibility is another challenge since the spine is effectively a stack of limited-motion ball joints. There is no simple combination of external single-axis hinges that can easily match the full range of motion of the human spine. A chain of external ball joints behind the spine can perform a close approximation, though it is again the parallel-bar length problem. Leaning forward from the waist, the suit shoulder joints would press down into the wearer’s body. Leaning back from the waist, the suit shoulder joints would lift off the wearer’s body. Again, this alignment slop with the wearer’s body can be permitted, or the suit can be designed to rapidly lengthen or shorten the exoskeleton spine under power assist as the wearer moves.
The exoskeleton suits or “combat jackets” come in three variants: Dog, Grunt and Tank. Cage appears to wear a Grunt suit, fitted with four weapons: A SCAR-H assault rifle with FN EGLM grenade launcher on the right arm, a triple-barrel cannon device on the left arm, an auto-cannon mounted on the right shoulder, and a 16-shot grenade/missile launcher on the left shoulder.
With all that said, who do you think would win in in the armored exoskeleton showdown? Would it be the armor from Avatar, or the armor from Edge of Tomorrow? Vote now! Your opinion matters!
Next Podcast Unlimited Poll: Better Wizard – Merlin Vs. Gandalf.